By Bhanvi Satija and Christy Santhosh

Oct 29 (Reuters) - Coya Therapeutics COYA.O said on Tuesday its experimental Alzheimer's drug was safe and increased levels of a type of immune cells that help prevent neuroinflammation in patients with Alzheimer's disease enrolled in a small, mid-stage trial.

The antibody drug COYA 301, part of the IL-2 treatment class, aims to enhance the function of regulatory T cells, which suppress immune responses.

This study specifically evaluated changes in levels of these regulatory T cells, or Tregs, to assess the drug's impact on the memory-robbing condition.

Currently, Eisai 4523.T and Biogen's BIIB.O Leqembi and Eli Lilly's LLY.N Kisunla are approved in the United States for early Alzheimer's disease, designed to clear a disease-related protein called beta-amyloid from the brain.

In a study involving 38 participants with Alzheimer's disease, patients were randomized to receive low doses of under-the-skin injection of the drug, either every two or four weeks.

Coya's chief business officer and incoming CEO Arun Swaminathan said the company was in discussions with the Alzheimer's Association, the Gates Foundation, and other strategic partners to run a much larger study of the drug and will move forward with the once-a-month dosing.

"In a five-month study, we were already able to see what would be considered clinically meaningful improvements in cognition," said Swaminathan.

While the role of Tregs is not fully understood in Alzheimer's disease, some studies show an increase of these cells is associated with neuroprotective effects.

Coya said that patients treated with the drug showed higher rates of reactions at the injection site compared to placebo, but these did not require any major intervention.

The Houston, Texas-based biotech said that once-a-month treatment with the drug showed slight improvement in cognitive function, and also improved beta-amyloid levels in the brain and spinal fluid.

(Reporting by Bhanvi Satija and Christy Santhosh in Bengaluru; Editing by Vijay Kishore)

((Bhanvi.Satija@thomsonreuters.com; Outside U.S. +91 9873062788;))