ViiV Healthcare, the global specialist HIV company majority owned by GSK, with Pfizer and Shionogi Limited as shareholders, has filed a New Drug Application in the US for fostemsavir, an investigational, first-in-class attachment inhibitor for the treatment of HIV-1 infection.

The drug is being developed for use in combination with other antiretroviral agents in heavily treatment-experienced adults with multidrug-resistant HIV-1 infection who are unable to form a suppressive regimen due to resistance, intolerance or safety considerations.

"Fostemsavir may provide an important treatment option for the group of people living with HIV who, for a variety of reasons, are not able to suppress their virus with other medicines and could be left with few or no treatments available to them," said ViiV's chief executive Deborah Waterhouse.

"In keeping with our mission of leaving no person with HIV behind, we have overcome many barriers to bring this important new medicine to people living with HIV, including investing in what is a very complex manufacturing process. We look forward to working with the FDA to make fostemsavir available to the people in the US who need it.”

The submission is backed by results from the pivotal phase III BRIGHTE study in heavily treatment-experienced people living with multidrug-resistant HIV. At Week 96, 60% of patients receiving fostemsavir plus optimised background treatment (OBT) in the randomised cohort achieved virologic suppression, an increase of 6% from Week 48 results.

Also, patients in the randomised cohort showed continued immunologic improvement through Week 96 as demonstrated by an increase in CD4+ T-cell counts.

“We’ve made incredible strides in our understanding and treatment of HIV over the past 30 years. However, the complexities of the virus mean that unsuccessful treatment and antiviral resistance are still major concerns for certain people living with HIV," said Kimberly Smith, head of R&D at ViiV.

"Through our perseverance in research and development, these individuals may soon have an entirely new way to target and treat HIV with fostemsavir, aiding them in their efforts to achieve viral suppression.”

Fostemsavir has been granted FDA Fast Track and Breakthrough Therapy Designations in the US.