Oct 15 (Reuters) - Danish drugmaker Novo Nordisk

and Omeros ( OMER ) have signed a licensing deal

worth up to $2.1 billion for the U.S.-based company's

experimental drug, which is being developed for rare blood and

kidney disorders, they said on Wednesday.

As part of the agreement, Novo gains exclusive global rights

to develop and commercialize Omeros' ( OMER ) drug zaltenibart, designed

to inhibit MASP-3 - a protein that acts as a key activator of

the alternative pathway of complement.

The complement pathway is a system of proteins in the blood

that enhances the immune system's ability to fight infections.

Omeros ( OMER ) is eligible to receive up to a total of $2.1 billion,

including $340 million upfront and near-term milestone payments.

The company had said in March it began enrollment for

late-stage trials studying the drug for paroxysmal nocturnal

hemoglobinuria (PNH), a rare blood disorder in which part of the

immune system attacks and damages the red blood cells and

platelets.

Zaltenibart has shown several potential advantages over

other alternative pathway inhibitors currently in development or

on the market, the companies said.

The drug was safe and well tolerated in the trials.

After the deal closes, expected in the fourth quarter of

2025, Novo aims to start a global program for zaltenibart in PNH

and explore development in a range of other rare blood and

kidney disorders.

Omeros ( OMER ) remains focused on securing approval for its other

experimental drug, narsoplimab, this quarter.

The company is pursuing approval for narsoplimab in the U.S.

and in Europe to treat transplant-associated thrombotic

microangiopathy, a complication that can arise after

hematopoietic cell transplantation.

Omeros ( OMER ) also retains certain rights to its preclinical MASP-3

programs unrelated to zaltenibart, including the ability to

develop and commercialize small-molecule MASP-3 inhibitors with

limited indication restrictions.