A retrospective cohort study evaluating the safety and efficacy of TAS-102 in patients with metastatic colorectal cancer (HGCSG1503): Analysis of cases of prior regorafenib.

Abstract

832 Background: The J003 trial and RECOURSE trial revealed the safety and efficacy of TAS-102 for patients with metastatic colorectal cancer (mCRC). In March 2014, TAS-102 was approved in Japan. However, in these pivotal trials, there were few cases in which regorafenib was administered as prior treatments, and also there were few reports on the effectiveness and safety of TAS-102 after administration of regorafenib. Methods: We retrospectively analyzed the clinical data of 126 patients who received TAS-102 after administration of regorafenib in the multi-institutional retrospective study (HGCSG1503). This study was analyzed by CTCAE v4.0 for adverse events (AEs), RECIST v1.1 for response rate (RR)/disease control rate (DCR), and Kaplan-Meier method for progression free survival (PFS) and overall survival (OS). Results: Patients characteristics were as follows; male/female 75/51, median age 66.5 (range 38-84), ECOG PS (0/1/2/3) 48/64/12/2, KRAS Exon2 wild/mutant 64/60 (2 patients; KRAS Exon2 was not tested). The initial starting dose was 70 mg/m2 (n = 100, 79.4%) and reduced dose (n = 26, 20.6%). Dose reductions were required in 30 patients (30.9%). The common ≥grade 3 AEs were neutrophil count decreased (45.1%), white blood cell decreased (34.9%), and anemia (28.6%). RR and DCR were 0% and 36.5%, respectively. Median PFS and OS were 2.1 and 5.7 months. In the analysis on the relationship between ECOG PS 0-1 and PS 2-3, median PFS was 2.2 vs. 1.4 months (HR 2.187, p = 0.008), and MST was 6.5 vs. 2.7 months (HR 2.424, p = 0.002). Conclusions: In this analysis, TAS-102 after administration of regorafenib in the real-world clinical practice showed similar efficacy and safety to the pivotal clinical trials, except for patients with PS 2-3. Clinical trial information: 000020551.