FDA Approves ISENTRESS For HIV-1 Newborns

The integrase inhibitor raltegravir serves as a combination therapy with ART regimens.

The US Food and Drug Administration (FDA) has approved raltegravir (ISENTRESS), an integrase inhibitor from Merck Pharmaceuticals, as a combination therapy with antiretroviral treatments (ART) for treating HIV-1 in certain newborns.

ISENTRESS is designated as part of a combination therapy for neonates — newborn patients between birth and 4 weeks of age —that weigh at least 2 kg. Its approval was backed by open-label, multicenter clinical data that showed the pharmacokinetics for oral ISENTRESS in 42 full-term HIV-1 exposed newborns. All tested patients were at high risk of acquiring the infection from their mothers.

The data came from the IMPAACT P1110 study, a 2-cohort trial. In the first cohort, newborns received 2 single ISENTRESS doses for oral suspension — one within 48 hours of birther and the other between 7 and 10 days of age. In the second cohort, newborns received daily ISENTRESS for 6 weeks at doses set by patient weight.

All the patients also received a standard ART regimen for the prevention of HIV transmission from the mothers. By the study’s end, all patients tested negative for the virus, and the drug’s safety profile was comparable to that observed in adult patients.

ISENTRESS was first approved as an adult HIV-1 infection therapy in 2007, the first such integrase inhibitor for the disease. It is regulated in 112 countries as a combination therapy for HIV-1 infection in adult and adolescent patients, according to Merck.

The drug functions by inhibiting the virus’ DNA insertion into human DNA by the integrase enzyme. It has shown clinically rapid antiviral activity, and it limits HIV virus’ ability to replicate and infect new cells in patients.

Dr. Eliav Barr, senior vice president, global clinical development, infectious diseases and vaccines, Merck Research Laboratories, said few ART agents are approved for the newborn population with HIV-1 infections, because of limited clinical research.

“With this FDA approval, ISENTRESS becomes the only integrase inhibitor approved in the U.S. for the treatment of HIV-1, in combination with other antiretroviral agents, for neonates weighing at least 2 kg,” Barr said. “This achievement underscores Merck's unwavering commitment to the development of treatment options for HIV-1."

A press release regarding the approval was made available.