NEW YORK – Rain Therapeutics on Wednesday said it will study its MDM2 inhibitor milademetan in combination with Roche's atezolizumab (Roche's Tecentriq) in solid tumors with CDKN2A loss and wild-type p53.
The companies are collaborating on a Phase I trial that they expect to begin in the second half of 2022. The trial will be sponsored by Rain, and Roche will supply atezolizumab for study participants. This initial study will assess the safety, tolerability, and efficacy of the combination treatment.
Based on research showing that CDKN2A encodes for a protein that inhibits MDM2, researchers believe that tumors that have CDKN2A loss may depend on MDM2 to proliferate. As such, the combination of milademetan and a checkpoint inhibitor "presents a strong mechanistic rationale," Rain CEO Avanish Vellanki said in a statement.
"We believe the therapeutic index afforded by milademetan will enable a synergistic combination with PD-L1 checkpoint inhibition and are excited about the potential for favorable results from the Phase I study to support moving into subsequent studies across various MDM2-dependent cancers," Vellanki continued.
In 2020, Rain licensed milademetan from Daiichi Sankyo. The company is studying the drug in liposarcoma, MDM2-amplified solid tumors, and Merkel cell carcinoma. In November, Rain began a Phase II basket trial of milademetan in MDM2-amplified advanced solid tumors.