Phase II Study of Roniciclib in Combination with Cisplatin/Etoposide or Carboplatin/Etoposide as First-Line Therapy in Patients with Extensive-Disease Small Cell Lung Cancer

This phase II study evaluated the efficacy and safety of the pan-cyclin–dependent kinase inhibitor roniciclib with platinum-based chemotherapy in patients with extensive-disease SCLC. In this randomized, double-blind study, unselected patients with previously untreated extensive-disease SCLC received roniciclib, 5 mg, or placebo twice daily according to a 3 days–on, 4 days–off schedule in 21-day cycles, with concomitant cisplatin or carboplatin on day 1 and etoposide on days 1 to 3. The primary end point was progression-free survival. Other end points included overall survival, objective response rate, and safety. A total of 140 patients received treatment: 70 with roniciclib plus chemotherapy and 70 with placebo plus chemotherapy. Median progression-free survival times was 4.9 months (95% confidence interval [CI]: 4.2–5.5) with roniciclib plus chemotherapy and 5.5 months (95% CI: 4.6–5.6) with placebo plus chemotherapy (hazard ratio [HR] = 1.242, 95% CI: 0.820–1.881, p = 0.8653). Median overall survival times was 9.7 months (95% CI: 7.9–11.1) with roniciclib plus chemotherapy and 10.3 months (95% CI: 8.7–11.9) with placebo plus chemotherapy (HR = 1.281, 95% CI: 0.776–1.912, p = 0.7858). The objective response rates were 60.6% with roniciclib plus chemotherapy and 74.6% with placebo plus chemotherapy. Common treatment-emergent adverse events in both groups included nausea, vomiting, and fatigue. Serious treatment-emergent adverse events were more common with roniciclib plus chemotherapy (57.1%) than with placebo plus chemotherapy (38.6%). Roniciclib combined with chemotherapy demonstrated an unfavorable risk-benefit profile in patients with extensive-disease SCLC, and the study was prematurely terminated.