TARPEYO®/Kinpeygo® (developed under the project name Nefecon®) is a second-generation, synthetic, non-halogenated form of the corticosteroid budesonide. The delayed release formulation of budesonide has shown greater efficacy for protein reduction and slowing the decline in kidney function in primary immunoglobulin A (IgA) as well as a much better safety profile than conventional corticosteroids. As such, it will likely experience high uptake for high-risk patients.

Calliditas Therapeutics AB has partnered with STADA Arzneimittel AG to commercialize Kinpeygo in Europe and with Everest Medicines to commercialize TARPEYO in Mainland China, Hong Kong, Macau, Taiwan, South Korea and Singapore.


  1. Calliditas Therapeutics AB, Everest Medicines and STADA Arzneimittel AG
  2. Delayed release corticosteroid formulation
  3. Daily oral administration to reduce proteinuria in adults with IgA nephropathy at risk of rapid disease progression
  4. Also being evaluated to treat autoimmune hepatitis (AIH) and primary biliary cholangitis
  5. ~500k diagnosed prevalent adult cases of IgA nephropathy in the G7 markets in 2023

Why is it a drug to watch?

With its modified targeted drug release technology, this second-generation synthetic nonhalogenated form of budesonide provides superior safety and efficacy compared with first-generation corticosteroids. The 4-mg delayed-release capsule is enteric-coated so it remains intact until it reaches the ileum where it targets the mucosal B cells, including Peyer’s patches, responsible for the IgA-causing complexes. Because of the absorption characteristics, it may result in fewer side effects than other corticosteroids despite prolonged use.

Submissions for regulatory approval have been based on data from the phase 3, placebo-controlled NefIgArd clinical trial. The study was conducted with adult patients with primary IgA nephropathy who were at risk of progressing to end-stage renal disease (ESRD) despite maximum tolerated treatment with optimized renin-angiotensin system (RAS) blockade. Budesonide treatment lasted nine months, followed by a 15-month observational follow-up period off the study drug. The results demonstrated slowed progression of IgA nephropathy with budesonide:

  1. 34% reduction in proteinuria (urine protein-to-creatinine ratio [UPCR]) at nine months with budesonide, compared with 5% with placebo
  2. Greater reductions in UPCR with budesonide continued at two years
  3. Significantly greater reduction in eGFR with budesonide vs placebo at nine months and two years

Review and
approval status

November 2016

  • Orphan drug designation: EMA

November 2020

  • Breakthrough therapy designation: Mainland China NMPA

December 2021

  • Accelerated approval granted: U.S. FDA

July 2022

  • CMA granted: EMA

November 2022

  • NDA accepted: Mainland China NMPA

February 2023
For adult patients with IgA neuropathy at risk of rapid disease progression (UPCR ≥1.5 g/g)

  • CMA granted: U.K. MHRA

June 2023

  • sNDA accepted: U.S. FDA

August 2023

  • Priority review granted: U.S. FDA

September 2023

  • MAA filed: EMA

October 2023

  • MAA filed: U.K. MHRA

December 2023

  • Approved: U.S. FDA

Actual and expected launch:

  • 2021: United States
  • 2022: European Union, United Kingdom
  • 2024: Mainland China

Patents estimated to expire beginning in 2028

How will budesonide impact the market for IgA nephropathy/Berger’s disease?

  1. The IgA nephropathy market is poised for robust growth, primarily due to the emergence of various therapies targeting the disease at different stages in its pathogenesis.
  2. Before the approval of TARPEYO/Kinpeygo, IgA nephropathy treatment was based only on supportive therapy, which included long-standing genericized therapies such as renin-angiotensin-aldosterone system (RAAS) inhibitors, diuretics, corticosteroids and immunosuppressants.
  3. TARPEYO/Kinpeygo will likely be used primarily with high-risk patients, in preference to general corticosteroids.

What gaps in treatment does budesonide fill?

IgA nephropathy is a rare, progressive kidney disorder that can lead to end-stage renal disease requiring dialysis or a kidney transplant. IgA nephropathy generally progresses slowly, and treatment is primarily directed at managing symptoms, minimizing kidney failure and improving patient quality of life through multidisciplinary supportive care. Clinicians are looking for a more holistic approach that takes into account all of these aims (i.e., reduce protein levels and improve kidney function and therefore quality of life). Therefore, effective, safe and well-tolerated drugs that protect kidney function or slow the progressive decline in GFR are needed. Because of its better efficacy and safety, budesonide will likely provide physicians with an alternative option to conventional corticosteroids.

What hurdles might it need to overcome to reach blockbuster status?

The extremely high price of TARPEYO/Kinpeygo will likely constrain its use, especially since nephrologists are reluctant to prescribe expensive therapies unless they are shown to be significantly more effective. In addition, other potential competitors that specifically treat IgA nephropathy have already been approved or are in late-stage development, which could make it a crowded market.

expected sales for IgA nephropathy in the G7 markets in 2029
probability of success for IgA neuropathy in South Korea
Source: Cortellis Competitive Intelligence, Drug Timeline & Success Rates Prediction current as of December 15, 2023

Drug Timeline &
Success Rates

– Source: Cortellis Competitive Intelligence, Drug Timeline & Success Rates Prediction current as of December 15, 2023

Drugs to Watch 2024

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