On Jul. 6, 2020, Merck announced new analyses from the Phase 2b trial (NCT03272347) evaluating the safety and efficacy of islatravir, the company’s investigational oral nucleoside reverse transcriptase translocation inhibitor (NRTTI), in combination with doravirine (PIFELTRO™), in adults with HIV-1 infection who had not previously received antiretroviral treatment. The first sub-analysis further characterized the tolerability and safety profile of islatravir in combination with doravirine (100 mg) through Week 48 across the three dose levels studied (0.25, 0.75, 2.25 mg). The second sub-analysis demonstrated that participants who initiated treatment with islatravir and doravirine in combination with 3TC and switched to islatravir and doravirine maintained antiviral activity at Week 48 as measured by HIV-1 RNA <50 copies/mL similar to DELSTRIGO, with low rates of protocol defined virologic failure (PDVF). These latest findings will be made available this week in two oral presentations during the 23^rd International AIDS Conference (AIDS 2020: Virtual). The primary endpoints and full study design of the Phase 2b Week 48 trial results were originally presented at IAS 2019.

PIFELTRO (doravirine, 100 mg) is indicated in combination with other antiretroviral (ARV) agents for the treatment of HIV-1 infection in adult patients with no prior ARV treatment history or to replace the current ARV regimen in those who are virologically suppressed (HIV-1 RNA less than 50 copies per mL) on a stable ARV regimen with no history of treatment failure and no known substitutions associated with resistance to doravirine.

DELSTRIGO (doravirine 100 mg/3TC 300 mg/tenofovir disoproxil fumarate 300 mg) is indicated as a complete regimen for the treatment of HIV-1 infection in adult patients with no prior ARV treatment history or to replace the current ARV regimen in those who are virologically suppressed (HIV-1 RNA less than 50 copies per mL) on a stable ARV regimen with no history of treatment failure and no known substitutions associated with resistance to the individual components of DELSTRIGO. DELSTRIGO contains a boxed warning regarding post-treatment acute exacerbations of hepatitis B (HBV) infection.