Shares of TG Therapeutics are falling fast in Wednesday trading after the U.S. Food and Drug Administration announced it was pulling approval of the cancer drug Ukoniq (umbralisib).
Sarah Silbiger/Getty Images
Shares of TG Therapeutics are falling fast in Wednesday trading after the U.S. Food and Drug Administration announced it was pulling approval of the cancer drug Ukoniq (umbralisib).
On Wednesday morning, the regulatory agency said it pulled approval for Ukoniq based on ongoing safety concerns the government organization has been investigating. In February, the FDA launched its safety investigation following clinical data assessing Ukoniq to treat a related type of cancer that revealed a “possible increased risk of death in patients taking the medicine.”
Last year, Ukoniq, an inhibitor of phosphoinositide 3 kinase (PI3K) delta and casein kinase 1 (CK1) epsilon, was granted accelerated approval for the treatment of two different types of lymphoma. Ukoniq was approved for the treatment of adult patients with relapsed or refractory marginal zone lymphoma who have received at least one prior anti-CD20-based regimen and was also approved for adult patients with relapsed or refractory follicular lymphoma who have received at least three prior lines of systemic therapy.
PI3K inhibitors have become an especially troubling class of drugs for the FDA. Earlier this year, an FDA advisory committee overwhelmingly recommended halting single-arm clinical studies of PI3K inhibitors due to safety concerns. Instead, the FDA’s Oncologic Drug Advisory Committee recommended the use of randomized clinical trials in order to mitigate the safety concerns.
Ukoniq isn’t the only P13K inhibitor that has seen its share of safety concerns. Gilead Sciences has also withdrawn its P13K inhibitor Zydelig (idelalisib) from the market.
Data from the UNITY-CLL clinical trial, which has been assessing Ukoniq in patients with chronic lymphocytic leukemia sparked concerns with the FDA due to an increase of reported serious adverse events. In that study, Ukoniq was paired with a CD20-targeting monoclonal antibody. The FDA said the similarities between the three types of cancer Ukoniq was being used for under approval or in the clinic, it was inclined to re-evaluate the drug’s safety risks.
As BioSpace reported earlier this year, the FDA said the clinical “results showed a possible increased risk of death in patients receiving the combination of Ukoniq and the monoclonal antibody compared to the control.” Patients who received the drug combination also experienced more serious adverse events than those in the control arm, the FDA said.
“Updated findings from the UNITY-CLL clinical trial continued to show a possible increased risk of death in patients receiving Ukoniq. As a result, we determined the risks of treatment with Ukoniq outweigh its benefits,” the FDA said in a brief statement Wednesday.
Additionally, the regulatory agency noted that TG Therapeutics voluntarily withdrew Ukoniq from the market for the approved uses in the two types of lymphoma.
With the approval withdrawal, the FDA said health care officials should stop prescribing Ukoniq and switch patients to alternative treatments. Additionally, those patients who are already prescribed Ukoniq should be informed of the safety concerns and advised to stop taking the medication. However, the FDA noted that in limited circumstances where a lymphoma patient is seeing benefits from the drug, TG Therapeutics will be allowed to continue to supply that patient under the agency’s expanded access program.
The approval withdrawal for Ukoniq comes one day after the FDA delayed the potential approval of TG Therapeutics’ ublituximab, an experimental treatment for relapsing multiple sclerosis. The FDA set a new PDUFA target date of Dec. 28, 2022, and added the three-month extension following its request for more clinical trial data.
