What happened
Shares of Rain Oncology (RAIN) were down 87% Monday afternoon after the precision oncology company released top-line results for its lead therapy, milademetan, to treat dedifferentiated liposarcoma, a type of cancer affecting fatty tissue, usually in the arms and legs.
So what
Rain said that milademetan, an inhibitor of the MDM2-p53 complex that reactivates p53, a known tumor inhibitor, taken orally, did not meet its primary endpoint of efficacy in a phase 3 trial to treat patients with dedifferentiated (DD) liposarcoma (LPS). Compared to trabectedin, the current standard of care for DD LPS, the median progression-free survival rate for milademetan was 3.6 months vs. 2.2 months for trabectedin, not a substantial difference. Based on the disappointing results, Rain said it does not plan to pursue further development of the therapy to treat DD LPS.
Now what
Milademetan is also is being looked at to treat various solid tumors, but the setback against DD LP will likely cause the company to regroup. With no other current therapy in its pipeline, the company will focus on its other trials regarding milademetan, including a phase 2 trial to treat MDM2-amplified advanced solid tumors and a phase 1/2 trial to treat advanced solid tumors showing a loss of the CDKN2A gene. The latter trial is expected to begin in the second quarter of 2023 and is a combination trial using milademetan with Roche (RHHBY 0.87%) therapy atezolizumab on patients who have previously failed or progressed on immunotherapy.
As of the first quarter, the biotech company said it had $109.8 million in cash, and it lost $20.5 million in the quarter. With no incoming revenue, the company's burn rate should allow it to fund operations into 2024.