UB Therapeutics is a biotechnology company developing a novel therapy for the treatment of multiple myeloma. The company’s compound is a cyclic peptide with potential anticancer therapeutic activity. The cyclic peptides block the action of deubiquitinases and the proteasome, induce apoptosis in vitro, and attenuate tumor growth in vivo. These cyclic peptides show in vitro and in vivo activity comparable to a small molecule proteasome inhibitor and similarly induce apoptosis in cancer cells. Whereas the immediate target of small molecules proteasome inhibitors such as bortezomib is the chymotrypsin-like β5 catalytic subunit of the proteasome, the cyclic peptides impair the recognition and subsequent proteasomal degradation of ubiquitinylated proteins.