FDA Grants Full Approval to Tarpeyo for Rare Kidney Disease

The FDA has granted full approval to Tarpeyo (budesonide) delayed release capsules to reduce the loss of kidney function in adults with primary IgA nephropathy (IgAN). It is an oral, delayed release formulation of budesonide, a corticosteroid designed to deliver treatment to an area of the gut believed to play a role in IgAN.

Primary immunoglobulin A nephropathy (IgAN) is a rare, progressive, chronic autoimmune disease that attacks the kidneys. Also called Berger’s disease, it can lead to progressive kidney damage. About 60,000 people in the United States have IgAN, according to the National Kidney Foundation. A 2023 study published in the journal Kidney Medicine used an Optum database to calculate a prevalence of 329 per 1 million, which would work out to about 110,000 people in having the disease in the current U.S. population.

Developed by Calliditas Therapeutics, Tarpeyo (pronounced tar-PAY-oh) was granted accelerated approval in December 2021 based on the surrogate marker of proteinuria, which is an elevation of protein level in the urine. The therapy targets the mucosal B cells in the ileum, which is the last part of the small intestine. The mucosal B cells are thought to play an important role in IgAN.

The whole acquisition cost (WAC) price of a month’s supply of the drug (120 capsules) is $15,123, according to the Red Book. Tarpeyo is available through Biologics by McKesson, a specialty pharmacy.

According to an analysis by Calliditas, 97% of patients with commercial insurance who have taken advantage of a company patient support program have paid less than $10 per prescription and 88% have had no out-of-pocket expense. People without health insurance may be eligible for the assistance program, which is called Tarpeyo Touchpoints.

When it was in development, Tarpeyo had a different name, Nefecon. The FDA’s approval is based on data from the phase 3 trial conducted at 132 hospital-based clinical sites in 20 countries. Researchers randomly assigned 364 patients to receive 16 milligrams per day of the drug plus optimized renin-angiotensin system inhibitor (RASi) treatment or a placebo, also with optimized RASi treatment, for nine months, followed by a 15-month observational follow-up period off study drug. The study participants had received supportive care (blood pressure control, sodium restriction and maximally tolerated RASi) throughout the two-year trial. The primary end point was time-weighted average of estimated glomerular filtration rate over the two-year study point. The results showed a statistically significant benefit from Tarpeyo on that end point (-2.47 mL/min per 1.73 m2 for the drug vs. -7.52 mL per 1.73 m2 for the placebo).

Most treatment-emergent adverse events were mild or moderate and included peripheral edema, hypertension, muscle spasms, acne and headache. Those events led to discontinuation in less than 10% of patients. The FDA-approved package insert for Tarpeyo says that most of the adverse reactions that occurred at a greater incidence for the drug relative to the placebo are consistent with hypercortisolism and resolve within three months after discontinuation.

The full results of the phase 3 study were published in September 2023 in The Lancet.