Phase I combination study of trabectedin (T) and capecitabine (C) in patients with advanced malignancies

Abstract

2079 Background: T binds to the minor groove of DNA, synergizes with functional nuclease excision repair and targets inducible transcription. T is active in several tumor types and exhibits preclinical synergy with C. The primary objective of this study is to determine the maximum tolerated dose (MTD) of T in combination with C. Secondary objectives include safety and pharmacokinetic (PK) analyses. Methods: Pts with advanced cancer, performance status 0–1 and adequate organ function are eligible. Pts received T starting at 0.4 mg/m2 over 3 hours on day 1 followed by C on days 2 through 15. The initial dose of C was 2000 mg/m2/day and was reduced to 1600 mg/m2/day due to GI dose-limiting toxicity. Dose escalation of T continued. Cycles are repeated every 3 weeks, with PK sampling included. Standard “3+3” dose escalation design, definitions of dose limiting toxicity (DLT), and dose modification for toxicity are implemented. Results: To date, 30 patients have received 112 cycles (range 1–12, median 4) of treatment at 7 dose levels. Two of 3 pts at dose level 4 (C 2000 mg/m2/d and T 0.9 mg/m2) and 2/6 pts at dose level 3 (C 2000 mg/m2/d and T 0.75 mg/ m2) developed gastrointestinal DLT (emesis, diarrhea, pancreatitis). C was subsequently reduced to 1600 mg/m2/d and a new T dose escalation was initiated at 0.6 mg/m2. Treatment has been well tolerated with C 1600 mg/m2/d and T up to the current dose of 0.9 mg/m2 (dose level 4a), with 1of 6 subjects experiencing grade 1 alkaline phosphatase. The most frequently reported related grade 3–4 adverse events (AEs) are diarrhea (23%), neutropenia (20%), nausea (16.6%), hand-foot syndrome (16.6%) and vomiting (13%). Anti-tumor activity to date includes a confirmed partial response lasting 8 months (m) in a patient with cholangiocarcinoma, and prolonged stable disease in 2 patients with breast cancer (6 and 7m), ovarian cancer (11m) and chondrosarcoma (9m). Conclusions: The combination of C 1600mg/m2/d and T up to 0.9mg/m2 is tolerable and has promising activity in several tumor types. Dose escalation of T continues at 1.1 mg/m2. Biologic and pharmacokinetic analyses will be presented. [Table: see text]