23 Apr 2025
23rd April 2025
Brussels, April 23rd, 2025
Poster Presentation at BHIVA 2025: Results from the FOST Switch Study on Fostemsavir in HIV Treatment.
Switching from Boosted Protease Inhibitor-Based ART to Fostemsavir + Optimized Background Regimen in Virally Suppressed Individuals with Limited Therapeutic Options.
A new study examining the switch from boosted protease inhibitor (bPI)-based antiretroviral therapy (ART) to fostemsavir (FTR) plus an optimized background regimen (OBR) will be presented as a poster at BHIVA 2025. The presentation is scheduled for April 23, 2025, from 1:35 PM to 2:35 PM GMT.
The poster reviews outcomes for the first participants to reach week 12 who met the criteria for the preplanned study data and safety monitoring board (DSMB) to review efficacy and safety data.
The study, titled "Switching Boosted Protease Inhibitor-Based Antiretroviral Therapy to Fostemsavir + Optimized Background Regimen in Virally Suppressed People with HIV with Limited Therapeutic Options," addresses a critical challenge in HIV treatment—individuals with extensive ART experience, resistance, and intolerance who are on bPI-containing regimens. These patients face an increased risk of drug-drug interactions (DDIs) and long-term metabolic side effects. Despite the growing need for better treatment options, limited data exist on switching to FTR, particularly regarding its impact on tolerability, DDIs, and quality of life.
The FOST Switch study is a phase IV, proof-of-concept, non-randomized, single-arm, multi-center study in virally suppressed, ART-experienced people with HIV on bPI therapy. With a target of 60 participants, all individuals were switched from their current bPI-containing regimens to FTR plus an OBR. The primary endpoint is the proportion of participants with HIV viral loads ≥50 copies/mL at week 48. Secondary objectives include viral load at week 24, adverse events, and tolerability-related treatment discontinuations.
Prof Marta Boffito, Chief Investigator of FOST Switch, Consultant Physician at Chelsea and Westminster Hospital and Imperial College London in London, stated: “It is a great privilege to be involved in this study which has the potential to improve the quality of life of people harbouring multi-drug resistant HIV with limited therapeutic options. The introduction of new drugs such as FTR into HIV clinical practice is still very much needed to ensure that access to simple and well tolerated antiretroviral combinations are available to all.”
Contributing Sites: Chelsea and Westminster (UK), St Mary’s (UK), Mortimer Market (UK), University of Torino (Italy).
NEAT ID's mission is to support and develop Clinical Research on Infectious Diseases and spread expertise, resources and funds. NEAT ID provides training and mobility of scientists at all levels and foster lasting research collaborations Internationally. Please visit our website for more details: https://www.NEAT-ID.org.
The study is sponsored by NEAT ID and funded by ViiV.
Notes to editors:
1. NEAT ID's mission is to support and develop Clinical Research on Infectious Diseases and spread expertise, resources and funds. NEAT ID provides training and mobility of scientists at all levels and foster lasting research collaborations Internationally. Please visit our website for more details: https://www.NEAT-ID.org
2. Prof Marta Boffito is a Consultant Physician at Chelsea and Westminster Hospital and Imperial College London in London, United Kingdom. Prof Boffito serves as Lead of the Clinical Research Facility and HIV Service Director at Chelsea and Westminster Hospital where she runs numerous research projects and clinical trials.
Media contact: Polly.Parks@NEAT-ID.org +44 07850 695261