Single-arm phase II trial to evaluate efficacy and tolerance of regorafenib monotherapy in patients over 70 with previously treated metastatic colorectal adenocarcinoma FFCD 1404 - REGOLD.

Background: Regorafenib significantly increases overall survival (OS) in patients with metastatic colorectal cancer previously treated but gives toxicities.

Objectives: to assess the efficacy and safety of regorafenib at it's approved dose in the older population.

Patients And Methods: This multicenter single-arm phase II enrolled patients ≥70 years old after the failure of fluoropyrimidine-based chemotherapy, anti-VEGF, and anti-EGFR treatment. The primary endpoint was disease control rate (DCR) 2 months after initiation of regorafenib (160 mg/day, 3 weeks on/1 week off).

Results: Forty-three patients were enrolled, with a median age of 77 years. The 2 months DCR was 31.4% in the 35 evaluable patients. For the 42 patients that received at least one dose of regorafenib, median progression-free survival and OS were 2.2 and 7.5 months. The median time to autonomy degradation and quality of life degradation was 3.1 and 3.2 months, respectively. A grade 3-4 treatment-related adverse events was observed in 35/42 patients, notably: fatigue (45.2%), hand-foot skin reaction (19.0%), hypertension (21.4%), and diarrhea (7.1%). There is a trend to achieve DCR in patients ≤80 years and a trend to discontinue the study due to toxicity in patients with ECOG ≥1, over 80 years and with impaired baseline autonomy.

Conclusion: Treatment with regorafenib in pretreated patients ≥70 years is feasible and demonstrate similar efficacy that was observed in previous studies in young patients. Fatigue is the most frequent severe adverse event. However, caution should be taken for older patients with ECOG ≥1, over 80 years, and with impaired baseline autonomy.