Addition of Bevacizumab to Fluorouracil-Based First-Line Treatment of Metastatic Colorectal Cancer: Pooled Analysis of Cohorts of Older Patients From Two Randomized Clinical Trials

Colorectal cancer (CRC) occurs predominantly in older persons. To provide more statistical power to assess risk/benefit in older patients, we examined the clinical benefit of bevacizumab (BV) plus fluorouracil-based chemotherapy in first-line metastatic CRC (mCRC) treatment in patients aged ≥ 65 years, using data pooled from two placebo-controlled studies.

Pooled efficacy data for 439 patients ≥ 65 years old randomized to BV plus chemotherapy (n = 218) or placebo plus chemotherapy (n = 221) in study 1 and study 2 were retrospectively analyzed on an intent-to-treat basis for overall survival (OS), progression-free survival (PFS), and objective response. Safety analysis was based on reports of targeted adverse events in treated patients.

Median OS with BV plus chemotherapy was 19.3 v 14.3 months with placebo plus chemotherapy (hazard ratio [HR] = 0.70; 95% CI, 0.55 to 0.90; P = .006). Patients treated with BV plus chemotherapy had a median PFS of 9.2 v 6.2 months for placebo plus chemotherapy patients (HR = 0.52; 95% CI, 0.40 to 0.67; P < .0001). The objective response rate was 34.4% with BV plus chemotherapy versus 29.0% with placebo plus chemotherapy (difference not statistically significant). Rates of BV-associated adverse events in the pooled BV plus chemotherapy group were consistent with those reported in the overall populations for the two studies.

Analysis of pooled patient cohorts age ≥ 65 years from two similar trials in mCRC indicates that adding bevacizumab to fluorouracil-based chemotherapy improved OS and PFS, similar to the benefits in younger patients. Also, the risks of treatment do not seem to exceed those in younger patients with mCRC.