Current Standard of Care and Treatment Options

Treating IgA Nephropathy (IgAN) has evolved significantly in recent years. The current standard of care follows a “layered” approach, starting with a strong foundation of supportive care and adding disease-specific therapies if the risk of kidney decline remains high ^[1][2].

The primary goal of all these treatments is to protect your kidney function by reducing the amount of protein leaking into your urine (proteinuria). Current guidelines aim for a proteinuria level below 0.5 g/day, though reaching levels below 0.3 g/day may offer even greater long-term protection ^[3][1].

Layer 1: The Foundation (Supportive Care)

Before starting newer drugs, every patient should have “optimized” supportive care. This foundation alone can significantly slow the progression of the disease for many people.

• RAAS Blockade: This is the use of ACE inhibitors (like lisinopril) or ARBs (like losartan). These drugs do more than just lower blood pressure; they reduce the pressure inside the kidney’s filters, which helps stop protein from leaking out ^[4][2]. Doctors aim for the “maximally tolerated dose” to get the most benefit. Monitoring of blood potassium and creatinine is required. ACE inhibitors and ARBs are generally avoided during pregnancy.
• Blood Pressure Control: Guidelines suggest aiming for a properly standardized clinic systolic blood pressure below 120 mm Hg when tolerated to protect the kidneys from further strain ^[1].
• Dietary Sodium Restriction: Limiting salt to less than 2 grams of sodium per day (about one teaspoon of salt) is essential, as salt can interfere with the effectiveness of your blood pressure medications ^[1].

Layer 2: Kidney Protection (SGLT2 Inhibitors)

If your risk remains high despite the foundation, your doctor may add an SGLT2 inhibitor (such as dapagliflozin or empagliflozin). Originally used for diabetes, these drugs have been shown to provide significant “kidney-protective” benefits for people with IgAN, even if they do not have diabetes ^[5][6].

• What to expect: When you first start an SGLT2 inhibitor, it is normal to see a small, temporary dip in your kidney function numbers (eGFR). This is usually a sign the drug is working to reduce pressure in the kidney ^[7], but a large or persistent fall should be evaluated.
• Side effects: Common risks include an increased chance of genital yeast infections, volume depletion, and more rarely, a serious condition called ketoacidosis. These medications are often temporarily stopped during periods of severe illness or surgery (“sick day rules”) ^[8][9].

Layer 3: Disease-Specific Therapies

For patients who still have high levels of protein in their urine (typically >0.5 g/day or >1 g/day) despite Layer 1 and 2, newer targeted therapies may be considered ^[1].

Sparsentan (Filspari)

Sparsentan is a newer type of medication called a Dual Endothelin-Angiotensin Receptor Antagonist (DEARA). Unlike other drugs that are added to your ACE inhibitor or ARB, Sparsentan is usually used instead of them ^[10]. It must not be co-administered with an ACE inhibitor or ARB.

• How it works: It blocks two different pathways that cause kidney stress and scarring. In clinical trials, it reduced proteinuria by approximately 40% to 50% more than standard ARB treatment alone ^[11][10].
• Monitoring: Because it can affect fluid levels and liver function, patients require regular blood tests and monitoring for low blood pressure, hyperkalemia, or swelling (edema) ^[11]. It carries serious warnings for embryo-fetal toxicity, requiring strict pregnancy prevention and contraception.

Targeted-Release Budesonide (Tarpeyo/Nefecon)

This is a specialized steroid designed to release its medicine in a specific part of the gut (the ileum) to target mucosal immunity ^[12].

• How it works: By targeting the gut, it seeks to modulate the immune activity that causes IgAN. It is typically taken for a 9-month course ^[12].
• Side effects: While it is designed to be more “targeted” than traditional steroids, it remains a corticosteroid, meaning patients must be monitored for adrenal suppression, increased infection risk, mood or metabolic effects, swelling (edema), high blood pressure, and acne ^[12][13].

Finding Your Path

These therapies are not “one-size-fits-all.” Eligibility depends on your specific eGFR levels, your biopsy results (MEST-C score), and how your body responds to the foundational treatments ^[1][2]. Your care team will use these tools to select the options that are right for your risk profile. Additionally, systemic glucocorticoids (like prednisone) may be considered in carefully selected high-risk patients, while rapidly progressive disease may require urgent specialist treatment with glucocorticoids plus cyclophosphamide.