Rain Oncology Scraps Milademetan

Rain Oncology says it will not pursue further development of milademetan in dedifferentiated liposarcoma after reporting disappointing topline data from its pivotal Phase 3 MANTRA trial. The trial did not meet its primary endpoint of progression free survival (PFS).

In the study, the median PFS for milademetan was 3.6 months vs 2.2 months for standard-of-care trabectedin. The most common adverse events in the milademetan arm included nausea, thrombocytopenia, anemia, vomiting and neutropenia, according to the company. Rain expects to present the MANTRA data at an upcoming medical conference.

Milademetan is described as an oral small molecule inhibitor of the MDM2-p53 complex that reactivates p53. It has shown antitumor activity in an MDM2-amplified subtype of LPS and other solid tumors in a Phase 1 clinical trial, Rain says. It is also evaluating milademetan in a Phase 2 tumor-agnostic basket trial in certain solid tumors with MDM2 amplification (MANTRA-2).