One of Novartis’ most important clinical catalysts of the year came Thursday, with the accelerated approval in the US of its rare kidney disease drug.
Atrasentan, which is now named Vanrafia, is a once-daily pill that may be used to treat protein accumulation in patients with primary IgA nephropathy (IgAN).
Specifically, the drug may be used in patients at risk of rapid disease progression, which is generally defined using the urine protein-to-creatinine ratio, according to
a release
. The drug can be added on top of supportive care, such as the widely used renin-angiotensin system inhibitors, with or without the kidney disease meds known as SGLT2 inhibitors.
Novartis has not yet disclosed the list price for Vanrafia.
IgAN is a chronic disease that occurs when abnormal antibodies build up in the kidney’s tiny filters, which can damage the organ. Some people who have IgAN eventually require dialysis or a transplant.
Importantly, the FDA did not require a risk evaluation mitigation strategy (REMS) program for Vanrafia. But patients must have their liver enzyme levels tested before and during treatment “when clinically indicated,” according to Novartis, as some similar drugs have been linked with increases in aminotransferases, hepatotoxicity and liver failure. The company also warned that Vanrafia may cause serious birth defects.
Unlike Travere Therapeutics’ Filspari, which won full approval last year for the disease, Vanrafia is not subject to a drug safety program, or REMS. Filspari is only available via a REMS because of risk of liver toxicity and birth defects.
Vanrafia, a selective endothelin A receptor antagonist, was approved on the strength of the ALIGN trial. In that study, it demonstrated a
significant 36.1% cut
in proteinuria, compared with placebo, after 36 weeks of treatment.
Reduction in protein in the urine is a surrogate biomarker for improvement in IgAN, though, and may not translate into actual clinical benefit. And so the ALIGN trial is continuing, with the aim of showing a decline in patients’ estimated glomerular filtration rate (eGFR), a measure of kidney function.
Those data could come next year, and the Swiss pharma hopes they will support full FDA approval. But if no benefit on kidney function is seen, the drug could be withdrawn.
Two other IgAN drugs — Calliditas Therapeutics’ Tarpeyo and Travere’s Filspari — also gained accelerated approval based on proteinuria reductions. However, when it came to their confirmatory eGFR readouts, Tarpeyo managed a hit and converted to full approval, but Filspari did not — despite posting a stronger effect on proteinuria.
As far as Novartis is concerned, that is a problem for the future. Its focus now is on ramping up sales. Novartis obtained Vanrafia via its
$3.2 billion acquisition of Chinook Therapeutics
in 2023, and the pill will have to do well commercially to help justify that deal.
Novartis US President Victor Bultó told
Endpoints News
ahead of the FDA decision that the company expects atrasentan to reach blockbuster status worldwide. He said that Novartis expects about a population of about 45,000 in the US to be eligible to receive the drug.
The company has another Chinook-originated IgAN asset in zigakibart. A subcutaneous anti-APRIL antibody, zigakibart is currently in Phase 3 trials, with results expected in 2026.
Novartis has yet another IgAN drug, Fabhalta, which was developed in-house and got US accelerated approval
last August
. Its pivotal study is continuing, and kidney function data could come late this year.
In an interview, Bultó explained that the three treatments tackle the heterogeneous disease in different ways.
“For many patients, the damage to the kidney has already happened, so you will need to manage the damage with drugs like atrasentan, drugs like iptacopan [Fabhalta]. What we will do with zigakibart hopefully — the anti-APRILs — is try to work upstream so that damage is minimized and we can treat as soon as possible,” said Bultó. “When we talk with nephrologists, they fully anticipate this to be a combination market, given the heterogeneity of the patients, and today, about 60% of them are already multiple therapies trying to slow down that proteinuria and that progression.”
Editor’s note: This article was updated to include further comments from Novartis.