Veliparib monotherapy following carboplatin/paclitaxel plus veliparib combination therapy in patients with germline BRCA-associated advanced breast cancer: results of exploratory analyses from the phase III BROCADE3 trial.

BACKGROUND: In the BROCADE3 trial, addition of the poly(ADP-ribose) polymerase inhibitor, veliparib, to carboplatin/paclitaxel improved progression-free survival (PFS) (hazard ratio 0.71, 95% confidence interval 0.57-0.88; P = 0.002) in patients with advanced human epidermal growth factor receptor 2-negative, germline BRCA1/2-mutated breast cancer. A subset of patients discontinued both carboplatin and paclitaxel before progression and continued on veliparib/placebo maintenance monotherapy until progression. Analyses in this patient subgroup are reported. PATIENTS AND METHODS: Patients were randomized 2 : 1 to veliparib plus carboplatin/paclitaxel or placebo plus carboplatin/paclitaxel. Veliparib (120 mg twice daily) or placebo was given on days -2 to 5, carboplatin (area under the curve 6 mg/ml) on day 1, and paclitaxel (80 mg/m2) on days 1, 8, and 15 of 21-day cycles. Patients who discontinued both carboplatin and paclitaxel before progression received blinded study drug monotherapy at an increased dose of 300-400 mg twice daily continuously. PFS was the primary endpoint. Exploratory analyses were carried out in the subgroup of patients who received blinded study drug as monotherapy. A time-varying Cox model including data from all patients was also used to evaluate treatment effect in the combination and monotherapy phases. RESULTS: A total of 136 of 337 patients randomized to veliparib plus carboplatin/paclitaxel and 58/172 patients randomized to placebo plus carboplatin/paclitaxel discontinued both carboplatin and paclitaxel before progression and continued on blinded veliparib or placebo monotherapy. In this blinded monotherapy subgroup, investigator-assessed median PFS from randomization was 25.7 months with veliparib versus 14.6 months with placebo. Hazard ratios from a time-varying Cox model favored veliparib during both combination therapy and monotherapy. Any-grade adverse events occurring in the monotherapy phase were primarily gastrointestinal. The most common grade ≥3 adverse events were neutropenia and anemia (4% each with veliparib; 5% and 2%, respectively, with placebo). CONCLUSIONS: Veliparib maintenance monotherapy had a tolerable safety profile and may extend PFS following combination chemotherapy.

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.

The genetics of birth timing: insights into a fundamental component of human development.

The timing of birth necessitates the coupling of fetal maturation with the onset of parturition, and occurs at characteristic, but divergent gestations between mammals. Preterm birth in humans is an important but poorly understood outcome of pregnancy that uncouples fetal maturation and birth timing. The etiology of preterm birth is complex, involving environmental and genetic factors whose underlying molecular and cellular pathogenic mechanisms remain poorly understood. Animal models, although limited by differences with human physiology, have been crucial in exploring the role of various genetic pathways in mammalian birth timing. Studies in humans of both familial aggregation and racial disparities in preterm birth have contributed to the understanding that preterm birth is heritable. A significant portion of this heritability is due to polygenic causes with few true Mendelian disorders contributing to preterm birth. Thus far, studies of the human genetics of preterm birth using a candidate gene approach have met with limited success. Emerging research efforts using unbiased methods may yield promising results if concerns about study design can be adequately addressed. The findings from this frontier of research may have direct implications for the allocation of public health and clinical resources as well as spur the development of more effective therapeutics.