Tolerability of veliparib (V) in combination with carboplatin (C)/paclitaxel (P): Based chemoradiotherapy (CRT) in subjects with stage III non-small cell lung cancer (NSCLC).

8546 Background: CRT is a standard for patients with Stage III NSCLC. V is a potent, orally bioavailable PARP1/2 inhibitor that can delay DNA repair following chemotherapy or radiation induced damage. A Phase 2 study indicated favorable efficacy of V vs placebo when added to C/P in advanced NSCLC (Ramalingam et al. Clin Cancer Res. 2016). Based on these results, a Phase 1/2 trial was initiated to study the safety and efficacy of V/C/P-based CRT in the treatment of Stage III NSCLC. Methods: Subjects without prior NSCLC therapy suitable for definitive CRT received V plus C AUC 2 + P 45 mg/m weekly + 60 Gy over 6-9 weeks. V was escalated from 60 mg BID to a maximum planned dose based on prior studies of 240 mg BID via 3+3 design with allowed over-enrollment followed by consolidation therapy of V 120 mg BID + C AUC 6 + P 200 mg/m for up to two 21-day cycles. Results: Thirty-one subjects (median age 64; 10 male) have been enrolled to date into dosing cohorts at 60 mg (7), 80 mg (9), 120 mg (7) and 200 mg (8). PK of V was dose proportional. CRT or V required dose reduction for 0 or 1 subject, respectively. Four (13%) subjects discontinued study during CRT. No DLTs have been observed and an MTD has not yet been identified. The most common any grade AEs were fatigue (16), esophagitis (15), nausea (13), neutropenia (12), thrombocytopenia (12), constipation (10) and decreased appetite (10). 21 SAEs were observed including 8 with reasonable attribution to V but outside the DLT window including G3/4 febrile neutropenia (2), G3 dehydration (1), G3 vomiting (1), G3 radiation esophagitis (1), G3 esophageal stricture (1), G3 intractable N/V (1) and G5 sepsis during consolidation (1). Of 21 subjects evaluable for tumor assessment, best response was CR (1), PR (11), SD (6), and PD (3). Conclusions: V/C/P-based CRT followed by V/C/P consolidation therapy is a tractable regimen for the treatment of Stage III NSCLC. A randomized placebo-controlled Phase 2 extension of this study is planned. Clinical trial information: NCT02412371.

Duke Scholars

Author Joseph Kamel Salama Radiation Oncology