Ridaforolimus as a single agent in advanced endometrial cancer: results of a single-arm, phase 2 trial

This open-label, multicentre, phase 2 trial evaluated the efficacy and tolerability of the mammalian target of rapamycin inhibitor ridaforolimus in women with advanced endometrial cancer.

Women with measurable recurrent or persistent endometrial cancer and documented disease progression were treated with ridaforolimus 12.5 mg intravenously once daily for 5 consecutive days every 2 weeks in a 4-week cycle. The primary end point was clinical benefit response, defined as an objective response or prolonged stable disease of 16 weeks or more.

In all, 45 patients were treated with single-agent ridaforolimus. Clinical benefit was achieved by 13 patients (29%), including 5 (11%) with confirmed partial responses and 8 (18%) with prolonged stable disease. All patients with clinical benefit response received ridaforolimus for more than 4 months. In this heavily pretreated population, the 6-month progression-free survival was 18%. Ridaforolimus was generally well tolerated: adverse events were predictable and manageable, consistent with prior studies in other malignancies. Overall, the most common adverse events were diarrhoea (58%) and mouth sores (56%); most common grade 3 or higher adverse events were anaemia (27%) and hyperglycaemia (11%).

Single-agent ridaforolimus has antitumor activity and acceptable tolerability in advanced endometrial cancer patients. Further clinical evaluation of ridaforolimus is warranted.