By Bhanvi Satija and Christy Santhosh

Oct 29 (Reuters) - Coya Therapeutics ( COYA ) 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 ( ESALF ) and Biogen's Leqembi and

Eli Lilly's ( LLY ) 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.