unesbulin + dacarbazine

Unesbulin + dacarbazine is an investigational, fixed-drug combination under evaluation for the treatment of advanced leiomyosarcoma and potentially other solid tumors. - **Unesbulin (PTC596)** is a novel, orally bioavailable small molecule that binds the colchicine-binding site on tubulin, disrupting microtubule polymerization. This effect leads to G2/M phase cell cycle arrest and apoptosis (cell death) in cancer cells. Unesbulin is not a substrate for p-glycoprotein, potentially circumventing some mechanisms of drug resistance seen with other tubulin-binding agents. - **Dacarbazine (DTIC)** is a well-established intravenous alkylating chemotherapeutic agent. The combination has demonstrated more effective tumor suppression in preclinical models than either agent alone, supporting ongoing clinical trials in advanced, refractory, or relapsed leiomyosarcoma. The recommended phase II dose is unesbulin 300 mg orally twice weekly plus dacarbazine 1,000 mg/m² IV every 21 days. - Developed and sponsored by **PTC Therapeutics**, this combination is being studied in international, randomized phase II/III trials against dacarbazine plus placebo, with endpoints including progression-free survival and objective response rate[1][2][3][5][6][7].