G2G Bio Confirms Safety of Dementia Injection GB-5001 in Phase 1 Trial

GB-5001, a long-acting injectable being developed by G2G Bio to treat Alzheimer’s disease dementia, demonstrated safety and tolerability in a Phase 1 trial.

According to a company disclosure on the 27th, G2G Bio announced final results from a Phase 1 trial evaluating the safety, tolerability and pharmacokinetics of GB-5001, a donepezil injection, in healthy male volunteers.

The trial was conducted at Chungnam National University Hospital and was approved by the Ministry of Food and Drug Safety and the hospital’s Institutional Review Board (IRB).

The incidence of adverse drug reactions in the 140-mg multiple-dose group (four intramuscular injections) was 12.50% (1/8 participants, 3 events). No deaths, serious adverse events or drug hypersensitivity reactions occurred during the trial, and no participants discontinued because of adverse events.

Pharmacokinetic analysis showed that after four doses administered at 28-day intervals, blood exposure increased with each dose and approached steady state within three to four doses.

The mean blood concentration at steady state (Cav,ss) was 20.32 ng/mL, similar to the 22.65 ng/mL for the 5-mg oral dose. The maximum blood concentration at steady state (Cmax,ss) was 24.93 ng/mL, lower than the 32.08 ng/mL for the 5-mg oral Aricept tablet, indicating less fluctuation between peak and trough concentrations.

The company said, “Repeated dosing at 4-week intervals showed predictable accumulation, with stable steady state reached within three to four doses.” It added, “Compared with daily oral donepezil, the injection may reduce the risk of adverse effects associated with fluctuations in blood concentrations, suggesting it could be another treatment option for patient groups with low medication adherence.”

With single doses, dose proportionality in systemic exposure was confirmed across the 70- to 280-mg range, and increasing the dose did not show a clear effect on safety.

The Phase 1 trial consisted of a single-dose study (Parts A and B) and a multiple-dose study (Part C). The single-dose study ran from Jan. 3 to Oct. 16, 2024, and the multiple-dose study ran from Sept. 17, 2025, to April 24, 2026.

The company plans to conduct follow-up clinical studies based on the pharmacology and safety results at steady state obtained in this trial.

The company said, “Statistically, the probability that an investigational drug will ultimately receive marketing approval is about 10%.” It added, “Results during clinical trials and the product approval process may not meet expectations, and the commercialization plan may therefore be changed or abandoned.”