Last updated, April 3, 2026

Dear Healthcare Provider,

We are writing to inform you of an important update regarding TAVNEOS® (avacopan), which was approved by the U.S. Food and Drug Administration (FDA) in Oct 2021 for the adjunctive treatment of adult patients with severe active anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV) in combination with standard therapy including glucocorticoids.1 TAVNEOS was developed by ChemoCentryx, Inc. Amgen acquired ChemoCentryx in Oct 2022, after TAVNEOS had been on the market for a year.

On January 16th, 2026, the FDA requested that ChemoCentryx voluntarily withdraw TAVNEOS from the U.S. market. The FDA raised concerns about the process followed by ChemoCentryx to re-adjudicate primary endpoint results for 9 of the 331 patients in the ADVOCATE trial. Hepatotoxicity, described in Warnings and Precautions in the U.S. Prescribing Information (USPI), was also raised in the context of the benefit-risk profile of the medicine. Amgen is not aware of any issues with underlying patient data and remains confident that TAVNEOS offers an effective treatment for AAV, with a favorable benefit-risk profile based on review of clinical trial data and real world evidence.

On January 28th, 2026, following the FDA regulatory process, Amgen informed the FDA that it did not intend to withdraw TAVNEOS from the market.

On March 31, 2026, the FDA issued a Drug Safety Communication (DSC) in which they alerted patients and health care professionals about serious liver injury cases, including fatal cases, of drug-induced liver injury (DILI) associated with TAVNEOS. Some cases of DILI involved vanishing bile duct syndrome (VBDS), a rare and severe liver injury.

Hepatotoxicity is a known risk of TAVNEOS. In clinical trials for TAVNEOS, serious liver injury was observed, and the approved label for TAVNEOS includes a warning about hepatoxicity. Since approval in 2021, cases of VBDS have been reported outside the United States, primarily in Japan, and in patients aged 65 years and older, including cases with a fatal outcome.2 As reported in the DSC, the majority of VBDS cases occurred within 60 days of TAVNEOS initiation and might present with clinical symptoms of jaundice, pruritus, or fatigue. VBDS may affect patients of any age or ethnicity receiving TAVNEOS.

Patient safety always comes first for Amgen and in 2024 we proactively submitted a proposed update to the FDA to add VBDS to the TAVNEOS label.

We will inform you of any further updates. At this time, healthcare providers should refer to the USPI guidance for important safety information related to TAVNEOS. Related to hepatotoxicity, the DSC also includes additional recommendations for monitoring symptoms and liver panel tests, as well as guidance for discontinuation of TAVNEOS.

For all questions, contact Medical Information at +1-800-772-6436 (+1-800-77-Amgen) or www.amgenmedinfo.com.

Amgen continues to work with the FDA to determine next steps, while keeping patient safety, needs, and support at the forefront.

We remain confident that TAVNEOS is an important and effective medicine for severe active ANCA-associated vasculitis based on robust clinical data and real-world evidence demonstrating the effectiveness and favorable benefit–risk profile.

We would like to take this opportunity to provide a brief review of some of the important evidence supporting the favorable benefit-risk profile of TAVNEOS.

Efficacy and Safety Profile

  • The Phase 3 ADVOCATE trial demonstrated that, in combination with standard therapy in each arm, the TAVNEOS arm was noninferior to the prednisone taper arm in achieving remission at week 26 (72.3% vs 70.1%, p<0.001 for noninferiority) and superior in sustaining remission at week 52 (65.7% vs 54.9%, p<0.001 for noninferiority; p=0.007 for superiority).3
  • Secondary outcomes* showed that the TAVNEOS arm had less glucocorticoid exposure and glucocorticoid toxicity, fewer relapses, greater improvement in estimated glomerular filtration rate, and better physical and mental health-related quality of life metrics over 52 weeks.4-6
  • An integrated safety analysis of two Phase 2 trials (CLEAR and CLASSIC) and one Phase 3 trial (ADVOCATE) included 239 patients comprising the avacopan group and 200 patients not receiving avacopan (the non-avacopan group). The overall exposure-adjusted rates of AEs and SAEs were lower in the avacopan group versus the non-avacopan group.7
  • Due to observations of abnormality on liver function testing among some patients receiving TAVNEOS in clinical trials, liver injury is an important identified risk of avacopan and described under Hepatotoxicity in Warnings and Precautions in the U.S. Prescribing Information (USPI), which includes recommendations for regular liver test panel monitoring for patients receiving TAVNEOS. Other Warnings and Precautions include serious hypersensitivity reactions, hepatitis B virus reactivation, and serious infection.1
  • As a consequence of liver injury, VBDS has been reported in the post-marketing setting. Most cases were reported from Japan in patients aged 65 years and older, including cases with a fatal outcome.2 The majority of VBDS cases occurred within 60 days of TAVNEOS initiation, as reported in the DSC. VBDS may affect patients of any age or ethnicity receiving TAVNEOS and is often accompanied by jaundice, pruritus, or fatigue.

Ongoing Commitment to Patient Safety

Amgen remains committed to patient safety with its routine safety surveillance and signal detections activities. Amgen continues to conduct a multi-country, FDA-required post-marketing study as well as multiple U.S.-based real-world observational studies to further characterize the effectiveness and safety profile of TAVNEOS. Additional ongoing studies in Europe and Japan are also prospectively monitoring patients receiving TAVNEOS for safety events.

Based on robust clinical and real-world data demonstrating efficacy and effectiveness with a favorable benefit–risk profile, Amgen remains confident that TAVNEOS represents an important treatment option for patients with severe, active ANCA-associated vasculitis (GPA and MPA), a rare, serious autoimmune diseases with limited therapeutic alternatives.

Any suspected adverse events should be reported to +1 805-447-3505 or +1-800-772-6436 (+1-800-77-Amgen) or the FDA (1-800-FDA-1088, www.fda.gov/medwatch). For questions, contact Medical Information at +1-800-772-6436 (+1-800-77-Amgen) or www.amgenmedinfo.com.

We are providing TAVNEOS Patient FAQs to support your discussions with patients, which you may share at your discretion.

Sincerely,

Paul Burton, MD PhD FRCP
Chief Medical Officer


* Prespecified secondary endpoints not adjusted for multiplicity and should be considered exploratory. Results should be interpreted with caution.


INDICATION

TAVNEOS (avacopan) is indicated as an adjunctive treatment of adult patients with severe active anti- neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (granulomatosis with polyangiitis [GPA] and microscopic polyangiitis [MPA]) in combination with standard therapy including glucocorticoids. TAVNEOS does not eliminate glucocorticoid use.

IMPORTANT SAFETY INFORMATION

CONTRAINDICATIONS

Serious hypersensitivity to avacopan or to any of the excipients.

WARNINGS AND PRECAUTIONS

Hepatotoxicity: Serious cases of hepatic injury have been observed in patients taking TAVNEOS, including life-threatening events. Obtain liver test panel before initiating TAVNEOS, every 4 weeks after start of therapy for 6 months and as clinically indicated thereafter. Monitor patients closely for hepatic adverse reactions, and consider pausing or discontinuing treatment as clinically indicated (refer to section 5.1 of the Prescribing Information). TAVNEOS is not recommended for patients with active, untreated, and/or uncontrolled chronic liver disease (e.g., chronic active hepatitis B, untreated hepatitis C, uncontrolled autoimmune hepatitis) and cirrhosis. Consider the risks and benefits before administering this drug to a patient with liver disease.

Serious Hypersensitivity Reactions: Cases of angioedema occurred in a clinical trial, including 1 serious event requiring hospitalization. Discontinue immediately if angioedema occurs and manage accordingly. TAVNEOS must not be readministered unless another cause has been established.

Hepatitis B Virus (HBV) Reactivation: Hepatitis B reactivation, including life-threatening hepatitis B, was observed in the clinical program. Screen patients for HBV. For patients with evidence of prior infection, consult with physicians with expertise in HBV and monitor during TAVNEOS therapy and for 6 months following. If patients develop HBV reactivation, immediately discontinue TAVNEOS and concomitant therapies associated with HBV reactivation, and consult with experts before resuming.

Serious Infections: Serious infections, including fatal infections, have been reported in patients receiving TAVNEOS. The most common serious infections reported in the TAVNEOS group were pneumonia and urinary tract infections. Avoid use of TAVNEOS in patients with active, serious infection, including localized infections. Consider the risks and benefits before initiating TAVNEOS in patients with chronic infection, at increased risk of infection, or who have been to places where certain infections are common.

ADVERSE REACTIONS

The most common adverse reactions (≥5% of patients and higher in the TAVNEOS group vs. prednisone group) were nausea, headache, hypertension, diarrhea, vomiting, rash, fatigue, upper abdominal pain, dizziness, blood creatinine increased, and paresthesia.

DRUG INTERACTIONS

Avoid co-administration of TAVNEOS with strong and moderate CYP3A4 enzyme inducers. Reduce TAVNEOS dose when co-administered with strong CYP3A4 enzyme inhibitors to 30 mg once daily. Consider dose reduction of CYP3A4 substrates when co-administering TAVNEOS. Coadministration of avacopan and 40 mg simvastatin increases the systemic exposure of simvastatin. While taking TAVNEOS, limit simvastatin dosage to 10 mg daily (or 20 mg daily for patients who have previously tolerated simvastatin 80 mg daily for at least one year without evidence of muscle toxicity). Consult the concomitant CYP3A4 substrate product information when considering administration of such products together with TAVNEOS.

TAVNEOS is available as a 10 mg capsule.

Please see Full Prescribing Information and Medication Guide for TAVNEOS.

To report a suspected adverse event, call 1-833-828-6367. You may report to the FDA directly by visiting www.fda.gov/medwatch or calling 1-800-332-1088.


References

  1. TAVNEOS® (avacopan) prescribing information, Amgen.
  2. Hishida E, Nagata D. Intern Med. 2026;65:941-942.
  3. Jayne DRW, Merkel PA, Schall TJ, Bekker P. N Engl J Med. 2021;384:599-609.
  4. Jayne DRW, et al. N Engl J Med. 2021;384:599-609; supplementary appendix.
  5. Data on file, Amgen; [1]; 2020.
  6. Strand V, et al. Lancet Rheumatol. 2023;5:e451-e460.
  7. Merkel PA, George MD, Yue H, et al. ACR Open Rheumatol. 2025;7:e70001.