In what is welcome and exciting news for many immunoglobulin A (IgA) nephropathy (IgAN) patients, the Food and Drug Administration (FDA) has approved the first medication ever to reduce proteinuria (increased protein levels in the urine) in patients at risk of rapid disease progression. 

IgA deposits that build up in the kidneys can cause them to leak blood and protein into the urine. Researchers are hopeful this drug will be a game-changer in reducing protein levels that can lead to further complications. Proteinuria currently affects nearly 7% of the United States population. 

About the Drug 

Tarpeyo® is a delayed-release capsule form of budesonide developed by Calliditas Therapeutics. It is a corticosteroid and immunosuppressant. While budesonide has been used to treat and manage a variety of conditions, such as Crohn’s disease, ulcerative colitis, and asthma, Tarpeyo is the first formulation approved to treat proteinuria in IgAN patients. 

The drug was approved after a randomized, double-blind study that tracked patients with IgAN, reduced kidney function, and proteinuria taking a stable dose of maximally tolerated renin-angiotensin system (RAS) inhibitor therapy. Participants receiving Tarpeyo had an average 34% reduction in urine protein-to-creatinine ratio (UPCR) compared to participants receiving the placebo, who had an average 5% reduction.

While it has not been established whether Tarpeyo slows kidney function decline in IgAN patients, researchers are optimistic that it represents a significant step forward in the overall management of the disease. “We are very excited to bring the first and only FDA-approved treatment to reduce proteinuria in IgAN to market,” said  Renée Aguiar-Lucander, Chief Executive Officer of Calliditas. “Tarpeyo represents an FDA-approved product to help these patients who are at risk of rapid disease progression.”

Safety Information and Side Effects

The FDA reports that patients who have allergic reactions to budesonide or any ingredients in Tarpeyo must not take the medication. Since Tarpeyo is an immunosuppressant, patients should not take Tarpeyo if they have tuberculosis; untreated fungal, bacterial, systemic viral or parasitic infections, or ocular herpes simplex (an eye infection). Calliditas offers complete safety information here. 

*FDA. (2021, Dec. 15). FDA approves first drug to decrease urine protein in IgA nephropathy, a rare kidney disease. 

*PR Newswire. (2021, Dec. 15). FDA grants Calliditas Therapeutics Accelerated Approval of TARPEYO™ (budesonide) to Reduce Proteinuria in IgA Nephropathy