Abstract 3551
Background
The effectiveness of reintroduction of oxaliplatin for metastatic colorectal cancer (mCRC) refractory to both oxaliplatin and irinotecan was previously reported in a single arm, open-label phase II study (RE-OPEN, Suenaga, 2015). We conducted a phase I study to determine the maximum tolerated dose (MTD) and the safety of oxalipatin plus trifluridine/tipiracil (FTD/TPI, also known as TAS-102) in patients with refractory mCRC (UMIN000015764).
Methods
Three dosages of intravenous oxaliplatin (50, 65 and 85 mg/m2) on days 1 and 15 and a fixed dose of FTD/TPI 35 mg/m2 bid on days 1–5, 15–19 every 4 weeks were investigated in patients with refractory mCRC by using a 3 + 3 design. Eligible patients had received prior oxaliplatin-based treatment that achieved a response or stable disease followed by confirmed disease progression at least 6 months before entering the study.
Results
12 patients were enrolled in the study. Characteristics of patients were as follows: median age, 62 (range, 47–68) years; male/female, 6/6; ECOG PS 0, 75%; number of prior regimens ≥3, 33.3%; and median oxaliplatin-free interval, 24.3 (range, 6.2–71.4) months. 3 of 6 patients of the oxaliplatin 85mg/m2 cohort had dose-limiting toxicities (DLTs): treatment delay on 2nd cycle ≥8 days due to grade ≥2 neutropenia or grade 2 AST/ALT increased. No DLTs were observed in the other cohorts. The median number of treatment cycles was 3 (range, 1–9): 9 patients continued the treatment until disease progression; and 3 patients discontinued due to toxicity or patient’s refusal. In safety, grade ≥3 adverse events were neutropenia (n = 3), thrombocytopenia (n = 1), anorexia (n = 1) and nausea (n = 1). There was no evidence of allergic reaction to oxaliplatin and severe peripheral sensory neuropathy.
Conclusions
According to the results of this phase I study, a combination of trifluridine/tipiracil 35 mg/m2 bid on days 1–5, 15–19 and oxaliplatin 85 mg/m2 on days 1 and 15 every 4 weeks could be a candidate for recommended dose of the trifluridine/tipiracil+oxaliplatin regimen in patients with refractory mCRC.
Clinical trial identification
UMIN000015764 (release date, 1/12/2014).
Legal entity responsible for the study
Cancer Institute Hospital of the Japanese Foundation for Cancer Research.
Funding
Japanese Foundation for Cancer Research.
Editorial Acknowledgement
Not applicable
Disclosure
All authors have declared no conflicts of interest.