By Puyaan Singh and Bhanvi Satija

March 17 (Reuters) - R1 Therapeutics said on Tuesday it

had launched operations with a $77.5 million Series A funding

round and an exclusive license to develop and commercialize a

drug for high phosphate levels in chronic kidney disease

patients.

The company licensed AP306, being developed as a monotherapy

for hyperphosphatemia in patients on dialysis, from China-based

Alebund Pharmaceuticals.

Chief Executive Krishna Polu said regulators have "worked

hard to identify pathways for accelerated approval of drugs

around surrogate endpoints," creating momentum in kidney

therapeutics that is drawing greater interest from investors and

drugmakers and "provides opportunities to get new medicines to

patients faster."

Surrogate endpoints are indirect measures - like lab tests

or imaging - used instead of outcomes such as living longer or

feeling better.

R1's immediate focus is to move AP306 into a mid-stage trial

in the first half of 2026, with data expected in the first half

of next year, Polu said.

If successful, the company plans to start late-stage

development by the end of 2027, and will raise capital to fully

fund the program, carry out regulatory submissions and launch

early.

The current round should carry the program through mid-stage

and initial late-stage preparations.

Polu said existing treatments have changed little in 60

years and often require multiple pills with meals and cause

stomach problems.

AP306 is a single pill taken two or three times daily by

shutting down all three known active phosphate transporters in

the gut, he added.

R1 intends to commercialize AP306 in the U.S. by itself, and

seek partners in Europe, the UK and Japan.

Polu said Medicare's Transitional Drug Add-on Payment

Adjustment, which temporarily pays for new dialysis drugs while

the agency collects data to decide future coverage, will be

supportive of the therapy's commercial opportunity.

The funding round was co-led by Carlyle's Abingworth,

DaVita's ( DVA ) Venture Group and F-Prime, with Curie.Bio,

SymBiosis and U.S. Renal Care also participating.