Multinational phase 2 study of lurbinectedin for relapsed Ewing sarcoma

Lurbinectedin is a selective inhibitor of oncogenic transcription, with activity in small-cell lung cancer. In mice bearing Ewing sarcoma xenografts, lurbinectedin delayed tumor growth. Based on this observation a phase 2 study evaluated lurbinectedin in patients with relapsed Ewing sarcoma. The ORR was 14.3% (95% CI 4.0-32.7) with median duration of response of 4.2 months (2,9-5.5), median PFS 2.7 months (1.4-4.3), and median OS 12.0 months (8.5-18.5). No deaths or discontinuations were due to toxicity. The authors conclude that lurbinectedin could represent a valuable addition to therapies for Ewing sarcoma.