The FDA has decided to extend the Prescription Drug User Fee Act (PDUFA) review date for TG Therapeutics’s ublituximab until December 2022.
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The U.S. Food and Drug Administration has decided to extend the Biologics License Application (BLA) Prescription Drug User Fee Act (PDUFA) review date for TG Therapeutics’s ublituximab, a treatment for patients with relapsing multiple sclerosis (MS). The new target PDUFA date is Dec. 28, 2022, which is a three-month extension from the one previously set.
The extension comes after the FDA requested more information from TG related to clinical trials for ublituximab. When it was submitted, the FDA viewed the information as a significant amendment to the BLA.
According to guidance released by the FDA for 2018-2022, major amendments to the application can extend the review time by two to three months, depending on whether the amendment is related to manufacturing processes or a change related to clinical data. The guidance also states that the FDA should limit PDUFA extensions to situations in which the new information supplements the original application in a way that might enhance the chances of application approval.
TG Therapeutics CEO Michael Weiss commented on the extension.
“While we are disappointed with the extension of our PDUFA goal date for ublituximab, a delay of this duration is not unprecedented, with both of the currently marketed CD20s in MS experiencing a similar 3-month PDUFA extension prior to approval. As we were targeting a launch for late this year or early next, we do not believe this will impact our overall launch plans for ublituximab in RMS,” he said. “We will continue to work with the FDA to complete the review of the ublituximab BLA and plan to be prepared and ready to launch upon approval. We believe ublituximab has the potential to offer RMS patients a valuable treatment option that can be administered in a one-hour infusion every six months following the first dose.”
Ublituximab is a glycoengineered monoclonal antibody that is altered to target B-cells that express CD-20, which plays a role in B-cell differentiation. As Ublituximab uses CD-20 to locate and bind to B-cells, cell death is induced through a series of immune system reactions, such as antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity.
In summation, Ublituximab prevents the abnormal growth or dysregulation of B-cell-related diseases such as relapsing MS. This mechanism was enhanced through a glycoengineering process that removes the antibody’s normally present sugar molecules, increasing the ADCC activity.
The safety and efficacy of ublituximab was demonstrated in two Phase III studies, the Ultimate I and Ultimate II clinical trials, which were shared with the FDA within the BLA. The most recent data analysis from these trials was presented at the Americas Committee for Treatment and Research in Multiple Sclerosis medical forum earlier this year.
The Ultimate I and Ultimate II studies followed a similar double-blind, randomized design, but they were conducted separately. Participant responses to the treatment were held in comparison to a subset of participants that received teriflunomide treatment, an FDA-approved immunomodulatory treatment for MS.
The primary endpoints were met in both studies. Participants demonstrated a statistically significant reduction in annualized relapse rate (APR) over a 96-week period, in comparison to participants receiving teriflunomide. Between these studies, 1,094 participants were enrolled across ten countries.
