TMB-365/TMB-380 is a promising long-acting combination of broadly neutralizing antibodies (bNAbs) with complementary mechanisms of action, offering a complete switch regimen for HIV treatment without the need for susceptibility screening.
A single infusion every 8 weeks is safe and can maintain HIV suppression with potential for wider application.
Taipei-March 12, 2025 – TaiMed Biologics (4147.TWO) today announced the presentation of 24-week Phase 2a clinical study data at the 2025 Conference on Retroviruses and Opportunistic Infections (CROI) in San Francisco. The study results highlight the superior safety and efficacy profile of TMB-365/TMB-380—a first-of-its-kind long-acting dual bNAb regimen—for HIV maintenance therapy in participants switched from daily oral cART.
TMB-365 is a second-generation version of Trogarzo® (ibalizumab), featuring enhanced potency, broader viral coverage, and extended half-life. TMB-380 is a novel broadly neutralizing antibody (bNAb) with similar long-acting properties. Designed to work together, this dual regimen targets different steps in HIV’s entry process, thereby enhancing viral suppression and reducing resistance risk. By eliminating the need for daily medication or frequent susceptibility screening, TMB-365/TMB-380 could open a new era in first-line HIV maintenance therapy.
Study Overview
  • Study Design: TMB-365/TMB-380 was administered in a Phase 2a clinical trial (NCT05275998) to participants virally suppressed on continuous combination antiretroviral therapy (cART) for at least six months.
  • Dose: Building on earlier Phase 1b data, participants switched from oral cART to a single 4,800 mg infusion of TMB-365 and 4,800 mg of TMB-380 every eight weeks for 24 weeks (three IV infusions total). At Week 24, participants restarted their oral cART regimen.
  • Enrollment: Of 29 individuals screened, 21 (age range: 24–67) were enrolled and received at least one infusion. One participant was excluded due to a non-drug-related event before the first dose. Two participants discontinued early due to Grade 2 (moderate) rash. Eighteen participants completed the full 24-week study regimen, with one missing Week 24 data.
Key Findings
  1. Durable Viral Suppression
  • No pre-defined virologic failures were reported. Virologic failure was defined as two consecutive viral load measurements above 50 copies/mL.
  • Among participants who completed the Week 24 visit (n=17), 94% (16 out of 17) maintained HIV-1 RNA levels below 50 copies/mL. Only one participant recorded a detectable viral load (59 copies/mL) slightly above the detectable level at Week 24, prior to restarting standard cART.
  1. Favorable Safety Profile
  • No serious adverse events (SAEs), Grade 3, or Grade 4 adverse events (AEs) were observed.
  • A total of 16 events were deemed probably or definitely related to TMB-365/TMB-380, including mild to moderate rash, fatigue, headache, flushing, fever, chills, and body aches.
  • There were no acute infusion reactions, and no participants experienced significant, treatment-limiting immune responses to the combination therapy.
  1. Pharmacokinetics (PK) and Immunological Markers
  • By Week 24, mean serum concentrations were 29 μg/mL for TMB-365 and 107 μg/mL for TMB-380, supporting the potential for long-acting suppression.
  • CD4 cell counts remained steady throughout the 24-week period, indicating stable immune function in participants.
  1. No Susceptibility Screening Required
  • Given TMB-365/TMB-380’s broad breadth of activity and high potency, participants were not pre-screened for susceptibility to either bNAb.
  • This feature lowers barriers to treatment access and could make TMB-365/TMB-380 a practical switch regimen for a wider range of individuals living with HIV.
This clinical trial was not a double-blind placebo-controlled study; therefore, no statistical p-values were reported for the results.
“We are honored that our study was accepted for late-breaking presentation at CROI, highlighting the high scientific merit and groundbreaking nature of our results among numerous research studies .” said Dr. Jimmy Chang, CEO of TaiMed Biologics. “TMB-365/TMB-380 is the first long-acting mAb combination to achieve a high rate of viral suppression without screening requirements, thanks to its robust potency, broad coverage, and low resistance risk. It simplifies treatment by reducing the burden of daily dosing, while maintaining strong efficacy and safety.”
“The efficacy and safety data from this trial surpass the results of other known long-acting combination therapies. These strong Phase IIa results show that TMB-365/TMB-380 offers distinct advantages over other long-acting treatment options. We’re confident that TMB-365/TMB-380 will reshape HIV treatment management. We will actively look forward to forging strategic collaborations with global pharmaceutical partners to realize its commercial potential. We see the global market for long-acting HIV maintenance therapies exceeding USD 10 billion, and TMB-365/TMB-380 is well-positioned to play a pivotal role,” Dr. Chang added.

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