GSK's ViiV Healthcare Advances Long-Acting HIV Treatment Development

GSK's ViiV Healthcare has made significant strides in its quest to develop a six-month long-acting HIV treatment regimen, presenting clinical data on three potential candidates at the 2025 Conference on Retroviruses and Opportunistic Infections (CROI) in San Francisco. The company's efforts aim to address the growing demand for less burdensome treatment options for patients living with HIV.

N6LS Shows Promise as Six-Month Intravenous Treatment

ViiV Healthcare's phase 2b study of N6LS, an investigational broadly neutralizing antibody, demonstrated encouraging results. The trial, involving 134 adults living with HIV, compared intravenous and subcutaneous administration of N6LS every six months, combined with monthly long-acting cabotegravir, against standard-of-care antiretroviral therapy.

After six months, 96% of patients receiving intravenous N6LS maintained HIV-1 RNA levels below 50 copies/mL, matching the efficacy of the standard-of-care group. However, the subcutaneous administration group showed slightly lower efficacy at 88%. Tolerability issues were more prevalent in the subcutaneous group, with 16% of patients experiencing grade 3 or 4 skin redness.

Based on these findings, ViiV Healthcare has decided to advance the six-month intravenous formulation of N6LS to the next phase of trials.

VH184 and VH499: Potential Cornerstones of Future Regimens

ViiV Healthcare also presented data on two additional molecules that could form part of its six-month treatment regimen:

1. VH184, a third-generation integrase strand transfer inhibitor (INSTI), showed promising results in a study of 22 adults who had not previously received antiretroviral therapy. The candidate demonstrated its ability to reduce viral load without causing drug resistance mutations or serious side effects.

2. VH499, an investigational capsid inhibitor, was evaluated in a phase 2 trial involving 23 adults. The study reported decreases in viral loads, although one person on the low dose developed a mutation associated with reduced susceptibility to capsid inhibitors.

Both VH184 and VH499 are being considered as potential partners for N6LS in ViiV's planned six-month treatment regimen. The company is currently conducting phase 1 trials to assess long-acting formulations of these candidates.

Next Steps and Future Outlook

David Redfern, ViiV Chairman, indicated that the company aims to analyze the data from these studies this year and make a regimen selection for treatment in 2026. Pivotal studies could potentially begin in 2027, marking a significant step forward in the development of long-acting HIV treatments.

As the race for market share in HIV treatment intensifies, with competitors like Gilead also vying for position, ViiV Healthcare's progress in developing a six-month regimen could represent a major advancement in patient care and treatment adherence.