Acta Pharmaceuticals has initiated a Phase I first-in-human clinical trial of GSM-779690T, an investigational oral compound, in healthy adults. The randomized, double-blind, placebo-controlled study is designed to evaluate the candidate's safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD). According to the ClinicalTrials.gov listing (NCT07690228), the trial will enroll 72 healthy volunteers aged 18–55 at Nucleus Network in Melbourne, Australia, with primary completion expected in August 2026.
While Acta has not publicly disclosed the molecular target or intended indication for GSM-779690T, the trial's pharmacodynamic endpoints provide insight into the program's scientific rationale. In addition to standard PK assessments, the study will evaluate changes in specific amyloid-beta (Aβ) peptide isoforms, biomarkers commonly used to demonstrate target engagement by gamma-secretase modulators (GSMs). Unlike earlier gamma-secretase inhibitors, which broadly blocked enzyme activity and were associated with significant toxicity, gamma-secretase modulators are designed to selectively alter the enzyme's processing of amyloid precursor protein, reducing production of the aggregation-prone Aβ42 peptide while preserving other physiological gamma-secretase functions. Although no GSM has yet been approved for Alzheimer's disease, the approach has long been investigated as a potentially safer strategy for modifying amyloid biology.
The Phase I study employs parallel single-ascending-dose and multiple-ascending-dose cohorts. Participants will receive either placebo or GSM-779690T as oral capsules. Safety assessments include adverse events, vital signs, physical examinations, laboratory testing, and electrocardiography, monitored through seven days following dosing in the single-ascending-dose cohorts and 21 days following dosing in the multiple-ascending-dose cohorts. Secondary endpoints include plasma PK parameters after single and multiple doses, together with PD assessments of Aβ peptide isoforms. An independent Data Monitoring Committee will oversee the study.
The trial is expected to generate initial safety, PK, and PD data by August 2026, with overall study completion anticipated in July 2027. If the compound demonstrates an acceptable safety profile and evidence of target engagement, the results would support subsequent clinical evaluation in patients.