Phase II Study of the Histone Deacetylase Inhibitor Romidepsin in Relapsed Small Cell Lung Cancer (Cancer and Leukemia Group B 30304)

Introduction:Treatment of small cell lung cancer (SCLC) is initially gratifying with most patients responding to platinum-based chemotherapy. Treatment of relapsed disease gives much lower response rates of short duration. We undertook this study of the protein deacetylase inhibitor Romidepsin in chemosensitive recurrent SCLC based on preclinical data that suggested this to be an active target.Methods:Patients had recurrent chemosensitive SCLC (relapse ≥90 days since completion of platinum-based chemotherapy). Treatment was administered as weekly infusions of Romidepsin at 13 mg/m2 for 3 of 4 weeks. We designed a two-stage phase II study targeting a response rate of 30% (<10% response would be uninteresting and ≥30% worthy of further study).Results:Sixteen patients (10 male, 6 female) were accrued to the first stage of this study. Most (11 patients, 69%) presented with extensive-stage SCLC, and all had received prior chemotherapy, with 11 having received prior radiation. Eastern Cooperative Oncology Group performance status was excellent with 0 in 6 patients (38%) and 1 in 10 patients. No objective responses were seen, and stable disease was the best response seen in 3 patients (19%). Toxicity was modest with 3 patients suffering grade 3 toxicity (lymphopenia, insomnia, nausea, vomiting, and hyponatremia) and one patient with grade 4 thrombocytopenia. Median progression-free survival was 1.8 months, and median overall survival was 6 months.Conclusion:Romidepsin given on a weekly schedule in patients with chemosensitive, recurrent SCLC was inactive and will not be pursued further in this setting.