ViiV Healthcare submits regulatory application to the European Medicines Agency for fostemsavir, an investigational, first-in-class attachment inhibitor for the treatment of HIV in adults with few treatment options available

Deborah Waterhouse, CEO of ViiV Healthcare, said: “ViiV Healthcare is proud to be sending a regulatory submission to the EMA for a medicine that is intended for people living with HIV who have been unable to suppress their virus and have few treatment options remaining. Treatment regimens may fail due to the constantly changing nature of HIV and individuals can be left with limited options due to challenges with tolerability, safety and drug-to-drug interactions.  Although these individuals make up a small percentage of the total number of people who live with HIV, their unmet treatment needs are life-threatening and we are committed to addressing them through innovative new medicines like fostemsavir.”

This submission is supported by data from the pivotal phase III BRIGHTE study in heavily treatment-experienced people living with multidrug-resistant HIV. The 96-week study results were presented in July of 2019 at the 10^th International AIDS Society Conference on HIV Science (IAS 2019) in Mexico City.

About BRIGHTE
The efficacy of fostemsavir in heavily treatment-experienced adults with HIV-1 infection is based on 96-week data from the phase III, partially-randomised, international, double-blind, placebo-controlled BRIGHTE study (NCT02362503).

The BRIGHTE trial was conducted in 371 heavily treatment-experienced adults living with HIV-1 infection with multidrug resistance. All trial participants were required to have a viral load ≥400 copies/mL and ≤2 classes of antiretroviral medications remaining at baseline due to resistance, intolerability, contraindication, or other safety concerns. Trial participants were enrolled in either a randomised or nonrandomised cohort defined as follows:

• Within the randomised cohort (n = 272), participants had 1, but no more than 2, fully active and available antiretroviral agent(s) at screening which could be combined as part of an efficacious background regimen. Randomised participants received either blinded fostemsavir 600 mg twice daily (n = 203) or placebo (n = 69) in addition to their current failing regimen for 8 days of functional monotherapy. Beyond Day 8, randomised participants received open-label fostemsavir 600 mg twice daily plus an investigator-selected optimised background therapy.
• Within the nonrandomised cohort (n = 99), participants had no fully active and approved antiretroviral agent(s) available at screening. Nonrandomised participants were treated with open-label fostemsavir 600 mg twice daily plus OBT from Day 1 onward. The use of an investigational drug(s) as a component of the optimised background therapy was permitted in the nonrandomised cohort.

The primary endpoint analysis, based on the adjusted mean decline in HIV-1 RNA from Day 1 at Day 8 in the randomised cohort, demonstrated superiority of fostemsavir to placebo (0.79 vs. 0.17 log10 copies/mL decline, respectively; P<0.0001, Intent-to-Treat-Exposed [ITT-E] population). In the randomised cohort, HIV-1 RNA <40 copies/mL was achieved in 53%, 54%, and 60% of subjects at Weeks 24, 48, and 96, respectively (ITT-E, Snapshot algorithm). Mean changes in CD4+ cell count from baseline continued to increase over time (i.e., 90 cells/mm3 at Week 24, 139 cells/mm3 at Week 48, and 205 cells/mm3 at Week 96). The most common adverse reactions (incidence ≥5%, all grades) were nausea and diarrhoea. The proportion of participants who discontinued treatment with fostemsavir due to an adverse event was 7% at Week 96 (randomised: 5% and nonrandomised: 12%).

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