LONDON-- July 19, 2021 -- For media and investors only

ViiV Healthcare, the global specialist HIV company majority owned by GlaxoSmithKline plc (“GSK”), with Pfizer Inc. and Shionogi Limited as shareholders, today presented 48-week data from the SALSA study at the International AIDS Society Conference 2021 (IAS 2021), being held virtually 18-21 July. The 2-drug regimen (2DR) Dovato (dolutegravir/lamivudine) demonstrated non-inferior efficacy compared to continuation of a current antiretroviral regimen (CAR) of at least three drugs[*], with zero cases of virologic failure and no development of resistance, in a diverse population of virologically suppressed adults with HIV-1 who have not experienced prior virologic failure.[1]

The SALSA study population provides a broad representation of people living with HIV on a variety of different regimens of at least three drugs. It included more than 120 study sites across North America, Europe, Asia Pacific, South America and Africa, and a significant proportion of female participants (39%), participants aged 50 or over (39%), and participants of different racial backgrounds (59% white; 19% black; 14% Asian).[1,2]

Josep Llibre, MD, PhD, Consultant, Infectious Diseases Department, Germans Trias i Pujol University Hospital, Barcelona, and a principal investigator of the SALSA study, said: “It is exciting to have more data re-affirming Dovato’s efficacy and positive barrier against resistance development, showing that people can keep their HIV under control while taking fewer medicines. The results are particularly meaningful given that the SALSA trial demographics represent the people living with HIV that we see in daily practice, including women, people over 50 years old and a range of different ethnic groups. These findings give physicians another reason to feel confident switching virologically suppressed people to this 2-drug regimen.”

The primary endpoint was met at Week 48, demonstrating that switching to Dovato was non-inferior to continuing a CAR in the Intention to Treat-Exposed (ITT-E) analysis (defined as all participants randomised to the study), based on the proportion of participants with plasma HIV-1 RNA ≥50 copies per millilitre (c/mL) at Week 48 (Snapshot virologic failure: 0.4% of participants in the Dovato arm vs 1.2% in the CAR arm; adjusted difference: -0.8% [95% CI: -2.4%, 0.8%]). Dovato also demonstrated a non-inferior rate of virologic suppression at Week 48, with 94.3% (232/246) of participants achieving HIV-1 RNA <50 c/mL versus 92.7% (229/247) of participants on a CAR (adjusted difference: 1.6% [95% CI: -2.8%, 5.9%]).[1]

The study findings showed that no participants in either arm met protocol-defined confirmed virologic withdrawal criteria, and as such no resistance mutation development was reported.[1]

Kimberly Smith, M.D., Head of Research & Development at ViiV Healthcare, said: “At ViiV Healthcare, we are committed to ensuring our clinical trials are diverse and representative of the global HIV community; this study is an excellent example of that, and it is exciting to see that the results continue to be outstanding. SALSA is the second switch study to demonstrate Dovato’s non-inferior efficacy and high barrier to resistance, with no participants experiencing virologic failure in the Dovato arm of the study. These findings demonstrate its versatility for participants who had previously been on a broad range of different regimens, cementing its place in the HIV treatment paradigm.”

Overall adverse event (AE) rates were similar between the Dovato and CAR arms (73% [180/246] vs 70% [172/247], respectively). Rates of AEs leading to study withdrawal were low in both the Dovato and CAR arms (2% [5/246] vs 1% [3/247], respectively) and there were no serious drug-related AEs in either group. All drug-related AEs in the Dovato arm were grade 1-2 (i.e. mild). The most common AEs in the Dovato arm were weight increase (8%), headache (7%) and COVID-19 (6%), while headache (7%), upper respiratory tract infection (6%), and COVID-19 (4%) were the most common in the CAR arm.1 At Week 48, changes in fasting lipids were small and comparable between the study arms. From baseline to Week 48, changes in bone and proximal tubular renal biomarkers generally favoured Dovato, suggesting improved or maintained bone and renal function when switching to the dolutegravir-based 2DR. Small changes in inflammatory biomarkers in both directions were observed across both arms, with no evidence of immune activation or inflammation differing between treatment arms.[1]