The Food and Drug Administration (FDA) has extended the review period for the Biologics License Application (BLA) for ublituximab for the treatment of patients with relapsing forms of multiple sclerosis (RMS). 

The new Prescription Drug User Fee Act (PDUFA) target date is December 28, 2022. The FDA extended the goal date to allow time to review additional clinical information that was deemed to be a major amendment to the application.

Ublituximab is an investigational glycoengineered monoclonal antibody that targets CD20, a cell surface antigen present on pre-B and mature B lymphocytes. Following cell surface binding to B lymphocytes, ublituximab results in antibody-dependent cellular cytotoxicity and complement-mediated cytotoxicity. Glycoengineering is expected to enhance the potency of ublituximab. 

The BLA submission includes data from 2 identical, randomized, double-blind, active-controlled phase 3 trials, ULTIMATE 1 ( Identifier: NCT03277261) and ULTIMATE 2 ( Identifier: NCT03277248). These studies compared the efficacy and safety of ublituximab to teriflunomide in patients with relapsing multiple sclerosis. Results from both studies showed that treatment with ublituximab demonstrated a statistically significant reduction in annualized relapse rate over a 96-week period compared with teriflunomide.

Commenting on the FDA action, Michael S. Weiss, Chairman and CEO of TG Therapeutics 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 1-hour infusion every 6 months following the first dose.”


TG Therapeutics announces FDA extension of BLA PDUFA date for ublituximab to treat patients with RMS. News release. TG Therapeutics, Inc. Accessed May 31, 2022.