ViiV Healthcare and GSK’s long-acting injectable antiretroviral treatment (ART) Cabenuva has demonstrated superior efficacy in a Phase III trial in comparison to daily oral therapy in individuals with human immunodeficiency virus (HIV) who struggle with treatment adherence.

The agent was approved by the US Food and Drug Administration (FDA) in January 2021, as a complete HIV treatment regimen dosed once monthly or once every other month.

It was also approved in the EU in October 2021 under the name Vocabria + Rekambys.

While Cabenuva replaces the need for HIV patients to adhere to daily oral pills, it must be administered by a healthcare professional as a regimen of two intramuscular injections.

Cabenuva’s formulation consists of two separate agents: Vocabria, developed by ViiV and GSK, and Rekambys, developed by Janssen.

While Cabenuva has an injectable formulation, both of the active ingredients also exist as oral forms, which can be taken together.

Normally, patients are first given the oral combination daily for one month before they can receive Cabenuva.

Interim data from the Phase III LATITUDE study demonstrated Cabenuva’s superior efficacy in successfully maintaining viral load suppression compared to daily tablets in patients who had previously shown issues with adherence to ART.

The full data of the interim study will be presented at an upcoming scientific conference.

Cabenuva has already demonstrated positive efficacy results in previous clinical trials.

For example, in the Phase III ATLAS clinical trial, Cabenuva met its primary endpoint, with 98% of participants having greater than or equal to 50 copies of plasma HIV-1 RNA per millilitre after 48 weeks.

A control group who continued their oral current ART regimen achieved the same result of 98%.

Furthermore, in the Phase IIIb SOLAR clinical trial, Cabenuva demonstrated similar efficacy in suppressing viral activity compared to Gilead’s Biktarvy, a leading oral ART.

Side effects were more common in patients who received Cabenuva compared to those who received Biktarvy.

For Cabenuva, the most common side effects were pyrexia (3%), headache (2%), fatigue (2%), and diarrhoea (2%) while in the case of Biktarvy the side effects mostly were weight gain (more than 1%) and abnormal hepatic function (more than 1%).

However, most of the side effects associated with the injection site were short-lived (a median of three days).

Competition in the HIV field is fierce. The availability of numerous oral ARTs with strong efficacy and safety profiles means that patients can, for the most part, lead normal lives, and many patients are reluctant to switch to a new type of treatment if their current regimen is working well.

However, a subgroup of patients still struggles to adhere to daily pills for numerous reasons.

These include forgetting to take their daily medications and worrying about others finding their medication due to the stigma that still often exists around HIV.

As poor adherence is associated with drug resistance and disease progression, this subgroup could benefit greatly from injectables such as Cabenuva, as the alternative treatment could improve their quality of life.

In a post-Phase IIIb SOLAR clinical trial survey, 90% of respondents preferred the long-lasting formulation in comparison to the oral daily pills.

The main reason patients gave for choosing to take the long-lasting formulation was convenience, as patients then had no need to carry HIV medication with them or remember to take it every day.

The growth potential of long-acting injectables in HIV is strong.

Overall, the longer the interval is between doses, the larger the patient shares these therapies are likely to gain, especially if they continue demonstrating superior efficacy.

The appeal of long-acting injectables will increase further if patients can begin to self-administer these therapies, something that GSK is already investigating for Cabenuva.