Challenges for novel antiretroviral development in an era of widespread TLD availability.

Over 80% of people living with HIV in low-and-middle-income countries (LMICs) take first-line TDF/XTC/DTG (TLD). Due to hard-fought activism, in >100 LMICs TLD now costs under $45pppy under Voluntary License. With final DTG patents expiring by 2029, generic TLD will soon be available globally. We identify seven critical benchmarks underpinning TLDs success which novel ART should now meet, and an eighth for which novel ART should aim. These are superior efficacy; a high genetic barrier to resistance; safety in hepatitis B coinfection; favourable drug-drug interaction profiles including with antimycobacterials; efficacy in HIV-2; safety in pregnancy, long-acting formulation availability and affordable pricing from the outset. We illustrate when generic TLD will become available worldwide and compare this with trial programmes and approval timelines for two case-study novel ART combinations: islatravir/doravirine and cabotegravir/rilpivirine. We demonstrate that currently these regimens and trial programmes will not meet key benchmarks required to compete with TLD.