Phase 1 study of veliparib with carboplatin and weekly paclitaxel in Japanese patients with newly diagnosed ovarian cancer.

This phase 1, open-label, dose-escalation study was conducted to determine the safety, tolerability, pharmacokinetics and preliminary efficacy of veliparib with carboplatin and weekly paclitaxel in Japanese women with newly diagnosed, advanced ovarian cancer. Patients received veliparib at 100 or 150 mg b.i.d. on days 1-21 with carboplatin (area under the concentration-time curve 6 mg/mL•min) on day 1 and paclitaxel 80 mg/m2 on days 1, 8 and 15 every 3 weeks for up to 6 21-day cycles. Dose escalation followed a 3 + 3 design to determine dose-limiting toxicities, maximum tolerated dose and the recommended phase 2 dose. Nine patients (median age 62 [range 27-72] years) received a median of 5 (range 3-6) cycles of treatment (3 at 100 mg, 6 at 150 mg). There were no dose-limiting toxicities. The most common adverse events of any grade were neutropenia (100%), alopecia (89%), peripheral sensory neuropathy (78%), and anemia, nausea and malaise (67% each). Grade 3 or 4 adverse events were associated with myelosuppression. Pharmacokinetics of carboplatin/paclitaxel were similar at both veliparib doses. Response, assessed in five patients, was partial in four and complete in one (objective response rate 100%). The response could not be assessed in four patients who had no measurable disease at baseline. The recommended phase 2 dose of veliparib, when combined with carboplatin/paclitaxel, is 150 mg b.i.d. Findings from this phase 1 trial demonstrate the tolerability and safety of veliparib with carboplatin/paclitaxel, a regimen with potential clinical benefit in Japanese women with ovarian cancer.

Phase 1 dose-escalation study of single-agent veliparib in Japanese patients with advanced solid tumors.

Veliparib (ABT-888) is a potent, orally bioavailable poly(ADP-ribose) polymerase-1 and -2 inhibitor. This phase 1 study evaluated the tolerability, pharmacokinetic profile, safety, and preliminary antitumor activity of single-agent veliparib in Japanese patients with advanced solid tumors. Eligible patients were assigned to treatment with veliparib at 200 or 400 mg dose; veliparib was self-administered orally twice daily on days 1-28 of 28-day cycles. Dose escalation, following a 3 + 3 design, defined dose-limiting toxicities, the maximum tolerated dose, and the recommended phase 2 dose. Sixteen patients were enrolled (median age, 59 years). Fourteen patients had high-grade serous ovarian cancer, one had primary peritoneal cancer, and one had BRCA-mutated breast cancer. The most frequent treatment-emergent adverse events were nausea and vomiting (93.8% each), decreased appetite (62.5%), abdominal pain, diarrhea, and malaise (31.3% each). A grade ≥3 toxicity was observed in 50% of patients; one patient each in the 200 mg (n = 4) and 400 mg (n = 12) cohorts experienced serious adverse events. Dose-limiting toxicities were observed for one patient at the 400 mg dose. No toxicities leading to death were reported. The recommended phase 2 dose was defined as 400 mg twice daily. The veliparib pharmacokinetic profile was consistent with that reported for the Western population. Two patients, both with ovarian cancer, had a RECIST partial response. Veliparib monotherapy showed manageable tolerability and safety profiles and a predictable pharmacokinetic profile at a 400 mg twice-daily dose, and supports the inclusion of Japanese patients in the multinational phase 3 study (NCT02470585).