Last week, Gilead Sciences and Merck announced that they have paused the Phase II trial of HIV treatment islatravir and lenacapavir, according to BioSpace.

The companies stated, “This temporary pause has been implemented out of an abundance of caution, to allow the companies to consider potential protocol adjustments to the trial in light of Merck’s announcement on November 18 regarding the decision to stop dosing in the Phase II IMAGINE-DR clinical trial evaluating the once-weekly combination of MK-8507 and islatravir.”

Islatravir is a nucleoside reverse transcriptase translocation inhibitor for the treatment of HIV. Lenacapavir is an investigational drug belonging to the class of HIV capsid inhibitor, which could also be used for HIV. Both these drugs have not been approved for HIV yet.

Dr. Joan Butterton, Senior Director in the Department of Clinical Pharmacology at Merck Research Laboratories, said, “Merck remains resolute in its commitment to help address the unmet needs of people living with HIV and continue to do our part in the global efforts to help end the HIV pandemic, which includes the ongoing development of islatravir.”

“All clinical studies provide important learnings to help us in the fight against HIV, and we are grateful to the patients and investigator for their contributions,” she added.

In July, Gilead announced new results from its ongoing Phase II/III CAPELLA trial of lenacapavir in heavily treatment-experienced people with multi-drug resistant HIV, according to BioSpace. The data showed the drug achieved high rates of viral suppression at Week 26 when given every six months along with other antiretroviral drugs.

At the time, Prof. Jean-Michel Molina of the University of Paris said, “Despite the advances in treating HIV infection, there remains an unmet need for treatment options for people who struggle with multi-drug resistance. “

“The CAPELLA results are exciting as they demonstrate that an undetectable viral load is achievable in a patient population that has typically had challenges with viral suppression over the course of their journey living with HIV,” he added.

Merck is facing a few setbacks, which is looking to develop MK-8507 as an oral, once-a-week treatment for the treatment of HIV. Islatravir is currently used along with doravirine in a once-daily setting to treat HIV.