TG Therapeutics, Inc.’s Ukoniq (umbralisib) is the latest drug to stumble over the safety issues that have long plagued the phosphatidylinositol 3-kinase (PI3K) inhibitor class. The small group of leukemia and lymphoma therapies are getting a new level of regulatory attention as the US FDA builds out from its 2021 crackdown on “dangling” and “delinquent” accelerated approvals in oncology.
The FDA is “investigating a possible increased risk of death” with Ukoniq, according to a drug safety communication issued on 3 February 2022 – almost exactly one year after the PI3K delta and casein kinase 1 (CK1) epsilon inhibitor’s accelerated approval on 5 February 2021 for two indications: relapsed or refractory marginal zone lymphoma (MZL) patients who received at least one prior