GSK plc Shares Early Clinical Data From ViiV Healthcare Showing VH184 Maintains Drug Levels Up To Six Months After A Single Injection

GSK plc announced new early-stage clinical data through ViiV Healthcare, its specialist HIV company in which Pfizer and Shionogi are shareholders. The update focuses on VH184, a third-generation integrase strand transfer inhibitor that is currently in development as a long-acting option for HIV treatment. Results from a phase 1 study show that a single injection of VH184 can maintain drug concentrations for as long as six months. In-vitro research from a separate study adds to this picture by showing that VH184 demonstrates improved potency and a stronger resistance profile when compared to bictegravir, especially in strains of HIV that carry mutations linked to reduced susceptibility to second-generation INSTIs.

Additional findings from other parts of ViiV Healthcare’s long-acting pipeline were also presented at the 33rd Conference on Retroviruses and Opportunistic Infections in Denver. Among these was VH499, an investigational long-acting capsid inhibitor. Early data suggest that VH499 is generally well tolerated and may be suitable for ultra long-acting dosing intervals, with the possibility of administration twice a year. These updates, combined with ongoing progress in other pipeline candidates such as lotivibart, reinforce ViiV Healthcare’s broader strategy to expand treatment choices for people living with HIV by reducing the frequency of dosing and moving toward more durable, low-maintenance therapies.

Dr. Kimberly Smith, who oversees Research and Development at ViiV Healthcare, noted that the company’s R&D priorities focus on making HIV treatment less demanding for individuals. She described the new VH184 data as encouraging, particularly because the therapy has shown signals of a high barrier to resistance and the potential for twice-yearly dosing. She also pointed to the early VH499 results, which suggest it could be viable as a six-month injectable option. According to her, these emerging findings underline the company’s long-term goal of developing ultra long-acting regimens that match the needs and preferences of people living with HIV.

VH184 continues to show promise for long-acting use. In the phase 1 clinical study involving adults without HIV, researchers tested two long-acting formulations delivered either subcutaneously or intramuscularly. Both showed prolonged drug coverage, and one of the formulations maintained steady levels through the seventh month after administration. This duration supports the idea that VH184 could be developed into a regimen requiring only two injections per year. The therapy was generally well tolerated, with the most common effects being mild injection site reactions such as redness, slight pain, or small nodules. A smaller number of participants experienced grade 2 or grade 3 reactions, but overall the safety profile remained in line with previous studies and similar to approved drugs in the integrase inhibitor class.

The in-vitro findings presented at the same scientific meeting further strengthened the case for VH184. When tested against viral strains known to carry mutations associated with resistance to current second-generation INSTIs, VH184 showed improved performance compared with bictegravir. It maintained activity across a wide range of resistant strains, including those involving multiple substitutions, an indication that it may offer a higher barrier to resistance in real-world settings. This characteristic is especially important as resistance remains a challenge for long-term HIV management.

The combined clinical and laboratory results highlight VH184 as a next-generation INSTI candidate with extended durability, improved antiviral coverage, and long-acting potential. The next stage of development will involve phase 2b studies that are expected to refine dose selection and confirm whether twice-yearly administration is effective and practical for people living with HIV. VH499, the capsid inhibitor also included in the new updates, is showing equally promising signs in its early evaluations. In an ongoing phase 1 study involving adults without HIV, participants received a single intramuscular or subcutaneous injection at doses ranging from 100 mg to 1200 mg. Both delivery routes supported long-lasting drug levels strong enough to indicate a potential dosing interval of around six months. 

VH499 was also generally well tolerated, with most participants reporting temporary injection site pain. The majority of these reactions were mild or moderate and resolved quickly. There were no serious adverse events, and no participants withdrew from the study because of side effects. These early results will help guide further development as researchers determine the most suitable dosing schedule for VH499. What has been presented so far builds on earlier proof-of-concept data shared at the 2025 CROI meeting, meaning the scientific foundation around VH499 and VH184 is steadily becoming stronger. Together, they represent two key components in the pipeline of potential future ultra long-acting therapies.

As ViiV Healthcare continues advancing research across these assets, the long-term vision centers on expanding treatment options that reduce the need for daily medication and support patient-friendly dosing schedules. The findings presented at CROI 2026 point toward the possibility of a new generation of therapies that combine durability, convenience, and strong antiviral performance, moving closer to treatment approaches designed to fit seamlessly into the lives of people living with HIV.