Atrasentan data backs up Novartis’ $3.5bn Chinook deal

Novartis’ bid to build a strong presence in the treatment of rare kidney disease IgA nephropathy (IgAN) has been boosted by phase 3 data with atrasentan, the main asset in its $3.5 billion acquisition of Chinook Therapeutics earlier this year.

Results of the ALIGN study show that the oral endothelin A receptor antagonist (ERA) met its main objective of reducing levels of protein in the urine (proteinuria), a surrogate marker for kidney function, more effectively than placebo after 36 weeks’ treatment.

The drug was given on top of supportive care with a renin-angiotensin system (RAS) inhibitor in the study, which is continuing to accrue data and should have a readout on estimated glomerular filtration rate (eGFR) – another marker for kidney function – in the first quarter of 2026.

Armed with the new data, Novartis is hoping to file for accelerated approval of atrasentan for IgAN while it waits for the full eGFR dataset from ALIGN.

IgAN is a progressive disease, occurring when antibodies accumulate in the kidneys, causing inflammation and scarring, and is a major cause of chronic kidney disease (CKD) and kidney failure.

Each year, approximately 25 people per million worldwide are newly diagnosed with the condition and, for a long time, the standard treatment was broad-spectrum immunosuppressant drugs with potentially serious side effects.

In 2021, Calliditas Therapeutics’ corticosteroid-based Tarpeyo (budesonide) became the first FDA-approved therapy for IgAN, and in February it was joined by Travere Therapeutics’ Filspari (sparsentan), which is in the same class as atrasentan.

Novartis has its sights set on the IgAN with three different therapies for the disease. Alongside atrasentan is oral complement factor B inhibitor iptacopan, which reported top-line phase 3 results earlier this month, as well as zigakibart (BION-1301), a subcutaneously administered anti-APRIL antibody, which was due to start phase 3 testing in IgAN in the third quarter of this year.

Novartis is additionally angling to file for accelerated approval of iptacopan while it waits for the final data of the APPLAUSE trial in IgAN, which came after positive results for the drug in ultra-rare blood disorder paroxysmal nocturnal haemoglobinuria (PNH).

The Swiss pharma group paid $3.2 billion upfront for Chinook in a deal agreed in June that also includes another $300 million in the form of a contingent value right (CVR) tied to regulatory approvals for atrasentan in IgAN, as well as follow-up indication focal segmental glomerulosclerosis (FSG).