TG's BRIUMVI is working. Subcutaneous dosing is the next bet

The technology

TG Therapeutics sells one drug, BRIUMVI (ublituximab), an antibody against CD20 on B cells for relapsing multiple sclerosis. The company says the antibody is glycoengineered, stripped of certain sugar molecules so that it depletes B cells at low doses, and given by infusion. In real-world use, later infusions took a median of 63 minutes.

The long-term record is solid. Seven-year data shown at MSToronto2026 found that 88.3% of continuously treated patients were free of 24-week confirmed disability progression, with an annualized relapse rate of 0.018 in year seven. In the ENABLE real-world study of 1,076 patients, 99.2% stayed relapse-free on treatment.

TG is trying to extend the franchise in two ways: a single-infusion start, backed by the phase 3 ENHANCE trial, and a quarterly self-injected version under the skin, now in phase 3. Further out are azer-cel, an off-the-shelf CD19 CAR-T cell therapy being tested in progressive MS, and BRIUMVI trials in myasthenia gravis and schizophrenia.

The odds

The commercial drug carries no approval risk. The open questions are line extensions. ENHANCE already met its bioequivalence endpoint, and TG targets a supplemental filing in the second half of 2026. The subcutaneous phase 3 is a non-inferiority test of drug exposure, a lower bar than a new efficacy trial. TG said phase 1 modeling put the lower bound of the 90% confidence interval at 1.15 for the quarterly regimen, against a 0.80 threshold.

Base rates matter more for azer-cel. The BIO, Informa and QLS study found that only 7.9% of drugs entering phase 1 reach approval. TG guided to preliminary phase 1 azer-cel data in progressive MS in the second half of 2026, and has scheduled a late-breaking talk at MSToronto2026 for October 23.

The money

BRIUMVI U.S. net sales were $227.7 million in the second quarter, up about 64%, and TG raised its 2026 U.S. BRIUMVI target to $890 million to $905 million and its total revenue target to about $950 million. The company is profitable, though second-quarter net income fell to $7.8 million from $28.2 million as it spent $54.6 million on subcutaneous manufacturing and a second manufacturer.

Cash, cash equivalents and investment securities were $612.3 million at June 30. Debt rose this year: TG took a $750 million term loan from Blue Owl in March, maturing in 2031, and used part of it to repay a $250 million loan. It has also bought back stock, $200 million worth through April 30 at an average of $29.28 a share, per the first-quarter release.

The risks

Concentration is the main one. Nearly all revenue comes from one drug in one indication. The 10-Q warns of substantial competition and says TG relies on third parties that are its sole source of supply for drug substance and drug product. BRIUMVI is in-licensed, so disputes with licensors could hurt the business.

The label also carries real warnings. In MS trials, infusion reactions occurred in 48% of patients and serious infections in 5% versus 3% on teriflunomide, with three infection-related deaths on BRIUMVI, according to the safety information in TG's release.

Our read

TG is a profitable one-product company with a growing drug and a plan to protect it. The single-infusion start and the subcutaneous version both look like low-risk extensions, and the subcutaneous one could widen the market if it reaches patients who want home dosing. The debt load and the bet on new indications raise the stakes. The subcutaneous phase 3 readout, due at year-end 2026 or early 2027, is the event that will shape the next few years.