Phase II trial of DJ-927, an oral tubulin depolymerization inhibitor, in the treatment of metastatic colorectal cancer

3591 Background: DJ-927, a novel oral tubulin depolymerization inhibitor, causes apoptosis and DNA cell division arrest. It is not a substrate for the MDR and has excellent activity in preclinical colorectal cancer models. Methods: We are conducting a two-stage, multi-center, phase II trial to assess the efficacy of DJ-927 administered initially as second-line therapy following failure of irinotecan or oxaliplatin based therapy (n= 39). DJ-927 is given as a single oral dose on day 1 of a 21-day cycle at a dose range of 27 - 35 mg/m2. Results: Thirty-nine patients were enrolled, including 14 with prior irinotecan based therapy and 25 who had received prior oxaliplatin therapy. The median age was 56 years (range: 30–87) and the median ECOG PS at baseline was 1 (range: 0–2). A total of 155 courses (range: 1–24) have been administered with a median of 2 courses. Nine patients required dose reduction due to toxicity. Thirty-seven patients were evaluable for efficacy. There were 2 CRs and 2 PRs (10.3%) reported that were confirmed as per RECIST criteria. Fourteen patients (35.9%) had SD, including 6 patients (15.4%) with SD >12 weeks. The most common Grade 3 or 4 AEs were neutropenia (48.7%), fatigue (10.3%), neuropathy (7.8%), and nausea (5.0%).Six patients experienced febrile neutropenia, all requiring hospitalization but tolerated treatment with subsequent dose reduction. There were 13 episodes (33.3%) of peripheral neuropathy reported; however, only 3 (7.8%) were grade 3 or 4. Six patients withdrew due to adverse events. Conclusions: The results of this study indicate activity of DJ-927 as second line therapy in patients with metastatic colorectal cancer. Severe toxicity was generally limited to reversible neutropenia and peripheral neuropathy. This novel oral agent is well tolerated and warrants further evaluation in combination with other active agents. [Table: see text]