FDA Issues Liver Injury Warning for Amgen's Rare Disease Drug Tavneos

Federal Health Regulators Put Amgen's Kidney Disease Drug on Notice Over Serious Liver Risks

The U.S. Food and Drug Administration has issued a formal warning about a rare but potentially life-threatening liver injury risk associated with Tavneos, a drug made by biotechnology giant Amgen that is used to treat a serious kidney and blood vessel disease. The agency announced it is requiring updates to the drug's prescribing information and its patient medication guide to reflect this newly identified danger, following a review of cases reported after the drug reached the market.

Tavneos, known by its chemical name avacopan, was approved by the FDA in October 2021. It is prescribed for adults suffering from a condition called ANCA-associated vasculitis, a rare autoimmune disease in which the body's immune system attacks small blood vessels, primarily in the kidneys. The drug works by blocking a specific protein in the immune system that plays a role in this destructive process, offering patients an alternative to long-term steroid treatment.

What the FDA Found and Why It Matters

According to the FDA, the agency identified cases of serious liver injury, including at least one death and at least one liver transplant, among patients taking Tavneos. These cases were discovered through the agency's post-market safety surveillance system, which monitors adverse events reported by patients, doctors, and manufacturers after a drug is already in use by the public. The FDA confirmed the liver injuries occurred even in patients who had no previous history of liver problems.

The agency stated that liver injury was identified as early as a few weeks after patients began taking the drug, though in some cases it appeared later during treatment. Signs of liver trouble that patients and doctors are now being urged to watch for include yellowing of the skin or eyes, dark-colored urine, severe tiredness, loss of appetite, pain in the upper right side of the stomach, and nausea or vomiting. These are classic warning signs that the liver may not be functioning properly.

New Requirements for Monitoring and Labeling

As part of its safety action, the FDA is requiring that Tavneos carry a boxed warning, which is the most serious type of warning the agency can require on a prescription drug label. This is sometimes referred to informally as a 'black box warning' and signals that the drug carries a significant risk of serious or life-threatening adverse effects. The updated label will instruct healthcare providers to check liver function through blood tests before patients begin taking Tavneos, and to continue monitoring liver function regularly throughout treatment.

The FDA is also recommending that doctors consider stopping the drug in patients who show signs of liver injury during treatment. The agency's updated guidance specifies that patients and caregivers should be counseled on the warning signs of liver problems and told to seek medical attention immediately if they experience any of those symptoms. These changes apply to all healthcare professionals who prescribe Tavneos as well as to patients currently on the medication.

Amgen's Response and the Drug's Place in Treatment

Amgen, headquartered in Thousand Oaks, California, is one of the world's largest biotechnology companies. Tavneos represented a significant addition to the treatment options available for ANCA-associated vasculitis, which affects a relatively small number of people but can cause severe kidney damage and even kidney failure if not treated aggressively. Prior to Tavneos, treatment typically relied heavily on corticosteroids, which carry their own significant long-term side effects including bone loss, high blood sugar, and increased infection risk.

The drug was approved based on clinical trial results showing it was as effective as standard steroid-based treatment at achieving remission in patients with this serious condition. Its approval was seen as a meaningful step forward for patients with few good options. However, the post-market reports of liver injury have now prompted the FDA to take action to better protect patients who are currently using or may be prescribed the medication in the future.

What Patients Currently Taking Tavneos Should Know

The FDA's warning does not mean that Tavneos is being pulled from the market or that all patients should immediately stop taking it. Rather, the agency is stressing the importance of careful monitoring and informed decision-making between patients and their doctors. The risk of liver injury, while serious, appears to affect a minority of patients, and for many people with ANCA-associated vasculitis, the benefits of the drug in controlling a potentially organ-destroying disease may still outweigh the risks.

Patients who are currently taking Tavneos are encouraged to speak with their prescribing physician about what monitoring steps are in place and what symptoms they should watch for. Anyone experiencing signs of liver problems should contact their doctor right away rather than waiting for a scheduled appointment. The FDA has also urged healthcare providers to report any new cases of liver injury associated with Tavneos through the agency's MedWatch safety reporting program, which helps regulators continue tracking and assessing risks in real time.

• Watch for yellowing of the skin or eyes
• Report dark urine or extreme fatigue to your doctor immediately
• Do not stop taking Tavneos without consulting your physician first
• Ensure your doctor is conducting routine liver function blood tests
• Report any side effects to the FDA's MedWatch program

This warning is a reminder of how important ongoing drug safety monitoring is even after a medication has received FDA approval. Post-market surveillance plays a critical role in identifying risks that may not have been apparent during the clinical trials that preceded approval, particularly for serious side effects that are rare but potentially fatal.