FDA cites increased death risk in decision to yank approval for TG Therapeutics cancer drug
Following previously revealed safety concerns, the FDA on Wednesday said it has withdrawn TG Therapeutics’ cancer drug Ukoniq to treat two specific types of lymphoma, marginal zone lymphoma and follicular lymphoma.
The decision comes as updated findings from an ongoing trial of the drug, known generically as umbralisib, show an increased risk of death in patients, and FDA said the risks of treatment with Ukoniq outweigh its benefits.
“Health care professionals should stop prescribing Ukoniq and switch patients to alternative treatments. Inform patients currently taking Ukoniq of the increased risk of death seen in the clinical trial and advise them to stop taking the medicine,” FDA said in a statement.
TG Therapeutics in April voluntarily withdrew umbralisib, as well as its BLA and sNDA for the blood cancer combo program U2, of which umbralisib is a component, citing survival data that favored the control arm over the drug.
The biotech also announced yesterday that the FDA also extended the PDUFA date to Dec. 28 for ublituximab, the other half of U2, as a potential drug for relapsing forms of multiple sclerosis.
But these safety questions for Ukoniq have been percolating since late last year, as survival data had been a point of contention since November 2021, when TG first announced the FDA’s plans to hold a 2-day adcomm that was supposed to discuss U2, but was later canceled. The FDA issued its first warning of potential increased risk of death with Ukoniq in February.

In April, TG alluded to a “recent information request” from the FDA that showed survival results differed from an analysis submitted in February. That submission contained non-specific “improvements” over an early analysis showing a 1.04 hazard ratio, suggesting more patients died taking the drug than those in the control arm.
Despite the improvements, “neither the original preliminary OS results nor the updated preliminary OS results were statistically significant,” TG Therapeutics added.
At the time, CEO Michael Weiss noted the survival analysis was not included in the original NDA, and that the Phase III was not powered to measure survival.