Pazopanib maintenance after first-line etoposide and platinum chemotherapy in patients with extensive disease small-cell lung cancer: a multicentre, randomised, placebo-controlled Phase II study (KCSG-LU12-07)

BACKGROUND: We investigated whether pazopanib maintenance following first-line chemotherapy would improve survival in patients with extensive disease small-cell lung cancer (ED-SCLC). METHODS: This study is a randomised, placebo-controlled, phase II study that enroled ED-SCLC patients who had not progressed after four cycles of etoposide plus platinum therapy. Eligible patients were randomly assigned (1 : 1 ratio) to either placebo or pazopanib 800 mg per day until progression or unacceptable toxicity. The primary end point was progression-free survival (PFS). RESULTS: 97 patients were enroled and randomly assigned; 2 patients did not receive study drugs. In total, 95 patients received maintenance therapy (pazopanib, n=48; placebo, n=47) and were included in the analyses. Grade 3 toxicities for pazopanib maintenance were thrombocytopenia (10.4%, including one case with grade 4 toxicity), liver enzyme elevation (10.4%), fatigue (6.3%), and hypertension (6.3%). Median PFS was 3.7 months for pazopanib maintenance and 1.8 months for placebo (hazard ratio 0.44, 95% confidence interval: 0.29–0.69, P<0.0001). CONCLUSIONS: Pazopanib maintenance significantly prolonged PFS in patients with ED-SCLC. Given the toxicity profiles, however, relevant biomarkers to select patients for benefit from pazopanib should be further investigated.