The FDA about rare cases of anaphylaxis associated with the multiple sclerosis (MS) drug glatiramer acetate (Copaxone, Glatopa), the agency announced on Wednesday.
The warning indicates that anaphylaxis can occur at any time, from as early as after the first dose or after doses administered years after starting treatment.
"We are also adding new recommendations for patients and healthcare professionals about the critical importance of quickly recognizing and treating symptoms of anaphylaxis," the FDA wrote in a drug safety communication. "The updated prescribing information also instructs patients to stop taking the medicine and seek immediate medical attention by going to an emergency room or calling 911 if symptoms of anaphylaxis occur."
Glatiramer acetate is an injectable drug that was to treat relapsing forms of MS. It's available as both branded and generic products.
The FDA added the boxed warning based on 82 serious cases of anaphylaxis associated with glatiramer acetate from December 1996 through May 2024. Of these, 19 cases reported anaphylaxis more than 1 year after starting treatment. The median time to onset of anaphylaxis from starting glatiramer acetate was 5 months (range 1 day-72 months).
Of the 82 patients, 51 were hospitalized for anaphylaxis, including 13 who required care in the intensive care unit. Six patients died.
Most of the 82 patients experienced anaphylaxis within 1 hour of taking glatiramer acetate. One case entailed shock and sudden death after the first dose.
Patients who experienced anaphylaxis were treated with epinephrine or adrenaline in 32 cases, corticosteroids in 21 cases, mechanical ventilation in five cases, and cardiopulmonary resuscitation in one case.
Symptoms of an anaphylactic reaction generally appear within 1 hour of injection and include wheezing or difficulty breathing; swelling of the face, lips, or throat; and hives, the FDA noted. They can quickly progress to more serious symptoms, including severe rash or shock.
Early symptoms of anaphylaxis can be similar to post-injection reactions, which are generally transient, self-limited, and resolve within 30 minutes, the agency pointed out. Those associated with anaphylaxis are typically more severe, worsen, or last longer, and require urgent medical attention.
The 82 cases included only reports submitted through the FDA Adverse Event Reporting System () database and those found in the medical literature, "so there are likely additional cases about which we are unaware," the FDA said.
"For context, there are more than 3 million patient-years of exposure to glatiramer acetate in the postmarket setting from 1996 through 2023," the agency added.
In July 2024, the also warned that anaphylactic reactions may occur months up to years after starting glatiramer acetate treatment.