Chugai buys 'Asia lag' firm Renalys for $98m upfront

Roche's Japanese unit Chugai Pharma has reached a deal to buy Renalys Pharma, a company set up to bring therapies developed elsewhere to markets in Asia.

Chugai is paying JP 15 billion ($98 million) upfront for Tokyo-based Renalys, with another JPY 16 billion on the table if its lead drug sparsentan reaches the market in Japan, South Korea, and Taiwan and achieves sales targets.

Sparsentan is an oral antagonist of endothelin type A (ETA) and angiotensin II subtype 1 (AT1) receptors, developed by Travere Therapeutics, which has been approved as Filspari in the US and Europe as a treatment for the rare kidney disorder IgA nephropathy, a leading cause of kidney failure.

Renalys was specifically founded to tackle Asia's 'drug lag', the delay in new drug approvals in Asian countries compared to their first approval in other parts of the world, specifically focusing on medicines for kidney diseases.

A study by the Tokyo Foundation published last year, for example, concluded that drug pricing policies in Japan have proved a disincentive to international companies bringing new therapies to market there, leading to a steep decline in its global pharma market share.

Co-founded by Catalys Pacific and SR One, Renalys emerged in January 2024 with a plan to start an open-label, registrational study for sparsentan to generate the data needed for approval in a Japanese IgAN patient population.

Since then, it has raised JPY 6 billion in a Series A financing, completed enrolment in the IgAN study, and received approval from the authorities in Japan to start follow-up phase 3 trials of sparsentan in two other kidney disease indications – focal segmental glomerulosclerosis (FSGS) and inherited disorder Alport syndrome (AS).

Travere – which made around $155 million in Filspari sales in the US alone in the first six months of the year – has already filed for approval of Filspari for FSGS in the US, but does not have an active development programme in AS.

Chronic kidney disease (CKD) and end-stage renal disease (ESRD) impose a significant burden on Japan’s healthcare system and represent a major social issue, according to Renalys, which says that the ageing of the population means it is also a growing problem.

Current treatments for IgAN in Japan are inadequate, according to the company, and rely on steroids, drugs targeting the renin-angiotensin-aldosterone system (RAAS), and surgery to remove the tonsils and reduce IgA levels.

"Transferring sparsentan to Chugai, a company recognised for its rare-disease and nephrology expertise, will accelerate access for patients across Asia," it said in a statement.