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

Issued: London, UK

ViiV Healthcare, the global specialist HIV company majority owned by GSK, with Pfizer Inc. and Shionogi Limited as shareholders, today announced the submission of a marketing authorisation application (MAA) to the European Medicines Agency (EMA) seeking approval of fostemsavir, an investigational, first-in-class attachment inhibitor for the treatment of HIV-1 infection.  This application seeks approval of fostemsavir, used in combination with other antiretrovirals, for the treatment of adults with multidrug resistant HIV-1 infection for whom it is otherwise not possible to construct a suppressive antiviral regimen due to resistance, intolerance or safety considerations.

The EMA’s Committee for Medicinal Products for Human Use (CHMP) has granted an accelerated assessment for the fostemsavir MAA. Accelerated assessment reduces the timeframe for review of a MAA and is awarded if the CHMP determines the product is of major interest for public health and therapeutic innovation.

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.

Kimberly Smith, M.D., Head of Research & Development at ViiV Healthcare, said: “The efficacy and safety findings from fostemsavir’s clinical development program demonstrate its unique potential for people living with multidrug-resistant HIV who are in need of new treatment options. Developing this medicine exemplifies ViiV’s mission and commitment to ensuring that no person living with HIV is left behind. We look forward to working with the EMA to make fostemsavir available to the people in Europe who need it.”

This application to the EMA follows the recent submission of a New Drug Application (NDA) for fostemsavir to the US Food and Drug Administration (FDA) in December 2019.  In the US, fostemsavir has been granted FDA Fast Track and Breakthrough Therapy Designations.  ViiV Healthcare plans to submit regulatory applications for fostemsavir to other global agencies in the coming months.

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%).

About fostemsavir

Fostemsavir, an investigational prodrug of temsavir, is a first-in-class HIV-1 attachment inhibitor that works by binding directly to the glycoprotein 120 (gp120) subunit on the surface of the virus. By binding to this location on the virus, fostemsavir blocks HIV from attaching to host immune system CD4+ T-cells and other immune cells, thereby preventing HIV from infecting those cells and multiplying. Because of this unique mechanism of action, there is no demonstrated resistance to other classes of antiretrovirals, which may help patients who have become resistant to most other medicines. Fostemsavir is not yet approved by regulatory authorities anywhere in the world and is being developed by ViiV Healthcare for the treatment of HIV-1-infected heavily treatment-experienced patients in combination with other antiretroviral agents.

About ViiV Healthcare

ViiV Healthcare is a global specialist HIV company established in November 2009 by GlaxoSmithKline (LSE: GSK) and Pfizer (NYSE: PFE) dedicated to delivering advances in treatment and care for people living with HIV and for people who are at risk of becoming infected with HIV. Shionogi joined in October 2012. The company’s aim is to take a deeper and broader interest in HIV/AIDS than any company has done before and take a new approach to deliver effective and innovative medicines for HIV treatment and prevention, as well as support communities affected by HIV.

For more information on the company, its management, portfolio, pipeline and commitment, please visit www.viivhealthcare.com.

About GSK

GSK is a science-led global healthcare company with a special purpose: to help people do more, feel better, live longer. For further information please visit www.gsk.com/about-us.

Cautionary statement regarding forward-looking statements

GSK cautions investors that any forward-looking statements or projections made by GSK, including those made in this announcement, are subject to risks and uncertainties that may cause actual results to differ materially from those projected. Such factors include, but are not limited to, those described under Item 3.D 'Principal risks and uncertainties' in the company's Annual Report on Form 20-F for 2018.