River 37

River 37 is a biotechnology company focused on developing next-generation proteasome inhibitors for the treatment of cancer. Launched by Apple Tree Partners (ATP), the company specifically targets the 19S regulatory particle of the proteasome, a novel approach compared to existing 20S proteasome inhibitors. By selectively inhibiting the 19S subunit, River 37 aims to overcome resistance mechanisms and reduce the off-target toxicities associated with first-generation therapies like bortezomib. The company's small molecule programs are designed to induce proteotoxic stress and apoptosis in malignant cells. Currently in the pre-clinical stage, River 37 is positioning its candidates for use in both hematological malignancies and various solid tumors.