Late-breaking oral presentation will highlight initial clinical results evaluating azer-cel, an allogeneic "off-the-shelf" CD19-directed CAR T-cell therapy, in patients with progressive multiple sclerosis

Additional presentations include Phase 3 ENHANCE data supporting the investigational BRIUMVI single dose initiation schedule, full Phase I subcutaneous BRIUMVI results, seven-year clinical outcomes and growing real-world evidence

TG Therapeutics, Inc. (NASDAQ:TGTX), today announced the schedule of upcoming presentations at the 10th Joint ACTRIMS-ECTRIMS Meeting, also referred to as MSToronto2026, being held October 21-23, 2026, in Toronto, Canada. The presentations include a late-breaking oral presentation highlighting initial results from a Phase 1 study evaluating azer-cel in patients with primary progressive multiple sclerosis (PPMS), as well as several presentations highlighting BRIUMVI^® (ublituximab-xiiy) across clinical trials and real-world settings in multiple sclerosis (MS).

Michael S. Weiss, Chairman and Chief Executive Officer of TG Therapeutics, stated, "We are extremely pleased that the first clinical results from our azer-cel program in progressive multiple sclerosis have been selected for a late-breaking oral presentation at MSToronto2026. We are also excited by the breadth of BRIUMVI data being presented at the meeting, which further expands the growing body of evidence supporting BRIUMVI in MS. Collectively, these BRIUMVI presentations highlight the continued evolution of the BRIUMVI franchise. The seven-year clinical outcome data along with the real-world experience with IV BRIUMVI, solidify the efficacy, safety and tolerability profile of BRIUMVI. And the pivotal data supporting our single dose initiation schedule and the full data from our Phase 1 subcutaneous BRIUMVI program set the stage for the next evolution of the BRIUMVI franchise. Additional insights into B-cell biology and the experience of patients transitioning to BRIUMVI will also be presented. We believe this growing body of evidence further strengthens the BRIUMVI profile today while supporting our efforts to continue improving and expanding the BRIUMVI treatment experience for patients with MS."

Regular abstracts are now available through the MSToronto2026 Online Program, and late-breaking abstracts will be available on October 21, 2026. Details of the presentations are outlined below.

TG PRESENTATIONS

LATE-BREAKING ORAL PRESENTATION:

Presentation Title: 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

Presentation Date/Time: Friday, October 23, 2026 from 10:45 - 10:55 AM ET
Session: Late-Breaking Abstracts - Scientific Session
Abstract/Presentation Number: Toronto-LBA-229 / Oral O135
Lead Author: Daniel Ontaneda, MD, PhD, Professor of Neurology, Cleveland Clinic Mellen Center

(Full text of this abstract will be available 10/21/26)

POSTER PRESENTATIONS:

Presentation Title: Seven-Year Safety and Efficacy Outcomes for Ublituximab Treatment in Relapsing MS

Presentation Date/Time: Wednesday, October 21, 2026 from 4:30 - 6:30 PM ET
Session: Poster Session 1
Abstract/Poster Number: 1340/P0367
Lead Author: Bruce Cree, MD, PhD, MAS - Weill Institute for Neurosciences, University of California, San Francisco, CA

Presentation Title: Real-world Safety and Efficacy Outcomes in Relapsing Multiple Sclerosis Patients Initiating Ublituximab in the Phase 4 Observational Study ENABLE

Presentation Date/Time: Wednesday, October 21, 2026 from 4:30 - 6:30 PM ET
Session: Poster Session 1
Abstract/Poster Number: 793/P0403
Lead Author: Carrie Hersh, DO, MSc, FAAN - Cleveland Clinic Lou Ruvo Center for Brain Health

Presentation Title: Randomized, Double-Blind Evaluation of a Consolidated Ublituximab Initial Dosing Regimen Versus Conventional Ublituximab Regimen

Presentation Date/Time: Thursday, October 22, 2026 from 4:30 - 6:30 PM ET
Session: Poster Session 2
Abstract/Poster Number: 1903/P1419
Lead Author: Derrick Robertson, MD - University of South Florida (USF) Morsani College of Medicine in Tampa, Florida

Presentation Title: Fc Biology and Genetic Diversity in Multiple Sclerosis: A Multi-Center Study

Presentation Date/Time: Thursday, October 22, 2026 from 4:30 - 6:30 PM ET
Session: Poster Session 2
Abstract/Poster Number: 1353/P1194
Lead Author: Nancy Monson, PhD - University of Texas Southwestern Medical Center, Dallas, TX

Presentation Title: Pharmacokinetic/Pharmacodynamic Evaluation of Ublituximab in Patients With Autoimmune Diseases

Session: ePoster
Abstract/Poster Number: 1333/EP2592
Lead Author: Krzysztof Selmaj, MD, PhD - Center of Neurology, Lodz, Poland

Presentation Title: Ublituximab Mitigates Wearing-off Effect and Improves B-cell Depletion Among Participants Transitioning From Ocrelizumab: Updates From the ENHANCE Study

Session: ePoster
Abstract/Poster Number: 1891/EP2579
Lead Author: Barry A. Singer, MD - Director, The MS Center for Innovations in Care, Missouri Baptist Medical Center, St. Louis, MO

Presentation Title: Improvement in Wearing-Off Effect Correlates With Increased Tregs and Decreased Inflammatory Monocytes After Switch to Ublituximab in the ENHANCE Study

Session: ePoster
Abstract/Poster Number: 1979/EP2777
Lead Author: Gabriel Pardo, MD - Director, Multiple Sclerosis Center of Excellence at Oklahoma Medical Research Foundation

NEURAXPHARM-SPONSORED PRESENTATION

Presentation Title: Real-world Data of Ublituximab in Relapsing Forms of Multiple Sclerosis: 48-Week Interim Results From the Non-interventional BRILL Study

Session: ePoster
Abstract/Poster Number: 532/EP2641
Lead Author: Anke Salmen, MD - St. Josef-Hospital Ruhr-University Bochum, Germany

Following the presentations, the data presented will be available on the Publications page, located within the Pipeline section, of the Company’s website at www.tgtherapeutics.com/publications.cfm.

ABOUT BRIUMVI^® (ublituximab-xiiy) 150 mg/6 mL Injection for IV

BRIUMVI is a novel monoclonal antibody that targets a unique epitope on CD20-expressing B-cells. Targeting CD20 using monoclonal antibodies has proven to be an important therapeutic approach for the management of autoimmune disorders, such as RMS. BRIUMVI is uniquely designed to lack certain sugar molecules normally expressed on the antibody. Removal of these sugar molecules, a process called glycoengineering, allows for efficient B-cell depletion at low doses.

BRIUMVI is indicated in the U.S. for the treatment of adults with RMS, including clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease and in several countries outside of the U.S. for the treatment of adult patients with RMS with active disease defined by clinical or imaging features.

A list of authorized specialty distributors can be found at www.briumvi.com.

IMPORTANT SAFETY INFORMATION

Contraindications: BRIUMVI is contraindicated in patients with:

Active Hepatitis B Virus infection
A history of life-threatening infusion reaction to BRIUMVI

WARNINGS AND PRECAUTIONS

Infusion Reactions: BRIUMVI can cause infusion reactions, which can include pyrexia, chills, headache, influenza-like illness, tachycardia, nausea, throat irritation, erythema, and an anaphylactic reaction. In MS clinical trials, the incidence of infusion reactions in BRIUMVI-treated patients who received infusion reaction-limiting premedication prior to each infusion was 48%, with the highest incidence within 24 hours of the first infusion. 0.6% of BRIUMVI-treated patients experienced infusion reactions that were serious, some requiring hospitalization.

Observe treated patients for infusion reactions during the infusion and for at least one hour after the completion of the first two infusions unless infusion reaction and/or hypersensitivity has been observed in association with the current or any prior infusion. Inform patients that infusion reactions can occur up to 24 hours after the infusion. Administer the recommended pre-medication to reduce the frequency and severity of infusion reactions. If life-threatening, stop the infusion immediately, permanently discontinue BRIUMVI, and administer appropriate supportive treatment. Less severe infusion reactions may involve temporarily stopping the infusion, reducing the infusion rate, and/or administering symptomatic treatment.

Infections: Serious, life-threatening or fatal, bacterial and viral infections have been reported in BRIUMVI-treated patients. In MS clinical trials, the overall rate of infections in BRIUMVI-treated patients was 56% compared to 54% in teriflunomide-treated patients. The rate of serious infections was 5% compared to 3% respectively. There were 3 infection-related deaths in BRIUMVI-treated patients. The most common infections in BRIUMVI-treated patients included upper respiratory tract infection (45%) and urinary tract infection (10%). Delay BRIUMVI administration in patients with an active infection until the infection is resolved.

Consider the potential for increased immunosuppressive effects when initiating BRIUMVI after immunosuppressive therapy or initiating an immunosuppressive therapy after BRIUMVI.

Hepatitis B Virus (HBV) Reactivation: HBV reactivation occurred in an MS patient treated with BRIUMVI in clinical trials. Fulminant hepatitis, hepatic failure, and death caused by HBV reactivation have occurred in patients treated with anti-CD20 antibodies. Perform HBV screening in all patients before initiation of treatment with BRIUMVI. Do not start treatment with BRIUMVI in patients with active HBV confirmed by positive results for HB surface antigen (HBsAg) and anti-HB tests. For patients who are negative for HBsAg and positive for HB core antibody [HBcAb+] or are carriers of HBV [HBsAg+], consult a liver disease expert before starting and during treatment.

Progressive Multifocal Leukoencephalopathy (PML): PML is an opportunistic viral infection of the brain caused by the JC virus (JCV) that typically only occurs in patients who are immunocompromised, and that usually leads to death or severe disability. JCV infection resulting in PML has been observed in patients treated with anti-CD20 antibodies, including BRIUMVI, and other MS therapies.

If PML is suspected, withhold BRIUMVI and perform an appropriate diagnostic evaluation. Typical symptoms associated with PML are diverse, progress over days to weeks, and include progressive weakness on one side of the body or clumsiness of limbs, disturbance of vision, and changes in thinking, memory, and orientation leading to confusion and personality changes.

MRI findings may be apparent before clinical signs or symptoms; monitoring for signs consistent with PML may be useful. Further investigate suspicious findings to allow for an early diagnosis of PML, if present. Following discontinuation of another MS medication associated with PML, lower PML-related mortality and morbidity have been reported in patients who were initially asymptomatic at diagnosis compared to patients who had characteristic clinical signs and symptoms at diagnosis.

If PML is confirmed, treatment with BRIUMVI should be discontinued.

Vaccinations: Administer all immunizations according to immunization guidelines: for live or live-attenuated vaccines, at least 4 weeks and, whenever possible, at least 2 weeks prior to initiation of BRIUMVI for non-live vaccines. BRIUMVI may interfere with the effectiveness of non-live vaccines. The safety of immunization with live or live-attenuated vaccines during or following administration of BRIUMVI has not been studied. Vaccination with live virus vaccines is not recommended during treatment and until B-cell repletion.

Vaccination of Infants Born to Mothers Treated with BRIUMVI During Pregnancy: In infants of mothers exposed to BRIUMVI during pregnancy, assess B-cell counts prior to administration of live or live-attenuated vaccines as measured by CD19⁺ B-cells. Depletion of B-cells in these infants may increase the risks from live or live-attenuated vaccines. Inactivated or non-live vaccines may be administered prior to B-cell recovery. Assessment of vaccine immune responses, including consultation with a qualified specialist, should be considered to determine whether a protective immune response was mounted.

Fetal Risk: Based on data from animal studies, BRIUMVI may cause fetal harm when administered to a pregnant woman. Transient peripheral B-cell depletion and lymphocytopenia have been reported in infants born to mothers exposed to other anti-CD20 B-cell depleting antibodies during pregnancy. Advise females of reproductive potential to use effective contraception during BRIUMVI treatment and for 6 months after the last dose.

Reduction in Immunoglobulins: As expected with any B-cell depleting therapy, decreased immunoglobulin levels were observed. Decrease in immunoglobulin M (IgM) was reported in 0.6% of BRIUMVI-treated patients compared to none of the patients treated with teriflunomide in RMS clinical trials. Monitor the levels of quantitative serum immunoglobulins during treatment, especially in patients with opportunistic or recurrent infections, and after discontinuation of therapy, until B-cell repletion. Consider discontinuing BRIUMVI therapy if a patient with low immunoglobulins develops a serious opportunistic infection or recurrent infections, or if prolonged hypogammaglobulinemia requires treatment with intravenous immunoglobulins.

Liver Injury: Clinically significant liver injury, without findings of viral hepatitis, has been reported in the postmarketing setting in patients treated with anti-CD20 B-cell depleting therapies approved for the treatment of MS, including BRIUMVI. Signs of liver injury, including markedly elevated serum hepatic enzymes with elevated total bilirubin, have occurred from weeks to months after administration.

Patients treated with BRIUMVI found to have an alanine aminotransaminase (ALT) or aspartate aminotransferase (AST) greater than 3x the upper limit of normal (ULN) with serum total bilirubin greater than 2x ULN are potentially at risk for severe drug-induced liver injury.

Obtain liver function tests prior to initiating treatment with BRIUMVI, and monitor for signs and symptoms of any hepatic injury during treatment. Measure serum aminotransferases, alkaline phosphatase, and bilirubin levels promptly in patients who report symptoms that may indicate liver injury, including new or worsening fatigue, anorexia, nausea, vomiting, right upper abdominal discomfort, dark urine, or jaundice. If liver injury is present and an alternative etiology is not identified, discontinue BRIUMVI.

Most Common Adverse Reactions: The most common adverse reactions in RMS trials (incidence of at least 10%) were infusion reactions and upper respiratory tract infections.

Physicians, pharmacists, or other healthcare professionals with questions about BRIUMVI should visit www.briumvi.com.

The full Summary of Product Characteristics approved in the European Union (EU) for BRIUMVI can be found here: Briumvi | European Medicines Agency (europa.eu).

ABOUT BRIUMVI PATIENT SUPPORT in the U.S.

BRIUMVI Patient Support is a flexible program designed by TG Therapeutics to support U.S. patients through their treatment journey in a way that works best for them. More information about the BRIUMVI Patient Support program can be accessed at www.briumvipatientsupport.com.

ABOUT TG THERAPEUTICS

TG Therapeutics is a fully integrated, commercial stage, biotechnology company focused on the acquisition, development and commercialization of novel treatments for B-cell diseases. In addition to a research pipeline including several investigational medicines, TG Therapeutics has received approval from the U.S. Food and Drug Administration (FDA) for BRIUMVI^® (ublituximab-xiiy) for the treatment of adult patients with relapsing forms of multiple sclerosis, including clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease, as well as approval by several foreign nations for BRIUMVI to treat adult patients with RMS who have active disease defined by clinical or imaging features. For more information, visit www.tgtherapeutics.com, and follow us on X (formerly Twitter) @TGTherapeutics and on LinkedIn.

BRIUMVI^® is a registered trademark of TG Therapeutics, Inc.

Cautionary Statement

This press release contains forward-looking statements that involve a number of risks and uncertainties. For those statements, we claim the protection of the safe harbor for forward-looking statements contained in the Private Securities Litigation Reform Act of 1995.

Any forward-looking statements in this press release are based on management's current expectations and beliefs and are subject to a number of risks, uncertainties and important factors that may cause actual events or results to differ materially from those expressed or implied by any forward-looking statements contained in this press release. In addition to the risk factors identified from time to time in our reports filed with the U.S. Securities and Exchange Commission (SEC), factors that could cause our actual results to differ materially include the below.

Such forward looking statements include but are not limited to statements regarding our plans, business strategies and operations related to the commercialization of BRIUMVI^® (ublituximab-xiiy) for RMS in the United States, or any jurisdictions outside of the United States; anticipated healthcare professional (HCP) and patient acceptance and use of BRIUMVI for the approved indications; and expectations and timing for any of our pipeline products or programs, including Azer-cel or BRIUMVI in MG.

Additional factors that could cause our actual results to differ materially include the following: the Company’s ability to continue to commercialize BRIUMVI; the risk that trends in prescriptions are not maintained or that prescriptions are not filled; the failure to obtain and maintain payor coverage; the risk that HCP interest in BRIUMVI will not be sustained; the risk that momentum in sales for BRIUMVI will not be sustained during the course of the year; the failure to obtain and maintain requisite regulatory approvals, including the risk that the Company fails to satisfy post-approval regulatory requirements, the potential for variations from the Company’s projections and estimates about the potential market for BRIUMVI due to a number of factors, including, further limitations that regulators may impose on the required labeling for BRIUMVI (such as modifications, resulting from safety signals that arise in the post-marketing setting or in the long-term extension study from the ULTIMATE I and II clinical trials); the Company’s ability to meet post-approval compliance obligations (on topics including but not limited to product quality, product distribution and supply chain, pharmacovigilance, and sales and marketing); the Company’s reliance on third parties for manufacturing, distribution and supply, and other support functions for our clinical and commercial products, including BRIUMVI, and the ability of the Company and its manufacturers and suppliers to produce and deliver BRIUMVI to meet the market demand for BRIUMVI; the risk that any individual patient’s clinical experience in the post-marketing setting, or the aggregate patient experience in the post-marketing setting, may differ from that demonstrated in controlled clinical trials such as ULTIMATE I and II; the risk that the Company does not achieve its 2026 development pipeline anticipated milestones or goals in the timeframe projected or at all; the risk that clinical trial data readouts may be delayed due to a number of factors including enrollment, data collection, data maturity or other factors; the uncertainties generally inherent in research and development, including the risk that the data from Phase 1 studies, including safety and efficacy, may not be replicated in registration directed or Phase 3 studies conducted in larger populations with longer follow-up; regulatory developments, legislative actions, executive orders, including the imposition of tariffs and policy changes in the U.S. and other jurisdictions; and general political, economic and business conditions. Further discussion about these and other risks and uncertainties can be found in our Annual Report on Form 10-K for the fiscal year ended December 31, 2025 and in our other filings with the SEC.

Any forward-looking statements set forth in this press release speak only as of the date of this press release. We do not undertake to update any of these forward-looking statements to reflect events or circumstances that occur after the date hereof. This press release and prior releases are available at www.tgtherapeutics.com. The information found on our website is not incorporated by reference into this press release and is included for reference purposes only.

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