MALVERN, Pa.--(BUSINESS WIRE)--Researchers at the Dana-Farber Cancer Institute and Progenra, Inc. announce the publication of a research article entitled “A Small Molecule Inhibitor of Ubiquitin-Specific Protease-7 Induces Apoptosis in Multiple Myeloma Cells and Overcomes Bortezomib Resistance” (Chauhan et al, Cancer Cell). Data presented in this study include a comprehensive in vitro and in vivo analysis of the novel small molecule USP7 inhibitor P5091, discovered by Progenra. This selective inhibitor of USP7 induces anti-multiple myeloma activity alone and in combination with approved chemotherapeutic agents in cultured cells. Further, P5091 inhibits the growth of bortezomib resistant multiple myeloma tumor cells and suppresses tumor burden in distinct animal tumor models. In particular, when tested at their respective maximum tolerated doses, P5091 and VELCADE® repressed myeloma xenograft growth with equivalent efficacies. The lead author of the study Dr. Dharminder Chauhan stated, “Targeting the ubiquitin proteasome system upstream of the proteasome, as exemplified by these studies with Progenra’s USP7 inhibitor P5091, offers a novel opportunity for new treatments for multiple myeloma and other refractory cancers.”