FDA approves antiretroviral Idvynso for adults with HIV

The FDA has approved Merck’s Idvynso (doravirine/islatravir) as an antiretroviral for adults, according to a recent news release. The once-daily, two-drug, single-tablet regimen antiretroviral is the first and only two-drug, non-integrase strand transfer inhibitor, tenofovir-free regimen. It is expected to be available in U.S. pharmacies after May 11.

Idvynso is indicated for adults with HIV-1 RNA levels below 50 copies per milliliter who are stable on their current antiretroviral therapy and have no history of virologic treatment failure or known resistance to doravirine.

The regimen combines 100 mg of doravirine, a non-nucleoside reverse transcriptase inhibitor, with 0.25 mg of islatravir, a next-generation nucleoside reverse transcriptase inhibitor. Together, these agents work to block HIV-1 replication through complementary mechanisms. Doravirine inhibits HIV-1 reverse transcriptase through noncompetitive inhibition, preventing the virus from converting its RNA into DNA. Islatravir, meanwhile, interferes with viral DNA synthesis by acting as a nucleoside analog that causes chain termination and inhibits the enzyme’s ability to continue copying viral genetic material.

This approval was made using the results from two phase 3 clinical trials, Trial 052 and Trial 051, which evaluated the safety and efficacy of switching to Idvynso in adults with suppressed HIV.

In Trial 052, 513 participants were randomized to either switch from Biktarvy (bictegravir/emtricitabine/tenofovir alafenamide) to Idvynso or remain on their existing regimen. At Week 48, 92% of participants who switched to Idvynso maintained viral suppression, compared with 94% of those who continued Biktarvy.

In Trial 051, which included 551 participants who were randomized to switch to Idvynso or remain on their current baseline ART (bART). Results showed that 96% of those who transitioned to Idvynso maintained viral suppression at Week 48, compared with 92% of participants who remained on their prior therapy.

“Advances in HIV treatment mean more people living with HIV are living longer — a remarkable achievement,” Carl Baloney, Jr., president and chief executive officer of AIDS United, said in the news release. “People aging with HIV face additional health challenges, including managing multiple chronic conditions and medications at the same time. It is essential that management of HIV considers these factors in addition to virologic suppression when choosing an HIV treatment regimen.”

Adverse reactions occurred in at least 2% of participants, the most common being diarrhea, dizziness and fatigue. Instances of severe skin reactions, such as Stevens-Johnson syndrome or toxic epidermal necrolysis, have also been reported.

Idvynso should not be taken with cytochrome P450 (CYP) 3A enzyme inducers, which may reduce its effectiveness.

According to a Merck spokesperson, the wholesale acquisition cost for a 30-day supply of Idvynso is $4,455, which is comparable to other daily antiretroviral therapies. However, actual out-of-pocket costs will vary depending on insurance coverage and patient assistance programs, they noted, in an email to Managed Healthcare Executive.

Patients and providers who want to learn more about insurance coverage, estimated out-of-pocket costs and potential support options for eligible patients can visit Merck’s website, which contains information about the Merck Access Program.