Phase II study of bevacizumab plus irinotecan on the treatment of relapsed resistant small cell lung cancer

Purpose: This phase II study investigates the efficacy and safety of DNA topoisomerase I inhibitor irinotecan plus bevacizumab a monoclonal antibody against VEGF (BEVIRI) in patients with relapsed chemo-resistant SCLC. Methods: Patients who previously completed treatment with cisplatin-etoposide who relapsed within 3 months, had measurable extensive-stage SCLC, ECOG performance status 0-2 and adequate hematologic, renal and hepatic function, were given intravenous irinotecan 175 mg/m² plus intravenous bevacizumab 7.5 mg/kg on day 1 and 15 in 30 day cycles for a target of at least four cycles. No patients had received prophylactic intracranial irradiation. Treatment response was assessed with computer tomography scans with the completion of two consecutive cycles. Primary endpoint was overall response rate (ORR). Results: Thirty-two patients were enrolled and 28 of them were eligible for evaluation of response, toxicity and survival. The median age was 63.5 years (range 48-73). The ORR (CR and PR) was 25 % (95 % CI 8.9-41.0) and including patients with stable disease overall disease control rate at 2 months was 89 % (95 % CI 77.41-100). The median duration of response was 6 months, median progression-free survival was 3 months (mean PFS: 3.2, 95 % CI 2.7-3.7), and median overall survival was 6 months (mean OS: 6.3, 95 % CI 5.4-7.1). The PFS rate at 6 months was 3.6 %, and 1-year OS rate was 3.6 %. The median number of cycles received was 4.5 (range 1-6). There were two (7.1 %) hematologic (neutropenia) and one (3.5 %) non-hematologic (proteinuria) serious grades 3-4 adverse reactions without necessitating treatment discontinuation. Conclusion: BEVIRI combination in relapsed chemo-resistant SCLC patients demonstrates promising efficacy and low toxicity compared to historical controls. Further investigation is warranted.