Vivoryon Therapeutics has hit upon the right dose of its Alzheimer’s disease candidate. Having seen a 33% dropout rate at 800 mg, the biotech has dialed down the dose to improve tolerability without causing a steep drop in target engagement, clearing it to move into the second part of the study.
Probiodrug, which changed its name to Vivoryon in 2019, presented data from a phase 2a clinical trial of the 800-mg dose of glutaminyl cyclase inhibitor PQ912 five years ago. At the time, the German biotech outlined plans to study lower doses of the candidate, now known as varoglutamstat. Vivoryon arrived at the Alzheimer’s Association International Conference in San Diego yesterday clutching the results of its work to find the right dose.
The independent data safety monitoring board has picked 600 mg twice daily, the highest dose tested in the phase 2b, as the regimen to take forward into the second part of the study. The decision reflects the tolerability and target engagement seen at the dose.
Four of the 181 patients experienced serious adverse events, and two discontinued treatment. All the adverse events were gastrointestinal, general or related to the nervous system or skin. The rates compare favorably to the data from the earlier SAPHIR study of the 800-mg dose, in which 15% of the participants suffered serious adverse events and 33% of subjects discontinued treatment.
Vivoryon achieved the improved tolerability without significantly sacrificing target engagement. In the earlier study of the 800-mg dose, Vivoryon saw a calculated target occupancy of 92%. The occupancy in the new study of the 600-mg dose came in at “nearly 90%.” Michael Schaeffer, chief business officer at Vivoryon, set out what the result means for the company.
“With the selected dose of 600 mg BID we believe we have a standalone safety profile for varoglutamstat while maintaining high target engagement, which is a critical factor in enabling disease modification,” Schaeffer said in a statement. “These combined results strengthen our belief that both Viviad and our ongoing U.S. study, Viva-Mind, have the potential to build on the Saphir results, which already reported a number of significant changes in AD-related parameters.”
Investors responded to the update by triggering a double-digit jump in Vivoryon shares Monday morning, raising the stock price to around 9 euros ($9).