Bcl-2 expression and prognostic significance in feline invasive mammary carcinomas: a retrospective observational study

BACKGROUND

Cats spontaneously develop invasive mammary carcinomas with high clinical aggressiveness, and are considered relevant animal models for human breast cancer. Bcl-2 is an anti-apoptotic pro-survival protein, whose expression is associated with a favorable outcome in human breast cancer. The aim of our study was to determine the frequency of Bcl-2 expression in feline invasive mammary carcinomas (FMCs), its relationship with other clinicopathologic variables, and its prognostic value. This retrospective study included 180 FMCs, diagnosed in female cats treated by surgery only, with a 2-year follow-up post-mastectomy. Bcl-2, ER, PR, Ki-67, HER2, and CK5/6 expression were determined by automated immunohistochemistry. A receiver-operating-characteristic curve was used to set the threshold for Bcl-2 positivity.

RESULTS

The cohort comprises 32% (57/180) luminal FMCs defined by ER and/or PR positivity, and 68% (123/180) triple-negative FMCs (negative for ER, PR, and HER2). Bcl-2 expression was considered as positive when at least 65% of tumor cells were immunohistochemically stained. Thirty-one out of 180 FMCs (17%) were Bcl-2-positive. There was no significant association between Bcl-2 expression, and the tumor size, nodal stage, histological grade, or ER, PR, Ki-67, HER2, and CK5/6 expression. By multivariate survival analysis (Cox proportional-hazards regression), Bcl-2 positivity in FMCs was associated with longer disease-free interval (p = 0.005, HR = 0.38), overall survival (p = 0.028, HR = 0.61), and cancer-specific survival (p = 0.019, HR = 0.54) independently of other powerful prognostic factors such as pathologic tumor size, pathologic nodal stage, and distant metastasis. The positive prognostic value of Bcl-2 was confirmed in both luminal FMCs, of which 9/57 (16%) were Bcl-2-positive, and in basal-like triple-negative (ER-, PR-, HER2-, CK5/6+) FMCs, of which 14/76 (18%) were Bcl-2-positive.

CONCLUSIONS

Compared to human breast cancer, Bcl-2 positivity in feline invasive mammary carcinomas is also associated with better outcome, but is less common, and not associated with ER, PR, and HER2 expression. Cats with spontaneous Bcl-2-positive FMCs could be useful in preclinical trials evaluating anti-Bcl-2 strategies for chemoresistant luminal or triple-negative breast cancers.

Interactions between cancer-associated fibroblasts and tumor cells promote MCL-1 dependency in estrogen receptor-positive breast cancers

Selective inhibition of BCL-2 is expected to enhance therapeutic vulnerability in luminal estrogen receptor-positive breast cancers. We show here that the BCL-2 dependency of luminal tumor cells is nevertheless mitigated by breast cancer-associated fibroblasts (bCAFs) in a manner that defines MCL-1 as another critical therapeutic target. bCAFs favor MCL-1 expression and apoptotic resistance in luminal cancer cells in a IL-6 dependent manner while their own, robust, survival also relies on MCL-1. Studies based on ex vivo cultures of human luminal breast cancer tissues further argue that the contribution of stroma-derived signals to MCL-1 expression shapes BCL-2 dependency. Thus, MCL-1 inhibitors are beneficial for targeted apoptosis of breast tumor ecosystems, even in a subtype where MCL-1 dependency is not intrinsically driven by oncogenic pathways.

Neratinib in Combination With Trastuzumab for the Treatment of Patients With Advanced HER2-positive Breast Cancer: A Phase I/II Study

BACKGROUND

Despite the availability of several human epidermal growth factor receptor 2 (HER2)-directed treatments, many HER2-positive (HER2⁺) breast cancers eventually progress because of primary or acquired resistance.

PATIENTS AND METHODS

A 2-part, open-label, multicenter phase I/II study was conducted to determine the recommended dose of neratinib when administered with trastuzumab (part I), and to assess the antitumor activity of this combination in women with locally advanced or metastatic HER2⁺ breast cancer previously treated with at least 1 prior trastuzumab-based regimen (part II). Patients received oral neratinib (160 or 240 mg/d) once daily plus intravenous trastuzumab 4 mg/kg (loading dose) then 2 mg/kg weekly. Diarrhea prophylaxis was not permitted. The primary endpoint in part II was investigator-assessed 16-week progression-free survival (PFS).

RESULTS

Forty-five patients received neratinib plus trastuzumab (part I: neratinib 160 mg/d, n = 4; neratinib 240 mg/d, n = 4; part II: neratinib 240 mg/d, n = 37). In part I, there were no dose-limiting toxicities and the recommended neratinib dose was 240 mg/d. In part II, the 16-week PFS rate was 44.8% (90% confidence interval, 28.8%-59.6%), and the median PFS was 15.9 weeks (95% confidence interval, 15.1-31.3 weeks) in 28 evaluable patients. Three patients had durable clinical benefit lasting 9.4 to 9.7 years. Diarrhea was the most common adverse event (grade 3, n = 7 [15.6%]; grade 4, n = 0). No clinically significant cardiac toxicity was seen.

CONCLUSIONS

Neratinib in combination with trastuzumab was well-tolerated and had encouraging antitumor activity in patients with advanced trastuzumab-pretreated HER2⁺ breast cancer. Durable responses can be achieved in some patients.

Exploitation of Precision Medicine Trials Data: Examples of Long Responders From the SHIVA01 Trial

Purpose

Precision medicine trials constitute a precious source of molecular data with prospective clinical annotations allowing the exploration of patients’ subpopulations according to specific clinical or biological questions. Using the SHIVA01—the first randomized trial comparing molecularly targeted therapy on the basis of tumor molecular profiling versus conventional chemotherapy in metastatic cancer patients who failed standard of care therapy—annotated database, we report cases of patients treated in the trial with targeted therapy who experienced an objective response or prolonged disease stabilization in light of patients’ molecular alterations.

Patients and Methods

We selected all patients included in SHIVA01 treated with a molecularly targeted agent (MTA) who experienced an objective response or disease stabilization that lasted longer than 6 months according to Response Evaluation Criteria in Solid Tumors version 1.1.

Results

Among the 170 patients who received MTAs in the SHIVA01 trial, 15 patients (9%) experienced an objective response (n = 3) or disease stabilization that lasted longer than 6 months (n = 12). The most frequent histologic subtypes were breast cancer (27%) and cervical cancer (20%). Six patients, including three patients with breast cancer, were treated with abiraterone on the basis of androgen receptor protein overexpression. Five patients were treated with everolimus on the basis of a PTEN heterozygous deletion with loss of protein expression, PIK3CA mutation, or both alterations. The remaining four patients were treated with tamoxifen, erlotinib, imatinib, and vemurafenib on the basis of progesterone receptor expression, EGFR amplification, KIT mutation, and BRAF mutation, respectively. TP53 mutations were absent in responder patients.

Conclusion

Analysis of patients who experienced objective responses or disease stabilization that lasted longer than 6 months allowed the identification of potential biomarkers of sensitivity and resistance to MTAs.

Phase I study of onapristone, a type I antiprogestin, in female patients with previously treated recurrent or metastatic progesterone receptor-expressing cancers

INTRODUCTION

Onapristone is a type I progesterone receptor (PR) antagonist, which prevents PR- mediated DNA transcription. Onapristone is active in multiple preclinical models and two prior studies demonstrated promising activity in patients with breast cancer. We conducted a study of extended release (ER) Onapristone to determine a recommended dose and explore the role of transcriptionally-activated PR (APR), detected as an aggregated subnuclear distribution pattern, as a predictive biomarker.

METHODS

An open-label, multicenter, randomized, parallel-group, phase 1 study (target n = 60; NCT02052128) included female patients ≥18 years with PRpos tumors. APR analysis was performed on archival tumor tissue. Patients were randomized to five cohorts of extended release (ER) onapristone tablets 10, 20, 30, 40 or 50 mg BID, or immediate release 100 mg QD until progressive disease or intolerability. Primary endpoint was to identify the recommended phase 2 dose. Secondary endpoints included safety, clinical benefit and pharmacokinetics.

RESULTS

The phase 1 dose escalation component of the study is complete (n = 52). Tumor diagnosis included: endometrial carcinoma 12; breast cancer 20; ovarian cancer 13; other 7. Median age was 64 (36-84). No dose limiting toxicity was observed with reported liver function test elevation related only to liver metastases. The RP2D was 50 mg ER BID. Median therapy duration was 8 weeks (range 2-44), and 9 patients had clinical benefit ≥24 weeks, including 2 patients with APRpos endometrial carcinoma.

CONCLUSION

Clinical benefit with excellent tolerance was seen in heavily pretreated patients with endometrial, ovarian and breast cancer. The data support the development of Onapristone in endometrial endometrioid cancer. Onapristone should also be evaluated in ovarian and breast cancers along with APR immunohistochemistry validation.

UCBG 2-08: 5-year efficacy results from the UNICANCER-PACS08 randomised phase III trial of adjuvant treatment with FEC100 and then either docetaxel or ixabepilone in patients with early-stage, poor prognosis breast cancer

PURPOSE

UNICANCER-PACS08 compared adjuvant FEC (5-FU; epirubicin; cyclophosphamide) then docetaxel to FEC then ixabepilone in poor prognosis early breast cancer (BC). We evaluated whether replacing docetaxel with ixabepilone would increase 5-year disease-free survival (DFS).

PATIENTS AND METHODS

Triple-negative breast cancer (TNBC) or oestrogen receptor (ER)+/progesterone receptor (PR)-/HER2- BC patients were randomised to receive standard FEC (3 cycles) followed by 3 cycles of either docetaxel (100 mg/m²) or ixabepilone (40 mg/m²). Radiotherapy was mandatory after conservative surgery; ER+ patients received endocrine therapy.

RESULTS

Seven hundred sixty-two patients were enrolled between October 2007 and September 2010. Baseline characteristics were balanced between arms. Median follow-up was 66.7 months. Median DFS was not reached; 5-year DFS rate was 76% with docetaxel and 79% with ixabepilone (hazard ratio [HR] = 0.80; 95% confidence interval [CI] = 0.58-1.10; p = 0.175). Median overall survival (OS) was not reached; 5-year OS rate was 86% versus 84% (HR = 0.97; 95% CI = 0.66-1.42; p = 0.897). TNBC patients treated with ixabepilone had a 23% lower risk of relapse compared to docetaxel (HR for DFS = 0.77; 95% CI = 0.53-1.11; p = 0.168). DFS was longer with ixabepilone than docetaxel in patients with grade II-III lymphocytic infiltration (HR = 0.55; 95% CI = 0.29-1.05; p = 0.063). All patients experienced ≥1 adverse events (AEs): 75% reported grade III-IV AEs and two (<1%) had grade V AEs (both with neutropenia and infection receiving ixabepilone).

CONCLUSION

After adjuvant FEC, ixabepilone was comparable to docetaxel for treating poor prognosis early BC patients. The benefit of ixabepilone in subgroups (patients with TNBC and grade II-III lymphocytic infiltration) requires further evaluation.

Buparlisib plus fulvestrant versus placebo plus fulvestrant for postmenopausal, hormone receptor-positive, human epidermal growth factor receptor 2-negative, advanced breast cancer: Overall survival results from BELLE-2

BACKGROUND

Buparlisib, a pan-phosphatidylinositol 3-kinase (PI3K) inhibitor, plus fulvestrant in the BELLE-2 study significantly improved progression-free survival (PFS) in patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer.

PATIENTS AND METHODS

In this phase III study, patients were randomised 1:1 to buparlisib (100 mg/day; continuously in 28-day cycles) or placebo, plus fulvestrant (500 mg on cycle 1 day 15, and day 1 of subsequent cycles). Overall survival (OS) was assessed in the overall population and patients with known PI3K pathway status (both had shown significant PFS improvements). OS by PIK3CA status in circulating tumour DNA (ctDNA) was an exploratory end-point.

RESULTS

A total of 2025 patients were screened for eligibility between 7th September 2012 and 10th September 2014, and 1178 received fulvestrant (500 mg) during a run-in phase; 31 discontinued. Of 1147 patients (median age 62 years), 98% had the Eastern Cooperative Oncology Group performance status ≤1, and 59% had visceral disease. Median follow-up from randomisation to data cut-off (23rd December 2016) was 37.6 months. Median OS trended in favour of the buparlisib arm in the overall population (33.2 versus 30.4 months; P = 0.045) and among patients with known PI3K pathway status (30.9 versus 28.9 months; P = 0.144); neither outcome was statistically significant. Median OS also trended in favour of buparlisib among patients with PIK3CA-mutant ctDNA (26.0 versus 24.8 months). Grade III/IV adverse events with ≥10% difference between the buparlisib versus placebo arms were elevated alanine aminotransferase (26% versus 1%), elevated aspartate aminotransferase (18% versus 3%) and hyperglycemia (15% versus <1%).

CONCLUSIONS

OS results were in favour of buparlisib plus fulvestrant versus placebo plus fulvestrant; however, there is no statistical significance and more frequent grade III/IV adverse events were reported. Use of more selective PI3K inhibitors might provide the greatest clinical benefit and tolerable safety profile in this setting. Further evaluation of the predictive benefit of PIK3CA-mutant ctDNA is warranted.

TRIAL REGISTRATION NUMBER

NCT01610284.

Prolonged perioperative thoracic epidural analgesia may improve survival after cytoreductive surgery with hyperthermic intraperitoneal chemotherapy for colorectal peritoneal metastases: A comparative study

OBJECTIVE

To assess the effectiveness of prolonged perioperative thoracic epidural analgesia (PEA) on long term survival of patients who underwent a complete cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for colorectal peritoneal metastases (CPM).

BACKGROUND

Grade III-IV morbidity affects long term outcomes after CRS and HIPEC. As compared with opioid administered via patient-controlled analgesia (PCA), PEA reduces morbidity.

METHOD

From 2005 to 2016, 150 patients underwent CRS plus HIPEC with or without prolonged PEA. Clinical data and outcomes collected from prospective database were analyzed. Survival was assessed in terms of analgesic method using Kaplan-Meier plots and a propensity score.

RESULTS

Patients 'characteristics of 59 patients in PCA group were comparable to those of 91 patients in PEA group, except for age, ASA score and fluid requirements, significantly more important in PEA group. Grade III-IV morbidity was 62.7% in PCA group compared with 36.3% in PEA group (p = 0.0015). Median overall survival (OS) of PEA group was 54.7 months compared to 39.5 months in PCA group (p = 0.0078). When adjusted on the covariates, using the propensity score, the PEA significantly improves OS [HR 0.40 (95% CI: 0.28-0.56)] (p < 0.0001) and disease free survival (DFS) [HR 0.61 (95% CI: 0.45-0.81] (p < 0.0007) CONCLUSIONS: In this retrospective study of patients who underwent a complete CRS and HIPEC for colorectal peritoneal metastases, the perioperative thoracic epidural analgesia prolonged for over 72 h reduced significantly the grade III-IV morbidity and may improve OS and DFS.

Health-related quality of life of postmenopausal women with hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer treated with ribociclib + letrozole: results from MONALEESA-2

PURPOSE

Evaluate patient-reported outcomes (PROs) for postmenopausal women with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer treated with first-line ribociclib plus letrozole.

METHODS

In the phase III MONALEESA-2 study (NCT01958021), 668 patients were randomized 1:1 to ribociclib (600 mg/day; 3-weeks-on/1-week-off) plus letrozole (2.5 mg/day) or placebo plus letrozole. PROs were assessed using the European Organisation for Research and Treatment of Cancer core quality-of-life (EORTC QLQ-C30) and breast cancer-specific (EORTC QLQ-BR23) questionnaires. Changes from baseline and time to deterioration in health-related quality of life (HRQoL) were analyzed using linear mixed-effect and stratified Cox regression models, respectively. Exploratory analysis of area-under-the-curve for change from baseline in pain score (AUC-pain) was performed.

RESULTS

On-treatment HRQoL scores were consistently maintained from baseline and were similar between arms. A clinically meaningful (> 5 points) reduction in pain score was observed as early as Week 8 and was maintained up to Cycle 15 in the ribociclib arm. A statistically significant increase in mean AUC-pain was also observed in the ribociclib arm. Scores for all other EORTC QLQ-C30 and EORTC QLQ-BR23 domains were maintained from baseline and were similar between arms.

CONCLUSIONS

HRQoL was consistently maintained from baseline in postmenopausal women with HR+, HER2- advanced breast cancer receiving ribociclib plus letrozole and was similar to that observed in the placebo plus letrozole arm. Together with the improved clinical efficacy and manageable safety profile, these PRO results provide additional support for the benefit of ribociclib plus letrozole in this patient population.

Abstract CT069: Baseline gene expression patterns of CDK4/6 inhibitor-naïve or -refractory HR+, HER2- advanced breast cancer in the phase Ib study of ribociclib plus everolimus plus exemestane

Background: Preclinical data suggest that combination of endocrine therapy (ET) with a cyclin-dependent kinase 4/6 inhibitor (CDK4/6i) and mammalian target of rapamycin inhibitor (mTORi) may overcome prior treatment resistance in hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer (ABC). The Phase Ib CLEE011X2106 study (NCT01857193) is investigating ribociclib (RIB; CDK4/6i) + everolimus (EVE; mTORi) + exemestane (EXE; ET) in patients with HR+, HER2- ABC resistant to letrozole or anastrozole. The objective of this analysis is to characterize baseline gene expression patterns in the CDK4/6i-naïve and -refractory groups, and assess the potential correlation with clinical activities.

Methods: Postmenopausal women with HR+, HER2- ABC resistant to letrozole or anastrozole, and who had received no prior CDK4/6i or whose disease had progressed on or within 1 month of CDK4/6i therapy, were enrolled in the CDK4/6i-naïve and -refractory dose expansion groups, respectively. More than 1 line of chemotherapy for ABC or prior treatment with EXE or an mTORi was not permitted. Patients received RIB (300 mg, 3-weeks on/1-week off) + EVE (2.5 mg, continuous) + EXE (25 mg, continuous) until disease progression or study discontinuation. Baseline tumor samples (collected after CDK4/6i therapy in the CDK4/6i-refractory group) were assessed for mRNA expression using the NanoString 230-gene nCounter® GX Human Cancer Reference panel.

Results: As of May 15, 2017, the 24-week clinical benefit rate was 56% (9/16) in the CDK4/6i-naïve group and 24% (4/17) in the -refractory group. Baseline tumor mRNA expression was evaluable in 14 patients: CDK4/6i naïve, n=8 (best response: 7 stable disease [SD], 1 progressive disease [PD]); CDK4/6i refractory, n=6 (2 SD, 4 PD). Across all patients (both groups), those with SD tended to have higher ESR1 expression compared with those experiencing PD, with a trend for higher baseline ESR1 expression in the CDK4/6i-naïve group compared with the -refractory group. Also across all patients, higher overall baseline expression of cell cycle control genes and mitogen-activated protein kinase (MAPK) pathway genes appeared to trend with PD. Additionally, in the CDK4/6i-refractory group, there was a trend for higher CDK2 and/or CCNE1 expression in patients with PD compared with SD. A heat map of 24 genes indicated differences in gene expression patterns between the CDK4/6i-naïve and -refractory groups.

Conclusions: Gene expression patterns differ between CDK4/6i-naïve and -refractory tumors. Higher expression of cell cycle control genes (particularly CDK2 and CCNE1) and MAPK pathway genes appears to trend with resistance to the RIB + EVE + EXE combination after progression on prior CDK4/6i. Due to the small number of samples, further investigation is needed.

Citation Format: Aditya Bardia, Shanu Modi, Javier Cortes, Mario Campone, Luc Dirix, Brigette Ma, J Thaddeus Beck, Jorge Chaves, Amy Weise, Jacqueline Vuky, Gilberto Lopes, Miguel Gil-Gil, Xiaochun Liu, Wei He, Faye Su, Michelle Miller, Mariana Chavez-MacGregor. Baseline gene expression patterns of CDK4/6 inhibitor-naïve or -refractory HR+, HER2- advanced breast cancer in the phase Ib study of ribociclib plus everolimus plus exemestane [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr CT069.

Abstract P5-21-06: Alpelisib plus letrozole in estrogen receptor-Positive (ER+), human epidermal growth factor receptor 2-negative (HER2–) advanced breast cancer (aBC): Safety and preliminary efficacy analysis from a phase 1b trial

Background

Endocrine therapy is the standard first-line treatment for postmenopausal patients (pts) with ER+, HER2– aBC. However, resistance eventually develops, often through dysregulation of PI3K/AKT/mTOR pathway, specifically mutations in PIK3CA, the gene encoding the p110α subunit of PI3K. The oral, selective PI3K inhibitor alpelisib and letrozole synergistically inhibits tumor growth in preclinical models of ER+ breast cancer. Alpelisib plus letrozole in pts with ER+ aBC is being investigated in arm 2 of a multi-arm, phase 1b study (NCT01872260).

Methods

Postmenopausal women with ER+, HER2− aBC received alpelisib (300 mg QD; continuous, 28 days cycle) plus letrozole (2.5 mg QD; continuous). Primary endpoints were to confirm MTD/RP2D of alpelisib plus letrozole in the escalation phase and to further characterize safety and tolerability in the expansion phase. Secondary and exploratory endpoints included efficacy, pharmacokinetics, and biomarkers.

Results

As of August 19, 2016, 56 pts had received alpelisib plus letrozole: 19 pts were enrolled in the escalation phase (designated here as previously treated group), of which, 95% of pts were previously treated for aBC and 37 pts were enrolled in the expansion phase (designated here as first-line group), of which, 81% of pts were treatment-naïve for aBC. 16 previously treated pts and 11 first-line pts (48% of all pts) have discontinued treatment. Most common reasons for treatment discontinuation in the full population were disease progression (23.2%) and adverse events (AEs) (8.9%). Median duration of exposure of combination (alpelisib plus letrozole) was 23 weeks and 12.7 weeks in previously treated and first-line groups, respectively. Most frequently reported any grade treatment-related AEs (≥20% incidence) in all pts were hyperglycemia (48.2%), diarrhea (48.2%), nausea (33.9%), and decreased appetite (28.6%). Most common, grade 3 or 4 AEs (≥3% incidence) suspected to be treatment-related in all pts included hyperglycemia (17.9%), rash (5.4%), and diarrhea (3.6%). Median progression-free survival was 5.7 months in the previously treated group and was not reached in the first-line group. A summary of best overall response, overall response rate and clinical benefit rate in evaluable pts is shown in the table.

 Alpelisib+Letrozole (Previously Treated group) [N=19]Alpelisib+Letrozole (First-line group) [N=27]All subjects (N=46)Best overall response, n (%)Confirmed CR000Confirmed PR04 (14.8)4 (8.7)NCRNPD6 (31.6)9 (33.3)15 (32.6)SD8 (42.1)9 (33.3)17 (37.0)PD2 (10.5)1 (3.7)3 (6.5)Unknown3 (15.8)3 (11.1)6 (13.0)ORR (CR+PR), % (95% CI)0 (0.0-17.6)14.8 (4.2-33.7)8.7 (2.4-20.8)CBR [CR+PR+(SD/NCRNPD)], % (95% CI)36.8 (16.3-61.6)70.8 (48.9-87.4)55.8 (39.90-70.9)CBR; clinical benefit rate; CI, confidence interval; CR, complete response; NCRNPD; Non-CR/Non-PD; ORR; overall response rate; PD; progressive disease; SD, stable disease.

Conclusions

Based on these preliminary data, the combination of alpelisib plus letrozole had manageable safety profile in pts with ER+, HER2– aBC and demonstrated encouraging clinical activity, particularly in the first-line patient population.

Citation Format: Juric D, Gonçalves A, Hamilton E, Boni V, Mayer IA, Turri S, Wang Y, Vogl FD, Sellami D, Campone M. Alpelisib plus letrozole in estrogen receptor-Positive (ER+), human epidermal growth factor receptor 2-negative (HER2–) advanced breast cancer (aBC): Safety and preliminary efficacy analysis from a phase 1b 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 P5-21-06.

Abstract P6-08-10: Impact of age at diagnosis of metastatic breast cancer on overall survival in the real-life "ESME" cohort

Background

Young age is a known poor prognosis factor in early stage breast cancer (BC). Its value is less documented for metastatic BC (MBC). Guidelines state that age should not guide the treatment strategy. We used the ESME database to evaluate the impact of age at MBC diagnosis on overall survival (OS).

Patients and Methods

ESME is a unique national cohort, collecting retrospective data using clinical trial-like methodology. It included all consecutive MBC patients (pts) who initiated at least 1 treatment in one of the 18 participating French cancer centers between 01/01/2008 and 12/31/2014. The database was locked on 12/8/2016. Primary objective were the comparisons of MBC characteristics between age groups (&lt;40, 40 to 60 and &gt;60 years (y)) and the evaluation of the impact of age at MBC diagnosis on OS.

Interaction between age and tumor subtype was tested using a Cox regression model.

ResultsAmong 16 703 included pts, 1539 had no information on tumor receptors (ER/PR/HER2) and 682 had an exclusion criteria (unknown age, men or other cancer in the last 5y), leaving 14 482 for analysis. At the onset of MBC, 902 pts (6.2%), 6269 (43.3%) and 7311 (50.5%) were &lt;40y, 40y to 60y and older than 60y respectively. Median follow-up was 54.8 months.

Pts &lt;40 had significantly more aggressive presentations than other age groups: more HER2+ (26.5%), and triple negative (26.4%) subtypes, more visceral involvement (57.1%), and shorter time to metastasis (26.9% between 6 to 24 months) (all p-value vs other age groups &lt;0.0001).

MBC characteristics according to age groups Age at MBC diagnosis (years)p-value &lt;4040-60&gt;60 Tumor subtype   &lt;0.0001HR+/HER2-425 (47.12)3816 (60.87)5262 (71.97) HR-/HER2-238 (26.39)1126 (17.96)884 (12.09) HER2+239 (26.5)1327 (21.17)1165 (15.93) Type of metastasis, N(%)   &lt;0.0001Bone only219 (24.31)1832 (29.23)2367 (32.41) Non visceral168 (18.65)1046 (16.69)1314 (17.99) Visceral514 (57.05)3389 (54.08)3623 (49.6) Time to first metastasis (months), N(%)   &lt;0.0001&lt; 6304 (33.74)1882 (30.1)2107 (28.9) [6-12[65 (7.21)241 (3.85)209 (2.9) [12-24[177 (19.64)760 (12.15)564 (7.7) ≥24355 (39.4)3370 (53.89)4416 (60.53) Number of metastatic sites, N(%)   0.51 site709(78.6)4948 (78.93)5805 (79.4) 2 sites163(18.07)1130 (18.03)1313(17.96) ≥3 sites30(3.33)191 (3.05)193 (2.64) 

Overall, median OS was identical in the different age groups: 39.1, 41.1 and 39.8 months for pts &lt;40, 40-60 and &gt;60, respectively (p=0.2).

Tumor subtype and age showed a significant interaction on OS (p&lt;0.0001), especially among HER2+ MBC

Overall survival (months) according to tumor subtypes and age groups Age groups (years)p-value (log-rank)Tumor subtype&lt;4040-60&gt;60 HR+/HER2-46,4 (CI 95% 40.5-55.4)47,8 (CI 95% 46-50)44,2 (CI 95% 42.1-46.3)0.0023HER2+60,7 (CI 95% 45.6-76.4)50,4 (CI 95% 46.3-56.3)44 (CI 95% 38.8-48.9)&lt;0.0001Triple negative14 (CI 95% 11.5-16.5)14,7 (CI 95% 13.7-15.9)15,7 (CI 95% 14.6-17.1)0.01

. Anti-HER2 with first-line treatment was given preferentially to young pts: 86.6, 81.9 and 74.9%for pts &lt;40, 40-60 and &gt;60, respectively (p&lt;0.0001).

Conclusion

At onset of MBC, young age was associated with more aggressive presentations, however with no global impact on OS. Pts &lt;40 with HER2+ disease carried a better prognosis, maybe related to therapy.

Citation Format: Frank S, Tchokothe C, Carton M, Mouret-Fourme E, Dubot C, Campone M, Pistilli B, Dalenc F, Mailliez A, Levy C, D'Hondt V, Debled M, Leheurteur M, Coudert B, Perrin C, Gonçalves A, Uwer L, Ferrero J-M, Eymard J-C, Petit T, Mouret-Reynier M-A, Guesmia T, Bachelot T, Robain M, Cottu P. Impact of age at diagnosis of metastatic breast cancer on overall survival in the real-life "ESME" cohort [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 P6-08-10.

Abstract P1-07-07: Overtime distribution and predictors of local recurrences (LRs) in patients with hormone receptor positive (HR+) and node positive (N+) breast cancers (BCs): 10 -year follow-up analysis of UNICANCER-PACS 01 and PACS04 trials

Purpose:Incidence of LRs in patients (pts) treated for HR+ HER2- localized BC and distribution overtime have not been described in recent years after introduction of new generation of adjuvant therapies and more extensive use of radiotherapy. We evaluated the incidence and distribution overtime of LRs in pts with HR+ HER2- N+ BCs who entered PACS 01 and PACS04 trials.

Patients and Methods: Data were analyzed from 2909 pts with HR+/HER2- BC out of 5008 included in both trials. Pts underwent mastectomy or lumpectomy plus axillary dissection for a localized N+ BC and, according to study design, were randomized to: 6 cycles of FE100C (standard arm) versus FE100C x 3 cycles followed by docetaxel 100 mg/m2 x 3 cycles (FEC-D) (PACS01) or 6 cycles of Epirubicin 75mg/m2 and Docetaxel 75 mg/m2 (ED75)(PACS04). Loco-regional radiotherapy was mandatory after lumpectomy and recommended in other cases. All pts received 5 years of hormone therapy (HT). A competing risk multivariate analysis was conduct using Fine and Gray model to identify risk factors associated to isolated LRs. Competing events were nodal recurrence, contralateral BC, distant metastasis and death. Cumulative incidence associated to each event was estimated by a Kablfleish-Prentice estimator.

Results: Pts' median age was 50 (22-65); 67.2% underwent lumpectomy, 32.8% mastectomy; 67.6% had 1 to 3 N+, 32.4% more than 3 N+; 45.7% had lymphovascular invasion; 49.5% received FE100C, 35.8% ET75, 14.7% had FEC-D; while radiotherapy was given to 97.3% and HT to 92.2%, of whom 90.5% received tamoxifen. At a median follow-up of 9.1 years, 60 pts (2.1%) experienced LR as first event. The 5-year and 10-year cumulative incidence of LRs were 1.04% and 2.53%, respectively. The cumulative incidence of LRs increased from the 5th year, and the annual risk tended to remain constant over time. Multivariate analysis of competing risk showed that younger age, conservative surgery and omission of HT (not prescribed or non-adherence) were independently associated with risk of developing LRs.

Table 1. Multivariate analysis on competing risk of predictors of LRsVariablesHR 95%CIP valueAge at entry (&lt;35 years, ≥ 35)*0.95 [0.92; 0.99]0.009Mastectomy, lumpectomy0.39 [0.17; 0.86]0.020&gt; 20mm, ≤20 mm0.68 [0.37; 1.24]0.203N+ &gt;3, 1-31.73 [0.99; 3.02]0.055Grade II/III, I1.06 [0.50; 2.24]0.885PR+,PR-1.78 [0.70; 4.53]0.223Type of chemotherapy 3FEC-3D, 6FEC/6ET1.32 [0.65; 2.69]0.446Number of cycles 6, &lt;60.71 [0.17; 0.75]0.630Hormone therapy Yes,No0.36 [0.17; 0.75]0.006*treated as continuous variable

Conclusion: Our analysis showed that incidence of LRs in pts with HR+ N+ BCs treated within PACS trials were considerably lower as compared to earlier studies. These findings may reflect differences in treatment era, as the more extensive use of radiotherapy and new generation of adjuvant chemotherapy. Despite current adjuvant strategies, young age at diagnosis and omission of HT remain independent risk factors of LRs.

Citation Format: Pistilli B, Filleron T, Mazouni C, Zingarello A, Lacroix-Triki M, Rivera S, Coudert B, Serin D, Canon J-L, Campone M, Bachelot T, Goncalves A, Levy C, Cottu P, Petit T, Eymard J-C, Tunon De Lara C, Roché H, Roca L, Lemonnier J, Delaloge S. Overtime distribution and predictors of local recurrences (LRs) in patients with hormone receptor positive (HR+) and node positive (N+) breast cancers (BCs): 10 -year follow-up analysis of UNICANCER-PACS 01 and PACS04 trials [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 P1-07-07.

Abstract P1-09-11: A phase Ib study of oral administration of lucitanib in combination with fulvestrant in patients with HR+ metastatic breast cancer (mBC)

FGFR1 amplification could mediate resistance to endocrine therapy and FGFR1 inhibition reverses this resistance. This phase Ib seeks to evaluate whether the combination of lucitanib, a potent FGFR/VEGFR/PDFGR inhibitor, in combination with fulvestrant, an endocrine agent, reverses resistance to fulvestrant.

Eligible patients for this study were postmenopausal with ER+/HER2- mBC and have relapsed during or after treatment with fulvestrant. There were 2 parts in the study: a dose allocation to assess the tolerability of the combination in terms of DLTs and MTD using a modified Continual Reassessment Method (mCRM) [part I] and a dose expansion, with patients assigned to 2 different cohorts based on FGFR amplification, to further evaluate the tolerability of the combination and to identify the recommended phase II dose (RP2D) [part II]. Surrogate target hitting biomarkers were also dosed at baseline and on-treatment. The sponsor decided to halt the clinical development in mBC indication and the study was prematurely terminated after 18 patients (15 in part I and 3 in part II). The presentation will focus on these 18 patients.

Patients had ECOG PS 0 or 1 and median number of previous treatments in metastatic setting was 3. Two doses of lucitanib (10mg daily n=9 and 12.5mg daily n=6) in combination with 500 mg/month of fulvestrant were tested in part I. At the 10mg dose level, one patient experienced a DLT (grade 3 hypertension). Based on global lucitanib development program data, it was decided to start Part II with lucitanib 10mg daily. The most common related grade ≥3 toxicities occurring in more than 10% of patients were hypertension (78%) and asthenia (22%). All patients required at least one dose interruption mainly for toxicities, while 13 patients (72%) required at least a dose reduction for toxicities. Thirteen patients (72%) withdrew from the study for disease progression, 3 (17%) for adverse events (at 10mg) and 2 (11%) for non-medical reasons. Three patients achieved a confirmed partial response (as per RECIST v1.1), one at 10mg and two at 12.5mg. About 55% of the patients experienced clinical benefit with a median duration of the benefit of 39.6 weeks and a maximun duration of the benefit of 79.1 weeks for 1 patient (PR at Cycle 4). Biomarker modulations were consistent with lucitanib mode of action; targeting VEGFRs (significant increase of VEGFA, IL8, PlGF) and FGFR1 (significant increase of FGF23).

The combination is feasible but requires close patient monitoring and intensive management of adverse events. Those are in line with the anti-angiogenic activity of lucitanib.

  10mg (N=12)12.5mg (N=6)All (N=18)Objective Response Rate (ORR)n(%) 11 (8.3)2 (33.3)3 (16.7) 95% CI 3[1.5;35.4][9.7;70.0][5.8;39.2]Clinical Benefit Rate (CBR)n(%) 24 (33.3)6 (100.0)10 (55.6) 95% CI 3[13.8;61.0][61.0;100.0][33.7;75.4]Duration of Clinical Benefitmedian (weeks)28.171.339.6 95% CI 3[27.9; 32.7][29.1; 79.1][27.9; 79.1]1: CR or PR 2: CR or PR or stabilization (SD or NonCR/NonPD) &gt;24 weeks or at end of cycle 6 3: 95% Wilson method of Confidence interval of the estimate

Citation Format: Campone M, Bachelot T, Penault-Llorca F, Pallis A, Agrapart V, Pierrat M-J, Poirot C, Paux G, Dubois F, Xuereb L, Robert R, Andre F. A phase Ib study of oral administration of lucitanib in combination with fulvestrant in patients with HR+ metastatic breast cancer (mBC) [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 P1-09-11.

Abstract P5-21-18: Subsequent treatment for postmenopausal women with hormone receptor-positive, HER2-negative advanced breast cancer who received ribociclib + letrozole vs placebo + letrozole in the phase III MONALEESA-2 study

Background: In the Phase III MONALEESA-2 study (NCT01958021), ribociclib (RIB; cyclin-dependent kinase 4/6 inhibitor [CDK4/6i]) + letrozole (LET) significantly prolonged progression-free survival (PFS) vs placebo (PBO) + LET in postmenopausal women with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2–) advanced breast cancer (ABC). The optimal treatment sequence following first-line CDK4/6i-based therapy is not yet known. Here we report the subsequent therapies received following discontinuation from MONALEESA-2.

Methods: The MONALEESA-2 study enrolled 668 patients (pts) with HR+, HER2– ABC. Pts were randomized 1:1 to receive RIB (600 mg/day; 3-weeks-on/1-week-off) + LET (2.5 mg/day; continuous) or PBO + LET. Following discontinuation of MONALEESA-2 study treatment, pts were followed for information regarding post-study treatment, including type and duration of therapy.

Results: At data cut-off (January 2, 2017), the median duration of follow-up was 26.4 months. Median PFS was 25.3 vs 16.0 months in the RIB + LET vs PBO + LET arms (hazard ratio=0.568; 95% confidence interval [CI]: 0.457–0.704; p=9.63x10–8). 203 (60.8%) vs 246 (73.7%) pts had discontinued RIB + LET vs PBO + LET. The median time to end of treatment was 20.3 months in the RIB + LET arm vs 13.7 months in the PBO + LET arm. First subsequent antineoplastic treatment was reported for 172/203 (84.7%) vs 212/246 (86.2%) pts who received RIB + LET vs PBO + LET; second subsequent therapy was reported for 45/203 (22.2%) vs 68/246 (27.6%) pts. The median time to first subsequent therapy (from randomization to the first post-study dose of therapy) was 24.2 (95% CI: 20.9–27.6) vs 16.7 (95% CI: 14.8–19.3) months in pts who received RIB + LET vs PBO + LET; median time to initiation of second subsequent therapy was not reached in either arm. The most common type of first subsequent therapy was single-agent hormonal therapy in 90 (44.3%) vs 87 (35.4%) pts who discontinued RIB + LET vs PBO + LET; chemotherapy was the most common second subsequent therapy in 20 (9.9%) vs 36 (14.6%) pts. Chemotherapy alone was the first subsequent treatment after MONALEESA-2 discontinuation in 32 (15.8%) vs 55 (22.4%) pts treated with RIB + LET vs PBO + LET.

Conclusions: RIB + LET significantly prolongs PFS and delays the start of subsequent lines of therapy vs PBO + LET in pts with HR+, HER2– ABC. The most common first subsequent therapy following discontinuation of RIB + LET or PBO + LET was single-agent hormonal therapy, and fewer pts treated with RIB + LET received subsequent chemotherapy compared with those who received PBO + LET.

Citation Format: Blackwell KL, Paluch-Shimon S, Campone M, Conte P, Petrakova K, Favret A, Blau S, Beck JT, Miller M, Sutradhar S, Monaco M, Burris HA. Subsequent treatment for postmenopausal women with hormone receptor-positive, HER2-negative advanced breast cancer who received ribociclib + letrozole vs placebo + letrozole in the phase III MONALEESA-2 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 P5-21-18.

Abstract P6-14-02: Real-life activity of eribulin among metastatic breast cancer patients in the multicenter national observational ESME program

Background: In 2014, UNICANCER (composed of 18 French Comprehensive Cancer Centers) launched the Epidemiological Strategy and Medical Economics (ESME) program to investigate real-world data in solid tumors. Real-world data give the opportunity to assess for the activity of specific drugs outside clinical trials. Eribulin is approved for pre-treated metastatic breast cancer (MBC). Marketing authorization has been granted in France in July 2012. However few data are available regarding its efficacy in real life. We evaluated eribulin use as second and third line of chemotherapy in MBC patients from the ESME database.

Methods: Data from all newly diagnosed MBC patients having initiated at least one treatment between Jan. 2008 and Dec. 2014 are included in the ESME database. Data were collected retrospectively using a clinical trial-like methodology. Primary endpoint was overall survival (OS), defined from the starting date of second or third line chemotherapy (eribulin versus other chemotherapy). Progression-free survival (PFS) was calculated as a secondary endpoint.

Results: Of 16,703 MBC patients included in the ESME database, 7,412 received at least 2 lines of chemotherapy: eribulin/other chemotherapy, total 1,966/5,446, second line 363/5,446, third line 654/2,669. Depending on second or third line chemotherapy use classification, median age was 59 years (range 20-97) and 58 year (range 21 – 94), triple negative tumors accounted for 20% and 19% of cases, and median follow-up reached 26 months and 22 months respectively.

Table reports median OS and PFS, according to lines and type of chemotherapy.

 OS eribulin (months)OS other chemotherapy (months)pPFS Eribulin (months)PFS other chemotherapy (months)pSecond line12.4 (11.3-15.1)11.8 (11.3-12.3)0.4654.1 (3.7-4.9)4.1 (4.0-4.3)0.9225Third line10.3 (9.3-11.5)7.7 (7.3-8.0)&lt;.00013.6 (3.2-3.9)3.0 (2.9-3.2)0.0058

Supportive analyses (using a propensity score for adjustment and as a matching factor for nested case–control analyses) and sensitivity analyses will be available for full presentation at the meeting.

Conclusion: In this large-scale real-life setting, MBC patients treated with third line eribulin showed an improved OS and PFS compared with those receiving another chemotherapy. The difference was not statistically significant for second line treatment.

Citation Format: Jacot W, Heudel P-E, Fraisse J, Gourgou S, Guiu S, Dalenc F, Pistilli B, Campone M, Levy C, Debled M, Leheurteur M, Chaix M, Lefeuvre C, Goncalves A, Uwer L, Ferrero J-M, Eymard J-C, Petit T, Mouret-Reynier M-A, Courtinard C, Cottu P, Robain M, Mailliez A. Real-life activity of eribulin among metastatic breast cancer patients in the multicenter national observational ESME program [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 P6-14-02.

Abstract PD7-06: MAAT: Menses after adjuvant treatment. Prediction of menses recovery after chemotherapy for early breast cancer (BC) by using a nomogram model in UNICANCER PACS04 and PACS05 trials

Purpose:The likelihood of menses recovery (MR) is largely variable in premenopausal patients (pts) receiving adjuvant chemotherapy for BC. Quantifying this probability for each single patient could impact discussion of chemotherapy side effects and better individualize fertility counseling.We performed a pooled analysis from PACS04 and PACS05 randomized trials aiming to develop a nomogram to estimate the probability of menses recovery at 6 and 18 months (mos) after the end of adjuvant chemotherapy (CT) for premenopausal pts with early BC.

Patients and Methods: The analyzed population consisted of 1683 pts who were premenopausal and ≤ 50 (out of 4524 enrolled in both trials). In PACS05 node-negative BC pts were randomized to 4 or 6 cycles of FE100C (standard arm); in PACS04 node-positive pts were randomized to 6 cycles of FE100C or 6 cycles of Epirubicin 75mg/m2 and Docetaxel 75 mg/m2 (ED75). Endocrine therapy (ET) (Tamoxifen) x 5 years was mandatory for ER+ BC. Variables significantly associated with MR in the univariate analysis (P&lt;0.20) were included in the multivariate analysis. Using this data set, a logistic regression-based nomogram was developed to predict MR at 6 and 18 mos.

Results: Pts' characteristics were: median age 43 (22-50), median body mass index (BMI) at baseline 22.6 (15.6-54.7), at the end of chemotherapy 22.8 (15.8-58.6). ED75 was administrated to 517 (30.7%), while 802 (47.7%) received 6FE100C, 364 (21.6) 4FE100C. Trastuzumab was given to 122 (7.2%), ET to 1229 (73%) pts. CT-induced amenorrhea was observed in 1407 (83.6%) pts. Factors associated to MR were assessed on 1210 pts (excluding pts who recovered menses during CT or of whom date of recovery was not specified). At a median follow-up of 90 mos, 28.2% (342/1210) of pts had recovered menstrual cycles: 11% (133/1210) at 6 mos and 24.3% (294/1210) at 18 mos. Multivariate analysis showed that younger age, higher BMI at the end of CT, non-alkylating agents and absence of ET were independently associated to MR.

Table 1 Multivariate Cox regression analysis of menses recoveryVariablesHR (95%CI)P valueAge1.49 (1.16-1.93)&lt; 0.002Age2*0.99 [0.98-0.99]&lt;0.0001BMI after CT1.02 (0.99-1.04)0.07Alkylating agents0.72 (0.57-0.90)0.004Endocrine Therapy0.50 (0.40-0.62)&lt;0.001* The quadratic term in the age variable accounts for the non-linearity of the relation between the age and the probability of recovering menses. Overall this probability tend to decrease when age increase with a greater decrease for the older patients.

Nomogram concordance-index was 0.749 and 0.750 for predicting MR at 6 and 18 mos respectively. A better calibration was observed at 18 mos, comparing nomogram predictions with the actual probability of MR in the 1210 women.

Conclusion:Our analysis confirmed the possibility of developing a user-friendly nomogram for predicting menses recovery after adjuvant chemotherapy. As next step, we will externally validate our nomogram on CANTO premenopausal population, one of the biggest national cohorts aiming to assess the long-term impact of cancer treatments toxicities (UNICANCER NCT01993498 - http://etudecanto.org/).

Citation Format: Pistilli B, Mazouni C, Zingarello A, Faron M, Saghatchian M, Grynberg M, Spielmann M, Kerbrat P, Roché H, Lorgis V, Bachelot T, Campone M, Levy C, Goncalves A, Lesur A, Veyrat C, Vanlemmens L, Lemonnier J, Delaloge S. MAAT: Menses after adjuvant treatment. Prediction of menses recovery after chemotherapy for early breast cancer (BC) by using a nomogram model in UNICANCER PACS04 and PACS05 trials [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 PD7-06.

Abstract P1-10-07: Efficacy and safety results from a randomized, phase II study of CC-486 in combination with fulvestrant in postmenopausal women with estrogen receptor–positive (ER+), human epidermal growth factor receptor 2–negative (HER2−) metastatic breast cancer (MBC)

Background: Most patients diagnosed with breast cancer have ER+ tumors. Treatment of ER+ MBC typically involves endocrine therapy, including aromatase inhibitors and selective ER modulators such as tamoxifen; however, many patients develop resistance. Fulvestrant, an ER antagonist, is a commonly prescribed second- or third-line therapy for postmenopausal patients who have progressed on endocrine therapy; although, most patients will eventually develop resistance to this drug as well. It was hypothesized that CC-486, an oral formulation of azacitidine, may resensitize patients to endocrine therapy and possibly delay resistance to fulvestrant through the epigenetic regulation of certain genes.

Methods: 97 postmenopausal female patients aged ≥ 18 years with ER+, HER2− MBC refractory to an aromatase inhibitor were randomized 1:1 to receive CC-486 300 mg on days 1 through 21 and fulvestrant 500 mg on days 1 and 15 of cycle 1 and day 1 of subsequent 28-day cycles or the same fulvestrant regimen alone. The primary endpoint was progression-free survival (PFS) based on investigator's assessment using RECIST version 1.1 and summarized by the Kaplan-Meier method. A Cox proportional hazards model was used to estimate the hazard ratio (HR; including a 2-sided 95% CI), and a log-rank test was used to calculate P values for comparisons between treatment arms. Key secondary endpoints included objective response rate (ORR), overall survival (OS), and safety.

Results: 48 patients were included in the CC-486 + fulvestrant arm and 49 in the fulvestrant-alone arm. Median age was 63 years. Baseline characteristics were generally balanced between treatment groups, with some exceptions. The CC-486 + fulvestrant treatment cohort had fewer patients aged ≥ 65 years (40% vs 49%), with an ECOG PS of 1 (25% vs 57%), or with liver metastases (29% vs 43%) than did the fulvestrant-alone cohort. At the time of this analysis, 36 patients (75%) in the CC-486 + fulvestrant arm and 40 patients (82%) in the fulvestrant-alone arm had discontinued treatment, mostly due to progressive disease (81% and 90%, respectively). Median PFS was 5.5 months in both treatment groups (HR 0.87; 95% CI, 0.54 - 1.42; P = 0.599). ORR was 8.3% vs 2.0% in patients receiving CC-486 + fulvestrant vs fulvestrant alone, respectively. Median OS has not been reached. In patients who received CC-486 + fulvestrant, the most common any-grade nonhematologic treatment-emergent adverse events (TEAEs) were nausea (78%), vomiting (78%), diarrhea (44%), and constipation (41%), and the most frequent any-grade hematologic TEAE was neutropenia (26%). Of patients who discontinued due to AEs, most patients receiving CC-486 + fulvestrant treatment discontinued due to gastrointestinal (GI) TEAEs.

Conclusion: The addition of CC-486 to fulvestrant did not improve PFS in patients with ER+, HER2− MBC compared with fulvestrant alone, and GI TEAEs were reported in a majority of patients. These results do not support further evaluation of this combination in this setting.

Citation Format: Campone M, Sachdev J, Bianchi GV, Beck JT, Martínez-Jáñez N, Cortes J, Schmidt M, Zamagni C, Chen P, Miller J, Fandi A, Gianni L. Efficacy and safety results from a randomized, phase II study of CC-486 in combination with fulvestrant in postmenopausal women with estrogen receptor–positive (ER+), human epidermal growth factor receptor 2–negative (HER2−) metastatic breast cancer (MBC) [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 P1-10-07.

Abstract P5-20-03: Impact of prior adjuvant trastuzumab (aT) on clinical characteristics, patterns of recurrence and outcome in 2863 patients with Her2 positive (HER2+) metastatic breast cancer (MBC)- Results from the French ESME UNICANCER program

Background: The management of HER2+ BC has changed dramatically with the introduction and widespread use of HER2-targeted therapies, especially in the adjuvant setting. However, there is relatively limited real-world information on the impact of adjuvant Trastuzumab (aT) on patterns of recurrence and outcome of HER2+ MBC.

Methods: In 2014, the 18 French Cancer Centers launched the Epidemiological Strategy and Medical Economics (ESME) program to provide real-world data on MBC patients (pts). All pts who started a 1st-line treatment for MBC between 01-Jan-2008 and 31-Dec-2014 were included. We examined clinical characteristics and outcomes (overall survival [OS] and time to next treatment [TNT]) in patients with HER2+ MBC pretreated with trastuzumab in the adjuvant setting (aT) compared with trastuzumab-naïve patients (nT) and patients with de novo HER2+ MBC (dn). Multivariate analyses adjusted for baseline demographic, prognostic factors and year of diagnosis (prior or after 2005, when aT was approved and widely administered in France for early HER2+ breast cancer).

Results: Among the 15170 pts of the ESME database, 2863 (19%) were HER2+: 1093 pts (38%) had de novo and 1765 pts (62%) recurrent MBC; 63% were Hormone Receptor (HR) +; 54%, 25% and 21% had respectively 1, 2, or &gt; 2 metastatic sites (68% visceral and 12% brain). Median time to 1st metastasis was 43.4 months (m) (95% CI: 24.6-84.4): 54 m in HR+ and 30 m in HR-. Among pts with recurrent MBC, 55% (995) had received aT. As 1st-line therapy for MBC, 90 % of pts received HER2-targeted agents (73% T-based). With a median follow-up of 46 m, median OS is 45 m (95% CI: 42.5-48). OS is significantly higher in de novo compared to recurrent MBC: 54 m (95% CI: 50.2-60.4) vs. 38.4 m (95% CI: 36.7-41.9), (p &lt; 0.0001). Among pts with recurrent cancers, median OS is inferior in pts who had received aT, as compared to those who had not: 33.4 m (95% CI: 29.6-36.7) vs. 49.5 m (95% CI: 44.3-56.8), (p &lt; 0.0001). Statistically significant differences persist after adjustment for age at MBC, disease-free interval, metastatic sites and RH status in the multivariate model (HR=1.45, 95% CI: 1.26-1.67) but not after adjustment for year of diagnosis (prior or after 2005) (HR=0.90, 95% CI: 0.70-1.15).

Conclusions: These large-scale real-world data in patients with HER2+ MBC provide evidence that the survival outcome remain similar in patients with failure of adjuvant trastuzumab compared with trastuzumab-naïve patients after adjustment for year of diagnosis. De novo HER2+ MBC pts have the best outcomes. Data on clinical characteristics of metastasis and time to next treatment for the three subgroups will be presented at the meeting.

Citation Format: Saghatchian M, Carton M, Piot I, Pérol D, Pistilli B, Brain E, Ghouadni A, Ricci F, Vanlemmens L, Loeb A, Levy C, Goncalves A, Dalenc F, Lefeuvre-Plesse C, Campone M, Jaffre A, Gourgou S, Cailliot C, Robain M, Dieras V. Impact of prior adjuvant trastuzumab (aT) on clinical characteristics, patterns of recurrence and outcome in 2863 patients with Her2 positive (HER2+) metastatic breast cancer (MBC)- Results from the French ESME UNICANCER program [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 P5-20-03.

Abstract PD4-06: First-line ribociclib + letrozole in hormone receptor-positive, HER2-negative advanced breast cancer: Efficacy by baseline circulating tumor DNA alterations in MONALEESA-2

Background: The addition of first-line ribociclib (RIB; cyclin-dependent kinase 4/6 inhibitor) to letrozole (LET) significantly improved progression-free survival (PFS) compared with placebo (PBO) + LET in patients (pts) with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2–) advanced breast cancer (ABC) in the Phase III MONALEESA-2 study. Identifying biomarkers that predict response to treatment remains a key challenge in pts with HR+ ABC. Here we analyze results from MONALEESA-2 by molecular alterations detected in circulating tumor DNA (ctDNA) at baseline, including PIK3CA mutations and other alterations considered to be important in HR+ ABC.

Methods: Postmenopausal women (N=668) with HR+, HER2– ABC who had not received any prior therapy for ABC were randomized 1:1 to RIB (600 mg/day; 3-weeks-on/1-week-off) + LET (2.5 mg/day; continuous) or PBO + LET. The primary endpoint was PFS. Biomarker analysis of the ctDNA mutation profile was an exploratory endpoint. Plasma samples for ctDNA analysis were collected at baseline and end of treatment. ctDNA was analyzed using next-generation sequencing with a targeted panel of ˜550 genes.

Results: Baseline ctDNA was successfully sequenced in 494 pts (RIB + LET: n=212; PBO + LET: n=215); 67 (14%) of 494 pts were removed from the analysis due to limited tumor DNA in circulation. 427 (86%) pts had ≥1 alteration, including 1,573 mutations, 513 short insertions/deletions, 166 amplifications, and 8 translocations. Alterations (frequency) were commonly observed in the following genes: PIK3CA (33%), TP53 (12%), ZNF703/FGFR1 (5%), and ESR1 (4%), and in genes involved in receptor tyrosine kinase (RTK) signaling (12%). RIB + LET treatment benefit was consistent in pts with wild-type (WT) and altered PIK3CA, and in pts with WT and altered TP53 (Table). RIB + LET improved PFS regardless of RTK or ZNF703/FGFR1 alterations. However, there was a weak trend for increased benefit in pts with WT vs altered RTK genes and in pts with WT vs altered ZNF703/FGFR1 genes. These results should be interpreted with caution due to the small number of pts with these alterations. There were too few ESR1 alterations for firm conclusions to be drawn.

 Events, n/NMedian PFS, months Gene(s)RIB + LETPBO + LETRIB + LETPBO + LETHazard ratio (95% confidence interval)PIK3CAWT54/14393/14229.614.70.44 (0.31–0.62)Altered40/6955/7319.212.70.53 (0.35–0.81)TP53WT72/180129/19427.614.70.44 (0.33–0.59)Altered22/3219/2110.25.50.43 (0.23–0.83)ZNF703/FGFR1WT88/202139/20524.814.60.47 (0.36–0.62)Altered6/109/1010.611.40.73 (0.23–2.29)RTKWT81/189128/18724.814.40.46 (0.35–0.61)Altered13/2320/2821.311.40.72 (0.34–1.53)

Conclusions: Consistent RIB + LET treatment benefit was observed compared with PBO + LET, irrespective of the status of baseline ctDNA biomarkers.

Citation Format: Hortobagyi GN, Stemmer S, Campone M, Sonke GS, Arteaga CL, Paluch-Shimon S, Petrakova K, Villanueva C, Nusch A, Grischke E-M, Chan A, Jakobsen E, Marschner N, Hart LL, Alba E, Ohnstand HO, Blau S, Yardley DA, Solovieff N, Su F, Germa C, Yap Y-S. First-line ribociclib + letrozole in hormone receptor-positive, HER2-negative advanced breast cancer: Efficacy by baseline circulating tumor DNA alterations in MONALEESA-2 [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 PD4-06.

Veliparib with temozolomide or carboplatin/paclitaxel versus placebo with carboplatin/paclitaxel in patients with BRCA1/2 locally recurrent/metastatic breast cancer: randomized phase II study

Background

Homologous recombination defects in BRCA1/2-mutated tumors result in sensitivity to poly(ADP-ribose) polymerase inhibitors, which interfere with DNA damage repair. Veliparib, a potent poly(ADP-ribose) polymerase inhibitor, enhanced the antitumor activity of platinum agents and temozolomide in early phase clinical trials. This phase II study examined the safety and efficacy of intermittent veliparib with carboplatin/paclitaxel (VCP) or temozolomide (VT) in patients with BRCA1/2-mutated breast cancer.

Patients and methods

Eligible patients ≥18 years with locally recurrent or metastatic breast cancer and a deleterious BRCA1/2 germline mutation were randomized 1 : 1 : 1 to VCP, VT, or placebo plus carboplatin/paclitaxel (PCP). Primary end point was progression-free survival (PFS); secondary end points included overall survival (OS) and overall response rate (ORR).

Results

Of 290 randomized patients, 284 were BRCA+, confirmed by central laboratory. For VCP versus PCP, median PFS was 14.1 and 12.3 months, respectively [hazard ratio (HR) 0.789; 95% CI 0.536-1.162; P = 0.227], interim median OS 28.3 and 25.9 months (HR 0.750; 95% CI 0.503-1.117; P = 0.156), and ORR 77.8% and 61.3% (P = 0.027). For VT (versus PCP), median PFS was 7.4 months (HR 1.858; 95% CI 1.278-2.702; P = 0.001), interim median OS 19.1 months (HR 1.483; 95% CI 1.032-2.131; P = 0.032), and ORR 28.6% (P < 0.001). Safety profile was comparable between carboplatin/paclitaxel arms. Adverse events (all grades) of neutropenia, anemia, alopecia, and neuropathy were less frequent with VT versus PCP.

Conclusion

Numerical but not statistically significant increases in both PFS and OS were observed in patients with BRCA1/2-mutated recurrent/metastatic breast cancer receiving VCP compared with PCP. The addition of veliparib to carboplatin/paclitaxel significantly improved ORR. There was no clinically meaningful increase in toxicity with VCP versus PCP. VT was inferior to PCP. An ongoing phase III trial is evaluating VCP versus PCP, with optional continuation single-agent therapy with veliparib/placebo if chemotherapy is discontinued without progression, in this patient population.

Clinical trial information

NCT01506609.

Canine invasive mammary carcinomas as models of human breast cancer. Part 2: immunophenotypes and prognostic significance

PURPOSE

Relevant animal models of human breast cancer are currently needed, especially for the aggressive triple-negative breast cancer subtype. Recent studies and our results (Part 1) indicate that spontaneous canine invasive mammary carcinomas (CMCs) resemble human breast cancer by clinics and pathology as well as behavior and prognostic indicators. We hypothesized that the current molecular classifications of human breast cancer, used for therapeutic decision, could be relevant to dogs.

METHODS

Three hundred and fifty female dogs with spontaneous CMC and a 2-year follow-up were retrospectively included. By immunohistochemistry, CMCs were classified according to Nielsen (Clin Cancer Res 10:5367-5374, 2004) and Blows (PlosOne doi: 10.1371/journal.pmed.1000279, 2010) into the subtypes of human breast cancer.

RESULTS

Four immunophenotypes were defined either according to Nielsen classification (luminal A 14.3%, luminal B 9.4%, triple-negative basal-like 58.6%, and triple-negative nonbasal-like 17.7% CMCs); or to Blows classification (luminal 1-: 11.4%, luminal 1+: 12.3%, Core basal phenotype: 58.6%, and five-negative phenotype: 17.7%). No HER2-overexpressing CMC as defined by a 3 + immunohistochemical score was observed in our cohort. By univariate and multivariate analyses, both immunophenotypical classifications applied to CMCs showed strong prognostic significance: luminal A or luminal 1+ CMCs showed a significantly longer disease-free interval (HR = 0.46), Overall (HR = 0.47), and Specific Survival (HR = 0.56) compared to triple-negative carcinomas, after adjustment for stage.

CONCLUSIONS

In our cohort, triple-negative CMCs largely predominated (76%), were much more prevalent than in human beings, and showed an aggressive natural behavior after mastectomy. Dogs are thus potent valuable spontaneous models to test new therapeutic strategies for this particular subtype of breast cancer.

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.

Efficacy of palbociclib plus fulvestrant after everolimus in hormone receptor-positive metastatic breast cancer

BACKGROUND

Palbociclib, a CDK4-6 inhibitor, combined with endocrine therapy (ET) is a new standard of treatment for Hormone Receptor-positive Metastatic Breast Cancer. We present the first real-life efficacy and tolerance data of palbociclib plus fulvestrant in this population.

METHODS

From November 2015 to November 2016, patients receiving in our institution palbociclib + fulvestrant according to the Temporary Authorization for Use were prospectively analyzed.

RESULTS

60 patients were treated accordingly; median age was 61 years; 50 patients (83.3%) had visceral metastasis, and 10 (16.7%) had bone-only disease. Patients had previously received a median of 5 (1-14) lines of treatment, including ET (median 3) and chemotherapy (median 2); 28 (46.7%) received previously fulvestrant and all everolimus. With a median follow-up of 10.3 months, median progression-free survival (mPFS) was 5.8 months (95% CI 3.9-7.3). Patients pretreated with fulvestrant had a similar PFS of 6.4 months (HR 1.00; 95% CI 0.55-1.83; P = 1.00). The most common AEs (adverse events) were neutropenia (93%), anemia (65%), and thrombocytopenia (55%).

CONCLUSION

In this heavily pretreated population including everolimus, fulvestrant plus palbociclib provides an mPFS of 5.8 months with the same magnitude of benefit for fulvestrant-pretreated patients.

Efficacy of buparlisib in treating breast cancer

INTRODUCTION

Breast cancer is the most frequent cancer in women. Despite a decline in breast cancer mortality, prognosis of advanced breast cancer remains poor. In a desperate need to improve breast cancer outcomes, newer agents that target molecular pathways are being tested. Deregulation of the phosphoinositide 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) is frequently found in breast cancer. This can lead to resistance of endocrine therapy and anti-HER2 therapies. Targeting this pathway may restore sensitivity to these compounds. Buparlisib (BKM-120) is an orally active pan-PI3K inhibitor evaluated in different tumor types. Areas covered: Buparlisib is one of the most investigated PI3K inhibitors. Preclinical and clinical studies of buparlisib in breast cancer are analyzed and discussed. This article reviews the status of buparlisib, completed and ongoing trials, and its safety. Expert opinion: PI3K inhibitors show promising results in breast cancer. However, we raise a number of issues including the identification of biomarkers to predict treatment response and strategies to counteract resistance. Moreover, its toxicity profile could limit its extensive use.

Neoadjuvant trastuzumab, pertuzumab, and chemotherapy versus trastuzumab emtansine plus pertuzumab in patients with HER2-positive breast cancer (KRISTINE): a randomised, open-label, multicentre, phase 3 trial

BACKGROUND

HER2-targeted treatments have improved outcomes in patients with HER2-positive breast cancer in the neoadjuvant, adjuvant, and metastatic settings; however, some patients remain at risk of relapse or death for many years after treatment of early-stage disease. Therefore, new strategies are needed. We did a phase 3 trial to assess a neoadjuvant regimen for HER2-positive breast cancer that replaces traditional systemic chemotherapy with targeted treatment.

METHODS

We did a randomised, open-label phase 3 KRISTINE trial in 68 Translational Research In Oncology centres (hospitals and specialty cancer centres in Asia, Europe, USA, and Canada). Eligible participants were aged 18 years or older with centrally confirmed HER2-positive stage II-III operable breast cancer (>2 cm tumour size), an Eastern Cooperative Oncology Group performance status of 0-1, and a baseline left ventricular ejection fraction of at least 55% (by echocardiogram or multiple-gated acquisition scan). We randomly assigned participants (1:1) to receive either trastuzumab emtansine plus pertuzumab or docetaxel, carboplatin, and trastuzumab plus pertuzumab. We did the randomisation via an interactive response system under a permuted block randomisation scheme (block size of four), stratified by hormone receptor status, stage at diagnosis, and geographical location. Patients received six cycles (every 3 weeks) of neoadjuvant trastuzumab emtansine plus pertuzumab (trastuzumab emtansine 3·6 mg/kg; pertuzumab 840 mg loading dose, 420 mg maintenance doses) or docetaxel, carboplatin, and trastuzumab plus pertuzumab (docetaxel 75 mg/m²; carboplatin area under the concentration-time curve 6 mg/mL × min; trastuzumab 8 mg/kg loading dose, 6 mg/kg maintenance doses) plus pertuzumab [same dosing as in the other group]). All treatments were administered intravenously. The primary objective was to compare the number of patients who achieved a pathological complete response (ypT0/is, ypN0), between groups in the intention-to-treat population (two-sided assessment), based on local evaluation of tumour samples taken at breast cancer surgery done between 14 days and 6 weeks after completion of neoadjuvant therapy. Safety was analysed in patients who received at least one dose of study medication. This trial is registered with ClinicalTrials.gov, number NCT02131064, and follow-up of the adjuvant phase is ongoing.

FINDINGS

Between June 25, 2014, and June 15, 2015, we randomly assigned 444 patients to neoadjuvant treatment with trastuzumab emtansine plus pertuzumab (n=223) or docetaxel, carboplatin, and trastuzumab plus pertuzumab (n=221). A pathological complete response was achieved by 99 (44·4%) of 223 patients in the trastuzumab emtansine plus pertuzumab group and 123 (55·7%) of 221 patients in the docetaxel, carboplatin, and trastuzumab plus pertuzumab group (absolute difference -11·3 percentage points, 95% CI -20·5 to -2·0; p=0·016). During neoadjuvant treatment, compared with patients receiving docetaxel, carboplatin, and trastuzumab plus pertuzumab, fewer patients receiving trastuzumab emtansine plus pertuzumab had a grade 3-4 adverse event (29 [13%] of 223 vs 141 [64%] of 219) or a serious adverse event (11 [5%] of 223 vs 63 [29%] of 219). The most common grade 3-4 adverse events in the trastuzumab emtansine plus pertuzumab group were decreased platelet count (three [1%] of 223 patients vs 11 [5%] of 219 with docetaxel, carboplatin, and trastuzumab plus pertuzumab), fatigue (three [1%] vs seven [3%]), alanine aminotransferase increase (three [1%] vs four [2%]), and hypokalaemia (three [1%] vs five [2%]). The most common grade 3-4 adverse events in the docetaxel, carboplatin, and trastuzumab plus pertuzumab group were neutropenia (55 [25%] of 219 vs one [<1%] of 223 with trastuzumab emtansine plus pertuzumab), diarrhoea (33 [15%] vs 2 [<1%]), and febrile neutropenia (33 [15%] vs 0). No deaths were reported during neoadjuvant treatment.

INTERPRETATION

Traditional neoadjuvant systemic chemotherapy plus dual HER2-targeted blockade (docetaxel, carboplatin, and trastuzumab plus pertuzumab) resulted in significantly more patients achieving a pathological complete response than HER2-targeted chemotherapy plus HER2-targeted blockade (trastuzumab emtansine plus pertuzumab); however, numerically more grade 3-4 and serious adverse events occurred in the chemotherapy plus trastuzumab and pertuzumab group. Further efforts to improve the efficacy of chemotherapy without imparting more toxicity are warranted.

FUNDING

F Hoffmann-La Roche and Genentech.

Lomustine and Bevacizumab in Progressive Glioblastoma

BACKGROUND

Bevacizumab is approved for the treatment of patients with progressive glioblastoma on the basis of uncontrolled data. Data from a phase 2 trial suggested that the addition of bevacizumab to lomustine might improve overall survival as compared with monotherapies. We sought to determine whether the combination would result in longer overall survival than lomustine alone among patients at first progression of glioblastoma.

METHODS

We randomly assigned patients with progression after chemoradiation in a 2:1 ratio to receive lomustine plus bevacizumab (combination group, 288 patients) or lomustine alone (monotherapy group, 149 patients). The methylation status of the promoter of O⁶-methylguanine-DNA methyltransferase (MGMT) was assessed. Health-related quality of life and neurocognitive function were evaluated at baseline and every 12 weeks. The primary end point of the trial was overall survival.

RESULTS

A total of 437 patients underwent randomization. The median number of 6-week treatment cycles was three in the combination group and one in the monotherapy group. With 329 overall survival events (75.3%), the combination therapy did not provide a survival advantage; the median overall survival was 9.1 months (95% confidence interval [CI], 8.1 to 10.1) in the combination group and 8.6 months (95% CI, 7.6 to 10.4) in the monotherapy group (hazard ratio for death, 0.95; 95% CI, 0.74 to 1.21; P=0.65). Locally assessed progression-free survival was 2.7 months longer in the combination group than in the monotherapy group: 4.2 months versus 1.5 months (hazard ratio for disease progression or death, 0.49; 95% CI, 0.39 to 0.61; P<0.001). Grade 3 to 5 adverse events occurred in 63.6% of the patients in the combination group and 38.1% of the patients in the monotherapy group. The addition of bevacizumab to lomustine affected neither health-related quality of life nor neurocognitive function. The MGMT status was prognostic.

CONCLUSIONS

Despite somewhat prolonged progression-free survival, treatment with lomustine plus bevacizumab did not confer a survival advantage over treatment with lomustine alone in patients with progressive glioblastoma. (Funded by an unrestricted educational grant from F. Hoffmann-La Roche and by the EORTC Cancer Research Fund; EORTC 26101 ClinicalTrials.gov number, NCT01290939 ; Eudra-CT number, 2010-023218-30 .).

Approving cancer treatments based on endpoints other than overall survival: an analysis of historical data using the PACE Continuous Innovation Indicators™ (CII)

Background

There is an active debate about the role that endpoints other than overall survival (OS) should play in the drug approval process. Yet the term ‘surrogate endpoint’ implies that OS is the only critical metric for regulatory approval of cancer treatments. We systematically analyzed the relationship between U.S. Food and Drug Administration (FDA) approval and publication of OS evidence to understand better the risks and benefits of delaying approval until OS evidence is available.

Scope

Using the PACE Continuous Innovation Indicators (CII) platform, we analyzed the effects of cancer type, treatment goal, and year of approval on the lag time between FDA approval and publication of first significant OS finding for 53 treatments approved between 1952 and 2016 for 10 cancer types (n = 71 approved indications).

Findings

Greater than 59% of treatments were approved before significant OS data for the approved indication were published. Of the drugs in the sample, 31% had lags between approval and first published OS evidence of 4 years or longer. The average number of years between approval and first OS evidence varied by cancer type and did not reliably predict the eventual amount of OS evidence accumulated.

Conclusions

Striking the right balance between early access and minimizing risk is a central challenge for regulators worldwide. We illustrate that endpoints other than OS have long helped to provide timely access to new medicines, including many current standards of care. We found that many critical drugs are approved many years before OS data are published, and that OS may not be the most appropriate endpoint in some treatment contexts. Our examination of approved treatments without significant OS data suggests contexts where OS may not be the most relevant endpoint and highlights the importance of using a wide variety of fit-for-purpose evidence types in the approval process.

MONARCH 3: Abemaciclib As Initial Therapy for Advanced Breast Cancer

Purpose

Abemaciclib, a cyclin-dependent kinase 4 and 6 inhibitor, demonstrated efficacy as monotherapy and in combination with fulvestrant in women with hormone receptor (HR)–positive, human epidermal growth factor receptor 2 (HER2)–negative advanced breast cancer previously treated with endocrine therapy.

Methods

MONARCH 3 is a double-blind, randomized phase III study of abemaciclib or placebo plus a nonsteroidal aromatase inhibitor in 493 postmenopausal women with HR-positive, HER2-negative advanced breast cancer who had no prior systemic therapy in the advanced setting. Patients received abemaciclib or placebo (150 mg twice daily continuous schedule) plus either 1 mg anastrozole or 2.5 mg letrozole, daily. The primary objective was investigator-assessed progression-free survival. Secondary objectives included response evaluation and safety. A planned interim analysis occurred after 189 events.

Results

Median progression-free survival was significantly prolonged in the abemaciclib arm (hazard ratio, 0.54; 95% CI, 0.41 to 0.72; P = .000021; median: not reached in the abemaciclib arm, 14.7 months in the placebo arm). In patients with measurable disease, the objective response rate was 59% in the abemaciclib arm and 44% in the placebo arm ( P = .004). In the abemaciclib arm, diarrhea was the most frequent adverse effect (81.3%) but was mainly grade 1 (44.6%). Comparing abemaciclib and placebo, the most frequent grade 3 or 4 adverse events were neutropenia (21.1% v 1.2%), diarrhea (9.5% v 1.2%), and leukopenia (7.6% v 0.6%).

Conclusion

Abemaciclib plus a nonsteroidal aromatase inhibitor was effective as initial therapy, significantly improving progression-free survival and objective response rate and demonstrating a tolerable safety profile in women with HR-positive, HER2-negative advanced breast cancer.