The U.S. Food and Drug Administration (FDA) has approved Sunlenca (lenacapavir), a new type of medication for the most common variant of HIV, HIV-1 (human immunodeficiency virus type 1).
Lenacapavir is designed for heavily treatment-experienced adults with multidrug-resistant HIV who are not able to adequately manage the virus with their current treatment regimen. It is an injectable medication administered under the skin (subcutaneously) once every six months.
Developed by Gilead Sciences, lenacapavir is the first of a new class of HIV medications called capsid inhibitors, which work by blocking the virus’s protein shell (the capsid), thereby interfering with essential steps of the virus’s life cycle.
In a clinical trial, lenacapavir was able to lower the viral load in patients who were not responding adequately to other therapies.
“Today’s approval ushers in a new class of antiretroviral drugs that may help patients with HIV who have run out of treatment options,” said Debra Birnkrant, MD, the director of the division of antivirals with the FDA’s Center for Drug Evaluation and Research, in a statement. “The availability of new classes of antiretroviral medications may possibly help these patients live longer, healthier lives.”
Drug Resistance Can Be a Problem With HIV Medications
At the end of 2021, 28.7 million people were receiving antiretroviral therapy (ART) globally, out of an estimated 38.4 million people living with HIV, according to the World Health Organization (WHO). The WHO estimates that up to 10 percent of adults who start HIV treatment experience drug resistance.
According to Gilead, an estimated 2 percent of people taking ART are considered heavily treatment-experienced and are unable to keep their viral load low because of drug resistance, intolerance, or safety considerations.
Once a person gets HIV, the virus begins to multiply in the body, sometimes changing form (mutating). Some mutations that develop while a person is taking HIV medicines can lead to drug-resistant HIV.
The National Institutes of Health (NIH) explains that when this happens, HIV medicines that once were working well lose their effectiveness. In other words, the HIV medicines cannot prevent the drug-resistant HIV from multiplying.
About 8 in 10 People on Lenacapavir Lowered Their Virus Levels to Undetectable
The FDA based its lenacapavir approval on research involving 72 people with HIV who had high levels of virus in their blood despite taking antiretroviral drugs. These individuals were divided into two groups and received either the medication or a placebo.
The group who took lenacapavir received an initial so-called loading dose — given as oral tablets and subcutaneous injections — followed by maintenance injections every six months.
After 26 weeks of lenacapavir, plus other antiretroviral drugs, about 8 out of 10 people had levels of HIV that were low enough to be considered undetectable. After 52 weeks, 83 percent of participants continued to have HIV suppression.
Scientists noted few adverse effects other than injection site reactions (such as redness and swelling) and nausea.
Lenacapavir Can Help HIV ‘Go Into Hibernation’
William Schaffner, MD, an infectious-disease specialist and a professor of preventive medicine and health policy at the Vanderbilt University School of Medicine in Nashville, Tennessee, calls lenacapavir “an attractive option” for individuals with multidrug-resistant HIV.
“If we can suppress the virus in the body, it in effect goes into hibernation,” Dr. Schaffner says. “When you do this, you can prevent the development of more serious disease — namely, you can stop people from going from HIV to AIDS.”
While there is still no cure for HIV, treatments have advanced to a point where the life expectancy for someone with HIV who receives medication is the same as that of a person without the virus, according to Schaffner.
“We are still struggling to develop a vaccine to prevent HIV in the first place, but we have made enormous advances,” Schaffner says.
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