Prognostic Factors and Survival Outcomes of Patients With Early HER2+ Breast Cancer Treated With Trastuzumab in a Brazilian Public Reference Center: A Real-World Study

PURPOSE

Trastuzumab was introduced into the Brazilian public health care service for early breast cancer (BC) in 2012. This study describes the survival outcomes and prognostic factors related to early HER2+ BC treatment in a Brazilian reference cancer center.

PATIENTS AND METHODS

This were a retrospective, single-center, observational study of early HER2+ BC patients treated with trastuzumab in the (neo)adjuvant setting between 2012 and 2018 at Hospital Pérola Byington. Demographic, clinical, disease-free survival (DFS) and overall survival (OS) data were evaluated. Multivariate analysis was performed to assess independent prognostic factors.

RESULTS

One hundred seventy-six and 353 patients treated in the neoadjuvant and adjuvant setting were included, respectively. The 3- and 5-year OS rates were 79% and 56% for the neoadjuvant group and 97% and 92% for the adjuvant group, respectively. Node positivity at diagnosis predicted poor OS for both groups. In the neoadjuvant group, stage III disease at diagnosis, delayed surgery, and lack of pathological complete response (pCR) predicted poor prognosis. The 3- and 5-year DFS rates were 67% and 46% in the neoadjuvant group and 91% and 86% in the adjuvant group, respectively. Histological grade 2, stage III disease at diagnosis, and lack of pCR predicted poor DFS for the neoadjuvant group. For the adjuvant group, node positivity at diagnosis predicted poor DFS.

CONCLUSION

Our results reveal multiple clinical parameters affecting survival outcomes according to the treatment setting. Patients treated with neoadjuvant therapy have a poor prognosis since they present with more advanced disease, indicating the importance of early diagnosis and optimized treatment.

Abstract GS2-02: GS2-02 Trastuzumab deruxtecan versus trastuzumab emtansine in patients with HER2-positive metastatic breast cancer: Updated survival results of the randomized, phase 3 study DESTINY-Breast03

Background: Trastuzumab deruxtecan (T-DXd) is approved in the United States and European Union for use in patients (pts) with HER2+ unresectable/metastatic breast cancer (mBC) after ≥1 prior anti–HER2 regimen(s). Approval was based on the randomized, multicenter, open-label, phase 3 DESTINY-Breast03 study (NCT03529110), in which T-DXd demonstrated statistically significant and clinically meaningful improvement in progression-free survival (PFS) compared with trastuzumab emtansine (T-DM1). At the primary interim analysis (data cutoff May 21, 2021), the risk of disease progression or death was reduced by 72% with T-DXd (P < 0.001; Cortes et al. N Engl J Med 2022). Overall survival (OS) data were immature for both treatment groups; although the prespecified cutoff for significance was not reached (NR), a trend toward benefit with T-DXd was observed. With further follow-up, we report results from the prespecified OS analysis of DESTINY-Breast03 (data cutoff July 25, 2022), including updated efficacy and safety.

Methods: Pts with HER2+ mBC previously treated with trastuzumab and a taxane in either the metastatic setting or (neo)adjuvant setting with progression within 6 mo of therapy, who could have received pertuzumab, were randomly assigned 1:1 to receive T-DXd 5.4 mg/kg every 3 weeks (Q3W) or T-DM1 3.6 mg/kg Q3W until disease progression. The primary endpoint was PFS by blinded independent central review (BICR). The key secondary endpoint was OS (80% powered at 2-sided significance level of 5%); other secondary endpoints included objective response rate (ORR), duration of response (DoR), PFS based on investigator assessment, and safety.

Results: 524 pts received either T-DXd (n = 261) or T-DM1 (n = 263). As of the updated data cutoff, median duration of study follow-up was 28.4 mo (range, 0.0-46.9 mo) for T-DXd and 26.5 mo (range, 0.0-45.0 mo) for T-DM1. Median treatment duration was 18.2 mo (range, 0.7-44.0 mo) for T DXd and 6.9 mo (range, 0.7-39.3 mo) for T-DM1. The risk of death was reduced by 36% (HR, 0.64; P = 0.0037) with T-DXd; median OS (mOS) was NR (95% CI, 40.5 mo-not evaluable [NE]), with 72 (27.6%) OS events, for T-DXd vs NR (95% CI, 34.0 mo-NE), with 97 (36.9%) OS events, for T-DM1. Landmark 12-mo OS rate was 94.1% (95% CI, 90.4-96.4) for T-DXd vs 86.0% (95% CI, 81.1-89.8) for T-DM1; 24-mo OS rate was 77.4% (95% CI, 71.7-82.1) for T-DXd vs 69.9% (95% CI, 63.7-75.2) for T-DM1. The P value for OS crossed the prespecified boundary (P = 0.013) and was statistically significant. mPFS by BICR was 28.8 mo (95% CI, 22.4-37.9 mo) with T-DXd, compared with 6.8 mo (95% CI, 5.6-8.2 mo) with T-DM1; HR, 0.33; nominal P < 0.000001. Key efficacy and safety results are shown in the table. Grade ≥3 treatment-emergent adverse events were experienced by 56.4% of T-DXd-treated pts and 51.7% of T DM1-treated pts. Drug-related interstitial lung disease/pneumonitis, as evaluated by an independent adjudication committee, was experienced by 39 pts (15.2%) in the T-DXd arm and 8 pts (3.1%) in the T DM1 arm; no adjudicated drug-related grade 4 or 5 events were observed in pts who received T-DXd.

Conclusions: Updated results confirm the superiority of T-DXd compared with T-DM1 for pts with HER2+ mBC previously treated with an anti-HER2 therapy, with highly clinically meaningful and statistically significant benefit in OS and PFS and a manageable safety profile with longer treatment duration.

Editorial Acknowledgment

Under the guidance of authors, assistance in medical writing and editorial support was provided by Laura Halvorson, PhD, and Rachel Hood, PhD, of ApotheCom, and was funded by Daiichi Sankyo.

Funding

This study was funded by Daiichi Sankyo and AstraZeneca.

Table. Summary of Efficacy Results for T-DXd and T-DM1

Citation Format: Sara Hurvitz, Roberto Hegg, Wei-Pang Chung, Seock-Ah Im, William Jacot, Vinod Ganju, Joanne Win Yang Chiu, Binghe Xu, Erika Hamilton, Srinivasan Madhusudan, Hiroji Iwata, Sevilay Altintas, Jan-Willem Henning, Giuseppe Curigliano, José Manuel Pérez-García, Anton Egorov, Yali Liu, Jillian Cathcart, Shahid Ashfaque, Javier Cortés. GS2-02 Trastuzumab deruxtecan versus trastuzumab emtansine in patients with HER2-positive metastatic breast cancer: Updated survival results of the randomized, phase 3 study DESTINY-Breast03 [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr GS2-02.

Trastuzumab deruxtecan versus trastuzumab emtansine in patients with HER2-positive metastatic breast cancer: updated results from DESTINY-Breast03, a randomised, open-label, phase 3 trial

BACKGROUND

An improvement in progression-free survival was shown with trastuzumab deruxtecan versus trastuzumab emtansine in patients with HER2-positive metastatic breast cancer in the progression-free survival interim analysis of the DESTINY-Breast03 trial. The aim of DESTINY-Breast03 was to compare the efficacy and safety of trastuzumab deruxtecan versus trastuzumab emtansine.

METHODS

This open-label, randomised, multicentre, phase 3 trial was done in 169 study centres in North America, Asia, Europe, Australia, and South America. Eligible patients were aged 18 or older, had HER2-positive unresectable or metastatic breast cancer previously treated with trastuzumab and a taxane, had an Eastern Cooperative Oncology Group performance status 0-1, and at least one measurable lesion per Response Evaluation Criteria in Solid Tumours version 1.1. Patients were randomly assigned (1:1) to receive trastuzumab deruxtecan 5·4 mg/kg or trastuzumab emtansine 3·6 mg/kg, both administered by intravenous infusion every 3 weeks. Randomisation was stratified by hormone receptor status, previous treatment with pertuzumab, and history of visceral disease, and was managed through an interactive web-based system. Within each stratum, balanced block randomisation was used with a block size of four. Patients and investigators were not masked to the treatment received. The primary endpoint was progression-free survival by blinded independent central review. The key secondary endpoint was overall survival and this prespecified second overall survival interim analysis reports updated overall survival, efficacy, and safety results. Efficacy analyses were performed using the full analysis set. Safety analyses included all randomly assigned patients who received at least one dose of study treatment. This study is registered with ClinicalTrials.gov, NCT03529110.

FINDINGS

Between July 20, 2018, and June 23, 2020, 699 patients were screened for eligibility, 524 of whom were enrolled and randomly assigned to receive trastuzumab deruxtecan (n=261) or trastuzumab emtansine (n=263). Median duration of study follow-up was 28·4 months (IQR 22·1-32·9) with trastuzumab deruxtecan and 26·5 months (14·5-31·3) with trastuzumab emtansine. Median progression-free survival by blinded independent central review was 28·8 months (95% CI 22·4-37·9) with trastuzumab deruxtecan and 6·8 months (5·6-8·2) with trastuzumab emtansine (hazard ratio [HR] 0·33 [95% CI 0·26-0·43]; nominal p<0·0001). Median overall survival was not reached (95% CI 40·5 months-not estimable), with 72 (28%) overall survival events, in the trastuzumab deruxtecan group and was not reached (34·0 months-not estimable), with 97 (37%) overall survival events, in the trastuzumab emtansine group (HR 0·64; 95% CI 0·47-0·87]; p=0·0037). The number of grade 3 or worse treatment-emergent adverse events was similar in patients who received trastuzumab deruxtecan versus trastuzumab emtansine (145 [56%] patients versus 135 [52%] patients). Adjudicated drug-related interstitial lung disease or pneumonitis occurred in 39 (15%) patients treated with trastuzumab deruxtecan and eight (3%) patients treated with trastuzumab emtansine, with no grade 4 or 5 events in either group.

INTERPRETATION

Trastuzumab deruxtecan showed a significant improvement in overall survival versus trastuzumab emtansine in patients with HER2-positive metastatic breast cancer, as well as the longest reported median progression-free survival, reaffirming trastuzumab deruxtecan as the standard of care in the second-line setting. A manageable safety profile of trastuzumab deruxtecan was confirmed with longer treatment duration.

FUNDING

Daiichi Sankyo and AstraZeneca.

Treatment With Adjuvant Abemaciclib Plus Endocrine Therapy in Patients With High-risk Early Breast Cancer Who Received Neoadjuvant Chemotherapy: A Prespecified Analysis of the monarchE Randomized Clinical Trial

Importance

Patients selected to receive neoadjuvant chemotherapy (NAC) are usually those at higher risk of relapse, and there is a need to find better therapeutic options for these patients.

Objective

To determine the efficacy and safety outcomes for patients with hormone receptor (HR)-positive, ERBB2 (formerly HER2)-, high-risk early breast cancer enrolled in the randomized clinical trial monarchE who received NAC.

Design, Setting, and Participants

The monarchE randomized clinical trial was a multicenter, phase 3, open-label study that evaluated adjuvant treatment with abemaciclib plus endocrine therapy (ET) compared with ET alone in patients with HR+, ERBB2-, and node-positive early breast cancer who were at high risk of recurrence. Patients were recruited between July 2017 and August 2019 from 603 sites in 38 countries. This subgroup analysis was performed with primary outcome data, with a cutoff date of July 8, 2020.

Intervention

Enrolled patients were randomized (1:1) to receive standard of care ET for at least 5 years with or without treatment with abemaciclib (150 mg, twice daily) for 2 years (treatment period) or until criteria were met for discontinuation.

Main Outcomes and Measures

Prior chemotherapy (NAC vs adjuvant vs none) was a stratification factor in monarchE, and and a prespecified exploratory analysis included outcomes in patients who received NAC. The data presented in this article are from the primary outcome analysis (395 invasive disease-free survival [IDFS] events; cutoff date, July 8, 2020; median follow-up 19 months [IQR, 15.6-23.9 months]). Invasive disease-free survival (the primary end point of monarchE) and distant relapse-free survival (DRFS) were evaluated using the Cox proportional hazard model and Kaplan-Meier method.

Results

Of the 5637 patients (mean [SD] age, 49.9 [10.6] years; 2046 women [99.5%]; 462 Asian [22.8%], 54 Black [2.7%], and 1473 White participants [70.8%]) enrolled in monarchE, 2056 (37%) received treatment with NAC. In this subgroup, treatment with abemaciclib and ET demonstrated clinically meaningful benefit in IDFS (hazard ratio, 0.61; 95% CI, 0.47-0.80) and DRFS (hazard ratio, 0.61; 95% CI, 0.46-0.81), which corresponded with an absolute improvement of 6.6% in 2-year IDFS rates and 6.7% in 2-year DRFS rates. A consistent treatment benefit was observed across subgroups of pathological breast tumor size or number of positive lymph nodes at surgery.

Conclusions and Relevance

In the randomized clinical trial monarchE, treatment with adjuvant abemaciclib combined with ET demonstrated a clinically meaningful improvement in IDFS and DRFS for patients with HR+, ERBB2-, node-positive, high-risk early breast cancer who received NAC before trial enrollment.

Trial Registration

ClinicalTrials.gov Identifier: NCT03155997.

nextMONARCH Phase 2 randomized clinical trial: overall survival analysis of abemaciclib monotherapy or in combination with tamoxifen in patients with endocrine-refractory HR + , HER2- metastatic breast cancer

Purpose

Resistance to endocrine therapy poses a major clinical challenge for patients with hormone receptor-positive (HR +), human epidermal growth factor receptor 2-negative (HER2–) metastatic breast cancer (MBC). We present the preplanned 24-month final overall survival (OS) results, alongside updated progression-free survival (PFS), and objective response rate (ORR) results.

Methods

nextMONARCH is an open-label, controlled, randomized, Phase 2 study of abemaciclib alone or in combination with tamoxifen in women with endocrine-refractory HR + , HER2– MBC previously treated with chemotherapy. Patients were randomized 1:1:1 to: abemaciclib 150 mg and tamoxifen 20 mg (A + T), abemaciclib 150 mg (A-150), or abemaciclib 200 mg and prophylactic loperamide (A-200). OS was the main prespecified secondary endpoint. PFS, ORR, and safety at 24 months were compared to previously reported primary analysis results.

Results

Of the 234 patients enrolled, 12 were receiving study treatment at data cutoff (28Jun2019). Median follow-up was 27.2 months. Median OS was 24.2 months in the A + T arm, 20.8 months in A-150, and 17.0 months in A-200 (A + T versus A-200: HR 0.62; 95%CI [0.40, 0.97], P = 0.03 and A-150 versus A-200: HR 0.96; 95%CI [0.64, 1.44], P = 0.83). PFS and ORR results at 24 months were consistent with the primary analysis. The safety profile corresponded with previous reports.

Conclusion

The addition of tamoxifen to abemaciclib demonstrated greater OS benefit than monotherapy. This study confirmed the single-agent activity of abemaciclib in heavily pretreated women with endocrine-refractory HR + , HER2– MBC, as well as the previously reported primary PFS and ORR results, with no new safety signals observed.

Trial Registration ClinicalTrials.gov Identifier: NCT02747004.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10549-022-06662-9.

Clinical outcomes with alpelisib (ALP) plus fulvestrant (FUL) after prior treatment (tx) with FUL in patients (pts) with advanced breast cancer (ABC): A real-world (RW) analysis

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Background: ALP (α-selective PI3K inhibitor and degrader) + FUL was FDA approved and reflected in the NCCN guidelines in 2019 for pts with hormone receptor–positive/human epidermal growth factor receptor 2–negative (HR+/HER2−) ABC with PIK3CA mutations following progression on or after endocrine-based therapy (ET). The Phase III SOLAR-1 trial excluded prior FUL, and data on ALP + FUL after FUL are limited. As cyclin-dependent kinase 4/6 inhibitor (CDK4/6i) + ET (including FUL) is the standard in the first line (1L) or second line (2L) for pts with HR+/HER2− ABC, more data on ALP + FUL post-FUL are needed. Here we report patterns and clinical outcomes on RW use of ALP + FUL in pts with HR+/HER2– ABC with prior FUL exposure. Methods: This retrospective study used de-identified electronic health record data from the ConcertAI Patient360 Breast Cancer data product sourced from US oncology centers. Adults with HR+/HER2− ABC treated with ALP + FUL (index tx) who received prior FUL (monotherapy or in combination) in the metastatic setting were included; pts with a PIK3CA negative test on or prior to the index were excluded. Pts were followed until date of death or last activity. RW progression-free survival (rwPFS), defined as first documented progression/death from ALP + FUL start date, was assessed. Results: This analysis included 157 pts (median age, 63 y [57-71 y]) who received ALP + FUL from 2019 to 2021, with 11.5% pts in 1L, 17.8% in 2L, 26.8% in third line (3L), and 43.9% in fourth line and beyond (4L+). Prior FUL tx included CDK4/6i + FUL (74.5%), FUL alone (33.8%), and non-CDK4/6i + FUL (21.0%). In pts who received ALP + FUL in 1L (n = 18), prior FUL exposure was in the same line without documented progression. In the metastatic setting, 28.0% of pts received > 1 FUL-containing regimen and/or 72.0% received prior chemotherapy (CT). At the median duration of follow-up (8.7 mo [4.1-12.5 mo]), the median rwPFS was 5.7 mo (4.0-7.3 mo) in the overall population. The median rwPFS was also analyzed by line of therapy (Table). In pts with CDK4/6i + FUL as immediate prior therapy (n = 39), the median rwPFS was 6.2 mo (3.0-9.1 mo); 79.5% of these pts received ALP in ≤ 3L. At the time of analysis, 107 pts (68.2%) had discontinued ALP + FUL; the median time to discontinuation was 4.7 mo (3.7-6.1 mo). Following discontinuation of ALP + FUL, CT was the most common subsequent therapy (33.8%). Conclusions: This analysis on RW data from early years of ALP access in the US shows clinical benefit of ALP + FUL in pts with HR+/HER2− ABC with PIK3CA mutation even when exposed to prior FUL, confirming the oncogenic dependence of the tumor on the PIK3CA mutation. [Table: see text]

Trastuzumab Deruxtecan versus Trastuzumab Emtansine for Breast Cancer

BACKGROUND

Trastuzumab emtansine is the current standard treatment for patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer whose disease progresses after treatment with a combination of anti-HER2 antibodies and a taxane.

METHODS

We conducted a phase 3, multicenter, open-label, randomized trial to compare the efficacy and safety of trastuzumab deruxtecan (a HER2 antibody-drug conjugate) with those of trastuzumab emtansine in patients with HER2-positive metastatic breast cancer previously treated with trastuzumab and a taxane. The primary end point was progression-free survival (as determined by blinded independent central review); secondary end points included overall survival, objective response, and safety.

RESULTS

Among 524 randomly assigned patients, the percentage of those who were alive without disease progression at 12 months was 75.8% (95% confidence interval [CI], 69.8 to 80.7) with trastuzumab deruxtecan and 34.1% (95% CI, 27.7 to 40.5) with trastuzumab emtansine (hazard ratio for progression or death from any cause, 0.28; 95% CI, 0.22 to 0.37; P<0.001). The percentage of patients who were alive at 12 months was 94.1% (95% CI, 90.3 to 96.4) with trastuzumab deruxtecan and 85.9% (95% CI, 80.9 to 89.7) with trastuzumab emtansine (hazard ratio for death, 0.55; 95% CI, 0.36 to 0.86; prespecified significance boundary not reached). An overall response (a complete or partial response) occurred in 79.7% (95% CI, 74.3 to 84.4) of the patients who received trastuzumab deruxtecan and in 34.2% (95% CI, 28.5 to 40.3) of those who received trastuzumab emtansine. The incidence of drug-related adverse events of any grade was 98.1% with trastuzumab deruxtecan and 86.6% with trastuzumab emtansine, and the incidence of drug-related adverse events of grade 3 or 4 was 45.1% and 39.8%, respectively. Adjudicated drug-related interstitial lung disease or pneumonitis occurred in 10.5% of the patients in the trastuzumab deruxtecan group and in 1.9% of those in the trastuzumab emtansine group; none of these events were of grade 4 or 5.

CONCLUSIONS

Among patients with HER2-positive metastatic breast cancer previously treated with trastuzumab and a taxane, the risk of disease progression or death was lower among those who received trastuzumab deruxtecan than among those who received trastuzumab emtansine. Treatment with trastuzumab deruxtecan was associated with interstitial lung disease and pneumonitis. (Funded by Daiichi Sankyo and AstraZeneca; DESTINY-Breast03 ClinicalTrials.gov number, NCT03529110.).

Dual PD-1 and CTLA-4 Checkpoint Blockade Using Balstilimab and Zalifrelimab Combination as Second-Line Treatment for Advanced Cervical Cancer: An Open-Label Phase II Study

PURPOSE

Balstilimab (antiprogrammed death-1) and zalifrelimab (anticytotoxic T-lymphocyte-associated antigen-4) are two new checkpoint inhibitors emerging as promising investigational agents for the treatment of advanced cervical cancer. This phase II trial (ClinicalTrials.gov identifier: NCT03495882) evaluated the combination of balstilimab plus zalifrelimab in patients with recurrent and/or metastatic cervical cancer who relapsed after prior platinum-based therapy.

PATIENTS AND METHODS

Patients were intravenously dosed with balstilimab 3 mg/kg once every 2 weeks and zalifrelimab 1 mg/kg once every 6 weeks, for up to 24 months. The primary end point was objective response rate (ORR, RECIST version 1.1, assessed by independent central review). Secondary end points included duration of response, safety and tolerability, and survival.

RESULTS

In total, 155 women (median age, 50 years [range, 24-76 years]) were enrolled and treated with balstilimab plus zalifrelimab; 125 patients had measurable disease at baseline and one prior line of platinum-based therapy in the advanced setting, and these patients constituted the efficacy-evaluable population. The median follow-up was 21 months. The confirmed ORR was 25.6% (95% CI, 18.8 to 33.9), including 10 complete responders and 22 partial responders, with median duration of response not reached (86.5%, 75.5%, and 64.2% at 6, 9, and 12 months, respectively). The ORRs were 32.8% and 9.1% in patients with programmed death ligand-1-positive and programmed death ligand-1-negative tumors, respectively. For patients with squamous cell carcinoma, the ORR was 32.6%. The overall disease control rate was 52% (95% CI, 43.3 to 60.6). Hypothyroidism (14.2%) and hyperthyroidism (7.1%) were the most common immune-mediated adverse events.

CONCLUSION

Promising and durable clinical activity, with favorable tolerability, was seen in this largest trial to date evaluating dual programmed death-1/cytotoxic T-lymphocyte-associated antigen-4 blockade in patients with recurrent and/or metastatic cervical cancer. Further investigation of the balstilimab and zalifrelimab combination in this setting is continuing.

Abstract GS3-01: Trastuzumab deruxtecan (T-DXd; DS-8201a) vs. trastuzumab emtansine (T-DM1) in patients (pts) with HER2+ metastatic breast cancer (mBC): subgroup analyses from the randomized phase 3 study DESTINY-Breast03

Background: T-DXd is a HER2-targeting antibody-drug conjugate approved for the treatment of pts with advanced HER2+ mBC based on the DESTINY-Breast01 study (NCT03248492). DESTINY-Breast03 (NCT03529110) isa randomized, multicenter, open-label, phase 3 study assessing the efficacy and safety of T-DXd vs. T-DM1 in pts with HER2+ mBC previously treated with trastuzumab and taxane. In the primary analysis, T-DXd demonstrated a clinically meaningful and statistically significant improvement in PFS vs. T-DM1 (Corteset al, ESMO 2021). In this exploratory analysis, we provide additional efficacy and safety data in subgroups, including in pts with brain metastases (BMs). Methods: Pts were randomly assigned 1:1 to receive 5.4 mg/kg T-DXd or 3.6 mg/kg T-DM1 Q3W. Pts with clinically stable BMs were eligible. Lesions were measured per modified Response Evaluation Criteria in Solid Tumors version 1.1. The primary endpoint was progression-free survival (PFS) determined by blinded independent central review (BICR). PFS and overall response rate (ORR) were analyzed for subgroups.Sites of progression and post-end-of-study therapies were also investigated. Results: At data cutoff (May 21, 2021), 524 pts were randomly assigned to T-DXd (n=261) orT-DM1 (n=263). T-DXd demonstrated superior PFS by BICR vs. T-DM1 (HR, 0.28 [95%CI, 0.22-0.37]; P=7.8 x 10-22); median (m) PFS by BICR was not reached (95% CI, 18.5-NE) for T-DXd compared with 6.8 mo (95% CI, 5.6-8.2) forT-DM1. For pts with stable BMs at baseline (n=82), mPFS was 15.0 mo (95% CI,12.5-22.2) for T-DXd vs. 3.0 mo (95% CI, 2.8-5.8) for T-DM1 (HR, 0.25 [95% CI,0.31-0.45)]. Overall, confirmed ORR for T-DXd was 79.7% vs. 34.2% for T-DM1.For patients with stable BMs at baseline, ORR was 67.4% for T-DXd vs. 20.5% forT-DM1. Consistent PFS and ORR benefit was also observed across other subgroups(Table 1). At data cutoff, 84 (32.2%) pts treated with T-DXd had progressive disease (PD) versus 155 (58.9%) with T-DM1. In pts with stable BMs in the T-DXd arm, 48.8% of pts (21/43) had PD. In pts with stable BMs in the T-DM1 arm, 69.2%of pts (27/39) had PD. Data on sites of progression will be presented. Further analyses are underway and will be presented. Overall, the safety profile of T-DXd was manageable and comparable with its known safety profile. Adjudicated drug-related interstitial lung disease/pneumonitis was reported in 27 (10.5%) pts treated with T-DXd and 5 (1.9%) pts treated with T-DM1 overall, with no grade 4 or 5 events. Additional new safety data will be presented. Conclusion: DESTINY-Breast03,the first-reported randomized phase 3 trial comparing T-DXd to standard of care, met the primary endpoint with T-DXd demonstrating superior PFS vs. T-DM1and T-DXd had a manageable safety profile. In this exploratory analysis, consistent PFS and ORR benefit with T-DXd vs. T-DM1 was observed across subgroups in pts with HER2+ mBC previously treated with trastuzumab and taxane, including in pts with BMs.

Table 1.Subgroup Analyses forPFS and ORR of T-DXd versus T-DM1PFS by BICR HR (95% CI)Absolute ORR Difference (T-DXd-T-DM1) (95% CI)All patients (N=524)0.28 (0.22-0.37)45.5 (37.6-53.4)Hormone receptorPositive (n=272)0.32 (0.22-0.46)47.3 (36.1-58.4)Negative (n=248)0.30 (0.20-0.44)43.2 (31.5-55.0)Prior pertuzumabYes (n=320)0.31 (0.22-0.43)46.7 (36.5-56.9)No (n=204)0.30 (0.19-0.47)43.6 (30.5-56.7)Prior lines of therapya0-1 (n=258)0.33 (0.23-0.48)39.3 (27.3-51.2)≥2 (n=266)0.28 (0.19-0.41)51.6 (40.9-62.4)Visceral disease Yes (n=384)0.28 (0.21-0.38)48.3 (39.1-57.6)No (n=140)0.32 (0.17-0.58)39.1 (23.6-54.6)Brain metastases at baseline Yes (n=82)0.25 (0.13-0.45)46.9 (25.6-68.3)No (n=442)0.30 (0.22-0.40)45.5 (36.9-54.1)

Citation Format: Sara Hurvitz, Sung-Bae Kim, Wei-Pang Chung, Seock-Ah Im, Yeon Hee Park, Roberto Hegg, Min-Hwan Kim, Ling-Ming Tseng, Vanessa Petry, Chi-Feng Chung, Hiroji Iwata, Erika Hamilton, Giuseppe Curigliano, Binghe Xu, Caleb Lee, Yali Liu, Jillian Cathcart, Emarjola Bako, Sunil Verma, Javier Cortés. Trastuzumab deruxtecan (T-DXd; DS-8201a) vs. trastuzumab emtansine (T-DM1) in patients (pts) with HER2+ metastatic breast cancer (mBC): subgroup analyses from the randomized phase 3 study DESTINY-Breast03 [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr GS3-01.

Adjuvant abemaciclib combined with endocrine therapy for high-risk early breast cancer: updated efficacy and Ki-67 analysis from the monarchE study

BACKGROUND

Adjuvant abemaciclib combined with endocrine therapy (ET) previously demonstrated clinically meaningful improvement in invasive disease-free survival (IDFS) and distant relapse-free survival (DRFS) in hormone receptor-positive, human epidermal growth factor receptor 2-negative, node-positive, high-risk early breast cancer at the second interim analysis, however follow-up was limited. Here, we present results of the prespecified primary outcome analysis and an additional follow-up analysis.

PATIENTS AND METHODS

This global, phase III, open-label trial randomized (1 : 1) 5637 patients to adjuvant ET for ≥5 years ± abemaciclib for 2 years. Cohort 1 enrolled patients with ≥4 positive axillary lymph nodes (ALNs), or 1-3 positive ALNs and either grade 3 disease or tumor ≥5 cm. Cohort 2 enrolled patients with 1-3 positive ALNs and centrally determined high Ki-67 index (≥20%). The primary endpoint was IDFS in the intent-to-treat population (cohorts 1 and 2). Secondary endpoints were IDFS in patients with high Ki-67, DRFS, overall survival, and safety.

RESULTS

At the primary outcome analysis, with 19 months median follow-up time, abemaciclib + ET resulted in a 29% reduction in the risk of developing an IDFS event [hazard ratio (HR) = 0.71, 95% confidence interval (CI) 0.58-0.87; nominal P = 0.0009]. At the additional follow-up analysis, with 27 months median follow-up and 90% of patients off treatment, IDFS (HR = 0.70, 95% CI 0.59-0.82; nominal P < 0.0001) and DRFS (HR = 0.69, 95% CI 0.57-0.83; nominal P < 0.0001) benefit was maintained. The absolute improvements in 3-year IDFS and DRFS rates were 5.4% and 4.2%, respectively. Whereas Ki-67 index was prognostic, abemaciclib benefit was consistent regardless of Ki-67 index. Safety data were consistent with the known abemaciclib risk profile.

CONCLUSION

Abemaciclib + ET significantly improved IDFS in patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative, node-positive, high-risk early breast cancer, with an acceptable safety profile. Ki-67 index was prognostic, but abemaciclib benefit was observed regardless of Ki-67 index. Overall, the robust treatment benefit of abemaciclib extended beyond the 2-year treatment period.

A Long-Term Extension Study of Bevacizumab in Patients With Solid Tumors

BACKGROUND

Bevacizumab has been studied in numerous clinical trials in multiple types of cancer; however, patients may receive bevacizumab over an extended period of time. This study assessed the long-term safety and tolerability of bevacizumab among patients with solid tumors.

MATERIALS AND METHODS

Patients enrolled in a Roche/Genentech-sponsored trial who had derived benefit from bevacizumab therapy as monotherapy or in combination with anticancer drugs were eligible for continuation of bevacizumab in this long-term extension (LTE) study. The primary endpoints were the incidence of adverse events (AEs) of Common Terminology Criteria for AEs (CTCAE) grade ≥3 related to bevacizumab treatment, serious AEs (SAEs), and deaths.

RESULTS

Ninety-five patients with the following cancer types were enrolled in the LTE: ovarian cancer or peritoneal carcinoma (n = 41), non-small cell lung cancer (n = 16), glioblastoma multiforme (n = 14), breast cancer (n = 11), colorectal cancer (n = 7), or renal cell carcinoma (n = 6). The median (range) duration of bevacizumab treatment was 15.6 (0.0-81.0) months during the LTE and 57.5 (16.4-134.9) months overall (parent trial + LTE), with three patients receiving bevacizumab for >10 years. Overall, 17 patients (17.9%) experienced SAEs, and 21 (22.1%) had a bevacizumab-related AE of CTCAE grade ≥3 (proteinuria and hypertension were the most common). Four patients died: three from disease progression and one from an AE considered unrelated to bevacizumab.

CONCLUSION

The safety outcomes observed support the tolerability of long-term bevacizumab in patients with various solid tumors, with a median extended treatment duration of almost 5 years overall and >10 years in some individual patients. ClinicalTrials.gov identifier: NCT01588184.

IMPLICATIONS FOR PRACTICE

In this long-term extension study of patients with solid tumors, the median duration of bevacizumab treatment (including parent trials) was just under 5 years, with a long-term exposure in some patients of 7 to >10 years. Grade ≥3 adverse events related to bevacizumab were consistent with the established safety profile, with proteinuria and hypertension being the most common. Patients received bevacizumab over an extended period of time (beyond the length of most clinical trials), and the overall safety outcomes observed support the tolerability of long-term bevacizumab treatment in patients with solid tumors, with clinical benefit achieved over an extended period.

Abemaciclib combined with adjuvant endocrine therapy in patients with high risk early breast cancer who received neoadjuvant chemotherapy (NAC)

517

Background: monarchE, a phase 3, open-label, randomized study evaluating abemaciclib combined with adjuvant endocrine therapy (ET) compared to ET alone in patients with HR+, HER2-, high risk early breast cancer (EBC), resulted in a statistically significant improvement in invasive disease-free survival (IDFS) (HR = 0.713; 95% CI: 0.583, 0.871). NAC is used in patients with HR+, HER2- EBC at higher risk of recurrence despite often limited response, suggesting a need for enhanced adjuvant ET. Methods: Patients with ≥4 positive notes (LNS), or 1-3 LNS and either Grade 3 disease, tumor size ≥5 cm, or central Ki-67 ≥20% were eligible. Prior chemotherapy (NAC, adjuvant, none) was one of the stratifications factors. Prior therapy and tumor characteristics prior to study entry were collected. Here, we present the results of the prespecified subgroup of patients who received NAC. Results: Out of 5,637 randomized patients, 2056 (36.5%) received NAC. For 84.8%, the chosen regimen included anthracycline + cyclophosphamide + taxane, for 4.4%, it included anthracycline + taxane. A total of 1044 (50.8%) patients who received NAC had a radiologic tumor size between 2-5 cm and 599 (29.1%) had tumors ≥5 cm at diagnosis. 6.2%, 49.4% and 36.7% of patients had tumors with histologic Grade 1, 2, 3 respectively. 55.2% of patients had LNS ≥4+ and 44.4% had 1-3+ LNS. Central Ki-67 prior to NAC was ≥20% in 64.8% of patients with available Ki-67 results (664 (32.3%) patients had missing Ki-67 results). Evaluation of clinical and pathological measures of response will be presented. A multivariate cox regression analysis of IDFS in the intent-to-treat (ITT) population, identified prior chemotherapy as prognostic, suggesting patients who received NAC were at risk of a worse outcome. Primary outcome efficacy data for patients who received NAC are shown in the table below. Abemaciclib + ET demonstrated treatment benefit in terms of IDFS vs ET alone (HR: 0.614 95% CI: 0.473, 0.797) with 2-year IDFS rates of 87.2% vs 80.6%, respectively. The addition of abemaciclib to ET resulted in an improvement in distant relapse-free survival (DRFS) (HR: 0.609, 95% CI: 0.459, 0.809), with 2-year DRFS rates of 89.5% and 82.8%, respectively. Safety profile was similar to the overall safety population. Conclusions: Patients with HR+, HER2- EBC who received NAC were noted to be at a higher risk of recurrence. In this subgroup, abemaciclib combined with ET demonstrated a clinically meaningful treatment benefit in IDFS and DRFS, which was numerically greater than in the ITT population. Safety data were consistent with abemaciclib safety profile. Clinical trial information: NCT03155997. [Table: see text]

Abstract PS13-25: Management of abemaciclib associated diarrhea in patients with hormone receptor-positive/human epidermal growth factor receptor 2-negative advanced breast cancer: Analysis of the MONARCH plus study

Background:

In the phase III MONARCH plus study (NCT02763566) the cyclin-dependent kinase (CDK) 4&6 inhibitor abemaciclib in combination with non-steroidal aromatase inhibitors (NSAI) or with fulvestrant compared with placebo demonstrated its efficacy and acceptable safety profile at interim analysis in postmenopausal women with hormone receptor-positive, human epidermal growth factor receptor 2-negative (HR+/HER2-) locoregionally recurrent or metastatic breast cancer. One of the most common treatment-emergent adverse event (TEAE) was diarrhea, typically low grade and of early onset. We will further characterize abemaciclib-associated diarrhea and describe its management in MONARCH plus trial.

Methods:

MONARCH plus study included two cohorts of patients. Cohort A enrolled patients with initial treatment of endocrine therapy, received abemaciclib or placebo plus NSAI (anastrozole or letrozole); Cohort B enrolled patients who progressed on prior endocrine therapy, receiving abemaciclib or placebo plus fulvestrant. The relative dose intensity was defined as the percentage of actual dose received relative to the planned dose. The severity of diarrhea was reported by investigators and graded according to Common Terminology Criteria for Adverse Events Version 4.0 (CTCAE v4.0). Further analysis on diarrhea included time to onset, duration, supportive medication and dose modifications. Progression-free survival (PFS) was defined as time from randomization to death or progression (RECIST v1.1), and a stratified Cox proportional hazard model was used to estimate the hazard ratio (HR) between study intervention arm and placebo arm.

Results:

The median relative dose intensity of abemaciclib in abemaciclib plus NSAI arm and abemaciclib plus fulvestrant arm were 96.77% and 96.30% respectively. In abemaciclib plus NSAI arm and abemaciclib plus fulvestrant arm, the median time to onset of first reported diarrhea was 7 and 6 days and majority of diarrhea events occurred early (66.3% and 71.2% of patients reported diarrhea in Cycle 1 respectively). Diarrhea was typically of low grade (3.9% and 1.9% of patients reported Grade 3 in abemaciclib plus NSAI arm and abemaciclib plus fulvestrant arm, no Grade 4 diarrhea was reported in either arm). Median duration of grade ≥ 3 diarrhea was 2.5 and 3.5 days. Diarrhea was managed by dose adjustments and/or supportive medication (Table 1). Dose reductions were present in 2.0% and 2.9% of patients, and anti-diarrhea therapy was received in 30.2% and 32.7% of patients with abemaciclib plus NSAI and abemaciclib plus fulvestrant arm, respectively. As data cutoff, most diarrhea events were reported as resolved, and the incidence dropped below 10% (Grade 2) and 1% (Grade 3) by Cycle 2 in both arms and kept low incidence over time. Compared to the placebo arm, patients treated with abemaciclib combination who reported diarrhea within the first 7 days (abemaciclib + NSAI, HR [95% CI]: 0.289 [0.166, 0.502]; abemaciclib + fulvestrant, HR [95% CI]: 0.371 [0.213, 0.647]) had significant improvement in PFS.

Conclusion:

Majority of diarrhea events were of low grade in severity and well managed by anti-diarrheal medications, dose omissions or/and dose reductions in MONARCH plus patients.

Table 1. Summary of dose adjustments and supportive medications in patients experiencing diarrheaCohort ACohort BAbemaciclib + NSAIAbemaciclib + FulvestrantN = 205N = 104Diarrhea (any grade), n (%)164 (80.0)82 (78.8)1105 (51.2)52 (50.0)251 (24.9)28 (26.9)38 (3.9)2 (1.9)Outcome, number of events, n796333Recovered/resolved, n (%)757 (95.1)318 (95.5)Not recovered/resolved, n (%)17 (2.1)7 (2.1)Treatment change, n (%)Dose reduction4 (2.0)3 (2.9)Dose omission3 (1.5)3 (2.9)Treatment discontinuation00Anti-diarrhea therapies, n (%)62 (30.2)34 (32.7)loperamide48 (23.4)21 (20.2)berberine6 (2.9)6 (5.8)

Citation Format: Zefei Jiang, Xichun Hu, Qingyuan Zhang, Tao Sun, Yongmei Yin, Huiping Li, Min Yan, Zhongsheng Tong, Christina Pimentel Oppermann, Yunpeng Liu, Romulo Costa, Man Li, Xi Chen, Ying Cheng, Quchang Ouyang, Ning Liao, Xiaojia Wang, Xinhong Wu, Jifeng Feng, Roberto Hegg, Govindbabu Kanaka Setty, Amit Agarwal, Jyoti Bajpai, Jing Cheng, Gustavo Girotto, Chanchal Goswami, Wenjing Hu, Jian Huang, MA Coccia Portugal, Jin Yang, Rongsheng Zheng, Fabio Andre Franke, Qiang Liu, Yunjiang Liu, Yongkui Lu, Cristiano Souza, Shiying Yu, Nalini Kilara, Harsha Panchal, Ashish Singh, Shona Nag, Jian Liu, Bernardo Rapoport, Neonyana Keorapetse Rebecca Tabane, Hongxia Wang, Ning Wang, Rubing Han, Wanli Zhang. Management of abemaciclib associated diarrhea in patients with hormone receptor-positive/human epidermal growth factor receptor 2-negative advanced breast cancer: Analysis of the MONARCH plus study [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS13-25.

FLABRA, frontline approach for BRCA testing in an ovarian cancer population: a Latin America epidemiologic study

Aim: FLABRA evaluated the prevalence of BRCA mutations, genetic counseling and management approaches in patients with ovarian cancer in Latin America. Patients & methods: Patients with ovarian cancer from six Latin-American countries were enrolled. Tumor samples were tested for BRCA mutations (BRCA^mut). In cases with BRCA^mut, blood samples were analyzed to determine germline versus somatic mutations. Medical records were reviewed for counseling approach and treatment plan. Results: From 472 patients enrolled, 406 samples yielded conclusive results: 282 were BRCA wild-type (BRCA^wt), 115 were BRCA^mut and nine were variants of uncertain significance. In total, 110/115 were tested for germline mutations (77 germline and 33 somatic). Conclusion: Tumor testing to identify mutations in BRCA1/2 in ovarian cancer can help optimize treatment choices, meaning fewer patients require germline testing and genetic counseling, a scant resource in Latin America. Clinical trial registration: NCT02984423 (ClinicalTrials.gov).

Phase III, Randomized Study of Dual Human Epidermal Growth Factor Receptor 2 (HER2) Blockade With Lapatinib Plus Trastuzumab in Combination With an Aromatase Inhibitor in Postmenopausal Women With HER2-Positive, Hormone Receptor–Positive Metastatic Breast Cancer: Updated Results of ALTERNATIVE

PURPOSE

Human epidermal growth factor receptor 2 (HER2) targeting plus endocrine therapy (ET) improved clinical benefit in HER2-positive, hormone receptor (HR)–positive metastatic breast cancer (MBC) versus ET alone. Dual HER2 blockade enhances clinical benefit versus single HER2 blockade. The ALTERNATIVE study evaluated the efficacy and safety of dual HER2 blockade plus aromatase inhibitor (AI) in postmenopausal women with HER2-positive/HR-positive MBC who received prior ET and prior neo(adjuvant)/first-line trastuzumab (TRAS) plus chemotherapy. This updated article reflects minor numerical corrections in some secondary efficacy analyses that resulted from programming errors and that do not change the major conclusions of the study.

METHODS

Patients were randomly assigned (1:1:1) to receive lapatinib (LAP) plus TRAS plus AI, TRAS plus AI, or LAP plus AI. Patients for whom chemotherapy was intended were excluded. The primary end point was progression-free survival (PFS; investigator assessed) with LAP plus TRAS plus AI versus TRAS plus AI. Secondary end points were PFS (comparison of other arms), overall survival (OS), overall response rate (ORR), clinical benefit rate (CBR), and safety.

RESULTS

Three hundred fifty-five patients were included in this analysis: LAP plus TRAS plus AI (n = 120), TRAS plus AI (n = 117), and LAP plus AI (n = 118). Baseline characteristics were balanced. The study met its primary end point; superior PFS was observed with LAP plus TRAS plus AI versus TRAS plus AI (median PFS, 11 v 5.6 months; hazard ratio, 0.62 [95% CI, 0.45 to 0.88]; P = .0063). A consistent PFS benefit was observed in predefined subgroups. ORR, CBR, and OS also favored LAP plus TRAS plus AI. The median PFS with LAP plus AI versus TRAS plus AI was 8.3 versus 5.6 months (hazard ratio, 0.85 [95% CI, 0.62 to 1.17]; P = .3159). Common adverse events (AEs; ≥ 15%) with LAP plus TRAS plus AI, TRAS plus AI, and LAP plus AI were diarrhea (69%, 9%, and 51%, respectively), rash (36%, 2%, and 28%, respectively), nausea (22%, 9%, and 22%, respectively), and paronychia (30%, 0%, and 15%, respectively), mostly grade 1 or 2. Serious AEs were reported similarly across the 3 groups, and AEs leading to discontinuation were lower with LAP plus TRAS plus AI.

CONCLUSION

Dual HER2 blockade with LAP plus TRAS plus AI showed superior PFS benefit versus TRAS plus AI in patients with HER2-positive/HR-positive MBC. This combination offers an effective and safe chemotherapy-sparing alternative treatment regimen for this patient population.

MONARCH plus: abemaciclib plus endocrine therapy in women with HR+/HER2- advanced breast cancer: the multinational randomized phase III study

AIM

To compare the efficacy, safety, and tolerability of abemaciclib plus endocrine therapy (ET) versus ET alone in postmenopausal women with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer (ABC) from China, Brazil, India, and South Africa.

METHODS

This randomized, double-blind, phase III study was conducted between 9 December 2016 and 29 March 2019. Postmenopausal women with HR-positive, HER2-negative ABC with no prior systemic therapy in an advanced setting (cohort A) or progression on prior ET (cohort B) received abemaciclib (150 mg twice daily) or placebo plus: anastrozole (1 mg/day) or letrozole (2.5 mg/day) (cohort A) or fulvestrant (500 mg per label) (cohort B). The primary endpoint was progression-free survival (PFS) in cohort A, analyzed using the stratified log-rank test. Secondary endpoints were PFS in cohort B (key secondary endpoint), objective response rate (ORR), and safety. This interim analysis was planned after 119 PFS events in cohort A.

RESULTS

In cohort A, 207 patients were randomly assigned to the abemaciclib arm and 99 to the placebo arm. Abemaciclib significantly improved PFS versus placebo (median: not reached versus 14.7 months; hazard ratio 0.499; 95% confidence intervals (CI) 0.346-0.719; p = 0.0001). ORR was 65.9% in the abemaciclib arm and 36.1% in the placebo arm (p < 0.0001, measurable disease population). In cohort B, 104 patients were randomly assigned to the abemaciclib arm and 53 to the placebo arm. Abemaciclib significantly improved PFS versus placebo (median: 11.5 versus 5.6 months; hazard ratio 0.376; 95% CI 0.240-0.588; p < 0.0001). ORR was 50.0% in the abemaciclib arm and 10.5% in the placebo arm (p < 0.0001, measurable disease population). The most frequent grade ⩾3 adverse events in the abemaciclib arms were neutropenia, leukopenia, and anemia (both cohorts), and lymphocytopenia (cohort B).

CONCLUSION

The addition of abemaciclib to ET demonstrated significant and clinically meaningful improvement in PFS and ORR, without new safety signals observed in this population.Trial Registration: ClinicalTrials.gov identifier: NCT02763566.

Neoadjuvant atezolizumab in combination with sequential nab-paclitaxel and anthracycline-based chemotherapy versus placebo and chemotherapy in patients with early-stage triple-negative breast cancer (IMpassion031): a randomised, double-blind, phase 3 trial

BACKGROUND

Preferred neoadjuvant regimens for early-stage triple-negative breast cancer (TNBC) include anthracycline-cyclophosphamide and taxane-based chemotherapy. IMpassion031 compared efficacy and safety of atezolizumab versus placebo combined with nab-paclitaxel followed by doxorubicin plus cyclophosphamide as neoadjuvant treatment for early-stage TNBC.

METHODS

This double-blind, randomised, phase 3 study enrolled patients in 75 academic and community sites in 13 countries. Patients aged 18 years or older with previously untreated stage II-III histologically documented TNBC were randomly assigned (1:1) to receive chemotherapy plus intravenous atezolizumab at 840 mg or placebo every 2 weeks. Chemotherapy comprised of nab-paclitaxel at 125 mg/m² every week for 12 weeks followed by doxorubicin at 60 mg/m² and cyclophosphamide at 600 mg/m² every 2 weeks for 8 weeks, which was then followed by surgery. Stratification was by clinical breast cancer stage and programmed cell death ligand 1 (PD-L1) status. Co-primary endpoints were pathological complete response in all-randomised (ie, all randomly assigned patients in the intention-to-treat population) and PD-L1-positive (ie, patients with PD-L1-expressing tumour infiltrating immune cells covering ≥1% of tumour area) populations. This study is registered with ClinicalTrials.gov (NCT03197935), Eudra (CT2016-004734-22), and the Japan Pharmaceutical Information Center (JapicCTI-173630), and is ongoing.

FINDINGS

Between July 7, 2017, and Sept 24, 2019, 455 patients were recruited and assessed for eligibility. Of the 333 eligible patients, 165 were randomly assigned to receive atezolizumab plus chemotherapy and 168 to placebo plus chemotherapy. At data cutoff (April 3, 2020), median follow-up was 20·6 months (IQR 8·7-24·9) in the atezolizumab plus chemotherapy group and 19·8 months (8·1-24·5) in the placebo plus chemotherapy group. Pathological complete response was documented in 95 (58%, 95% CI 50-65) patients in the atezolizumab plus chemotherapy group and 69 (41%, 34-49) patients in the placebo plus chemotherapy group (rate difference 17%, 95% CI 6-27; one-sided p=0·0044 [significance boundary 0·0184]). In the PD-L1-positive population, pathological complete response was documented in 53 (69%, 95% CI 57-79) of 77 patients in the atezolizumab plus chemotherapy group versus 37 (49%, 38-61) of 75 patients in the placebo plus chemotherapy group (rate difference 20%, 95% CI 4-35; one-sided p=0·021 [significance boundary 0·0184]). In the neoadjuvant phase, grade 3-4 adverse events were balanced and treatment-related serious adverse events occurred in 37 (23%) and 26 (16%) patients, with one patient per group experiencing an unrelated grade 5 adverse event (traffic accident in the atezolizumab plus chemotherapy group and pneumonia in the placebo plus chemotherapy group).

INTERPRETATION

In patients with early-stage TNBC, neoadjuvant treatment with atezolizumab in combination with nab-paclitaxel and anthracycline-based chemotherapy significantly improved pathological complete response rates with an acceptable safety profile.

FUNDING

F Hoffmann-La Roche/Genentech.

Abemaciclib Combined With Endocrine Therapy for the Adjuvant Treatment of HR+, HER2-, Node-Positive, High-Risk, Early Breast Cancer (monarchE)

PURPOSE

Many patients with HR+, HER2- early breast cancer (EBC) will not experience recurrence or have distant recurrence with currently available standard therapies. However, up to 30% of patients with high-risk clinical and/or pathologic features may experience distant recurrence, many in the first few years. Superior treatment options are needed to prevent early recurrence and development of metastases for this group of patients. Abemaciclib is an oral, continuously dosed, CDK4/6 inhibitor approved for HR+, HER2- advanced breast cancer (ABC). Efficacy and safety of abemaciclib in ABC supported evaluation in the adjuvant setting.

METHODS

This open-label, phase III study included patients with HR+, HER2-, high-risk EBC, who had surgery and, as indicated, radiotherapy and/or adjuvant/neoadjuvant chemotherapy. Patients with four or more positive nodes, or one to three nodes and either tumor size ≥ 5 cm, histologic grade 3, or central Ki-67 ≥ 20%, were eligible and randomly assigned (1:1) to standard-of-care adjuvant endocrine therapy (ET) with or without abemaciclib (150 mg twice daily for 2 years). The primary end point was invasive disease-free survival (IDFS), and secondary end points included distant relapse-free survival, overall survival, and safety.

RESULTS

At a preplanned efficacy interim analysis, among 5,637 randomly assigned patients, 323 IDFS events were observed in the intent-to-treat population. Abemaciclib plus ET demonstrated superior IDFS versus ET alone (P = .01; hazard ratio, 0.75; 95% CI, 0.60 to 0.93), with 2-year IDFS rates of 92.2% versus 88.7%, respectively. Safety data were consistent with the known safety profile of abemaciclib.

CONCLUSION

Abemaciclib when combined with ET is the first CDK4/6 inhibitor to demonstrate a significant improvement in IDFS in patients with HR+, HER2- node-positive EBC at high risk of early recurrence.

Abstract 785: Genomic markers of response to monotherapy abemaciclib in the nextMONARCH 1 study

Background: Clinical data characterizing the genomic markers of response to single agent CDK4 & 6 inhibitors are lacking. Abemaciclib is the only CDK4 & 6 inhibitor indicated as monotherapy for HR+, HER2- advanced breast cancer (ABC) following progression on endocrine therapy (ET) and prior chemotherapy (CT) in the metastatic setting. We explored the genomic alterations detected in baseline circulating tumor DNA (ctDNA) from patients (pts) treated with abemaciclib monotherapy in the nextMONARCH 1 study.

Methods: nextMONARCH 1 (NCT02747004) was a Phase 2 study evaluating abemaciclib or abemaciclib + tamoxifen in women with HR+, HER2- ABC who had progressed on or after prior ET and had previously received CT. Pts (n=234) were randomized to abemaciclib 150 mg Q12H + daily tamoxifen 20mg (n=78), abemaciclib 150 mg Q12H (n=79), or abemaciclib 200 mg Q12H + prophylactic loperamide (n=77). Available baseline plasma samples for pts in the abemaciclib monotherapy arms (n=146; 94%) were analyzed by the Guardant360 next-generation sequencing (NGS)-based assay to identify potential tumor-related (i.e., somatic) genomic alterations including point mutations (SNV), indels, amplifications, and fusions in over 70 cancer-related genes.

Results: The majority of pts (91%) receiving abemaciclib monotherapy had at least one genomic alteration detected in baseline ctDNA. The intent to treat population and the translational research population had similar treatment benefit (7.4 mos [95% confidence interval, CI: 5.5, 9.1] versus 7.4 mos [CI: 5.5, 9.1], p=0.945). The most frequently altered genes detected in baseline ctDNA included: ESR1 (41%), PIK3CA (35%), TP53 (29%), FGFR1 (23%), GATA3 (20%), and MYC (20%). Overall, pts with any detectable ctDNA genomic alterations generally had a shorter median progression-free survival (mPFS) compared to pts without any detectable genomic alterations (6.8 mos [CI: 5.2, 9.0] versus 12.0 mos [CI: 5.4, 23.9], p=0.099). In particular, genomic alterations in PIK3CA, TP53, FGFR1, MYC, NF1, EGFR, ERBB2, or CCNE1 were associated with a significantly shorter mPFS in this heavily pretreated pt population. Pts with detected alterations in RB1 or ESR1 trended towards a shorter mPFS, while pts with detected alterations in GATA3 trended towards a longer mPFS.

Conclusions: To our knowledge, this is the first exploratory study to evaluate the genomic markers of response to monotherapy CDK4 & 6 inhibitor in a heavily pretreated pt population with HR+, HER2- ABC. These results provide insight into the genomic landscape of ABC and, if validated, could inform further trials of CDK4 & 6 inhibitors.

Citation Format: Erika P. Hamilton, Javier Cortes, Guy Jerusalem, Peter A. Kaufman, Ozgur Ozyilkan, Roberto Hegg, Lacey M. Litchfield, Hong Wang, Hillary T. Graham, Sameera R. Wijayawardana, Valerie M. Jansen, Miguel Martin. Genomic markers of response to monotherapy abemaciclib in the nextMONARCH 1 study [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 785.

A phase III trial of capivasertib and paclitaxel in first-line treatment of patients with metastatic triple-negative breast cancer (CAPItello290)

TPS1109

Background: Therapeutic options for patients with metastatic triple-negative breast cancer (TNBC) are limited to sequential chemotherapy, although recent advances with novel agents have been made for specific subgroups (PD-L1 inhibitor atezolizumab in combination with nab-paclitaxel in patients with PD-L1-positive tumors and PARP inhibitors in patients with germline BRCA mutations). The PI3K/AKT/PTEN signaling pathway is often activated in TNBC, mainly through activating mutations in PIK3CA or AKT1 and/or inactivating alterations in PTEN. The phase II PAKT study (NCT02423603) demonstrated that addition of the oral AKT inhibitor capivasertib to first-line paclitaxel resulted in significantly longer progression-free survival (PFS) and overall survival (OS) in patients with advanced TNBC, especially in patients with PIK3CA/AKT1/PTEN-altered tumors (Schmid et al, 2019). This phase III trial (NCT03997123) will further evaluate the efficacy and safety of capivasertib in combination with paclitaxel in first-line treatment of patients with metastatic TNBC in an unselected population and will also explore potential predictive markers of sensitivity to the combination of paclitaxel and capivasertib. Methods: Eligible patients for this double-blind, randomized, placebo-controlled trial must have metastatic TNBC or locally advanced disease not amenable to resection with curative intent. Patients must be candidates for single-agent taxane therapy and have received no prior systemic therapy for locally advanced inoperable or metastatic disease. Prior chemotherapy in the (neo)adjuvant setting must be completed ≥12 months prior to enrollment. Patients will be randomized 1:1 to paclitaxel 80 mg/m2 (days 1, 8 and 15) with either capivasertib 400 mg twice daily or placebo (days 2–5, 9–12 and 16–19) every 28 days, until objective radiologic disease progression as defined by RECIST 1.1, unacceptable toxicity or death. Stratification factors will be prior adjuvant chemotherapy, visceral versus non-visceral disease, and geographic region. Post-randomization central testing of tumor tissue (collected prior to enrollment) will be carried out to identify predictive markers of sensitivity to treatment. The primary endpoints of this study are PFS and OS. Secondary endpoints include safety and tolerability, time to second progression or death, objective response rate, duration of response, and clinical benefit rate. Enrollment for this study started in May 2019. Clinical trial information: NCT03997123 .

Overview of obesity and breast cancer in Brazil: 24 year of follow up

e13580

Background: Obesity is one of the major public health challenges of the 21st century. The prevalence of obesity is growing exponentially across all age groups and on all continents and it is associated with morbidities such as cardiovascular disease, diabetes mellitus type 2, dyslipidemia, hypertension and cancer. There is a higher risk of developing breast cancer in postmenopausal obese women, and with worse outcome for women of all ages. Objectives: To evaluate obesity prevalence in breast cancer patients and its association with recovering, survival, death, age, Human Epidermal Growth Factor Receptor 2 (HER2) and anti-human KI67 antibody(KI67). Methods: A retrospective cohort study was performed between 1994 and 2018 at the Breast Cancer Department, São Paulo State Government Women's Health Reference Center (Perola Byington Hospital), São Paulo, Brazil with 8824 breast cancer patients. From those, 2899 patients were excluded because they did not have description of weight and/or Body Mass Index (BMI). Survival analysis was performed according to BMI groups. Results: The participants had mean (SD) age of 54 (12.0) years and weight of 70 (15.0) kg. There were 769 (13%) deaths and the mean survival was 20 (2.0) years. 1787 (30%) participants were stratified in obese (BMI≥30Kg/m2) and 4138 (70%) non-obese Obese were older (p < 0,001) and had a higher frequency of HER2 negative (p < 0,04) than non-obese women. There were not a significant difference in frequencies of KI67, recovering and survival between groups. The prevalence of obesity was not different over 24 years. Conclusions: There was a relevant prevalence of obesity in breast cancer patients, which was associated with HER2 negative and age, but not with recovering or survival.

Prognostic factors impacting survival in early HER2-positive breast cancer (BC): Results from a 1,142 patients database study

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Background: early systemic therapy has reduced recurrence and mortality from BC, especially among HER2+ subtype. Despite these advances, the difficulty of developing countries in incorporating new treatments, as well as the molecular and phenotypic profiles of HER2+ BC, are associated with the heterogeneity of treatment responses, leading to poor prognosis and outcomes. However, real-world data on prognostic factors for early HER2+ BC patients are scarce, especially in the Brazilian context. Therefore, this study aims to evaluate the influence of prognostic factors on disease-free survival (DFS) and overall survival (OS) in early HER2+ BC patients. Methods: this retrospective study identified early HER2+ BC (stage I to III with positive immunohistochemistry and in-situ hybridization) patients from Pérola Byington’s public hospital database (São Paulo, Brazil) diagnosed between January 2010 to March 2018. Patients were excluded if they were less than 18 years old, participated in clinical trials, presented metastatic disease de novo, concurrent malignancy, or inconsistent data. Multivariate Cox regression was used to evaluate prognostic factors for survival, and OS and DFS were estimated by Kaplan-Meier analyses. Results: of the 1,625 patients identified in the database, 1,142 women were included in the study. Of those, 40% were diagnosed with less than 50 years old. Among the included patients, 40.3% were HR-/HER2+ and 59.7% were HR+/HER2+. In addition, 19.4% of patients were diagnosed at stage I, 42.9% at stage II and 37.7% at stage III. A total of 1033 patients were included in the DFS analysis, with a probability of 71.8% DFS in 5-years. For OS analysis, a probability of 75.4% OS in 5-years was observed for 1139 patients included. The multivariate analysis showed that tumor staging, lymph node involvement and pathological complete response (pCR) were independent prognostic factors for both DFS and OS. Conclusions: the study in the Brazilian cohort corroborates the literature, showing that tumor staging, pCR, and lymph node involvement are key markers for DFS and OS and they should be considered when managing the early HER2+ BC patients. [Table: see text]

Abstract OT2-08-02: Capivasertib and paclitaxel in first-line treatment of patients with metastatic triple-negative breast cancer: A phase III trial (CAPItello-290)

Background: Triple-negative breast cancer (TNBC) generally has an aggressive clinical course, including distant metastases and increased likelihood of death within 5 years of diagnosis compared with non-TNBCs. Therapeutic options for metastatic TNBC patients are limited to sequential chemotherapy, although recent advances with novel agents have been made for specific subgroups (PD-L1 inhibitor atezolizumab in combination with nab-paclitaxel in patients with PD-L1-positive tumors and PARP inhibitors in germline BRCA-mutant patients). However, improvements in progression-free survival (PFS) derived from immune-oncology and PARP inhibitors are still insufficient in terms of informing patient selection and overall magnitude of benefit. Developing novel treatments in both early and advanced TNBC settings remains a significant unmet need in the management of advanced breast cancer. The PI3K/AKT/PTEN signaling pathway is often activated in TNBC, mainly through activating mutations in PIK3CA or AKT1 and/or inactivating alterations in PTEN. The Phase II PAKT study (NCT02423603) demonstrated that addition of the oral AKT inhibitor capivasertib to first-line paclitaxel resulted in significantly longer PFS and overall survival (OS) in patients with advanced TNBC, especially in patients with PIK3CA/AKT1/PTEN-altered tumors (Schmid, 2018). The Phase III trial we report (NCT03997123) will further evaluate the efficacy and safety of capivasertib in combination with paclitaxel in first-line treatment of patients with metastatic TNBC in an unselected population and will also explore potential predictive markers of sensitivity to the combination of paclitaxel and capivasertib. Methods: Eligible patients for this double-blind, randomized, placebo-controlled trial must have metastatic TNBC or locally advanced disease not amenable to resection with curative intent. Patients must be candidates for single-agent taxane therapy and have received no prior systemic therapy for locally advanced inoperable or metastatic disease. Prior chemotherapy in the (neo)adjuvant setting must be completed ≥12 months prior to enrollment. Patients will be randomized 1:1 to paclitaxel 80 mg/m2 (days 1, 8 and 15) with either capivasertib 400 mg twice daily or placebo (days 2-5, 9-12, 16-19) every 28 days until objective radiologic disease progression as defined by RECIST 1.1, unacceptable toxicity, or death. Stratification factors will be prior adjuvant chemotherapy, visceral vs non-visceral disease, and geographic region. Post-randomization central testing of tumor tissue (collected prior to enrollment) will be carried out to identify predictive markers of sensitivity to treatment. The primary endpoints of this study are PFS and OS. Secondary endpoints include safety and tolerability, time to second progression or death, objective response rate, duration of response, and clinical benefit rate. Enrollment for this study opened in May 2019.

Citation Format: Peter Schmid, Javier Cortes, Mark Robson, Hiroji Iwata, Roberto Hegg, Sunil Verma, Marina Nechaeva, Binghe Xu, Vincent Haddad, Esteban Rodrigo Imedio, Gaia Schiavon, Andrew Foxley, Yeon Hee Park. Capivasertib and paclitaxel in first-line treatment of patients with metastatic triple-negative breast cancer: A phase III trial (CAPItello-290) [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr OT2-08-02.

Adjuvant denosumab in early breast cancer (D-CARE): an international, multicentre, randomised, controlled, phase 3 trial

BACKGROUND

Denosumab is a fully human monoclonal antibody that binds to, and inhibits, the receptor activator of RANKL (TNFSF11) and might affect breast cancer biology, as shown by preclinical evidence. We aimed to assess whether denosumab combined with standard-of-care adjuvant or neoadjuvant systemic therapy and locoregional treatments would increase bone metastasis-free survival in women with breast cancer.

METHOD

In this international, double-blind, randomised, placebo-controlled, phase 3 study (D-CARE), patients were recruited from 389 centres in 39 countries. We enrolled women (aged ≥ 18 years) with histologically confirmed stage II or III breast cancer and an Eastern Cooperative Oncology Group performance status of 0 or 1. On eligibility confirmation, investigators at each site telephoned an interactive voice response system to centrally randomly assign patients (1:1) based on a fixed stratified permuted block randomisation list (block size 4) to receive either denosumab (120 mg) or matching placebo subcutaneously every 3-4 weeks, starting with neoadjuvant or adjuvant chemotherapy, for about 6 months and then every 12 weeks for a total duration of 5 years. Stratification factors were breast cancer therapy, lymph node status, hormone receptor and HER2 status, age, and geographical region. The primary endpoint was the composite endpoint of bone metastasis-free survival. This trial is registered with ClinicalTrials.gov, NCT01077154.

FINDINGS

Between June 2, 2010, and Aug 24, 2012, 4509 women were randomly assigned to receive denosumab (n=2256) or placebo (n=2253) and included in the intention-to-treat analysis. The primary analysis of the study was done when all patients had the opportunity to complete 5 years of follow-up with an analysis data cutoff date of Aug 31, 2017. The primary endpoint of bone metastasis-free survival was not significantly different between the groups (median not reached in either group; hazard ratio 0·97, 95% CI 0·82-1·14; p=0·70). The most common grade 3 or worse treatment-emergent adverse events, reported in patients who had at least one dose of the investigational product (2241 patients with denosumab vs 2218 patients with placebo), were neutropenia (340 [15%] vs 328 [15%]), febrile neutropenia (112 [5%] vs 142 [6%]), and leucopenia (62 [3%] vs 61 [3%]). Positively adjudicated osteonecrosis of the jaw occurred in 122 (5%) of 2241 patients treated with denosumab versus four (<1%) of 2218 patients treated with placebo; treatment-emergent hypocalcaemia occurred in 152 (7%) versus 82 (4%). Two treatment-related deaths occurred in the placebo group due to acute myeloid leukaemia and depressed level of consciousness.

INTERPRETATION

Despite preclinical evidence suggesting RANKL inhibition might delay bone metastasis or disease recurrence in patients with early-stage breast cancer, in this study, denosumab did not improve disease-related outcomes for women with high-risk early breast cancer.

FUNDING

Amgen.

Everolimus Plus Endocrine Therapy for Postmenopausal Women With Estrogen Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative Advanced Breast Cancer: A Clinical Trial

Importance

Cotargeting the mammalian target of rapamycin pathway and estrogen receptor may prevent or delay endocrine resistance in patients receiving first-line treatment for advanced breast cancer.

Objective

To investigate the combination of everolimus plus endocrine therapy in first-line and second-line treatment settings for postmenopausal women with estrogen receptor-positive, human epidermal growth receptor 2-negative advanced breast cancer.

Design, Setting, and Participants

In the multicenter, open-label, single-arm, phase 2 BOLERO-4 (Breast Cancer Trials of Oral Everolimus) clinical trial, 245 patients were screened for eligibility; 202 were enrolled between March 7, 2013, and December 17, 2014. A median follow-up of 29.5 months had been achieved by the data cutoff date (December 17, 2016).

Interventions

Patients received first-line treatment with everolimus, 10 mg/d, plus letrozole, 2.5 mg/d. Second-line treatment with everolimus, 10 mg/d, plus exemestane, 25 mg/d, was offered at the investigator's discretion upon initial disease progression.

Main Outcomes and Measures

The primary end point was investigator-assessed progression-free survival in the first-line setting per Response Evaluation Criteria in Solid Tumors, version 1.0. Safety was assessed in patients who received at least 1 dose of study medication and at least 1 postbaseline safety assessment.

Results

A total of 202 women treated in the first-line setting had a median age of 64.0 years (interquartile range, 58.0-70.0 years) with metastatic (194 [96.0%]) or locally advanced (8 [4.0%]) breast cancer. Median progression-free survival was 22.0 months (95% CI, 18.1-25.1 months) with everolimus and letrozole. Median overall survival was not reached; 24-month estimated overall survival rate was 78.7% (95% CI, 72.1%-83.9%). Fifty patients started second-line treatment; median progression-free survival was 3.7 months (95% CI, 1.9-7.4 months). No new safety signals were observed. In the first-line setting, the most common all-grade adverse event was stomatitis (139 [68.8%]); the most common grade 3 to 4 adverse event was anemia (21 [10.4%]). In the second-line setting, the most common adverse events were stomatitis and decreased weight (10 [20.0%] each); the most common grade 3 to 4 adverse event was hypertension (5 [10.0%]). There were 50 (24.8%) deaths overall during the study; 40 were due to study indication (breast cancer).

Conclusions and Relevance

The results of this trial add to the existing body of evidence suggesting that everolimus plus endocrine therapy is a good first-line treatment option for postmenopausal women with estrogen receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer.

Trial Registration

clinicaltrials.gov Identifier: NCT01698918.

Subcutaneous vs Intravenous Trastuzumab for Patients With ERBB2-Positive Early Breast Cancer: Final Analysis of the HannaH Phase 3 Randomized Clinical Trial

Importance

Confirmation of long-term comparability between subcutaneous and intravenous trastuzumab is essential.

Objective

To evaluate efficacy and safety of subcutaneous trastuzumab compared with that of intravenous trastuzumab for patients with ERBB2 (HER2)-positive early breast cancer after 6 years' follow-up in the HannaH (Enhanced Treatment With Neoadjuvant Herceptin) trial.

Design, Setting, and Participants

Open-label, prospective, multicenter, international, neoadjuvant-adjuvant, randomized, phase 3 noninferiority clinical trial (primary end points: pathologic complete response and serum trough concentration predose cycle 8) conducted for 596 patients with ERBB2-positive early breast cancer enrolled from October 19, 2009, to December 1, 2010.

Interventions

Eligible patients received 8 cycles of chemotherapy (4 cycles of docetaxel, 75 mg/m2, followed by 4 cycles of fluorouracil, 500 mg/m2, epirubicin, 75 mg/m2, and cyclophosphamide, 500 mg/m2) with either fixed-dose subcutaneous trastuzumab, 600 mg, or intravenous trastuzumab (loading dose, 8 mg/kg; maintenance dose, 6 mg/kg) every 3 weeks in the neoadjuvant setting. Patients received an additional 10 cycles of subcutaneous trastuzumab or intravenous trastuzumab (according to their initial randomization) after surgery in the adjuvant setting to complete 1 year of anti-ERBB2 therapy.

Main Outcomes and Measures

Event-free and overall survival rates were calculated using the Kaplan-Meier method. Hazard ratios were estimated by Cox proportional hazards regression. Adverse events and serious adverse events were graded per standard criteria.

Results

In total, 294 women (mean [SD] age, 50.3 [11.1] years) treated with subcutaneous trastuzumab and 297 women (mean [SD] age, 49.5 [10.8] years) treated with intravenous trastuzumab were included in respective intention-to-treat populations. Six-year event-free survival rates (65% in both study groups; hazard ratio, 0.98; 95% CI, 0.74-1.29) and overall survival rates (84% in both study groups; hazard ratio, 0.94; 95% CI, 0.61-1.45) were similar between the subcutaneous and intravenous trastuzumab groups. Patients achieving a total pathologic complete response had longer event-free survival and higher 6-year overall survival rates than those with residual disease. Incidence of adverse events (290 of 297 [97.6%] vs 282 of 298 [94.6%]), grade 3 or higher adverse events (158 of 297 [53.2%] vs 160 of 298 [53.7%]), cardiac events (44 of 297 [14.8%] vs 42 of 298 [14.1%]), and serious adverse events (65 of 297 [21.9%] vs 45 of 298 [15.1%]) was comparable between the subcutaneous and intravenous trastuzumab treatment groups.

Conclusions and Relevance

This final analysis of the HannaH trial further confirms the comparable efficacy and safety of subcutaneous and intravenous trastuzumab and highlights the suitability of subcutaneous trastuzumab as an alternative route of administration for patients with ERBB2-positive early breast cancer.

Trial Registration

ClinicalTrials.gov identifier: NCT00950300.

Abstract P6-18-04: Ribociclib with a non-steroidal aromatase inhibitor and goserelin in premenopausal women with hormone receptor-positive, HER2-negative advanced breast cancer: MONALEESA-7 age subgroup analysis

Background: Younger patients (pts) with breast cancer may experience more aggressive disease and are more likely to die from their cancer vs older pts. In the Phase III MONALEESA-7 study (NCT02278120), the addition of ribociclib (RIB; cyclin-dependent kinase 4/6 inhibitor) to a non-steroidal aromatase inhibitor (NSAI) or tamoxifen (TAM) + goserelin significantly prolonged progression-free survival (PFS) in premenopausal women with hormone receptor-positive (HR+), HER2-negative (HER2–) advanced breast cancer (ABC; hazard ratio 0.553; p&lt;0.0001). RIB treatment benefit was observed irrespective of endocrine partner (NSAI or TAM). Here we report results from a MONALEESA-7 subgroup analysis in pts aged &lt;40 yrs and ≥40 yrs who received RIB or placebo (PBO) in combination with an NSAI + goserelin.

Methods: Pre- or perimenopausal women with HR+, HER2– ABC who had received no prior endocrine therapy and ≤1 line of chemotherapy for ABC were enrolled. Of the 672 pts randomized, 495 (74%) received RIB (600 mg/day, 3-weeks-on/1-week-off) or PBO + an NSAI (letrozole [2.5 mg/day] or anastrozole [1 mg/day]) and goserelin (3.6 mg every 28 days). The primary endpoint was locally assessed PFS; secondary endpoints included overall response rate (ORR), clinical benefit rate (CBR), and safety. A prespecified subgroup analysis was performed in pts aged &lt;40 yrs and ≥40 yrs.

Results: A total of 144 pts were aged &lt;40 yrs (RIB vs PBO arm: 78 vs 66) and 351 were aged ≥40 yrs (170 vs 181). As of August 20, 2017, in the RIB vs PBO arms, treatment was ongoing in 50% vs 23% of pts aged &lt;40 yrs and 54% vs 43% of pts aged ≥40 yrs; disease progression was the most common reason for treatment discontinuation (&lt;40 yrs: 37% vs 68%; ≥40 yrs: 35% vs 44%). Median PFS was prolonged in the RIB vs PBO arms both in pts aged &lt;40 yrs (not reached vs 10.8 months; hazard ratio 0.435; 95% confidence interval [CI] 0.276–0.686) and in pts aged ≥40 yrs (27.5 vs 19.1 months; hazard ratio 0.625; 95% CI 0.449–0.870). In pts with measurable disease, the ORR (RIB vs PBO arm) was 49% vs 32% in pts aged &lt;40 yrs and 51% vs 38% in pts aged ≥40 yrs; CBR was 81% vs 61% and 82% vs 65%, respectively. The most common Grade 3 adverse events (AEs; ≥5% of pts in either arm; RIB vs PBO arm) were neutropenia (&lt;40 yrs: 47% vs 5%; ≥40 yrs: 58% vs 3%), leukopenia (&lt;40 yrs: 18% vs 2%; ≥40 yrs: 14% vs 1%), diarrhea (&lt;40 yrs: 5% vs 0; ≥40 yrs: 1% vs 0), and increased alanine aminotransferase (&lt;40 yrs: 4% vs 2%; ≥40 yrs: 5% vs 1%); neutropenia was the only Grade 4 AE occurring in ≥5% of pts in either arm (&lt;40 yrs: 15% vs 0; ≥40 yrs: 8% vs 1%). New post-baseline QTcF &gt;480 ms (RIB vs PBO arm) occurred in 3% vs 2% of pts aged &lt;40 yrs and 7% vs 1% of pts aged ≥40 yrs.

Conclusions: Consistent treatment benefit was observed with RIB + NSAI vs PBO + NSAI in premenopausal women with HR+, HER2– ABC irrespective of age. RIB + NSAI had a manageable safety profile in pts aged &lt;40 yrs and in those aged ≥40 yrs, with a safety profile similar to that observed in the full study population.

Citation Format: Tripathy D, Campos-Gomez S, Lu Y-S, Franke F, Bardia A, Wheatley-Price P, Cruz FM, Hegg R, Cardoso F, Gaur A, Kong O, Diaz-Padilla I, Miller M, Hurvitz S. Ribociclib with a non-steroidal aromatase inhibitor and goserelin in premenopausal women with hormone receptor-positive, HER2-negative advanced breast cancer: MONALEESA-7 age subgroup analysis [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-18-04.

Abstract P1-14-01: Final results of NorBreast-231, a randomized phase II study evaluating weekly oral vinorelbine versus weekly paclitaxel as first-line chemotherapy in patients with advanced breast cancer

Background: Single-agent chemotherapy (CT) is the standard treatment option in endocrine receptor (ER)-positive advanced breast cancer (ABC) after failure of endocrine therapy (ET) or in patients (pts) without visceral crisis. Both weekly paclitaxel (WP) and oral vinorelbine (OV) are among the recommended treatment options in this setting. The aim of this study was to evaluate the efficacy and safety profiles of OV and WP in a face to face study.

Material and methods: Pts with ER-positive, HER2-negative ABC, with an age ≥18 years and with a documented locally recurrent or metastatic involvement previously untreated by CT were eligible. Pts were randomized to receive, as first-line CT, 3 weekly-cycles of either: ARM A: weekly OV, given as a 80 mg/m2 dose (following a first cycle at 60 mg/m2, dose escalation to 80 in the absence of grade 3 or 4 toxicity at cycle 1); ARM B: WP 80 mg/m2 per week. Primary endpoint was disease control rate (DCR). Pts were stratified according to prior taxane CT and visceral metastases.

Results: 131 pts have been treated (OV: 66, WP: 65). Baseline pts characteristics (Arms OV/WP): median age 58/61 years; median number of prior ET: 2/2; prior (neo) adjuvant CT 74/72%; prior anthracycline 67/62%; prior taxane: 41/42%; &gt;3 metastatic sites 42/48%; visceral metastases 79/79%. Median number of cycles (range): 6(1-55)/7(1-44); dose escalation of OV was performed in 75% of pts. Safety: most common non-hematological related G3/4 adverse events per pt were fatigue 8/2%, peripheral neuropathy 0/5%, nausea 3/0%, diarrhoea 3/2%, vomiting 3/0%, constipation 3/2%, alopecia (G2) 2/34%, no toxic deaths; febrile neutropenia was present in 2/0% of pts. Quality of life: over time, no major differences between both arms have been observed. Efficacy: DCR in the intent-to-treat population was [95%CI] 75.8 [63.6-85.5] /75.4 [63.1-85.2]%; overall response rate 20/40%; median progression-free survival: 5.5/6.4 months. Median overall survival was: OV 27.6/WP 22.3 months.

Conclusion: Both OV and WP reached similar DCR rates of 75%. Each regimen presented a specific tolerance profile, with, in particular, a lower incidence of alopecia and peripheral neuropathy with OV. OV and WP are valid first-line CT options for ER-positive/HER2-negative pts with ABC.

Citation Format: Aapro MS, Hegg R, Ruiz Borrego M, Staroslawska E, Morales S, Cinieri S, De Freitas Junior R, Garcia Estevez L, Szombara E, Hervieu H, Groc M, Villanova GR. Final results of NorBreast-231, a randomized phase II study evaluating weekly oral vinorelbine versus weekly paclitaxel as first-line chemotherapy in patients with advanced breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-14-01.

Abstract PD1-11: nextMONARCH 1: Phase 2 study of abemaciclib plus tamoxifen or abemaciclib alone in HR+, HER2- advanced breast cancer

Background

Abemaciclib is a selective CDK4 & 6 inhibitor approved on a continuous dosing schedule for HR+, HER2- advanced breast cancer (ABC) as monotherapy (MONARCH 1) and in combination with endocrine therapy (ET). A previous Phase 1b (NCT01394016) cohort of HR+ ABC patients (pts) demonstrated efficacy of abemaciclib monotherapy (150mg and 200mg Q12H starting dose); given the small sample size and nonrandomized design the impact of the starting dose was unclear. nextMONARCH 1 (NCT02747004) evaluated abemaciclib in 2 monotherapy arms, in a randomized setting. Abemaciclib has been associated with dose-dependent early onset diarrhea that is well managed with antidiarrheal therapy. nextMONARCH 1 also explored the 200mg Q12H abemaciclib dose in combination with prophylactic loperamide to reduce incidence/severity of diarrhea and dose adjustments. A third arm evaluated abemaciclib + tamoxifen as a strategy to overcome endocrine resistance.

Methods

nextMONARCH 1 is a multicenter, randomized, open-label, Phase 2 study of abemaciclib or abemaciclib + tamoxifen in women with HR+, HER2- ABC who have progressed on or after prior ET and previously received chemotherapy. Pts were stratified by presence of liver metastases and prior use of tamoxifen in the advanced setting. Randomization was 1:1:1 to abemaciclib 150mg Q12H + daily tamoxifen 20mg (Arm A) or abemaciclib 150mg Q12H (Arm B); or abemaciclib 200mg Q12H + prophylactic loperamide (Arm C). Key eligibilities were ≥2 chemotherapy regimens (1-2 administered in metastatic setting), measurable disease and no prior treatment with CDK4 & 6 inhibitors. Primary objective was progression free survival (PFS). Key secondary objectives included objective response rate (ORR), dclinical benefit rate (CBR), and safety. PFS analysis tested superiority of Arm A to C at ∼110 events across the 2 arms assuming a hazard ratio (HR) of 0.667 to achieve ∼80% power. Arm B would be considered non-inferior to Arm C if the observed PFS HR is &lt;1.2.

Results

234 pts were randomized to Arms A (n=78), B (n=79) and C (n=77). 166 PFS events have been observed (A: 57; B: 54; C: 55). Median PFS was 9.1 months in Arm A, 6.5 in Arm B and 7.4 in Arm C (A vs C: HR=.815, 95% CI, .556-1.193, p=.293; B vs C: HR=1.045, 95% CI, .711-1.535 p=.811). Investigator-assessed ORR was 34.6%, 24.1% and 32.5% (confirmed ORR: 25.6%, 19.0%, 28.6%) and CBR was 61.5%, 49.4% and 51.9% in Arms A, B and C, respectively. Prophylactic loperamide reduced the incidence and severity of diarrhea (C: 62.3%, Gr 3: 7.8%) compared to MONARCH 1 (90.2%, Gr 3: 19.7%, Dickler et al. 2017) resulting in similar rates of diarrhea with 150mg abemaciclib without prophylaxis (A: 53.8%, Gr 3: 1.3%; B: 67.1%, Gr 3: 3.8%). The adverse event profile across arms was generally consistent with other breast studies of abemaciclib.

Conclusions

nextMONARCH 1 confirmed single-agent activity of abemaciclib in heavily pretreated pts with HR+, HER2- ABC. Efficacy of abemaciclib monotherapy at 150mg was similar to 200mg. Combining tamoxifen with abemaciclib did not demonstrate a statistically significant improvement in PFS compared to abemaciclib monotherapy. Addition of prophylactic loperamide to abemaciclib 200mg resulted in diarrhea similar to 150mg without prophylaxis.

Citation Format: Hamilton E, Cortes J, Dieras V, Ozyilkan O, Chen S-C, Petrakova K, Manikhas A, Jerusalem G, Hegg R, Lu Y, Bear MM, Johnston EL, Martin M. nextMONARCH 1: Phase 2 study of abemaciclib plus tamoxifen or abemaciclib alone in HR+, HER2- advanced breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD1-11.

Abstract P3-04-01: The value of stereotactic vacuum-assisted biopsy in the investigation of microcalcifications in 1354 patients in public Brazilian hospital

Background: The gold standard for breast biopsy procedures is currently an open excision of the suspected lesion. However, an excisional biopsy inevitably makes a scar. The cost and morbidity associated with this procedure has prompted many physicians to evaluate less invasive, alternative procedures. More recently, image-guided percutaneous core-needle biopsy has become a frequently used method for diagnosing palpable and non-palpable breast lesions. Although sensitivity rates for core-needle biopsy are high, it has the disadvantage of histological underestimation, which renders the management of atypical ductal hyperplasia, papillary lesions, and fibroepithelial lesions somewhat difficult. Stereotactic vacuum assisted breast biopsy (VABB) was developed to overcome some of these negative aspects of core-needle biopsy. VABB allows for a sufficient specimen to be obtained with a single insertion and can provide a more accurate diagnosis and completely remove the lesion under real-time ultrasonic guidance. The advantage of complete lesion removal with VABB is to reduce or eliminate sampling error, to decrease the likelihood of a histological underestimation, to decrease imaging-histological discordance, to decrease the re-biopsy rate, and to diminish the likelihood of subsequent growth on follow-up, especially when stereotactic VABB is used to investigate microcalcifications. This method is expensive but cost effective when used to investigate microcalcifications classified as BI-RADS 4 and 5.

Methodology: We performed a review in 1,354 patients with suspicious mammography microcalcifications, classified as BI-RADS 4 or 5 that were seen in Perola Byington Hospital from July 2012 to July 2017 in São Paulo-Brazil. We have used aHologic Lorad Multicare Platinum Stereotactic Prone Breast Biopsy and a Surus Pearl (Hologic, Malbolrough, Massachusetts, USA), with gauge 9 probe. Four to eight fragments (median of 6) were obtained with the placement of a metal clip in the bed that the biopsy was performed, and histopathological analysis was made.

Results:The histopathological study of the lesions revealed benign alterations in 956 (68%) of our patients. The findings were positive for malignancy in 358 patients (29%) and the precursor lesions were diagnosed in 40 (3%). In 81 cases (5.9%) the findings were discordant. The sensitivity of the method was 84.4%, specificity was 96.1%, false negative rate was 4.5%, positive predictive value (PPV) was 89.8%, negative predictive value (NPV) was 93.8%. In literature review the sensitivity varies 91.5-100%, specificity 81.9-110%, false negative rate 0-3.3%, PPV 92.2-100% and NPV 80.5-99.5%. All patients with positive or discordant cases underwent surgical treatment to increase the margin or complete removal of the lesion. Conclusions: The VABB is an outpatient procedure that avoids hospital admissions for diagnostic elucidation in most of cases suspected of malignancy. It has high predictive value in both benign and malignant lesions, guiding therapeutic planning. In addition to presenting the cost lower than the surgical biopsy it indirect increases the supply of hospital beds for cancer treatment.

Citation Format: Mattar A, Amorim AG, Ramos MdNM, Shida JY, Fonseca GR, Hegg R, Gebrim LH. The value of stereotactic vacuum-assisted biopsy in the investigation of microcalcifications in 1354 patients in public Brazilian hospital [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-04-01.

Randomized phase II study evaluating weekly oral vinorelbine versus weekly paclitaxel in estrogen receptor-positive, HER2-negative patients with advanced breast cancer (NorBreast-231 trial)

BACKGROUND

Single-agent paclitaxel and vinorelbine are recommended treatments for advanced breast cancer (ABC) non-responsive to hormone therapy and without visceral crisis. This phase II trial compared first-line oral vinorelbine versus weekly paclitaxel for ABC.

METHODS

Eligible female patients had measurable locally recurrent/metastatic estrogen receptor-positive HER2-negative breast cancer and had received prior endocrine therapy (any setting) but no chemotherapy for ABC. Patients were stratified by prior taxane and visceral metastases and randomized to either oral vinorelbine 80 mg/m² (first cycle at 60 mg/m², escalated to 80 mg/m² in the absence of grade 3/4 toxicity) or intravenous paclitaxel 80 mg/m² on days 1, 8, and 15 every 3 weeks until disease progression or unacceptable toxicity. The primary endpoint was disease control rate (DCR; confirmed complete or partial response, or stable disease for ≥6 weeks).

RESULTS

The 131 randomized patients had received a median of 2 prior endocrine therapies; >70% had prior (neo)adjuvant chemotherapy and 79% visceral metastases. DCR was 75.8% (95% confidence interval: 63.6-85.5%) with vinorelbine and 75.4% (63.1-85.2%) with paclitaxel. The most common grade 3/4 adverse events were neutropenia (52%), fatigue (11%), and vomiting (5%) with vinorelbine, and neutropenia (17%), dyspnea (6%), hypertension (6%), and peripheral sensory neuropathy (5%) with paclitaxel. Grade 2 alopecia occurred in 2% of vinorelbine-treated and 34% of paclitaxel-treated patients. Neither arm showed relevant global health status changes.

CONCLUSION

Oral vinorelbine and paclitaxel demonstrated similar DCRs (∼75%). Safety profiles differed and, together with administration route and convenience, may influence treatment choice (EudraCT number, 2012-003530-16).

Atezolizumab and Nab-Paclitaxel in Advanced Triple-Negative Breast Cancer

BACKGROUND

Unresectable locally advanced or metastatic triple-negative (hormone-receptor-negative and human epidermal growth factor receptor 2 [HER2]-negative) breast cancer is an aggressive disease with poor outcomes. Nanoparticle albumin-bound (nab)-paclitaxel may enhance the anticancer activity of atezolizumab.

METHODS

In this phase 3 trial, we randomly assigned (in a 1:1 ratio) patients with untreated metastatic triple-negative breast cancer to receive atezolizumab plus nab-paclitaxel or placebo plus nab-paclitaxel; patients continued the intervention until disease progression or an unacceptable level of toxic effects occurred. Stratification factors were the receipt or nonreceipt of neoadjuvant or adjuvant taxane therapy, the presence or absence of liver metastases at baseline, and programmed death ligand 1 (PD-L1) expression at baseline (positive vs. negative). The two primary end points were progression-free survival (in the intention-to-treat population and PD-L1-positive subgroup) and overall survival (tested in the intention-to-treat population; if the finding was significant, then it would be tested in the PD-L1-positive subgroup).

RESULTS

Each group included 451 patients (median follow-up, 12.9 months). In the intention-to-treat analysis, the median progression-free survival was 7.2 months with atezolizumab plus nab-paclitaxel, as compared with 5.5 months with placebo plus nab-paclitaxel (hazard ratio for progression or death, 0.80; 95% confidence interval [CI], 0.69 to 0.92; P=0.002); among patients with PD-L1-positive tumors, the median progression-free survival was 7.5 months and 5.0 months, respectively (hazard ratio, 0.62; 95% CI, 0.49 to 0.78; P<0.001). In the intention-to-treat analysis, the median overall survival was 21.3 months with atezolizumab plus nab-paclitaxel and 17.6 months with placebo plus nab-paclitaxel (hazard ratio for death, 0.84; 95% CI, 0.69 to 1.02; P=0.08); among patients with PD-L1-positive tumors, the median overall survival was 25.0 months and 15.5 months, respectively (hazard ratio, 0.62; 95% CI, 0.45 to 0.86). No new adverse effects were identified. Adverse events that led to the discontinuation of any agent occurred in 15.9% of the patients who received atezolizumab plus nab-paclitaxel and in 8.2% of those who received placebo plus nab-paclitaxel.

CONCLUSIONS

Atezolizumab plus nab-paclitaxel prolonged progression-free survival among patients with metastatic triple-negative breast cancer in both the intention-to-treat population and the PD-L1-positive subgroup. Adverse events were consistent with the known safety profiles of each agent. (Funded by F. Hoffmann-La Roche/Genentech; IMpassion130 ClinicalTrials.gov number, NCT02425891 .).

First-Line Trastuzumab Plus an Aromatase Inhibitor, With or Without Pertuzumab, in Human Epidermal Growth Factor Receptor 2–Positive and Hormone Receptor–Positive Metastatic or Locally Advanced Breast Cancer (PERTAIN): A Randomized, Open-Label Phase II Trial

Purpose

To assess pertuzumab plus trastuzumab and an aromatase inhibitor (AI) in patients with human epidermal growth factor receptor 2 (HER2)–positive and hormone receptor–positive metastatic/locally advanced breast cancer (MBC/LABC).

Patients and Methods

The PERTAIN trial (NCT01491737) is an ongoing randomized, open-label, multicenter—80 sites and eight countries—phase II trial. Patients have HER2-positive, hormone receptor–positive MBC/LABC and no prior systemic therapy with the exception of endocrine. Random assignment was 1:1 to intravenous pertuzumab (840 mg loading dose followed by 420 mg every 3 weeks) plus trastuzumab (8 mg/kg followed by 6 mg/kg every 3 weeks), and oral anastrozole (1 mg every day) or letrozole (2.5 mg every day), or trastuzumab and an AI. Induction intravenous docetaxel every 3 weeks or paclitaxel every week could be administered for 18 to 24 weeks at the investigator’s discretion (decided before but given after random assignment). Primary end point was progression-free survival (PFS). Patients were stratified by whether they received induction chemotherapy and their time since adjuvant hormone therapy.

Results

One hundred twenty-nine patients were randomly assigned per arm (February 2012 to October 2014; intent-to-treat populations); 75 in one arm and 71 in the other were chosen to receive induction chemotherapy. Stratified median PFS was 18.89 months (95% CI, 14.09 to 27.66 months) in the pertuzumab plus trastuzumab arm and 15.80 months (95% CI, 11.04 to 18.56 months) in the trastuzumab arm (stratified hazard ratio, 0.65; 95% CI, 0.48 to 0.89; P = .0070). Serious adverse events (AEs) were reported for 42 (33.1%) of 127 and 24 (19.4%) of 124 patients in the safety populations of the pertuzumab plus trastuzumab and trastuzumab arms, respectively. Rates of grade ≥ 3 AEs were 64 (50.4%) of 127 and 48 (38.7%) of 124, respectively. There were no deaths as a result of AEs.

Conclusion

PERTAIN met its primary PFS end point. Pertuzumab plus trastuzumab and an AI is effective for the treatment of HER2-positive MBC/LABC. The safety profile was consistent with previous trials of pertuzumab plus trastuzumab.

Abstract PD3-11: Efficacy and safety of subcutaneous or intravenous trastuzumab in patients with HER2-positive early breast cancer after 5 years' treatment-free follow-up: Final analysis from the phase III, open-label, randomized HannaH study

Background HannaH (NCT00950300) compared subcutaneous and intravenous trastuzumab (H SC and H IV) as neoadjuvant–adjuvant therapy for HER2-positive breast cancer. The co-primary endpoints of pathological complete response (pCR) and serum trough concentration at predose cycle 8 demonstrated noninferiority between H SC and H IV. Efficacy analyses of event-free survival (EFS) and overall survival (OS) at a median follow-up of 40 months supported this noninferiority. Safety analyses also confirmed the consistency of the safety profile across both arms. In this final follow-up analysis, we report the long-term efficacy and safety outcomes at 5 years of treatment-free follow-up (TFFU; 6 years in total). The correlation between total pCR (tpCR; absence of invasive neoplastic cells in ipsilateral nodes and the breast) and EFS was also explored.

Methods Enrolled patients (n=596; pts) were randomized to receive 4 cycles of docetaxel, then 4 cycles of 5-fluorouracil/epirubicin/cyclophosphamide concurrently with 3-weekly fixed-dose 600mg H SC or H IV (loading: 8mg/kg; maintenance: 6mg/kg) in the neoadjuvant setting. Post-surgery, pts received an additional 10 cycles of H SC or H IV in the adjuvant setting to complete 1 year of anti-HER2 therapy. EFS (time from randomization to local, regional, or distant recurrence, contralateral breast cancer, or death) and OS were calculated using the Kaplan-Meier method. Adverse events (AEs) and serious AEs were recorded and graded per standard criteria.

Results In total, 297 pts were randomized to the H SC arm and 299 to the H IV arm; 294 and 297 pts were included in the respective efficacy analysis populations. Median duration of follow-up (including TFFU) was 70.8 and 71.4 months in the H SC and H IV arms, respectively. EFS and OS were similar across both study arms (Table 1). Pts who achieved tpCR had longer EFS and OS vs. those who did not (Table 1).

Table 1 H SCH IVHazard Ratio (95% CI)6-year EFS, % (95% CI)n=294n=297 Overall65 (59;70)65 (60;71)0.98 (0.74;1.29)tpCR status*tpCRn=102n=90   80 (73;88)83 (75;91)  no tpCRn=158n=173   57 (49;65)61 (54;69) 6-year OS, % (95% CI)n=294n=297 Overall84 (79;88)84 (79;88)0.94 (0.61;1.45)* Efficacy per protocol population

Cardiac AE incidence was low and consistent across study arms (Table 2).

Table 2Pts, n (%)H SC (n=297)H IV (n=298)Any AE290 (98)282 (95)≥ Grade 3 AE158 (53)160 (54)Serious AE65 (22)45 (15)Cardiac AE44 (15)42 (14)LVEF decline (≥10%-points from baseline to &lt;50%)11 (3.8)12 (4.2)LVEF, left ventricular ejection fraction

Conclusion Long-term efficacy EFS and OS results confirmed the noninferiority of H SC compared with H IV, as demonstrated by pCR and pharmacokinetic endpoints. tpCR was associated with longer EFS and OS. The overall safety profile of H SC was consistent with that of H IV.

Citation Format: Jackisch C, Stroyakovskiy D, Pivot X, Ahn J-S, Melichar B, Chen S-C, Meyenberg C, Al-Sakaff N, Heinzmann D, Hegg R. Efficacy and safety of subcutaneous or intravenous trastuzumab in patients with HER2-positive early breast cancer after 5 years' treatment-free follow-up: Final analysis from the phase III, open-label, randomized HannaH study [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr PD3-11.

Abstract P6-14-03: Randomized phase II study evaluating weekly oral vinorelbine versus weekly paclitaxel in estrogen receptor positive, HER2-negative patients with advanced breast cancer (NorBreast-231 trial)

Rationale: Quality of Life is of prime importance in Advanced Breast Cancer (ABC), a mostly non-curable disease. Both paclitaxel (P) and vinorelbine as single-agent chemotherapy (CT) are recommended treatment options in the management of ABC non-responsive to hormone therapy (HT) and with no visceral crisis. These agents are active with a good tolerance profile. The benefits and safety of oral vinorelbine (OV) and weekly P have however never been evaluated in a face to face trial.

Methods: Main eligibility criteria included: age ≥18 years, documented locally recurrent or metastatic involvement previously untreated by CT, estrogen receptor positive disease previously treated by at least one HT, HER2-negative status, Karnofsky PS ≥70 and presence of at least one measurable lesion. Study treatment (until progression): Arm A, OV 80 mg/m2 weekly (following a first cycle at 60 mg/m2 and dose escalation to 80 in the absence of grade 3 or 4 toxicity); Arm B: paclitaxel 80 mg/m2 weekly. One cycle was defined as three weeks of treatment. Patients were stratified according to prior taxane (yes/no) and visceral metastases (yes/no). Primary endpoint was disease control rate (DCR), defined as confirmed complete response/partial response/stable disease of a minimum duration of 6 weeks.

Results: 131 pts have been randomized (OV 66; P 65). Baseline patient characteristics (Arms A/B): median age 58/61 years; median number of previous HT 2/2; prior (neo)adjuvant CT 74/72%; prior anthracycline 64/62%; prior taxane 39/42%; &gt;3 metastatic sites 42/48%; visceral metastases 80/78%. Safety: the most common non-haematological related G3/4 adverse events (≥3% patients) were: fatigue 7.6/1.5%, peripheral neuropathy 0/4.6%, nausea 3/0%, diarrhoea 3/1.5%, vomiting 3/0%, constipation 3/1.5%; alopecia (G2) was present in 1.5/33.8%; no toxic deaths observed. Efficacy: DCR in the intent-to-treat population was [95%CI] 75.8 [63.6-85.5]/75.4 [63.1-85.2] %; overall response was 20/40%; stable disease was 56/35% respectively. Treatment exposure, other efficacy / safety parameters and quality of life results will be presented during the meeting.

Conclusion: Both OV and P reached similar DCR rates of 75%. As expected, each regimen presented a specific tolerance profile, with, in particular, a lower incidence of alopecia and peripheral neuropathy with OV.

Citation Format: Aapro M, Ruiz Borrego M, Staroslawska E, Morales S, Cinieri S, De Freitas Junior R, Garcia Estevez L, Szombara E, Hervieu H, Groc M, Villanova G, Hegg R. Randomized phase II study evaluating weekly oral vinorelbine versus weekly paclitaxel in estrogen receptor positive, HER2-negative patients with advanced breast cancer (NorBreast-231 trial) [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-14-03.

A randomized adaptive phase II/III study of buparlisib, a pan-class I PI3K inhibitor, combined with paclitaxel for the treatment of HER2- advanced breast cancer (BELLE-4)

Background

Phosphatidylinositol 3-kinase (PI3K) pathway activation in preclinical models of breast cancer is associated with tumor growth and resistance to anticancer therapies, including paclitaxel. Effects of the pan-Class I PI3K inhibitor buparlisib (BKM120) appear synergistic with paclitaxel in preclinical and clinical models.

Patients and methods

BELLE-4 was a 1:1 randomized, double-blind, placebo-controlled, adaptive phase II/III study investigating the combination of buparlisib or placebo with paclitaxel in women with human epidermal growth factor receptor 2-negative locally advanced or metastatic breast cancer with no prior chemotherapy for advanced disease. Patients were stratified by PI3K pathway activation and hormone receptor status. The primary endpoint was progression-free survival (PFS) in the full and PI3K pathway-activated populations. An adaptive interim analysis was planned following the phase II part of the study, after ≥125 PFS events had occurred in the full population, to decide whether the study would enter phase III (in the full or PI3K pathway-activated population) or be stopped for futility.

Results

As of August 2014, 416 patients were randomized to receive buparlisib (207) or placebo (209) with paclitaxel. At adaptive interim analysis, there was no improvement in PFS with buparlisib versus placebo in the full (median PFS 8.0 versus 9.2 months, hazard ratio [HR] 1.18), or PI3K pathway-activated population (median PFS 9.1 versus 9.2 months, HR 1.17). The study met protocol-specified criteria for futility in both populations, and phase III was not initiated. Median duration of study treatment exposure was 3.5 months in the buparlisib arm versus 4.6 months in the placebo arm. The most frequent adverse events with buparlisib plus paclitaxel (≥40% of patients) were diarrhea, alopecia, rash, nausea, and hyperglycemia.

Conclusions

Addition of buparlisib to paclitaxel did not improve PFS in the full or PI3K pathway-activated study population. Consequently, the trial was stopped for futility at the end of phase II.

Phase III, Randomized Study of Dual Human Epidermal Growth Factor Receptor 2 (HER2) Blockade With Lapatinib Plus Trastuzumab in Combination With an Aromatase Inhibitor in Postmenopausal Women With HER2-Positive, Hormone Receptor-Positive Metastatic Breast Cancer: ALTERNATIVE

Purpose Human epidermal growth factor receptor 2 (HER2) targeting plus endocrine therapy (ET) improved clinical benefit in HER2-positive, hormone receptor (HR)-positive metastatic breast cancer (MBC) versus ET alone. Dual HER2 blockade enhances clinical benefit versus single HER2 blockade. The ALTERNATIVE study evaluated the efficacy and safety of dual HER2 blockade plus aromatase inhibitor (AI) in postmenopausal women with HER2-positive/HR-positive MBC who received prior ET and prior neo(adjuvant)/first-line trastuzumab (TRAS) plus chemotherapy. Methods Patients were randomly assigned (1:1:1) to receive lapatinib (LAP) + TRAS + AI, TRAS + AI, or LAP + AI. Patients for whom chemotherapy was intended were excluded. The primary end point was progression-free survival (PFS; investigator assessed) with LAP + TRAS + AI versus TRAS + AI. Secondary end points were PFS (comparison of other arms), overall survival, overall response rate, clinical benefit rate, and safety. Results Three hundred fifty-five patients were included in this analysis: LAP + TRAS + AI (n = 120), TRAS + AI (n = 117), and LAP + AI (n = 118). Baseline characteristics were balanced. The study met its primary end point; superior PFS was observed with LAP + TRAS + AI versus TRAS + AI (median PFS, 11 v 5.7 months; hazard ratio, 0.62; 95% CI, 0.45 to 0.88; P = .0064). Consistent PFS benefit was observed in predefined subgroups. Overall response rate, clinical benefit rate, and overall survival also favored LAP + TRAS + AI. The median PFS with LAP + AI versus TRAS + AI was 8.3 versus 5.7 months (hazard ratio, 0.71; 95% CI, 0.51 to 0.98; P = .0361). Common adverse events (AEs; ≥ 15%) with LAP + TRAS + AI, TRAS + AI, and LAP + AI were diarrhea (69%, 9%, and 51%, respectively), rash (36%, 2%, and 28%, respectively), nausea (22%, 9%, and 22%, respectively), and paronychia (30%, 0%, and 15%, respectively), mostly grade 1 or 2. Serious AEs were reported similarly across the three groups, and AEs leading to discontinuation were lower with LAP + TRAS + AI. Conclusion Dual HER2 blockade with LAP + TRAS + AI showed superior PFS benefit versus TRAS + AI in patients with HER2-positive/HR-positive MBC. This combination offers an effective and safe chemotherapy-sparing alternative treatment regimen for this patient population.

Phase III, Randomized Study of Dual Human Epidermal Growth Factor Receptor 2 (HER2) Blockade With Lapatinib Plus Trastuzumab in Combination With an Aromatase Inhibitor in Postmenopausal Women With HER2-Positive, Hormone Receptor-Positive Metastatic Breast Cancer: ALTERNATIVE

Purpose Human epidermal growth factor receptor 2 (HER2) targeting plus endocrine therapy (ET) improved clinical benefit in HER2-positive, hormone receptor (HR)-positive metastatic breast cancer (MBC) versus ET alone. Dual HER2 blockade enhances clinical benefit versus single HER2 blockade. The ALTERNATIVE study evaluated the efficacy and safety of dual HER2 blockade plus aromatase inhibitor (AI) in postmenopausal women with HER2-positive/HR-positive MBC who received prior ET and prior neo(adjuvant)/first-line trastuzumab (TRAS) plus chemotherapy. Methods Patients were randomly assigned (1:1:1) to receive lapatinib (LAP) + TRAS + AI, TRAS + AI, or LAP + AI. Patients for whom chemotherapy was intended were excluded. The primary end point was progression-free survival (PFS; investigator assessed) with LAP + TRAS + AI versus TRAS + AI. Secondary end points were PFS (comparison of other arms), overall survival, overall response rate, clinical benefit rate, and safety. Results Three hundred fifty-five patients were included in this analysis: LAP + TRAS + AI (n = 120), TRAS + AI (n = 117), and LAP + AI (n = 118). Baseline characteristics were balanced. The study met its primary end point; superior PFS was observed with LAP + TRAS + AI versus TRAS + AI (median PFS, 11 v 5.7 months; hazard ratio, 0.62; 95% CI, 0.45 to 0.88; P = .0064). Consistent PFS benefit was observed in predefined subgroups. Overall response rate, clinical benefit rate, and overall survival also favored LAP + TRAS + AI. The median PFS with LAP + AI versus TRAS + AI was 8.3 versus 5.7 months (hazard ratio, 0.71; 95% CI, 0.51 to 0.98; P = .0361). Common adverse events (AEs; ≥ 15%) with LAP + TRAS + AI, TRAS + AI, and LAP + AI were diarrhea (69%, 9%, and 51%, respectively), rash (36%, 2%, and 28%, respectively), nausea (22%, 9%, and 22%, respectively), and paronychia (30%, 0%, and 15%, respectively), mostly grade 1 or 2. Serious AEs were reported similarly across the three groups, and AEs leading to discontinuation were lower with LAP + TRAS + AI. Conclusion Dual HER2 blockade with LAP + TRAS + AI showed superior PFS benefit versus TRAS + AI in patients with HER2-positive/HR-positive MBC. This combination offers an effective and safe chemotherapy-sparing alternative treatment regimen for this patient population.

Ribociclib with letrozole vs letrozole alone in elderly patients with hormone receptor-positive, HER2-negative breast cancer in the randomized MONALEESA-2 trial

Purpose

Determine the efficacy and safety of first-line ribociclib plus letrozole in elderly patients with HR+, HER2− advanced breast cancer.

Methods

668 postmenopausal women with HR+, HER2− advanced breast cancer and no prior systemic therapy for advanced disease were enrolled in the Phase III MONALEESA-2 trial (NCT01958021); 295 patients were aged ≥ 65 years. Patients were randomized to ribociclib (600 mg/day; 3-weeks-on/1-week-off) plus letrozole (2.5 mg/day) or placebo plus letrozole until disease progression, unacceptable toxicity, death, or treatment discontinuation. The primary endpoint was PFS, which was evaluated in elderly (≥ 65 years) and younger (< 65 years) patients. Secondary endpoints included response rates and safety.

Results

Ribociclib plus letrozole significantly improved PFS vs placebo plus letrozole in elderly (hazard ratio: 0.608; 95% CI 0.394–0.937) and younger patients (hazard ratio: 0.523; 95% CI 0.378–0.723). Overall response rates were numerically higher in the ribociclib vs placebo arm, regardless of age. Ribociclib plus letrozole was well tolerated in elderly patients, with the safety profile similar to the overall study population. Nausea, vomiting, alopecia, and diarrhea were > 10% more frequent in the ribociclib plus letrozole vs placebo plus letrozole arm in both subgroups; most events were grade 1/2. In elderly patients, grade 1/2 anemia and fatigue were > 10% more frequent in the ribociclib plus letrozole vs placebo plus letrozole arm and discontinuation rates were similar in both arms.

Conclusions

Addition of ribociclib to letrozole is a valid therapeutic option for elderly patients with HR+, HER2− advanced breast cancer in the first-line setting.