ViiV Healthcare, majority owned by GSK Plc ( GSK ) , with Pfizer Inc ( PFE ) and Shionogi Limited as shareholders, revealed data from a planned interim analysis of the LATITUDE phase 3 trial.

The data indicated that long-acting injectable antiretroviral treatment (ART) for HIV, Cabenuva (cabotegravir + rilpivirine), demonstrated superior efficacy in maintaining viral load suppression compared to daily oral therapy in individuals with a history of ART adherence challenges.

Related Content: Pfizer/GSK-Backed ViiV Healthcare's HIV Drug Associated With Increased Resistance, WHO Report Says.

During the randomized phase of the study, 146 participants received monthly LA-ART, and 148 continued on SOC. 

The primary endpoint was a comparison of regimen failure, defined as a combination of virologic failures (VF) and regimen discontinuations between arms. 

24.1% of participants on LA-ART experienced regimen failure compared to 38.5% on SOC (difference -14.4).

Although the primary endpoint did not meet the strict predefined stopping criterion for the interim analysis, key secondary endpoints of virologic failure (7.2% LA-ART vs. 25.4% SOC (difference -18.2%) and treatment-related failure (9.6% LA-ART vs. 26.2% SOC (difference -16.6%) favored the LA-ART regimen. 

The study's Data Safety Monitoring Board (DSMB) considered the totality of all the study endpoints together and concluded that the evidence indicated superior efficacy of long-acting ART over daily oral standard of care. 

The rate of adverse events (AEs) was similar in both arms. Three participants in the LA-ART arm had serious injection site reactions (ISR), and one participant discontinued due to an ISR.

Two confirmed virologic failures in each arm had new resistance-associated mutations (RAMs), including at least two new integrase inhibitor RAMs in both LA-ART participants.

On Monday, ViiV Healthcare released findings from its phase I study that showed an investigational formulation of cabotegravir, known as cabotegravir ultra long-acting (CAB-ULA), can be dosed at intervals of at least four months. 

Price Action: PFE stock closed higher by 4.26% at $27.19 on Wednesday.

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