FDA accepts supplemental NDAs for Pifeltro, Delstrigo for switching HIV regimens

The FDA has accepted to review supplemental new drug applications for two recently approved HIV regimens — Pifeltro and Delstrigo — which would expand the use of these medications to patients who are switching from a stable ART regimen and whose virus is suppressed, according to Merck.

“Our clinical development program continues to generate meaningful evidence for Pifeltro and Delstrigo in people living with HIV,” Michael Robertson, MD, executive director and section head for HIV and HCV at Merck Research Laboratories, said in a press release. “We are pleased that the FDA has accepted these supplemental new drug applications. We look forward to continuing our work with the goal of expanding HIV treatment options.”

Delstrigo, a fixed-dose combination tablet of doravirine (100 mg), lamivudine (300 mg) and tenofovir disoproxil fumarate (300 mg), and Pifeltro (100 mg), a non-nucleoside reverse-transcriptase inhibitor (NNRTI) to be used in combination with other ART medications, were approved by the FDA in August for the treatment HIV-1 infection in adults with no prior ART experience.

The FDA submissions for the supplemental NDAs were based on results of a phase 3 DRIVE-SHIFT trial that demonstrated noninferior efficacy of switching to Delstrigo compared with continuing a baseline regimen of two nucleoside reverse-transcriptase inhibitors plus a boosted protease inhibitor, boosted elvitegravir, or NNRTI. The researchers determined noninferior efficacy by the proportion of participants who switched to Delstrigo and had HIV-1 RNA levels of less than 50 copies/mL at week 48 compared with the proportion of participants who continued with their baseline regimen and had HIV-1 RNA levels of less than 50 copies/mL at week 24, according to Merck. The results were presented at IDWeek 2018.

The Prescription Drug User Fee Act date for the supplemental NDAs is Sept. 20, Merck said.

Disclosure: Robertson is an employee of Merck.