Phase II study of oral etoposide maintenance for patients with extensive stage small cell lung cancer who have responded to the induction on an EP regimen.

Abstract

Maintenance therapy for extensive stage small cell lung cancer (ES-SCLC) is still under debate. Many new agents fail during the maintenance course. As an active agent for SCLC, oral etoposide is worth being re-evaluated. This phase II study was performed to evaluate the toxicity/efficacy of the maintenance of patients with oral etoposide with ES-SCLC responding (complete remission [CR] + partial remission [PR]) to the induction of four cycles of etoposide plus cisplatin (EP) chemotherapy. Maintenance therapy with oral etoposide (50 mg/m2 , day 1-14, repeated every 21 days until disease progression or unacceptable toxicity occurs) was administered. The primary endpoints were grade 3 and 4 toxicities and progression free survival (PFS). Fifty-four patients with ES-SCLC received standard EP regimens as induction therapy; 31 responding patients were administered oral etoposide as the maintenance treatment. The most common hematological and non-hematological toxicity of the maintenance course was neutropenia and fatigue, respectively. Median PFS was nine months (95% confidence interval (CI): 8.33∼9.67 months), median overall survival (OS) was 14 months (95% CI: 11.58∼16.42 months). Significantly better PFS and OS were seen in patients responding to the induction EP chemotherapy. Oral etoposide maintenance is safe and effective for patients with ES-SCLC who responded to the induction of EP chemotherapy. Significant survival benefit was revealed in patients completely responding to an EP regimen. Further randomized control study is warranted.