“THIS REPRESENTS the fruits of years of research. Umbralisib is a more potent and selective PI3K inhibitor targeted to the delta isoform. This provides a more precise target for drugs that block that protein, and it more effectively disables signaling. The B cell is central to the survival of malignant B cells and can be targeted by PI3K inhibitors and Bruton’s tyrosine kinase inhibitors. Unintended toxicities of this approach include diarrhea,” said Louis M. Weiner, MD, Director of the Georgetown Lombardi Comprehensive Cancer Center, Washington, DC, who moderated a press conference where these data were discussed.

“Umbralisib appears to have a better side-effect profile than first-generation PI3K inhibitors with excellent efficacy. If further study confirms these results, umbralisib could emerge as a new treatment option for marginal zone lymphoma and possibly other indolent lymphomas,” Dr. Weiner commented.

Louis M. Weiner, MD

Thomas Habermann, MD

Also commenting on this study, Thomas Habermann, MD, Professor of Medicine at the Mayo Clinic School of Medicine, Rochester, Minnesota, said, “New drugs are needed for marginal zone lymphoma. The side-effect profile of umbralisib compares favorably with other drugs in the same class, and there was no evidence of colitis.”

He added, “I think umbralisib could be a good choice for marginal zone lymphoma, and it deserves further study.” ■

DISCLOSURE: Dr. Weiner disclosed financial ties with Jounce Therapeutics, Celldex Therapeutics, Forty Seven Inc, Immunome, BioXcel Therapeutics, Klus Pharma, Mersana Therapeutics, Origin Commercial Ventures, Tessa Therapeutics, and the Samyang Group. Dr. Habermann reported no conflicts of interest.