ViiV's Dovato Hits Non-Inferiority, But 3% Efficacy Gap vs. Biktarvy and Quality Questions Cloud Commercial Outlook

ViiV Healthcare's Dovato Matches Biktarvy Efficacy in HIV Trial

ViiV Healthcare's two-drug regimen, Dovato (dolutegravir/lamivudine), demonstrated non-inferior efficacy compared to Gilead's three-drug regimen, Biktarvy (bictegravir/emtricitabine/tenofovir alafenamide), in treatment-naïve adults living with HIV, according to findings from the Phase IIIb VOGUE study (NCT05979311). At week 48, virologic suppression was achieved in 89% of patients on Dovato versus 92% on Biktarvy, with similar rapid viral suppression times. The study also reinforced Dovato's high barrier to resistance, with no treatment-emergent resistance observed, and comparable safety profiles between the two groups. These results support the use of fewer daily drugs for lifelong HIV treatment without compromising efficacy or resistance barrier.

• The VOGUE study (NCT05979311) was a multi-country, open-label, randomised Phase IIIb trial involving 509 treatment-naïve adults living with HIV. It was the first head-to-head study comparing ViiV Healthcare's two-drug regimen Dovato (dolutegravir/lamivudine) against Gilead's three-drug regimen Biktarvy (bictegravir/emtricitabine/tenofovir alafenamide), including patients with high viral loads or low CD4+ cell counts.
• At week 48, Dovato achieved 89% virologic suppression, demonstrating non-inferiority to Biktarvy's 92%. Both regimens showed rapid and similar median times to viral suppression, around 4.1 weeks. Crucially, the study identified zero cases of treatment-emergent resistance across both arms, reinforcing Dovato's high barrier to resistance. The overall safety profiles were comparable, with no new safety signals reported.
• These findings support the clinical utility of Dovato as an effective two-drug regimen for initial HIV treatment, potentially reducing the number of daily medications for lifelong care. Despite Dovato achieving blockbuster status with £2.7bn ($3.4bn) in sales in FY2025, it was significantly outpaced by Biktarvy's $14.3bn. The broader HIV market is projected to grow from $26.5bn in 2023 to $32.1bn in 2033, driven by long-acting injectables and novel single-tablet regimens.

Addressing Lifelong HIV Treatment: The Promise of Two-Drug Regimens

While antiretroviral therapy (ART) has successfully transformed HIV into a manageable chronic condition, significant challenges prevent a cure and complicate lifelong treatment. These persistent hurdles underscore the need for innovative strategies that move beyond simple viral suppression to address the long-term health of people living with HIV.

• Persistence of Latent Viral Reservoirs: Despite effective viral suppression with ART, HIV persists in latent reservoirs within the body. This prevents a cure, as all attempts at a functional cure have so far failed, and contributes to chronic immune activation, oxidative stress, and mitochondrial dysfunction that preclude complete immune restoration.

• Suboptimal Treatment Adherence: Achieving and maintaining the high adherence level (>95%) required for virologic suppression is a major clinical challenge. Studies show that actual adherence is often much lower, with poor adherence dramatically increasing the odds of virological non-suppression (aOR 100.3; 95% CI: 28.90-348.12). Common reasons for non-adherence include simply forgetting, stigma, side-effect avoidance, and substance abuse.

• Emergence of Drug Resistance: The development of drug resistance is a primary cause of ART failure, rendering therapies less effective and limiting future treatment options. Cross-resistance, where resistance to one drug confers resistance to an entire class, can emerge, and mathematical models predict that transmitted drug resistance will increase as ART coverage expands globally.

• Treatment-Associated Toxicity: Current ART regimens are associated with toxicities and adverse side effects, which can be a significant predictor of mortality (HR 2.60; 95% CI: 1.82-3.71). These side effects also serve as a major barrier to treatment adherence, as patients may miss doses to avoid them.

• Health System and Access Barriers: Significant gaps exist in the HIV care continuum, particularly in resource-limited settings. These barriers include limited access to health services, user fees, long wait times, stigma from healthcare providers, and lack of consistent community-based services. Even in developed nations, delays between HIV diagnosis and ART initiation remain a challenge to implementing immediate treatment recommendations.

Navigating the Evolving HIV Treatment Landscape and Market Dynamics

Over the past five years, the HIV treatment landscape has been defined by the consolidation of integrase strand transfer inhibitor (INSTI)-based regimens and a concerted move toward simplification and novel delivery systems. Dolutegravir (DTG)-containing regimens, particularly the combination of tenofovir disoproxil fumarate, lamivudine, and dolutegravir (TLD), have become the standard first-line therapy in many high-burden regions like Southern Africa due to superior efficacy and tolerability. However, this transition has been accompanied by observations of excess weight gain, prompting ongoing safety assessments such as the ELDORADO trial comparing doravirine to DTG. In parallel, two-drug regimens (2DRs), notably dolutegravir/lamivudine (DTG/3TC), have demonstrated non-inferiority to traditional three-drug regimens in both treatment-naïve and experienced patients, offering a simplified single-tablet option with a favorable tolerability profile.

A significant paradigm shift has been the introduction and adoption of long-acting injectable therapeutics. The 2021 approval of injectable cabotegravir/rilpivirine marked the arrival of the first complete long-acting regimen for virologically suppressed individuals, while long-acting cabotegravir and lenacapavir have proven highly effective for pre-exposure prophylaxis (PrEP). While these injectables offer a transformative alternative to daily oral pills, persistent structural, financial, and clinical barriers hinder their widespread implementation. Concurrently, the development pipeline remains active with novel agents like islatravir, a nucleoside reverse transcriptase translocation inhibitor with a long intracellular half-life, and new classes of NNRTIs, which aim to address existing challenges and further expand treatment options.

Alongside therapeutic innovation, recent trial data underscore the critical impact of treatment strategies and the persistence of key challenges. Modern regimens like bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) continue to show high rates of virologic suppression in diverse populations, including heavily treatment-experienced women. Studies have also highlighted the robustness of DTG-based regimens, which can maintain viral suppression rates above 95% even at lower levels of adherence where non-DTG regimens falter. Despite these potent tools, significant hurdles remain, including high rates of loss-to-follow-up and the prevalence of pre-treatment drug resistance. Data from multiple African countries show concerning levels of resistance to NRTIs and NNRTIs, which are strongly associated with high viral loads and threaten the long-term success of ART programs. These findings emphasize the ongoing need for differentiated service delivery models, improved linkage to care, and continued surveillance to navigate the evolving dynamics of the HIV epidemic.