molecules of the month

The EpiCentRx Myc and CD47 downregulating molecule with a range of proposed mechanisms, RRx-001, is a Ph. III clinical candidate with an eyebrow-raising chemical structure that originated from an even more eyebrow-raising starting point, trinitroazetidine. The N-nitro motif in the starting point was replaced with the (only slightly) less concerning bromoacetamide group to render the molecule less impact sensitive. Though the molecule is reminiscent of the reactive chemotherapeutics frequently screened in the 60’s-80’s, it is surprisingly well-tolerated in humans, with over 300 patients having been treated with no dose-limiting toxicities or maximum tolerated dose. The authors suggest that RRx-001 is a nongenotoxic alkylating agent, reacting with thiol sulfurs to deplete cellular cysteine, thioredoxin, and GSH, indirectly leading to nucleic acid oxidation, and…