May 2025 update

In short

Zhittya marked three years of Parkinson's research studies. A new lab in Reno, Nevada began scaling up production of FGF-1.

The May 2025 update marked three years of the Parkinson's research. In May 2022, Zhittya dosed its first two participants with Parkinson's. By May 2025 the number had passed 200.

Dan Montano, the chief executive, said the amount of FGF-1 given had been raised step by step, from what the team called level 1 at the start to level 17, and that participants were being dosed over longer periods. In the team's view, higher and longer dosing appeared to be more helpful, and he expected the level to rise again within a few months. He thanked the volunteers who had taken part.

Regulatory outlook

The update discussed reports that new leadership at the FDA might stop requiring repeat animal testing where animal or human data already exist. Mr. Montano wrote that, if that happened, the data from the 200 people already dosed might let the company apply early in 2026 for a Phase II clinical trial in Parkinson's disease. He raised the possibility of a faster review path, since Parkinson's is an unmet medical need. He called this a long shot.

Videos of two participants

Mr. Montano wrote that his greatest joy over the three years had been seeing participants improve. The update linked to videos of two participants filmed at different stages of their time in the research.

Making FGF-1, and how much the brain needs

The update described the company's new manufacturing laboratory in Reno, Nevada. FGF-1 is a human protein made with recombinant DNA technology, in which cells are engineered to produce it. Dr. Jack Jacobs, the company's president, had overseen its manufacture for 27 years. Mr. Montano estimated that the company could now make as much FGF-1 in one year as had ever been made before, yet he expected supply to stay tight for several years.

He was frank about what the team got wrong. Three years earlier, it thought a single round of dosing would be enough for the brain. By May 2025 it was dosing at 17 times the original level, for up to three years, and he said improvements had been better. He wrote that the team was still guessing where all the FGF-1 goes in the brain, and that the open question was whether higher doses would bring faster improvement.

Other items

Dr. Jacobs returned to endothelial cell dysfunction, the damage to the cells lining blood vessels that he had discussed the month before, and reviewed research linking it to lasting symptoms after COVID-19. The update also described new studies in other research areas.

The update shared comments from participants and family members on topics that included mood, freezing, concentration at work and stiffness. It noted that the brain imaging studies at Washington University in St. Louis were continuing.

This summary covers the Parkinson's research in the May 2025 update. The complete update, including the other topics it covered, is below.