The oral formulation of budesonide, marketed as Tarpeyo, is the only FDA-approved therapy that significantly reduces the loss of kidney function in immunoglobulin A nephropathy patients.
Pictured: FDA headquarters/iStock, Grandbrothers
The FDA on Wednesday gave its full approval to Calliditas Therapeutics’ Tarpeyo (budesonide) delayed release capsules for the treatment of adults with primary immunoglobulin A nephropathy.
Tarpeyo is now the only authorized immunoglobulin A nephropathy (IgAN) treatment that significantly cuts the loss of kidney function, according to Calliditas’ announcement.
Calliditas CEO Renee Aguiar-Lucander in a statement said that the company is “thrilled” about Tarpeyo’s full approval, which will give IgAN patients a “pioneering treatment option” that can slow disease progression and help preserve kidney function.
Tarpeyo, which was “specifically developed to target the underlying cause of IgAN,” according to Aguiar-Luander, is an orally available formulation of budesonide delivered via delayed release capsules. It works by exerting an anti-inflammatory and immunosuppressive effect on glucocorticoid receptors, in turn lowering the production of the faulty IgA molecules that cause the autoimmune disease IgAN.
This mechanism of action helped pave the way for an accelerated approval for Tarpeyo in December 2021 for the treatment of IgAN in patients who are at high risk of disease progression. In August 2023, the FDA granted Tarpeyo’s supplemental New Drug Application for full approval its priority review designation.
As part of its obligations under the accelerated pathway, Calliditas ran the Phase III NefIgArd trial which assessed a once-daily 16-mg dose of Tarpeyo in adult IgAN patients who are on optimized therapy with renin-angiotensin system inhibitors.
The study showed that after nine months of treatment and 15 months of follow-up, patients treated with Tarpeyo saw significantly better kidney function, as measured by the estimated glomerular filtration rate (eGFR) versus placebo. At two years, patients given Tarpeyo saw 50% lower deterioration in kidney function than those in the placebo arm.
Tarpeyo’s label does not carry a boxed warning but comes with precautions against hypercorticism and adrenal axis suppression as well as the risk of immunosuppression.
The full approval of Tarpeyo comes more than a month after Travere released data from its Phase III PROTECT study in IgAN showing that its approved therapy Filspari (sparsentan) could substantially slow the rate of kidney function decline in IgAN patients.
The PROTECT data is Travere’s attempt at regaining Filspari’s footing in IgAN. The dual endothelin angiotensin receptor antagonist won the FDA’s accelerated approval in February 2023. However, in September 2023 the treatment fell short of one of its eGFR endpoints.
Novartis is another player in the IgAN arena. The company’s investigational endothelin A receptor antagonist atrasentan aced the Phase III ALIGN study in October 2023, inducing significant reductions in proteinuria compared with placebo.
Tristan Manalac is an independent science writer based in Metro Manila, Philippines. He can be reached at tristan@tristanmanalac.com or tristan.manalac@biospace.com.
