Ariad Pharmaceuticals has reported that ridaforolimus, an investigational oral mTOR inhibitor, has met the primary endpoint of improved progression-free survival compared to placebo in a Phase III trial conducted in patients with metastatic soft-tissue or bone sarcomas.

Based on the analysis of 552 PFS events in 711 patients, the study achieved its primary endpoint with a statistically significant 28% reduction in the risk of progression in patients receiving ridaforolimus compared to placebo.

In addition, patients receiving ridaforolimus had a statistically significant 21% improvement in median progression-free survival.

The placebo-controlled, randomised (1:1) and double-blind study evaluated oral ridaforolimus, administered at 40mg/day, in patients with metastatic soft-tissue or bone sarcomas who demonstrated a favourable response to prior conventional chemotherapy.

Merck, under an exclusive license and collaboration agreement with Ariad, is developing ridaforolimus for multiple cancer indications.

Merck is planning to file for marketing approval of oral ridaforolimus in 2011, depending on the final analysis of all available data from the trail.