Filspari

Filspari is used to slow kidney function decline in adults with primary immunoglobulin A nephropathy (IgAN) who are at risk for disease progression or to reduce proteinuria in adults and children 8 years and older with focal segmental glomerulosclerosis (FSGS) without nephrotic syndrome. It is taken orally once a day.

• Filspari is the first and only medicine approved by the FDA for FSGS and is currently the most commonly prescribed medicine for IgAN.

Filspari works by blocking two receptors, ETAR and AT1R, that drive kidney damage in IgAN and FSGS, helping to prevent kidney inflammation, scarring, and vasoconstriction. Filspari belongs to the drug class called Endothelin and Angiotensin II Receptor Antagonists.

Filspari (sparsentan) gained FDA approval on February 17, 2023. There is no generic.

Filspari will be provided to you by a certified pharmacy. Your healthcare provider will give you complete details. Take Filspari exactly as your healthcare provider tells you to take it. Do not stop taking Filspari unless your healthcare provider tells you. Your healthcare provider may change your dose, temporarily stop, or permanently stop treatment with Filspari if you develop side effects.

• Filspari is taken once a day.
• Swallow your Filspari tablets whole with water before your morning or evening meal.
• Take your dose of Filspari before the same meal each day.

If you cannot swallow the tablet whole, you may crush Filspari and mix it in water only right before you take it. Do not mix Filspari with other liquids.

• Crush the Filspari tablet in a clean pill crusher or mortar and pestle.
• Mix the crushed Filspari in half a cup of water. The crushed medicine will not completely dissolve in the water.
• Drink all of the mixture right away.
• If any of the pieces are left in the cup, add a little more water to the cup, swirl to mix, and drink right away.
• Do not store the mixed solution for later use.

Filspari carries a Boxed Warning for hepatotoxicity (liver toxicity) and embryo-fetal toxicity (serious birth defects). It can cause serious side effects, such as liver problems and serious birth defects.

Liver problems

Filspari can cause changes in liver tests. Liver failure was not observed in people treated with Filspari in clinical studies, but some medicines that are like Filspari have caused liver failure. Your healthcare provider will do blood tests to check your liver before starting treatment with Filspari and then every 3 months during treatment. Your healthcare provider may temporarily stop or permanently stop treatment with Filspari if you have changes in your liver tests.

Stop taking Filspari and get medical help right away if you develop any of the following signs of liver problems during treatment with Filspari:

• Nausea or vomiting
• Pain in the upper right side of your stomach area
• Tiredness
• Loss of appetite
• Yellowing of your skin or the white part of your eyes (jaundice)
• Dark “tea-colored” urine
• Fever
• Itching.

Because of the risk of liver problems, Filspari is only available through a restricted-access program called the Filspari Risk Evaluation and Mitigation Strategy (REMS). Before you begin treatment with Filspari, your healthcare prescriber will explain the Filspari REMS, you must read, and agree to all of the requirements of the Filspari REMS.

Serious birth defects

Filspari can cause serious birth defects if taken during pregnancy. Patients who can become pregnant should not be pregnant when they start taking Filspari or become pregnant during treatment with Filspari or for two weeks after stopping treatment with Filspari. Patients who can become pregnant should have a negative pregnancy test before starting treatment with Filspari.

Patients who can become pregnant are those who:

• Have entered puberty, even if they have not started their menstrual period, and
• Have a uterus, and
• Have not gone through menopause. Menopause means that you have not had a menstrual period for at least 12 months for natural reasons, or that you have had your ovaries removed.

Patients who cannot become pregnant are those who:

• Have not yet entered puberty, or
• Do not have a uterus, or
• Have gone through menopause. Menopause means that you have not had a menstrual period for at least 12 months for natural reasons, or that you have had your ovaries removed, or are infertile for any other medical reason, and this infertility is permanent and cannot be reversed.

Patients who can become pregnant should use effective birth control before starting treatment with Filspari, during treatment with Filspari, and for two weeks after stopping Filspari because the medicine may still be in your body.

• Talk with your healthcare provider or gynecologist (a healthcare provider who specializes in reproduction) to find out about options for effective forms of birth control that you may use to prevent pregnancy during treatment with Filspari.
• If you decide that you want to change the form of birth control that you use, talk with your healthcare provider or gynecologist to be sure that you choose another effective form of birth control.
• Do not have unprotected sex. Talk to your healthcare provider or pharmacist right away if you have unprotected sex or if you think your birth control has failed. Your healthcare provider may talk with you about using emergency birth control.
• Tell your healthcare provider right away if you miss a menstrual period or think you may be pregnant.
• If you are the parent or caregiver of a female child who started taking Filspari tablets before reaching puberty, you should check your child regularly to see if they are developing signs of puberty. Tell their healthcare provider right away if you notice that your child is developing breast buds or pubic hair. Their healthcare provider should decide if your child has reached puberty. Your child may reach puberty before having their first menstrual period.

Do not take Filspari if you:

• are pregnant, plan to become pregnant, or become pregnant during treatment with Filspari. Filspari may cause serious birth defects. See Important information above.
• are taking an angiotensin receptor blocker, endothelin receptor antagonist, or aliskiren. Ask your healthcare provider or pharmacist if you are not sure if you take any of these medicines.

Before taking Filspari, tell your healthcare provider about all of your medical conditions, including if you:

• have liver problems
• are pregnant or plan to become pregnant during treatment with Filspari. Filspari may cause serious birth defects
• are breastfeeding or plan to breastfeed. It is not known if Filspari passes into your breast milk. Do not breastfeed during treatment with Filspari. Talk to your healthcare provider about the best way to feed your baby during treatment with Filspari.

It is not known if Filspari is safe and effective in children less than 8 years of age with FSGS.

It is not known if Filspari is safe and effective in children with IgAN.

Common Side Effects

The most common side effects of Filspari also include:

• swelling of hands, legs, ankles, and feet (peripheral edema)
• dizziness
• low red blood cells (anemia).

Serious side effects

Filspari can cause serious side effects, including:

• Liver problems. See Important Information above
• Serious birth defects. See Important Information above
• Low blood pressure. Low blood pressure is common during treatment with Filspari and can also be serious. Tell your healthcare provider if you feel dizzy, light-headed, or faint. Stay hydrated during treatment with Filspari.
• Worsening of kidney function. This is common during treatment with Filspari and can also be serious. Your healthcare provider will check your kidney function during treatment with Filspari.
• Increased potassium in your blood. This is common during treatment with Filspari and can also be serious. Your healthcare provider will check your potassium blood level during treatment with Filspari.
• Fluid retention. Filspari can cause your body to hold too much water. Tell your healthcare provider right away if you have any unusual weight gain or swelling of your ankles or legs.

Your healthcare provider may change your dose, temporarily stop, or permanently stop treatment with Filspari if you develop side effects.

These are not all of the possible side effects of Filspari.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Filspari is available only through a restricted distribution program called the Filspari Risk Evaluation and Mitigation Strategies (REMS) due to the risk of liver damage.

• Prescribers must be certified with the Filspari REMS by enrolling and completing training.
• All patients must enroll in the Filspari REMS before initiating treatment and comply with monitoring requirements.
• Pharmacies that dispense Filspari must be certified with the REMS program and must dispense only to patients authorized to receive this medicine.
• Further information is available at www.filsparirems.com or 1-833-513-1325.

Before starting Filspari, your healthcare provider may discontinue or adjust the dosage of any interacting medications you may be taking.

Adult Dose of Filspari For IgAN

• Initial: 200 mg orally once daily
• After 14 days: Increase to 400 mg once daily if tolerated.

Dose of Filspari for FSGS

Weight > 50 kg

• Initial: 400 mg orally once daily
• After 14 days: Increase to 800 mg once daily if tolerated.

Weight ≤ 50 kg

• Initial: 200 mg orally once daily
• After 14 days: Increase to 400 mg once daily if tolerated.

If you miss a dose, take the next dose at the regularly scheduled time. Do not take 2 doses at the same time or take extra doses.

If you take too much Filspari, call your healthcare provider or go to the nearest hospital emergency room right away.

Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, herbal supplements, and grapefruit. Filspari and other medicines may affect each other and cause side effects. Especially tell your healthcare provider if you take:

• Strong CYP3A inhibitors (such as ketoconazole, itraconazole, or clarithromycin)
• Moderate CYP3A inhibitors (such as erythromycin, diltiazem, or verapamil)
• Strong CYP3A inducers (such as rifampin, phenytoin, or carbamazepine)
• Antacids. Avoid within 2 hours before or after Filspari. Examples include aluminum hydroxide, magnesium hydroxide, and calcium carbonate
• Acid-reducing agents, such as omeprazole, famotidine, and ranitidine.
• NSAIDs/COX-2 inhibitors, such as ibuprofen, naproxen, and celecoxib. Monitor for worsening renal function (increased kidney injury risk)
• CYP2B6, 2C9, and 2C19 substrates, such as warfarin, phenytoin, and clopidogrel
• Sensitive P-gp and BCRP substrates, such as digoxin, rosuvastatin, and dabigatran
• Agents increasing serum potassium, such as potassium supplements, spironolactone, and amiloride. Monitor potassium frequently (increased hyperkalemia risk)
• Grapefruit and grapefruit products.

Ask your healthcare provider or pharmacist if you are not sure if you take one of these medicines.

Store at room temperature between 68°F and 77°F (20°C and 25°C) in the original container. The bottle has a child-resistant closure.

Keep out of the reach of children.

Active ingredient: sparsentan

Inactive ingredients: colloidal silicon dioxide, lactose anhydrous, magnesium stearate, silicified microcrystalline cellulose, and sodium starch glycolate. Tablets are film-coated with material containing macrogol/polyethylene glycol, polyvinyl alcohol-partially hydrolyzed, talc, and titanium dioxide.

Filspari is available as 200 mg and 400 mg tablets.

Filspari (sparsentan) is distributed by Travere Therapeutics, Inc., San Diego, CA 92130.