UK study for people with triple-class drug resistance

Note: this page was edited on 31 August 2021 pending final approval of the two UK sites.

Simon Collins, HIV i-Base

A study designed to overcome multidrug HIV resistance in people whose currently combination is failing to achieve and maintain undetectable viral load. [1]

This is a two-part study. For the first week, participants will be randomised to one of four blinded arms. This will add islatravir, doravirine, both drugs or placebo to their current failing combinations. All participants will then add open-label islatravir and doravirine to optimised background ART for the next 48 weeks.

At the end of the study all participants will have the option to continue to use islatravir/doravirine.

Entry criteria include:

  • Adult or adolescent (12 years or older).
  • Weight >35 kg.
  • Viral load >500 copies/mL.
  • Drug resistance to at least three classes, including to NRTI and NNRTIs.
  • Limited alternative ART (based on drug resistance, tolerability/side effects, access or patient acceptability).

Exclusion criteria include genotypic resistance to doravirine or current ART that includes nevirapine, efavirenz or etravirine.

This is an international phase 3 study. It involves 93 sites in 17 countries to enrol only 100 participants – an indication of the difficulty of research for multidrug resistance.

The two expected site sites are the Royal Free Hospital (0207 472 6232) in London and Western General Hospital in Edinburgh (0131 537 2852).

Some study details are still being finalised.

For further details please contact research coordinators at either site.


  1. Doravirine/islatravir (DOR/ISL) in heavily treatment-experienced (HTE) participants for HIV type 1 (HIV-1) infection (MK-8591A-019).

Links to other websites are current at date of posting but not maintained.