TaiMed Biologics Reports IDWeek 2026 Data Highlighting TMB-365 and Its Potential Across Long-Acting HIV Combinations

Phase 1 results demonstrate TMB-365 antiviral activity and tolerability, supporting continued development as a differentiated antibody for combination HIV treatment

Complementary laboratory susceptibility findings support the scientific rationale for the TMB-365/TMB-380 antibody-only maintenance regimen

TAIPEI, Taiwan, Oct. 21, 2026 (GLOBE NEWSWIRE) -- TaiMed Biologics (TPEX: 4147), a commercial-stage CD4-targeted biologics company advancing antibody-based therapies for long-acting HIV treatment, today announced results from two studies to be presented at IDWeek 2026, October 21-24 in Washington, D.C. The findings highlight TMB-365's own clinical activity and potential as a component of multiple long-acting HIV combinations, alongside laboratory evidence of complementary antiviral susceptibility supporting the company's TMB-365/TMB-380 maintenance regimen.

“These data reinforce our view of TMB-365 as a differentiated antibody with potential across multiple long-acting HIV combinations,” said Jimmy Chang, Ph.D., Chief Executive Officer of TaiMed Biologics. “Its host-directed mechanism, antiviral activity and pharmacokinetic profile provide a foundation for exploring combinations with other antibodies and small-molecule antiretrovirals. TMB-365/TMB-380 is our most advanced application of this approach, and the susceptibility findings strengthen the scientific rationale for pairing these two antibodies.”

TMB-365: Clinical activity and a distinct role in future HIV combinations

TMB-365 is an investigational, second-generation monoclonal antibody derived from ibalizumab. It binds domain 2 of the CD4 receptor on host cells and inhibits HIV entry after attachment, providing a mechanism distinct from antibodies that target the virus directly. TMB-365 was engineered to improve the breadth of antiviral coverage and pharmacokinetics relative to ibalizumab. TaiMed is developing TMB-365 as a distinct antibody asset for use in combination HIV regimens.

The randomized, placebo-controlled Phase 1 study (NCT04027387) evaluated single intravenous doses of 400, 800 and 1,600 mg in 25 people living with HIV over 10 weeks. The lower-dose cohorts included participants with detectable HIV who were off antiretroviral therapy; the 1,600-mg cohort remained on stable combination antiretroviral therapy with suppressed HIV. Key findings included:

• Antiviral activity: Mean maximum HIV-1 RNA reductions were 1.55 and 1.57 log10 copies/mL at 400 and 800 mg, respectively. Antiviral effects were observed for up to two and four weeks, respectively.
• Tolerability: No serious treatment-emergent adverse events, Grade 3 or higher events, or adverse-event-related discontinuations were observed. All 23 treatment-emergent events were mild or moderate; six events in three participants were considered related to TMB-365. No anti-drug antibodies were observed.
• Target engagement and dosing potential: In a limited subset, mean CD4 receptor occupancy remained at or above 80% for five to six weeks at 800 and 1,600 mg. The pharmacokinetic findings support further evaluation of higher doses and dosing intervals of eight to 12 weeks.
• Resistance observations: No resistance or cross-resistance to TMB-365 or approved entry inhibitors was observed during the study.

Together, these results support continued development of TMB-365 beyond a single antibody pairing. Its host-directed mechanism and engineered properties provide a rationale for exploring combinations with complementary antibodies and long-acting small-molecule antiretrovirals. The safety, efficacy and dosing of such future combinations will require clinical evaluation.

TMB-365/TMB-380: Complementary susceptibility supports combination development

The second presentation reports laboratory susceptibility findings for TMB-365 and TMB-380, a broadly neutralizing antibody that targets the CD4-binding site on the HIV envelope protein gp120. Researchers evaluated a panel of 40 HIV pseudotypes: 20 susceptible to TMB-380 and 20 with reduced susceptibility or resistance to TMB-380. They also studied a laboratory-selected virus resistant to LM52, a precursor of TMB-365.

• TMB-365 retained activity against variants less susceptible to TMB-380: Its geometric mean IC50 was similar in the TMB-380-susceptible and reduced-susceptibility groups: 0.054 and 0.057 micrograms/mL, respectively. Of the 20 variants with reduced susceptibility or resistance to TMB-380, 19 were susceptible to TMB-365; one showed incomplete neutralization, with a maximum inhibition of 70%.
• Complementary activity was also seen in the precursor experiment: The LM52-resistant virus became more susceptible to VRC-07 and VRC-01, antibodies related to TMB-380, supporting the hypothesis that the two mechanisms may cover different viral susceptibility gaps.

These in vitro findings support a complementary-activity hypothesis for TMB-365/TMB-380. Their clinical implications for durable viral suppression and resistance outcomes require further study.

“The Phase 1 findings demonstrate TMB-365's antiviral activity in people living with HIV, while the laboratory study helps explain why its host-directed mechanism could complement a virus-directed antibody,” said Martin Markowitz, M.D., Medical Director of TaiMed Biologics and presenting author of both studies. “TMB-365's activity against variants with reduced susceptibility to TMB-380 is encouraging. Further clinical studies will determine whether that complementarity translates into durable viral suppression and favorable resistance outcomes.”

TMB-365/TMB-380 is being evaluated as an antibody-only maintenance regimen for virologically suppressed people living with HIV. In the earlier 20-participant Phase 2a study, dosing every eight weeks over 24 weeks produced no protocol-defined virologic failures among participants who completed treatment. An ongoing Phase 2b study is evaluating the regimen against continued oral antiretroviral therapy, with interim results expected by year-end 2026.

IDWeek 2026 presentation details

Oral Presentation 
Title: Single-dose escalation study of TMB-365 in people living with HIV: safety, pharmacokinetics, and antiviral activity.
Date & Time: Friday, October 23, 2:45-2:57 p.m. ET
Session: Hot Off the Press: New Pathways in HIV Treatment
Location: Room 103 AB

Poster Presentation
Title: TMB-365 and TMB-380: A potentially resistance repellant stand-alone maintenance bNAb regimen in suppressed people living with HIV-1 on combination antiretroviral therapy.
Date & Time: Thursday, October 22, 12:15-1:30 p.m. ET
Session: Resistance Mechanisms
Location & Poster Code: Poster Hall B-C, Poster P-82

About TaiMed Biologics
Founded in 2007, TaiMed Biologics (TPEX: 4147) is a leading commercial-stage biotechnology company focused on developing innovative therapies for HIV treatment. The company developed ibalizumab (Trogarzo^®), the first monoclonal antibody approved by the U.S. FDA for the treatment of HIV-1, and is advancing TMB-365/380, its lead clinical-stage long-acting maintenance therapy candidate for people living with HIV. TaiMed Biologics also offers comprehensive contract development and manufacturing (CDMO) services. Its shares trade on the Taipei Exchange.

Forward-Looking Statements
This press release contains forward-looking statements, including statements about the presentation of data at IDWeek 2026 and the development and potential of TMB-365, TMB-380, and the TMB-365/TMB-380 regimen. These statements are based on current expectations and involve risks and uncertainties, including those related to clinical development, regulatory review, and commercialization, that could cause actual results to differ materially. Forward-looking statements speak only as of the date of this release, and TaiMed Biologics undertakes no obligation to update them except as required by law.

Contacts

Investor Relations
Kenny Lin
hlin@taimedbio.com

Media
Mike Tattory
LifeSci Communications
mtattory@lifescicomms.com