Jan 5 (Reuters) - Zenas BioPharma ZBIO.O said on Monday its experimental drug cut the risk of disease flare-ups in a late-stage study of patients with a rare immune system-related condition that can damage organs over time.

The company said patients who received the drug candidate, obexelimab, saw a 56% reduction in the risk of flare-ups related to the immunoglobulin G4-related disease, or IgG4-RD, compared to placebo over a 52-week period, meeting the main goal of the study.

Last year, Amgen's AMGN.O Uplizna became the first treatment approved by the U.S. Food and Drug Administration to treat the rare autoimmune condition in which an overactive immune system can lead to inflammation and scarring in various organs, including the pancreas, liver and kidneys.

IgG4-RD affects about 20,000 people in the U.S.

Zenas' drug also performed better than placebo on four other secondary goals, including the proportion of patients achieving complete remission, the company said.

The trial enrolled 194 patients globally. Obexelimab is given as a weekly injection that patients can self-administer at home.

It was well tolerated, with no new safety concerns reported, Zenas said, adding that full data from the study will be presented at a future medical meeting.

Zenas plans to seek approval from U.S. and European regulators this year.

In 2023, the drugmaker partnered with Bristol Myers Squibb ZBIO.O, which holds exclusive rights to develop and market obexelimab in Japan, South Korea, Taiwan, Hong Kong, Singapore and Australia.

(Reporting by Sahil Pandey in Bengaluru; Editing by Sahal Muhammed)

((Sahil.Pandey@thomsonreuters.com;))