Rain Oncology Shares Plummet: Company Discloses Disappointing Cancer Study Data After Delaying Readout

Rain Oncology Inc RAIN announced topline Phase 3 MANTRA data of milademetan in patients with dedifferentiated (DD) liposarcoma (LPS).

The study did not meet its primary endpoint of progression-free survival (PFS) by blinded independent central review compared to the standard of care, Johnson & Johnson's JNJ Yondelis (trabectedin).

Related: Anticipation Builds For Rain Oncology's Phase 3 MANTRA Trial Results, Analyst Sees Promise.

The median PFS for milademetan was 3.6 months vs. 2.2 months for trabectedin, with a hazard ratio of 0.89, p=0.53. 

The most common treatment-emergent adverse events (TEAEs) in the milademetan arm included nausea, thrombocytopenia, anemia, vomiting, and neutropenia.

The most common Grade 3/4 TEAEs were thrombocytopenia (39.5%), neutropenia (25.5%), and anemia (18.6%). 

Dose reductions in the milademetan arm were 44.2% vs. 29.1% in the trabectedin arm. 

Discontinuation in the milademetan arm due to AEs was 11.6% vs. 19.0% for trabectedin. 

Based upon these topline data, Rain does not expect to pursue further development of milademetan in DD LPS. 

Price Action: RAIN shares are down 86.9% at $1.30 on the last check Monday.