FRANKFURT, Oct 30 (Reuters) - Novartis said its experimental drug atrasentan was shown to have a positive effect on an indicator of kidney health in people suffering from a rare type of kidney disease in an interim analysis of a late-stage drug trial.

Treatment with the drug candidate, acquired as part of the purchase of U.S. biotech firm Chinook for up to $3.5 billion, resulted in a meaningful improvement in proteinuria in patients suffering from IgA nephropathy when compared to placebo, the Swiss drugmaker said in a statement.

Proteinuria is excess protein in the urine, which can be a sign of the kidney failing to filter properly.

Novartis, which is working on two other drug candidates to treat IgAN, added it plans to review the interim results with the U.S. Food and Drug Administration with a view to seeking accelerated approval.

The trial will continue with more read-outs on kidney function expected in the first quarter of 2026, the company added.

Novartis has become more dependent on its drug development fortunes after it spun off its generic drugs division Sandoz earlier this month.

The prospect of treating IgAN has attracted a wide field of contenders in drug development.

Calliditas Therapeutics

in August won priority review status from U.S. regulators for its IgAN drug candidate. Other companies working on treatments include Roche and Vera Therapeutics.

plunged last month after its drug, which had already won accelerated approval in the United States, missed key secondary goals in an IgAN trial.

IgAN is a progressive autoimmune disease that mostly affects young adults and which can lead to kidney failure that requires dialysis or organ transplantation. No targeted treatment options are available.

IgAN is among the most common causes of kidney failure in young adults.

(Reporting by Ludwig Burger, editing by Rachel More and Jason Neely)