Major U.S. pharmaceutical giant Gilead Sciences has completely terminated the clinical study Wonders‑2, which was testing the company’s new HIV drugs. The decision was made after the U.S. Food and Drug Administration (FDA) refused to lift a previously imposed clinical hold on the trials, reported Fierce Biotech, citing representatives of the manufacturer and the agency.
The Wonders‑2 study began as a Phase II/III trial and included 73 patients. In parallel, another, larger study, Wonders‑1, involving approximately 675 people, was underway. Both trials tested a combination of two experimental drugs – GS‑1720 and GS‑4182 – comparing it with existing treatment.
GS‑4182 is a tablet formulation of the already approved lenacapavir, which Gilead sells under the brand name Sunlenca. GS‑1720 is an experimental therapy designed for weekly dosing.
Both studies were suspended in June 2025 due to safety concerns. In some patients receiving the drug combination, levels of CD4+ cells (a key indicator of immune function in HIV patients) and total white blood cell counts dropped. Later, blood counts in participants of the small study returned to normal. Despite this, the FDA did not lift the hold. Consequently, the company decided not to continue Wonders‑2 and has now fully terminated that trial.
Gilead Sciences is currently transitioning participants to standard care and continues developing other drugs, including long‑acting regimens based on lenacapavir – one of its key HIV medicines. Last year, the WHO included this drug in its recommendations for the treatment and prevention of HIV and sexually transmitted infections. It became the first FDA‑approved drug for pre‑exposure prophylaxis (PrEP) of HIV that requires administration only twice a year.