ST Pharm said Tuesday that its investigational HIV-1 drug candidate STP0404 was generally well tolerated in a U.S. phase 2a trial, with no grade 3 or higher treatment-emergent adverse events, serious adverse events, treatment discontinuations due to adverse events, or deaths reported during the 10-day treatment period.

According to a regulatory filing, the trial was conducted at 13 sites across the U.S. from May 23, 2023, to May 6, 2026. The randomized, double-blind, placebo-controlled study enrolled 36 adults aged 18 to 65 with HIV-1 infection to evaluate the antiviral activity, safety, tolerability and pharmacokinetics of STP0404.

Results showed that STP0404 was generally well tolerated during the 10-day treatment period.

Treatment-emergent adverse events (TEAEs) were reported in 60 percent of participants, but most were mild. No grade 3 or higher TEAEs, serious adverse events (SAEs), adverse events leading to treatment discontinuation, or deaths were reported.

ST Pharm said it plans to present detailed results from the phase 2a trial at an international scientific conference.

"Based on the evaluation of STP0404's antiviral activity, safety, tolerability and pharmacokinetics in patients with HIV-1 infection, we plan to develop a strategy for subsequent clinical trials aimed at providing a new treatment option alongside existing standard HIV-1 therapies," the company said.