The new indication would allow treatment-experienced patients with HIV to switch to Pifeltro in combination with other HIV medications or Delstrigo.
Officials with the FDA have accepted Merck’s supplemental New Drug Applications (sNDAs) to expand the use of doravirine (Pifeltro) and doravirine/lamivudine/tenofovir disoproxal fumarate (Delstrigo).
If approved, the new indication would allow treatment-experienced adults with HIV whose virus is suppressed to switch to doravirine in combination with other antiretroviral therapies (ARTs) or doravirine/lamivudine/tenofovir disoproxal fumarate, according to a Merck press release.
Doravirine 100 mg is a once-daily non-nucleoside reverse transcriptase inhibitor (NNRTI) used in combination with other antiretroviral medicines. Doravirine (100 mg)/lamivudine (3TC, 300 mg)/tenofovir disoproxal fumarate (TDF, 300 mg) is a once-daily fixed-dose combination tablet indicated for the treatment of HIV in adults who have not previously been treated with ART.
The sNDA submissions were based on results from the phase 3 DRIVE-SHIFT trial evaluating the efficacy of switching to doravirine/3TC/TDF compared with continuing a baseline regimen of 2 NRTIs plus a boosted inhibitor, boosted elvitegravir, or NNRTI. According to the data, 670 patients who demonstrated virological suppression on an antiretroviral regimen for at least 6 months were randomized to receive either doravirine/3TC/TDF immediately on day 1 or after 24 weeks.
At 48 weeks, 90.8% of study participants who switched to doravirine/3TC/TDF on day 1 had HIV RNA <50 copies/mL compared with 94.6% of those who continued their baseline regimen. Additionally, 1.6% in the doravirine/3TC/TDF group had HIV RNA ≥50 copies/mL at week 48 compared with 1.8% of patients in the baseline regimen. Patients who switched to doravirine/3TC/TDF also showed statistically significant decreases in fasting LDL-cholesterol and non-HDL-cholesterol compared with those who continued on a boosted protease inhibitor regimen.
“Our clinical development program continues to generate meaningful evidence for Pifeltro and Delstrigo in people living with HIV,” Dr Michael Robertson, executive director and section head for HIV and HCV, Merck Research Laboratories, said in a statement. “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.”
The Prescription Drug User Fee Act date for the sNDAs is September 20, 2019, according to Merck.
US FDA Accepts sNDAs for Pifeltro (doravirine) and Delstrigo (doravirine/lamivudine/tenofovir disoproxil fumarate) [news release]. Merck’s website. https://www.mrknewsroom.com/news-release/research-and-development-news/us-fda-accepts-sndas-pifeltro-doravirine-and-delstrigo-do. Accessed January 23, 2019.
Merck’s HIV Therapy DELSTRIGO (doravirine/lamivudine/tenofovir disoproxil fumarate) Meets Primary Efficacy Endpoint in Phase 3 DRIVE-SHIFT Study Evaluating Switch to DELSTRIGO from Other Antiretroviral Treatment Regimens [news release]. Merck’s website. https://www.mrknewsroom.com/news-release/corporate-news/mercks-hiv-therapy-delstrigo-doravirine-lamivudine-tenofovir-disoproxil-. Accessed January 23, 2019.