TG Therapeutics Shares Surge Following Positive Phase 1 Data for Briumvi

TG Therapeutics reported positive Phase 1 data for Briumvi in myasthenia gravis. The company also initiated a Phase 2 trial for Briumvi in this condition. Share prices have increased following the news.

TGTX shares surged after the company reported positive topline Phase 1 data for a subcutaneous formulation of BRIUMVI in patients with myasthenia gravis, and announced it is moving the program into a registration-directed Phase 2 trial. In the 11-patient study, 82% of participants achieved the Minimal Clinically Important Difference on the MG-ADL scale, with a mean 4.6-point improvement and a median time to improvement of just 30 days.

The data showed subcutaneous BRIUMVI exposure was at least equivalent to the approved intravenous regimen, with a safety profile generally consistent with IV BRIUMVI's established multiple sclerosis experience. That combination, comparable efficacy with the convenience of self-administration, is the crux of the bull case for expanding the franchise beyond MS.

TG Therapeutics is initiating a Phase 2 trial expected to enroll about 120 patients, evaluating BRIUMVI's ability to maintain clinical response in patients who initially respond to the FcRn inhibitor efgartigimod. Success would open a new indication for a drug already generating revenue in MS, though early-stage clinical results carry meaningful risk of not replicating at larger scale.