Gilead’s Sunlenca Tops Other Drugs in Heavily Treated People with HIV

HIV specifically targets immune cells, particularly CD4 cells, a type of T cell, and if untreated or poorly controlled, HIV infection can lead to the depletion of CD4 cells, an impaired immune system and ultimately the development of AIDS.

A June 2023 study, funded by Gilead Sciences and published in the journal Value in Health, compared different therapies for people with HIV who have been heavily treated with antiretroviral mediations. The study was published online in January 2023.

The authors, employees of Costello Medical, a private research and market access company in London that was hired by Gilead to conduct this study, note that both HIV viral load and CD4 cell count are important markers of HIV progression, with viral load increasing and CD4 cell count decreasing if the infection is left untreated or in the case of treatment failure. Furthermore, these markers are important in assessing the efficacy of antiretroviral treatments, which prevent HIV replication and result in virologic suppression while also restoring CD4 cell counts and the functioning of the immune system. Still, the efficacy of antiretroviral treatments may be limited by drug tolerability and treatment-related adverse events as well as by suboptimal adherence and drug resistance.

“There is currently a lack of evidence on the relative benefits of the various treatment options for HTE PWH (heavily treatment-experienced people with HIV), partly due to the challenges faced when comparing differently defined HTE populations across studies, the heterogeneity in the treatment landscape and the complexity of treatment regimens used by HTE PWH,” wrote first author Iro Chatzidaki, M.Sc., and colleagues.

For this study the researchers gathered results from previous studies of people to compare Gilead’s Sunlenca (lenacapavir), a viral capsid disrupter, with ViiV Healthcare’s Rukobia (fostemsavir), an HIV attachment inhibitor; and Theratechnologies Inc.’s Trogarzo (ibalizumab), a monoclonal antibody that binds to CD4 receptor thereby reventing HIV particle entry. Each of those drugs were combined with other treatments; for the purposes of this study the researchers called those other drugs “optimized background regimen,” or OBR. A fourth group in the study included patients who received only OBR.

The study was not a true comparison study with patients randomized into different treatment groups. Instead, the researchers made “indirect treatment comparisons” by sifting through and assembling data from other studies.

In the end, their complicated analysis showed that patients treated with Sunlenca plus OBR had 6.57 times better odds of achieving virologic suppression of HIV at weeks 24 to 28 than patients treated with Rukobia and OBR.

The comparisons were even more in Sunlenca’s favor when it came to Trogarzo and OBR alone.

“We have shown that lenacapavir (they used the generic name in the paper) + optimized background regimen is favored over key comparators in terms of achieving virologic suppression and therefore has potential to reduce the burden associated with virologic failure in people with multidrug-resistant HIV,” wrote Chatzidaki and colleagues.