Cobimetinib plus atezolizumab in BRAFV600 wild-type melanoma: primary results from the randomized phase III IMspire170 study

BACKGROUND

Emerging data suggest that the combination of MEK inhibitors and immunotherapeutic agents may result in improved efficacy in melanoma. We evaluated whether combining MEK inhibition and immune checkpoint inhibition was more efficacious than immune checkpoint inhibition alone in patients with previously untreated BRAF^V600 wild-type advanced melanoma.

PATIENTS AND METHODS

IMspire170 was an international, randomized, open-label, phase III study. Patients were randomized 1 : 1 to receive cobimetinib (60 mg, days 1-21) plus anti-programmed death-ligand 1 atezolizumab (840 mg every 2 weeks) in 28-day cycles or anti-programmed death-1 pembrolizumab (200 mg every 3 weeks) alone until loss of clinical benefit, unacceptable toxicity, or consent withdrawal. The primary outcome was progression-free survival (PFS), assessed by an independent review committee in the intention-to-treat population.

RESULTS

Between 11 December 2017, and 29 January 2019, 446 patients were randomized to receive cobimetinib plus atezolizumab (n = 222) or pembrolizumab (n = 224). Median follow-up was 7.1 months [interquartile range (IQR) 4.8-9.9] for cobimetinib plus atezolizumab and 7.2 months (IQR 4.9-10.1) for pembrolizumab. Median PFS was 5.5 months [95% confidence interval (CI) 3.8-7.2] with cobimetinib plus atezolizumab versus 5.7 months (95% CI 3.7-9.6) with pembrolizumab [stratified hazard ratio 1.15 (95% CI 0.88-1.50); P = 0.30]. Hazard ratios for PFS were consistent across prespecified subgroups. In exploratory biomarker analyses, higher tumor mutational burden was associated with improved clinical outcomes in both treatment arms. The most common grade 3-5 adverse events (AEs) were increased blood creatine phosphokinase (10.0% with cobimetinib plus atezolizumab versus 0.9% with pembrolizumab), diarrhea (7.7% versus 1.9%), rash (6.8% versus 0.9%), hypertension (6.4% versus 3.7%), and dermatitis acneiform (5.0% versus 0). Serious AEs occurred in 44.1% of patients with cobimetinib plus atezolizumab and 20.8% with pembrolizumab.

CONCLUSION

Cobimetinib plus atezolizumab did not improve PFS compared with pembrolizumab monotherapy in patients with BRAF^V600 wild-type advanced melanoma.

Trifluridine/tipiracil plus bevacizumab in patients with untreated metastatic colorectal cancer ineligible for intensive therapy: the randomized TASCO1 study

BACKGROUND

We designed an open-label, noncomparative phase II study to assess the safety and efficacy of first-line treatment with trifluridine/tipiracil plus bevacizumab (TT-B) and capecitabine plus bevacizumab (C-B) in untreated patients with unresectable metastatic colorectal cancer (mCRC) who were not candidates for combination with cytotoxic chemotherapies.

PATIENTS AND METHODS

From 29 April 2016 to 29 March 2017, 153 patients were randomly assigned (1:1) to either TT-B (N = 77) or C-B (N = 76). The primary end point was progression-free survival (PFS). The primary PFS analysis was performed after 100 events (radiological progression or death) were observed. Secondary end points included overall survival (OS), quality of life (QoL; QLQ-C30 and QLQ-CR29 questionnaires), and safety.

RESULTS

Median (range) duration of treatment was 7.8 (6.0-9.7) months and 6.2 (4.1-9.1) months in the TT-B and C-B groups, respectively. Median (range) PFS was 9.2 (7.6-11.6) and 7.8 (5.5-10.1) months, respectively. Median (range) OS was 18 (15.2 to NA) and 16.2 (12.5 to NA) months, respectively. QoL questionnaires showed no relevant changes over time for either treatment. Therapies were well tolerated. Patients receiving TT-B had more grade ≥3 neutropenia (47% versus 5% with C-B). Patients receiving C-B had more grade ≥3 hand-foot syndrome (12% versus 0% with TT-B) and grade ≥3 diarrhea (8% versus 1% with TT-B), consistent with the known safety profiles of these agents.

CONCLUSION

TT-B treatment showed promising clinical activity in untreated patients with unresectable mCRC ineligible for intensive therapy, with an acceptable safety profile and no clinically relevant changes in QoL.

CLINICAL TRIAL INFORMATION

NCT02743221 (ClinicalTrials.gov).

Efficacy and safety of CT-P6 versus reference trastuzumab in HER2-positive early breast cancer: updated results of a randomised phase 3 trial

PURPOSE

Neoadjuvant CT-P6, a trastuzumab biosimilar, demonstrated equivalent efficacy to reference trastuzumab in a phase 3 trial of HER2-positive early-stage breast cancer (EBC) (NCT02162667). We report post hoc analyses evaluating pathological complete response (pCR) and breast pCR alongside additional efficacy and safety measures.

METHODS

Following neoadjuvant treatment and surgery, patients received adjuvant CT-P6 or trastuzumab (6 mg/kg) every 3 weeks for ≤ 1 year.

RESULTS

In total, 271 and 278 patients received CT-P6 and trastuzumab, respectively. pCR and breast pCR rates were comparable between treatment groups regardless of age, region, or clinical stage. Overall, 47.6% (CT-P6) and 52.2% (trastuzumab) of patients experienced study drug-related treatment-emergent adverse events (TEAEs), including 17 patients reporting heart failure (CT-P6: 10; trastuzumab: 7). Two CT-P6 and three trastuzumab patients discontinued adjuvant treatment due to TEAEs.

CONCLUSION

Adjuvant CT-P6 demonstrated comparable efficacy and safety to trastuzumab at 1 year in patients with HER2-positive EBC, supporting CT-P6 and trastuzumab comparability.

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 <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.

Dabrafenib plus trametinib versus dabrafenib monotherapy in patients with metastatic BRAF V600E/K-mutant melanoma: long-term survival and safety analysis of a phase 3 study

Background

Previous analysis of COMBI-d (NCT01584648) demonstrated improved progression-free survival (PFS) and overall survival (OS) with combination dabrafenib and trametinib versus dabrafenib monotherapy in BRAF V600E/K-mutant metastatic melanoma. This study was continued to assess 3-year landmark efficacy and safety after ≥36-month follow-up for all living patients.

Patients and methods

This double-blind, phase 3 study enrolled previously untreated patients with BRAF V600E/K-mutant unresectable stage IIIC or stage IV melanoma. Patients were randomized to receive dabrafenib (150 mg twice daily) plus trametinib (2 mg once daily) or dabrafenib plus placebo. The primary endpoint was PFS; secondary endpoints were OS, overall response, duration of response, safety, and pharmacokinetics.

Results

Between 4 May and 30 November 2012, a total of 423 of 947 screened patients were randomly assigned to receive dabrafenib plus trametinib (n = 211) or dabrafenib monotherapy (n = 212). At data cut-off (15 February 2016), outcomes remained superior with the combination: 3-year PFS was 22% with dabrafenib plus trametinib versus 12% with monotherapy, and 3-year OS was 44% versus 32%, respectively. Twenty-five patients receiving monotherapy crossed over to combination therapy, with continued follow-up under the monotherapy arm (per intent-to-treat principle). Of combination-arm patients alive at 3 years, 58% remained on dabrafenib plus trametinib. Three-year OS with the combination reached 62% in the most favourable subgroup (normal lactate dehydrogenase and <3 organ sites with metastasis) versus only 25% in the unfavourable subgroup (elevated lactate dehydrogenase). The dabrafenib plus trametinib safety profile was consistent with previous clinical trial observations, and no new safety signals were detected with long-term use.

Conclusions

These data demonstrate that durable (≥3 years) survival is achievable with dabrafenib plus trametinib in patients with BRAF V600-mutant metastatic melanoma and support long-term first-line use of the combination in this setting.

Abstract OT2-01-12: ENCORE 602: A randomized, placebo-controlled, double-blind, multicenter phase 2 study (with a phase 1b lead-in) of atezolizumab with or without entinostat in patients with advanced triple negative breast cancer (aTNBC)

Background: Atezolizumab, a humanized anti-PDL1 antibody, has shown encouraging single agent activity in triple negative breast cancer. Entinostat is an oral, class I selective histone deacetylase (HDAC) inhibitor. In animal models, entinostat has been shown to selectively reduce immunosuppressive myeloid derived suppressor cells (MDSCs) and regulatory T cells (Tregs), enhancing response to immune checkpoint blockade. It is hypothesized that entinostat in combination with atezolizumab will show improved efficacy compared to atezolizumab alone.

Trial Design: ENCORE 602 is a Phase 1b/2 study evaluating the combination of entinostat plus atezolizumab in patients with aTNBC. The study has 2 phases: an open-label Dose Determination Phase (Phase 1b) followed by Phase 2. The objective of the Dose Determination Phase is to establish the recommended Phase 2 dose (RP2D) of weekly entinostat when given in combination with atezolizumab 1200 mg every 3 weeks. Phase 2 will evaluate the efficacy and safety of entinostat at the RP2D with atezolizumab in patients with aTNBC in a randomized (1:1), double-blind, placebo-controlled setting. The randomization will be stratified by geographic location (US vs ex-US).

Key Eligibility Criteria: Eligible patients will have 1) histologically- or cytologically-confirmed triple negative breast carcinoma that is either metastatic (stage IV of the TNM classification) or locally recurrent and not amenable to local curative treatment, 2) measurable disease based on imaging studies within 28 days before the first dose of study drug, and 3) received 1-2 prior lines of systemic therapy for locally recurrent and/or metastatic disease. Previous treatment with a PD-1/PD-L1-blocking antibody or a HDAC inhibitor is not permitted.

Specific Aims: In Phase 2, the primary endpoint is progression free survival (PFS), as assessed by the investigators using RECIST 1.1. Secondary endpoints include PFS by immune response RECIST (irRECIST), overall response rate, clinical benefit rate, overall survival, safety, and duration and time to response for those patients achieving a complete or partial response. Exploratory endpoints include PK, protein lysine acetylation, and immune correlates.

Statistical Methods: The primary analysis of PFS will be performed using a stratified log-rank test. Estimation of the hazard ratio for treatment effect will be determined using a stratified Cox proportional hazards model. 60 PFS events are estimated to provide 80% power to detect the targeted improvement in PFS with one-sided significance level of 0.1. An independent data safety monitoring board will meet at regular intervals to oversee trial conduct and patient safety.

Accrual: Up to 88 evaluable patients are anticipated if the study completes all phases of evaluation (6-18 patients in Phase 1b, 70 patients in Phase 2). The study was activated in May 2016 (NCT02708680).

Citation Format: Forero A, Stroyakovskiy D, Cha E, Cruickshank S, Hasapidis J, Meyers ML, Slamon DJ. ENCORE 602: A randomized, placebo-controlled, double-blind, multicenter phase 2 study (with a phase 1b lead-in) of atezolizumab with or without entinostat in patients with advanced triple negative breast cancer (aTNBC) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr OT2-01-12.

Subcutaneous versus intravenous formulation of trastuzumab for HER2-positive early breast cancer: updated results from the phase III HannaH study

BACKGROUND

HannaH (NCT00950300) was a phase III, randomized, international, open-label study that compared pharmacokinetics (PK), efficacy, and safety of two different trastuzumab formulations [subcutaneous (s.c.) and intravenous (i.v.)] in HER2-positive, operable, locally advanced, or inflammatory breast cancer in the neoadjuvant/adjuvant setting. The co-primary end points, to show noninferiority of s.c. versus i.v. trastuzumab in terms of serum concentration (Ctrough) and pathologic complete response (pCR) were met; safety profiles were comparable at 12 months' median follow-up. Secondary end points included safety and tolerability, PK profile, immunogenicity, and event-free survival (EFS). We now report updated safety and efficacy data after a median follow-up of 20 months.

PATIENTS AND METHODS

Patients (N = 596) were treated with eight cycles of neoadjuvant chemotherapy, administered concurrently with 3-weekly s.c. trastuzumab (fixed dose of 600 mg) or the standard weight-based i.v. method. Following surgery, patients continued trastuzumab treatment to complete 1 year of therapy. Updated analyses of PK, efficacy, safety, and immunogenicity data were carried out.

RESULTS

s.c. trastuzumab was generally well tolerated and the incidence of adverse events (AEs), including grade 3 or 4 AEs, between treatment groups was comparable. A slightly higher incidence of serious AEs (SAEs), mainly due to infections, was reported with s.c. treatment {64 [21.5%; 95% confidence interval (CI) 17.0%-26.7%] versus 42 (14.1%; 95% CI 10.4%-18.6%) in the i.v. group}; however, the differences were small and often based on rare events, with no observable pattern across reported events. An early analysis of EFS showed rates of 95% in both groups 1 year postrandomization. Exploratory analyses did not reveal an association between toxicity and body weight or exposure.

CONCLUSIONS

Overall, the safety profile of s.c. trastuzumab was consistent with the previously published data from HannaH and the known safety profile of i.v. trastuzumab. EFS rates were comparable between the i.v. and s.c. groups.

CLINICAL TRIAL NUMBER

NCT00950300.

MO19390 (SAiL): Incidence of hemorrhage with first-line bevacizumab (Bv)-based therapy in advanced non-small cell lung cancer (NSCLC)

e19000

Background: MO19390 (SAiL) is an international, multicenter, open-label study evaluating the safety of first-line Bv in combination with a range of chemotherapy regimens in over 2,000 patients (pts). We report interim safety data with a focus on the incidence of serious bleeding events, including pulmonary hemorrhage. Methods: Primary endpoint was safety; secondary endpoints included time to disease progression and overall survival. Eligibility criteria included: non-squamous NSCLC with no prior chemotherapy, no uncontrolled hypertension (systolic >150 mmHg and/or diastolic >100 mmHg) or active cardiovascular disease at baseline, ECOG PS 0–2, no history of grade [g])>2 hemoptysis, and no evidence of tumor abutting or invading major blood vessels. Pts received Bv (7.5 or 15mg/kg) with chemotherapy for up to six cycles, then non-progressors proceeded to receive Bv until disease progression. Results: Interim analyses were available for a safety population of 2,008 pts (data cut-off July 2008). Baseline characteristics for pts were (%): male 60.1; Caucasian/Asian/other 80.1/15.6/4.3; stage IIIB/IV 19.5/80.5 (no data for 3 pts); adenocarcinoma/large cell/other 85.8/7.1/7.1; central tumor location yes/no (Y/N) 27.3/72.7; cavitated tumor Y/N 2.6/97.4; smoking history Y/N 70/30; ECOG PS 0/1/2 38.1/56.1/5.8. The median age was 59 years. Serious bleeding events (g≥3) of any cause were reported in 43 pts (2.1%). Bv-related bleeding events (g≥3) were reported in 16 pts (0.8%), including hemoptysis in 5 pts (0.2%) and gastrointestinal hemorrhage in 3 pts (0.1%). Conclusions: In Bv-treated pts, significant bleeding and hemoptysis are rare events. Our results confirm the well established and manageable safety profile of Bv-based therapy in eligible non-squamous NSCLC pts. Updated results will be presented.

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