Update on Gilead’s once-weekly oral HIV GS-1720 and GS-4182 studies

2 April 2026. Related: Early access, Antiretrovirals.

Simon Collins, HIV i-Base

On 1 April 2026, Gilead was reported to have discontinued one of two phase 2/3 studies looking at the once-weekly oral combination of GS-1720 and GS-4182. [1]

GS-1720 is an oral, long-acting integrase strand transfer inhibitor (INSTI) and GS-4182 is a prodrug of the capsid inhibitor lenacapavir.

Both studies (WONDERS1 and 2) were put on hold in June last year due to safety concerns about reduced lymphocytes, including low CD4 counts. These have since either returned to baseline or to within a normal range. The FDA apparently doesn’t require any further safety follow-up.

The WONDERS2 study in treatment-naive participants has now been permanently stopped although the WONDERS1 switch study is still just showing as on hold. Both studies use Biktarvy in the control arm. [3, 4]

comment

Without more information it is difficult to comment on either the FDA or Gilead’s decisions about these studies.

Gilead has not yet issued a press statement about stopping the WONDERS2 study. [5]

References

1. Fierce biotech. Gilead cancels midstage HIV trial as FDA’s clinical hold remains intact. (1 April 2026).
   https://www.fiercebiotech.com/biotech/gilead-cancels-midstage-hiv-trial-fdas-clinical-hold-remains-intact
2. Gilead. Gilead Provides Update on Clinical Studies Evaluating GS-1720 and/or GS-4182 for the Treatment of HIV-1 Infection. (10 June 2025).
   https://www.gilead.com/company/company-statements/2025/gilead-provides-update-on-clinical-studies-evaluating-gs-1720-and-or-gs-4182-for-the-treatment-of-hiv-1-infection
3. ClinicaltTrials.gov. Study of Oral Weekly GS-1720 and GS-4182 Versus Biktarvy in People With HIV-1 Who Are Virologically Suppressed (WONDERS1).
   https://clinicaltrials.gov/study/NCT06544733″>https://clinicaltrials.gov/study/NCT06544733
4. ClinicaltTrials.gov. Study of Oral Weekly GS-1720 and GS-4182 Compared With Biktarvy in People With HIV-1 Who Have Not Been Treated (WONDERS2).
   https://clinicaltrials.gov/study/NCT06613685
5. Gilead press statements.
   https://www.gilead.com/company/company-statements