Rain Oncology Inc.’s only asset failed a pivotal phase III study for treating dedifferentiated liposarcoma, casting shadows on the future of the small molecule and the company’s direction. Milademetan, an oral inhibitor of the MDM2-p53 complex that reactivates p53, missed the Mantra study’s primary endpoint of progression-free survival compared to the standard of care treatment, Yondelis (trabectedin, Johnson & Johnson/Pharmamar SA).