Efficacy and safety of fruquintinib dose‐escalation strategy for elderly patients with refractory metastatic colorectal cancer: A single‐arm, multicenter, phase II study

Abstract Background Fruquintinib has demonstrated significant improvement in overall survival (OS) among previously treated metastatic colorectal cancer (mCRC) patients. However, the utilization of fruquintinib has been constrained by various toxicities, such as hand‐foot skin reaction (HFSR) and hypertension, particularly in elderly patients with reduced tolerance to the standard dosage. This study aims to investigate the efficacy and safety of fruquintinib dose‐escalation strategy for elderly refractory mCRC patients. Patients and Methods This open‐label, single‐arm, phase II trial included patients aged 65 years or over with mCRC who had progressed after two or more lines of chemotherapy. Fruquintinib was administered for 21 consecutive days of a 28‐day treatment cycle. The starting dose of fruquintinib was 3 mg/day and escalated to 4 mg/day in Week 2 and 5 mg/day in Week 3 if no significant drug‐related toxicity was observed. The highest tolerated dose from Cycle 1 would be administered in Cycle 2 and all subsequent cycles. Before commencing treatment, all enrolled patients underwent a G8 questionnaire and comprehensive geriatric assessments. The primary endpoint of the study was progression‐free survival (PFS). Results A total of 29 patients were enrolled and all started fruquintinib at 3 mg/day. Fifteen patients (51.7%) were subsequently escalated to 4 mg/day and 4 (13.8%) to 5 mg/day. Only four (13.8%) patients discontinued treatment due to adverse events (AEs). The median PFS was 3.8 months (95% CI, 2.7–4.9), and the median OS was 7.6 months (95% CI, 6.5–8.7). Treatment‐related adverse events (TRAEs) were observed in all 29 patients (100%). The most frequently occurring (>10%) TRAEs greater than Grade 3 were HFSR (20.7%), hypertension (20.7%), and diarrhea (10.3%). Conclusion Our study indicated that a dose of 4 mg/day was well tolerated by most elderly patients, suggesting that fruquintinib dose‐escalation strategy during the first cycle could serve as a viable alternative to the standard 5 mg/day dosing.