New Data Show HIV Therapy Delstrigo Non-inferior to Other Antiretroviral Regimens

New clinical trial data show non-inferior efficacy of HIV therapy doravirine (100 mg), lamivudine (3TC, 300 mg), and tenofovir disoproxil fumarate (TDF, 300 mg) compared with other antiretroviral treatment regimens, according to a Merck press release.

Doravirine/3TC/TDF (Delstrigo) was approved by the FDA in August 2018 for the treatment of HIV-1 infection in adult patients with no prior antiretroviral treatment experience. The latest data from the phase 3 DRIVE-SHIFT study were presented as a late-breaking oral presentation at IDWeek 2018 taking place October 3-7, 2018, in San Francisco, California.

For the study, 670 adults with HIV infection who demonstrated virologic suppression for at least 6 months on a stable antiretroviral treatment regimen were enrolled. Patients began treatment with doravirine/3TC/TDF immediately on day 1 or after 24 weeks. The primary endpoint was the proportion of participants with HIV-1 RNA <50 copies/mL, with the primary comparison between the immediate switch group (ISG) at week 48 and baseline regimen delayed switch group (DSG) at week 24, with a secondary comparison between the ISG and baseline regimen DSG at week 24.

According to the data, participants who immediately switched to doravirine/3TC/TDF maintained virologic control at the 48-week timepoint:

• 90.8% of participants who immediately switched to doravirine/3TC/TDF had HIV-1 RNA <50 copies/mL at week 48 and 94.6% of participants in the delayed switch group had HIV-1 RNA <50 copies/mL at week 24 (treatment difference: -3.8%, 95% confidence interval: -7.9, 0.3).
• 1.6% in the immediate switch group had HIV-1 RNA ≥50 copies/mL at week 48 compared with 1.8% of those who continued on their baseline regimen at week 24 (treatment difference: -0.2%, 95% confidence interval: -2.5, 2.1).

Additionally, the study showed that 93.7% of participants who switched to doravirine/3TC/TDF on day 1 had HIV-1 RNA <50 copies/mL compared with 94.6% of those who continued on their baseline regimen (treatment difference: -0.9%; 95% confidence interval: -4.7, 3.0), and 1.8% in both treatment groups had HIV-1 RNA ≥50 copies/mL at week 24 (treatment difference: 0.0%; 95% confidence interval: -2.3, 2.3).

At week 24, those who switched to doravirine/3TC/TDF on day 1 showed a statistically significant decrease in fasting LDL-cholesterol and non-HDL-cholesterol compared with those who continued on a boosted protease inhibitor regimen. Doravirine/3TC/TDF also showed decreases in cholesterol and triglyceride levels at this point.

The most commonly reported adverse effects in the trial were nasopharyngitis and headache. No genotypic or phenotypic resistance to any drug in the study were observed in patients receiving doravirine/3TC/TDF through 48 weeks of treatment, according to the release.

“These data build on the existing clinical profile of Delstrigo as seen in treatment-naïve patients, and suggests its potential to address a broader population,” Princy Kumar, MD, chief, Division of Infectious Diseases and Tropical Medicine at MedStar Georgetown University Hospital and professor of medicine and microbiology at Georgetown University School of Medicine, Washington, DC, said in the press release. “Data from this trial support another possible future option for people living with HIV, many of whom may require a change to a different treatment regimen.”

Reference

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://investors.merck.com/news/press-release-details/2018/Mercks-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/default.aspx. Accessed October 4, 2018.