NUCALA should not be administered to patients with a history of hypersensitivity to mepolizumab or excipients in the formulation.


In Trials 1, 2, and 3 (24 to 52 weeks' duration), serious adverse events that occurred in more than 1 patient and in a greater percentage of patients treated with NUCALA (n=263) than placebo (n=257) included 1 event, herpes zoster (2 patients vs 0 patients, respectively). Approximately 2% of patients receiving NUCALA withdrew from clinical trials due to adverse events compared with 3% of patients receiving placebo. Adverse reactions in Trials 2 and 3 are presented below.  

Adverse Reaction NUCALA (n=263) Placebo (n=257)
Headache 19% 18%
Injection site reaction 8% 3%
Back pain 5% 4%
Fatigue 5% 4%
Influenza 3% 2%
Urinary tract infection 3% 2%
Abdominal pain upper 3% 2%
Pruritus 3% 2%
Eczema 3% <1%
Muscle spasms 3% <1%

Long-term safety

  • 998 patients have received NUCALA in ongoing open-label extension studies, during which additional cases of herpes zoster have been reported. The overall adverse event profile was similar to the asthma trials

Systemic reactions, including hypersensitivity reactions

  • In 3 clinical trials, 3% of subjects who received NUCALA experienced systemic (allergic and nonallergic) reactions, compared to 5% in the placebo group. Systemic allergic/hypersensitivity reactions were reported by 1% of subjects who received NUCALA, compared to 2% of subjects in the placebo group. Manifestations included rash, pruritus, headache, and myalgia. Systemic nonallergic reactions were reported by 2% of subjects who received NUCALA and 3% of subjects in the placebo group. Manifestations included rash, flushing, and myalgia. A majority of the systemic reactions were experienced on the day of dosing.

Injection site reactions

  • Injection site reactions (eg, pain, erythema, swelling, itching, and burning sensation) occurred at a rate of 8% in patients treated with NUCALA compared with 3% in patients treated with placebo


  • Overall, 15/260 (6%) patients treated with NUCALA 100 mg SC developed anti-mepolizumab antibodies. The reported frequency may underestimate the actual frequency due to lower assay sensitivity in the presence of high drug concentration. Neutralizing antibodies were detected in 1 patient receiving NUCALA. The clearance of NUCALA was slightly increased (20%) by anti-mepolizumab antibodies. There was no evidence of a correlation between anti-mepolizumab antibody titers and change in blood eosinophil counts. The clinical relevance of the presence of anti-mepolizumab antibodies is not known

   818430R0 April 2017