“ST Pharm (237690) announced on the 21st that it presented interim analysis results of its phase 2a clinical trial for ‘Pirmitegravir’ (STP0404), a treatment for HIV-1 (Human Immunodeficiency Virus type 1), at the infectious disease conference ‘IDWeek 2025’ held in Atlanta, Georgia, USA.
At this conference, ST Pharm conducted an oral presentation under the theme ‘The First Proof-of-Concept Clinical Trial of an HIV-1 Allosteric Integrase Inhibitor, Pirmitegravir.’
The phase 2a trial evaluated the antiviral activity, safety, tolerability, and pharmacokinetic properties of Pirmitegravir in adults aged 18 to 65 infected with HIV-1. Participants consisted of adults who were either treatment-naive or had limited exposure to antiretroviral therapy (ART), and they received either Pirmitegravir or a placebo once daily for 10 days.
This interim analysis covers results from a total of 16 participants in cohorts 1 and 2 (200 mg and 400 mg, respectively).
According to the interim analysis results, there was a significant reduction in plasma HIV-1 RNA levels in the Pirmitegravir treatment group by Day 11 (p<0.0001), with a mean reduction of 1.191 to 1.552 log10 copies/mL (15.52 to 35.65-fold reduction). The FDA's HIV-1 infection treatment guidelines indicate that a reduction in HIV-1 RNA levels by ≥0.5 log10 copies/mL meets the primary efficacy endpoint. Of the 16 reported treatment-emergent adverse events (TEAE), three were possibly related to the study drug, but no serious adverse events (SAE), severe adverse reactions, or discontinuations due to adverse events were observed at the time of the interim analysis; all adverse events were resolved or recovered, ensuring safety and tolerability. Pirmitegravir's pharmacokinetic (PK) profile showed dose-dependent increases, with peak blood concentration reaching 4.5 to 5.5 hours post-dosing. The mean half-life was found to be 11.6 to 13.7 hours. No significant accumulation in the body was observed after repeated 10-day dosing. Based on the interim results, Pirmitegravir demonstrated excellent antiviral efficacy, an outstanding pharmacokinetic profile, safety, and tolerability. Currently, recruitment and dosing for cohort 3 (600 mg) are actively ongoing, with the aim of receiving the clinical trial report in the first half of next year. Meanwhile, ST Pharm, after conducting joint research with the Korea Research Institute of Chemical Technology for two years starting in 2014, acquired the entire technology in 2016, securing domestic and international patent rights and exclusive development rights, and has been developing it independently from preclinical trials to the present."