FDA Warns of Severe Allergic Reactions With Certain Multiple Sclerosis Drugs

Today, the FDA issued a warning about the risk of anaphylaxis, a rare but life-threatening allergic reaction, linked to certain multiple sclerosis (MS) drugs, including glatiramer acetate (Copaxone; Teva) and its generic counterpart, Glatopa, sold by Sandoz.¹

Today, the FDA issued a warning about the risk of anaphylaxis, a rare but life-threatening allergic reaction, linked to certain multiple sclerosis (MS) drugs. | Image Credit: Tada Images - stock.adobe.com

The regulator is adding a boxed warning—the most prominent safety alert—to highlight that anaphylaxis can occur at any point during treatment, from the first dose to years after starting the medication. Patients experiencing symptoms such as wheezing, swelling, or difficulty breathing are urged to seek immediate medical attention.

“This serious allergic reaction, called anaphylaxis, can occur at any time while on treatment, after the first dose or after doses administered months or years after starting the medicine,” wrote the FDA in a safety concern announcement. “For most patients who experienced anaphylaxis with glatiramer acetate use, the symptoms appeared within 1 hour of injection. In some cases, anaphylaxis resulted in hospitalization and death.”

Copaxone was first approved by the FDA in 1996, and Glatopa was approved in 2015.³ Both are used to treat patients with MS, by lessening the immune system’s abnormal attack on nerves in the brain and spinal cord, which helps decrease the number of MS relapses. An estimated 240,000 glatiramer acetate prescriptions were dispensed and estimated 32,000 patients received a dispensed prescription from US outpatient retail and mail order pharmacies in 2023, according to Symphony Health Metys.

The FDA’s decision comes after identifying 82 global cases of anaphylaxis linked to glatiramer acetate from December 1996 to May 2024.¹ In 19 of these cases, the reaction occurred more than a year into treatment. Symptoms typically appeared within one hour of administration and included wheezing, difficulty breathing, facial swelling, and hives. In severe cases, these reactions progressed to life-threatening conditions like shock. Six reported incidents resulted in fatalities.

Glatiramer acetate is approved for the treatment of relapsing forms of MS, a chronic condition affecting the central nervous system. The drug is administered via injection, and the FDA warns that patients should seek immediate medical attention if symptoms of an allergic reaction occur, particularly if they persist or worsen over time.

The FDA advises health care providers to inform patients of the potential risks and to monitor them for signs of anaphylaxis, especially after the first dose. Both Teva and Sandoz have not yet responded to requests for comment regarding the updated safety measures.

This latest warning underscores the importance of vigilance in monitoring side effects associated with MS medications, as timely intervention can be critical in managing severe allergic reactions.

“The initial symptoms of anaphylaxis can overlap with those of a common reaction called immediate post-injection reaction that is temporary and can start soon after a shot is given,” wrote the FDA.² “While immediate post-injection reaction is common, anaphylaxis is rare and its symptoms are typically more severe, worsen over time, and require treatment. Patients experiencing a reaction after the medicine is administered should seek immediate medical attention if the symptoms are more than mild, get worse over time, or do not go away within a brief time.”

References

1. FDA warns of serious allergic reactions with some multiple sclerosis drugs. Reuters. January 22, 2025. https://www.reuters.com/business/healthcare-pharmaceuticals/fda-warns-serious-allergic-reactions-with-multiple-sclerosis-drugs-2025-01-22/.

2. FDA adds Boxed Warning about a rare but serious allergic reaction called anaphylaxis with the multiple sclerosis medicine glatiramer acetate (Copaxone, Glatopa). FDA. Drug safety communication. January 22, 20352. https://www.fda.gov/drugs/drug-safety-and-availability/fda-adds-boxed-warning-about-rare-serious-allergic-reaction-called-anaphylaxis-multiple-sclerosis.

3. FDA adds boxed warning to MS drug Copaxone. Formulary Watch. January 22, 2025. https://www.managedhealthcareexecutive.com/view/fda-adds-boxed-warning-to-ms-drug-copaxone.