Moffitt Cancer Center, Tampa, FL
Hyo S. Han , Banu Arun , Bella Kaufman , Hans Wildiers , Michael Friedlander , Jean-Pierre M. Ayoub , Shannon L Puhalla , Bruce Allen Bach , Matthew Dudley , Madan Gopal Kundu , David Maag , Christine Ratajczak , Veronique Dieras
Background: In BROCADE3 (NCT02163694), addition of PARP inhibitor V to CP resulted in improved progression-free survival (PFS) (HR 0.71 [95% CI 0.57−0.88], p=0.002) in patients (pts) with advanced HER2-negative breast cancer and gBRCA1/2 mutation. A subset of pts transitioned to V/placebo (PL) monoTx at an intensified dose/schedule after CP discontinuation prior to progression (investigator discretion). Here, we evaluate the impact of this transition on efficacy and safety. Methods: Pts were randomized 2:1 to CP with V (n=337) or PL (n=172). V (120 mg po BID) or PL was given on Days (D) −2 to 5, C (AUC 6) on D1, and P (80 mg/m2) on D1, 8, and 15 (21-day cycles). Pts who transitioned to monoTx received V/PL 300-400mg BID daily until progression. A Cox model with a time varying covariate indicating transition from V/PL with CP to V/PL monoTx was fit to estimate treatment effect during combination and monoTx phases. PFS by cycles of CP prior to monoTx and AEs during monoTx are summarized. Results: A subgroup of 136 (40%) and 58 (34%) pts on the V and PL arms, respectively, received monoTx. When a Cox model with a time-varying covariate was fit for PFS (per investigator), the nominal P-value for treatment by covariate interaction was 0.038. The HRs (95% CI) for V vs PL during combination therapy and monoTx were 0.81 (0.62–1.06) and 0.49 (0.33–0.73). The Table summarizes PFS by cycles of C and/or P prior to monoTx. Common AEs (>20% of pts) during V or PL monoTx were nausea (52%/10%), fatigue (23%/12%), headache (21%/17%), and diarrhea (21%/9%). Seizures (2.2%/0%) were reported during monoTx. Rates of cytopenias for V or PL monoTx were: anemia 12%/14%; neutropenia 13%/12%; and thrombocytopenia 10%/5%. Conclusions: These analyses suggest that pts treated with V + CP derive benefit from both combination therapy as well as V monoTx after CP discontinuation. Pts receiving V monoTx after ≤ 6 cycles of VCP experienced a similar benefit to those who transitioned to monoTx after 7–12 cycles of VCP, suggesting that V maintenance therapy may be suitable following a limited duration of combination therapy. Clinical trial information: NCT02163694.
Cycles of C and/or P before monoTx | V + CP | PL + CP | V + CP | PL + CP | HR (95% CI) |
---|---|---|---|---|---|
Events, n/N at risk (%) | Median PFS, mo (95% CI) | ||||
≤6 | 15 / 27 (56) | 12 / 13 (92) | 18.4 (12.5, -) | 12.8 (6.2, 14.7) | 0.38 (0.16, 0.88) |
7–12 | 39 / 62 (63) | 21 / 27 (78) | 18.9 (15.1, 22.3) | 13.3 (10.6, 19.7) | 0.54 (0.31, 0.95) |
Any | 70 / 136 (52) | 45 / 58 (78) | 25.7 (20.5, -) | 14.6 (12.8, 19.7) | 0.49 (0.34, 0.73) |
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Abstract Disclosures
2020 ASCO Virtual Scientific Program
First Author: Shannon L Puhalla
2023 ASCO Annual Meeting
First Author: Sarina A. Piha-Paul
2015 Breast Cancer Symposium
First Author: Shannon Leigh Huggins-Puhalla
2015 ASCO Annual Meeting
First Author: Shannon Puhalla