Jimmy Chang, PhD, Discusses Long-Acting HIV Antibody Therapy at IDWeek 2026

Developing an HIV treatment that works for months between doses requires more than extending how long a drug stays in the body. Researchers must also determine whether the treatment can maintain viral suppression and remain effective against viruses with different susceptibility patterns. At IDWeek 2026 held in Washington, DC, from October 21 to 24, Jimmy Chang, PhD, CEO of Taiwan-based TaiMed Biologics, discussed how the company is investigating those questions through an experimental combination of 2 antibodies.

Speaking with Infection Control Today^®, Chang described research involving TMB-365, an antibody that targets the CD4 receptor on host cells, and TMB-380, a broadly neutralizing antibody that targets HIV. The company presented a phase 1 study of TMB-365 and a separate laboratory study examining the rationale for combining the antibodies. The program remains investigational, with a phase 2b maintenance-treatment study underway.

Targeting the Cell HIV Uses to Replicate

Chang explained that TMB-365 is designed to act early in the infection process by interfering with HIV entry into CD4 cells. These immune cells are important targets for the virus and central to the company’s development strategy.

“Basically, [the] antibody binds the receptor to prevent or inhibit the entry of HIV into the CD4 cell,” Chang said.

More specifically, TMB-365 binds domain 2 of the CD4 receptor and inhibits entry after HIV has attached. Its mechanism differs from that of TMB-380, which targets the CD4-binding site on the viral envelope protein gp120.

The distinction is important to the combination’s rationale. Rather than relying on 2 antibodies directed at the same target, the approach pairs a host-directed antibody with a virus-directed antibody. Chang emphasized that a longer dosing interval alone would not be enough. The combination also needs to provide effective antiviral activity.

“As people may recall in HIV therapy, we do need to have more than one drug to get very effective virus control,” he said. “The mechanisms have to be complementary.”

Examining the Potential for Longer Dosing Intervals

The phase 1 presentation evaluated single intravenous doses of 400, 800, and 1600 mg of TMB-365. Chang said the study examined safety and pharmacokinetics, including how the dose affected the duration of exposure.

According to TaiMed’s accompanying report, the randomized, placebo-controlled study included 25 people living with HIV followed over 10 weeks. All 23 treatment-emergent adverse events were mild or moderate; 6 events in 3 participants were considered related to TMB-365. No serious treatment-emergent adverse events, grade 3 or higher events, or adverse-event-related discontinuations were observed. Pharmacokinetic findings supported further evaluation of higher doses and dosing intervals of 8 to 12 weeks.

For Chang, the findings support continued investigation of a long-acting regimen. They do not establish that a single dose provides effective treatment for 3 months. That distinction separates a pharmacokinetic development goal from demonstrated clinical control of HIV.

Why Pair TMB-365 With TMB-380?

The second IDWeek presentation examined laboratory susceptibility. Chang described the goal as determining whether the antibodies could address gaps in each other’s antiviral coverage.

TaiMed reported testing 40 HIV pseudotypes, including 20 with reduced susceptibility or resistance to TMB-380. Of those 20, 19 were susceptible to TMB-365. One showed incomplete neutralization, reaching a maximum inhibition of 70%. A separate experiment involving a TMB-365 precursor also supported complementary activity, although it did not directly establish reciprocal protection against resistance to the final clinical combination.

These findings provide a reason to study the antibodies together. Whether the laboratory pattern translates into durable suppression in patients requires clinical evaluation.

Chang connected this work to the combination’s phase 2 program, where the question moves from susceptibility testing to maintaining HIV control over repeated doses.

Moving From 24 Weeks to 48 Weeks

Chang described a completed phase 2a study evaluating the combination over 24 weeks, with treatment administered approximately every 2 months. He reported encouraging safety and virologic findings.

The company’s published summary specifies that there were no virologic failures among participants who completed the study and no grade 3 or 4 adverse events or serious adverse events related to the study drugs. These results support further investigation but do not establish the regimen’s safety or efficacy for routine care. T

“The phase 2b study will further demonstrate whether a combination of these two antibodies is effective for a long period of time,” Chang said. “Phase 2a was a 24-week study…[the] phase 2b study is a 48-week study, so it’s almost like a year-long study.”

TaiMed reports that the ongoing phase 2b study includes 83 virologically suppressed adults with HIV-1 and compares the antibody regimen with continued daily oral combination antiretroviral therapy.

A Separate Research Direction Toward HIV Remission

Chang also discussed an earlier-stage concept: using the CD4-targeting antibody as a carrier to deliver latency-reversing agents into CD4 cells. The goal would be to reactivate latent HIV, potentially allowing infected cells to be recognized and eliminated.

“It is very difficult to get rid of the reservoir,” Chang said.

Latent reservoirs contain infected cells that are not actively producing new virus. They help explain why HIV can rebound when treatment stops. Researchers are investigating several approaches to these reservoirs, including reactivation strategies, but this remains a major scientific challenge.

Chang presented the targeted-delivery concept as a potential future application, not a demonstrated cure. A functional cure, or treatment-free remission, would mean sustained control without ongoing treatment rather than necessarily removing every trace of HIV.

For now, the clinical program’s immediate task is more specific: determine whether the 2-antibody regimen can safely maintain viral suppression over longer follow-up. The IDWeek presentations supplied early clinical and laboratory evidence to inform that work.