Regorafenib for previously treated metastatic colorectal cancer (mCRC): A subgroup analysis of 364 patients in the USA treated in the international, open-label phase IIIb CONSIGN study.
735 Background: In the phase III CORRECT study, regorafenib significantly improved overall survival and progression-free survival (PFS) vs placebo in patients with treatment-refractory mCRC. CONSIGN (NCT01538680) was a large phase IIIb study that included 2872 patients from 25 countries; it was designed to provide continued access to regorafenib for patients with mCRC who failed standard therapy and to further characterize the safety of regorafenib. In CONSIGN, adverse events (AEs) and PFS were consistent with those reported in phase III studies. We present a retrospective subgroup analysis of patients enrolled in CONSIGN in the USA. Methods: Patients with mCRC who progressed on standard therapies and had an ECOG PS 0─1 received regorafenib 160 mg QD for the first 3 weeks of each 4-week cycle. Treatment was continued until disease progression, death, or unacceptable toxicity. The primary endpoint was safety. PFS (per investigator) was the only efficacy variable assessed. Results: A total of 364 patients in the USA were assigned to treatment (all evaluable for safety). The median age was 60 years; 38% and 62% had ECOG PS 0 and 1, respectively. KRAS mutation was present in 59%, KRAS wt in 38%; 74% had ≥ 3 prior regimens for metastatic disease. Median duration of treatment was 2.3 months (range: 0–30). Median PFS (95% CI) was 2.3 (2.0–2.6) months (2.1 months KRAS wt; 2.3 months KRAS mutant). NCI-CTCAE v4.0 grade ≥ 3 AEs occurred in 81% of patients and were considered drug-related in 53% (Table). Grade ≥ 3 hepatobiliary disorders occurred in 2%. Grade ≥ 3 treatment-emergent laboratory toxicities included bilirubin (9%), AST (6%), and ALT (3%). Conclusions: In patients from the USA enrolled in CONSIGN, the safety profile of regorafenib was consistent with that of the overall population and the known safety profile of regorafenib in mCRC. Median PFS was in the range of that reported in phase III trials. Clinical trial information: NCT01538680. [Table: see text]