Primary immunoglobulin A nephropathy (IgAN) is a kidney disease that happens when an antibody, called IgA, builds up in the kidneys. This can make your kidneys swell and not work well. The kidneys become scarred and damaged, leading to kidney failure. IgAN is a long-term (chronic) disease, so your health care provider will help manage symptoms through blood pressure control, changes in your diet, and medicines like immunosuppressants and corticosteroids. Tarpeyo is a corticosteroid medicine that helps protect kidney function. It is the only FDA-approved medicine to work directly where the IgA is formed.
How Does Tarpeyo Work?
Kidney disease from IgAN starts when the body creates abnormal IgA antibodies (IgA1). Antibodies are made by your immune system. When they are normal, they help your immune system protect you from bacteria and viruses. When the IgA antibodies are abnormal, like in IgAN, they stick together, forming larger groups. The immune system sees these groups as foreign, causing inflammation in the kidney. Over time, the inflammation scars the filtering units in the kidneys, called glomeruli. This kidney damage allows blood and proteins to leak into your pee (urine). Over time, this damage can lead to kidney failure, requiring dialysis or kidney transplant.
People with IgAN may not feel bad at first, but over time they commonly experience the following symptoms due to kidney damage:
- Blood in pee, which makes your pee look pink or red
- Foamy pee from the extra proteins
- Swelling in hands, feet, ankles, or face, especially in the morning or after specific foods
- High blood pressure
- Feeling very tired or weak
- Lower back pain
- Need to pee more often at night while sleeping
- Slowed growth in kids
Since the immune system is overacting, health care providers usually use medicines that treat the symptoms, like high blood pressure, and that control the immune system, like immunosuppressants and corticosteroids. The goal of treatment is to slow down the damage to the kidneys. Using immunosuppressants or general corticosteroids can treat the overactive immune system but can cause a lot of unwanted side effects with long-term use.
Tarpeyo is a corticosteroid that targets that specific area in the gut that is thought to play a role in IgAN. The IgA1 antibodies are created in the ileum, which is a specific part of the gut. Tarpeyo decreases the amount of IgA1 that is made. This leads to less inflammation and kidney function loss, with less long-term side effects.
How Should I Use This Medicine?
Tarpeyo is a capsule that is taken every morning, at least 1 hour before a meal.
Do not open, chew, or crush the capsule before you swallow it. Do not eat grapefruit or drink grapefruit juice during treatment (see the Interactions section below).
Do not stop using Tarpeyo without talking with your health care provider. Like other corticosteroids that are taken long-term, Tarpeyo can stop your body from making its own natural steroids. If you stop Tarpeyo too quickly, your body will not have enough steroids. This can cause your body to have symptoms of withdrawal, like fatigue, body aches, nausea, low blood pressure, and headaches. Therefore, you need to slowly decrease (or taper) the amount you take before stopping completely. When your health care provider decides to stop treatment, they will tell you how to taper the dose.
Talk with your pharmacist or health care provider if you have questions about how to take Tarpeyo.
How Was It Studied for Nephropathy?
One study was done to look at the safety and effectiveness of Tarpeyo for the treatment of primary IgAN compared with placebo. Placebo studies help researchers see differences in benefit or harm of a medicine when compared with no treatment.
People in the study had a diagnosis of IgAN with extra protein in their urine. Everyone had to be on specific blood pressure medicines that lower the pressure in the kidneys, like ACE inhibitors or ARBs. Most people in the study were White (85%), with 11% identifying as Asian and 1% as other. Over half of the people were male (68%), with an average age of 43.
The study included people with kidney damage and persistent protein in their pee (proteinuria). Based on the following tests, people were losing too much protein in their pee and had mild-to-moderate kidney function loss:
- Urine protein-to-creatinine ratio (UPCR) ≥ 0.8 g/g or ≥ 1 g/day of protein in their urine; both tests measure how much protein is in the urine over 24 hours.
- Estimated glomerular filtration rate (eGFR) of 35 mL/min/1.73m2 or greater, which measures how well your kidneys are working and filtering. This means that the people in the study had mild-to-moderate kidney function loss.
People took either Tarpeyo or placebo for 9 months. After 9 months, people stopped treatment and were monitored for another 15 months. Tarpeyo was considered effective if there was a decrease in kidney function loss. This was defined as a decrease in UPCR over 9 months of treatment and a decrease in the amount of kidney function loss at 24 months, based on eGFR changes.
What Benefits Were Seen in the Studies?
People who took Tarpeyo in the study saw a decrease in kidney damage when looking at the changes in UPCR and eGFR over 9 and 24 months. The benefits continued after Tarpeyo was stopped at 9 months.
Protein in the urine. At the end of 9 months, people taking Tarpeyo saw a 35% decrease in protein in their urine compared with 5% in people taking the placebo. This decrease was maintained through the full 24 months.
Table 1. Percent (%) Decrease in UPCR
Tarpeyo | Placebo | |
3 months | 5% | 4% |
6 months | 24% | 8% |
9 months | 35% | 5% |
12 months | 52% | 3% |
18 months | 44% | 7% |
24 months | 34% | 4% |
Kidney function. At the end of 24 months, people taking Tarpeyo had less kidney function loss than people taking the placebo. In the first 9 months, people taking Tarpeyo had a small increase in their eGFR compared to a decrease in eGFR in people taking placebo. By the end of 24 months, the time to further kidney damage was longer in the people taking Tarpeyo. The table below shows the average change in eGFR compared to the first measurement of the study. A positive (+) change means that the kidney function was better, where a negative (-) change means that the kidney function was worse.
Table 2. Change From Initial eGFR
Tarpeyo | Placebo | |
3 months | + 3.5 mL/min/1.73 m2 | - 1.6 mL/min/1.73 m2 |
6 months | + 1.5 mL/min/1.73 m2 | - 2.9 mL/min/1.73 m2 |
9 months | + 1.5 mL/min/1.73 m2 | - 4.0 mL/min/1.73 m2 |
12 months | - 0.8 mL/min/1.73 m2 | - 5.3 mL/min/1.73 m2 |
18 months | - 3.8 mL/min/1.73 m2 | - 9.1 mL/min/1.73 m2 |
24 months | - 5.3 mL/min/1.73 m2 | - 11.2 mL/min/1.73 m2 |
The study showed that using Tarpeyo for 9 months may slow down the damage to the kidneys. This may help with symptoms and delay kidney failure leading to dialysis.
Your results may differ from what was seen in clinical studies. You and your health care provider should determine if the benefits outweigh any potential risks.
When Will the Medicine Start Working?
If Tarpeyo is working, you will start to see small changes in the symptoms, like less blood or protein in your pee, lower blood pressure, less swelling, and less fatigue. It can take up to a year to see the full benefits. These results can last for a few years. Contact your health care provider if you don’t see improvements or continue to have symptoms that bother you.
How Can I Prevent and Manage Side Effects?
Tarpeyo increases the risk for infections since it weakens your immune system. You may see more common colds, flu, or urinary tract infections. Stay away from people that have infections like chickenpox or measles. The best way to prevent infection is to reduce your exposure to germs by washing your hands and avoiding people who are sick. Talk with your health care provider to determine the right timing of vaccinations. Call your health care provider if you have any of the following symptoms of infection:
- Fever or chills
- Body aches
- Cough
- Tiredness
- Persistent headache
- Confusion
- Vision changes
- Painful rash
Tarpeyo can cause swelling or high blood pressure. Talk with your health care provider about maintaining a healthy lifestyle, including diet and exercise. Limiting salt in your diet, drinking plenty of water, and light exercise (like walking) may help prevent swelling and decrease your blood pressure. Your health care provider will monitor your blood pressure and make changes to your blood pressure medicines, if needed.
Other common side effects include nausea or upset stomach, muscle cramps, acne, and headache. Follow a good skin care regimen, like gentler cleaners and oil-free moisturizers, if you have acne during treatment. Talk to your health care provider about topical medicines if the acne is bothersome.
These are not all of the possible side effects. Talk with your health care provider if you are having symptoms that bother you. In the U.S., you can report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088. In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.
What Monitoring or Blood Tests May I Need Before Starting Tarpeyo and During Treatment?
Your health care provider may perform lab tests to monitor your health and assess how your body responds to the medicine. The following are key pieces to that monitoring.
- Blood pressure
- Urinalysis or 24-hour urine test to check the amount of protein in your pee
- Blood tests to check kidney function, like creatinine clearance
- Blood tests to check for hepatitis B virus
What Types of Interactions Can Happen?
Several medicines and foods can affect the blood levels of Tarpeyo. Talk with your health care provider if you are using any of the following medicines or foods:
- Strong CYP3A4 inhibitors, which include ceritinib (Zykadia), clarithromycin (Biaxin), idelalisib (Zydelig), itraconazole (Sporanox, Tosura), and ketoconazole (Nizoral)
- Medicines used for HIV (like elvitegravir/ritonavir, indinavir/ritonavir)
- Grapefruit or grapefruit juice
This is not a complete list of medicines that may interact with Tarpeyo. Tell your pharmacist or health care provider about all the prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, or other supplements you take or have recently taken. This will help them determine if there are any interactions or if you need a dosage adjustment.
Getting Your Medicine: What to Expect
Tarpeyo is considered a specialty medicine, which is a high-cost medication that is taken for rare, complex, or long-term (chronic) diseases. It requires a different process than picking up a prescription at your local pharmacy. This process helps you stay on track with your treatment. The manufacturer has a program to help support the process.
Here are some differences that you may expect.
Insurance approval. Your insurance may require approval for using this medicine, also called a prior authorization. The insurance company reviews the prescription from your health care provider to make sure it is covered and determines the process that needs to be followed.
Pharmacy access. You may be required to use a specific pharmacy to get your medicine. Your health care provider will work with you and your insurance company on which pharmacy to use and the information that will be provided.
Co-pay assistance. There is a co-pay assistance program from the manufacturer that may allow you to pay $0 for your prescription. Whether you are eligible depends on whether you have prescription insurance and what type of insurance you have. You can find out more at www.tarpeyo.com/savings-and-support or by calling 833-444-8277.