Press release: TG Therapeutics Announces Phase 1 Data Evaluating Azer-cel in Progressive Multiple Sclerosis in a Late-Breaking Oral Presentation at MSToronto2026

October 23, 2026

First reported clinical evaluation of an allogeneic CD19-directed CAR T-cell therapy in progressive MS demonstrated an encouraging preliminary safety profile with no high-grade CAR-T associated toxicities observed

89% of evaluable participants (16/19) had stable or improved disability scores at Day 90, despite documented progression prior to enrollment on high-efficacy therapies

NEW YORK–(BUSINESS WIRE)–Oct. 23, 2026– TG Therapeutics, Inc. today announced initial results from the Company’s Phase 1 study evaluating azercabtagene zapreleucel (azer-cel), an investigational, allogeneic CD19-directed chimeric antigen receptor (CAR) T-cell therapy, in patients with progressive multiple sclerosis (MS). The data represent the first reported clinical evaluation of an allogeneic CD19-directed CAR T-cell therapy in progressive MS and were presented in a late-breaking oral session at MSToronto2026, the 10th Joint Meeting of the Americas and European Committees for Treatment and Research in Multiple Sclerosis (ACTRIMS-ECTRIMS), being held October 21–23, 2026, in Toronto, Canada.

Michael S. Weiss, Chairman and Chief Executive Officer of TG Therapeutics, stated, “These initial azer-cel results are particularly encouraging given that all patients entered the study with progressive disability despite prior treatment with high-efficacy therapies, including anti-CD20 treatment. The safety findings to date, together with evidence of B-cell depletion in both the blood and cerebrospinal fluid, demonstrate biological activity at doses that appear tolerable, while stable or improved disability scores in most subjects provide a potential signal of clinical activity. Of particular interest, five of the 18 evaluable patients experienced improvements in disability scores, including three patients with improvements of two or more points on the EDSS scale, an encouraging early finding in a disease where even slowing progression can represent an important therapeutic advance.”

Mr. Weiss continued, “While these results remain preliminary, we believe an off-the-shelf CAR T-cell therapy has the potential to offer a meaningful new treatment option for patients with progressive MS, where substantial unmet need remains. We look forward to continuing dose escalation and evaluating longer-term outcomes, and we are grateful to the patients, their families, and the clinical teams who are making this research possible.”

TG PRESENTATION:

Late-Breaking Oral Presentation: First Clinical Evaluation of an Allogeneic CD19-Directed CAR T-Cell Therapy in Progressive Multiple Sclerosis: Initial Results from the Phase 1 TG-Azercel-101 Study

The presentation includes data from 26 participants with progressive MS treated across six azer-cel dose levels, ranging from 30 million to 500 million CAR T-cells, following bendamustine lymphodepletion. All participants had experienced progression independent of relapse activity (PIRA) within the prior 12 months despite high-efficacy disease-modifying therapy, and all had previously received anti-CD20 therapy. The median baseline EDSS score was 6.0, reflecting substantial disability, with patients typically requiring assistance to walk even relatively short distances. As of the September 3, 2026 data cutoff, median follow-up was 4.9 months, with a range of 0.1 to 15.0 months.

Presentation Highlights:

• Azer-cel demonstrated an encouraging initial safety profile in 26 participants, with no dose-limiting toxicities or high-grade CAR T associated toxicities observed across dose levels including no Grade ≥3 cytokine release syndrome (CRS), Grade ≥2 immune effector cell-associated neurotoxicity syndrome (ICANS), graft-versus-host disease, immune effector cell-associated hemophagocytic syndrome (IEC-HS) and no Grade ≥3 infections.
• Despite documented progression prior to enrollment, EDSS scores were stable or improved in 89% of evaluable participants at Day 90 (16/18) and 88% at Day 180 (7/8). Three participants achieved EDSS improvements of at least 2.0 points at Day 90, including one with a 4.0-point improvement.
• At Day 90, most evaluable participants demonstrated stable or improved walking performance (94%; 16/17), upper extremity function (94%; 17/18) and cognitive processing speed (78%; 14/18), with no gadolinium-enhancing T1 lesions or new or enlarging T2 lesions observed in any of the 22 participants evaluable by MRI.
• Peripheral blood B-cell counts were depleted to below 10 cells/µL in 96% of participants (25/26), and cerebrospinal fluid (CSF) samples from 21 participants showed a median reduction in CD19-positive B-cell events of 52.3% at Day 10. B-cell reconstitution was observed as early as Day 42 and favored transitional and naïve populations.

These initial findings are from an ongoing, open-label Phase 1 study and are limited by the small number of participants and short follow-up. Dose escalation and longer-term follow-up are ongoing.

The full data presentation is also available on the Publications page of the Company’s website at https://www.tgtherapeutics.com/publications/.

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