First-Line Biological Agents Plus Chemotherapy in Older Patients with Metastatic Colorectal Cancer: A Retrospective Pooled Analysis

4017 Background: Biological agents, in combination with chemotherapy, are recommended as first-line treatment of metastatic colorectal cancer (mCRC); however, evidence guiding appropriate management of elderly patients with mCRC is lacking. This study compared the efficacy and safety outcomes in older versus younger patients with mCRC who received first-line biological therapy. Methods: This retrospective analysis used pooled data from five Spanish TTD collaborative group studies of adults with advanced CRC who received first-line treatment with bevacizumab, cetuximab or panitumumab, stratified by age (≥65 vs < 65 years). Endpoints included progression-free survival (PFS), overall survival (OS), overall response rate (ORR) and safety. Results: In total, 999 patients from five studies were included in the analysis; 480 (48%) were aged ≥65 years and 519 (52%) were aged < 65 years; 733 (73.37%) were treated with bevacizumab, 189 (18.92%) received cetuximab and 77 (7.71%) received panitumumab. Median PFS did not significantly differ between patients aged ≥65 versus < 65 years (9.9 vs 9.4 months; hazard ratio [HR] 1.01; 95% confidence interval [CI] 0.88–1.17). Median OS was significantly shorter in older versus younger patients (21.3 vs 25.0 months; HR 1.21; 95% CI 1.04–1.41; P = 0.0132). There was no significant difference between older versus younger patients in ORR (59% vs 62%). Older patients experienced more treatment-related grade ≥3 adverse events. Conclusions: Biological agents are an effective first-line treatment option for elderly patients with mCRC, with comparable efficacy in PFS and ORR to that observed in younger patients and a manageable safety profile.