SAN DIEGO – Treatment with benralizumab (Fasenra) achieved remission at 36 and 48 weeks at rates similar to those of mepolizumab (Nucala) in a head-to-head phase 3 trial of the two drugs for patients with a relapsing or refractory case of the rare vasculitis eosinophilic granulomatosis with polyangiitis (EGPA).
Benralizumab, a monoclonal antibody from AstraZeneca that binds to the alpha chain of the interleukin (IL)-5 receptor, is indicated as an add-on maintenance treatment for patients 12 years and older with severe eosinophilic asthma but is not currently approved for EGPA. Mepolizumab is a humanized monoclonal antibody targeting IL-5 and the only approved drug for EGPA.
, presented the trial, , during a at the annual meeting of the American College of Rheumatology. A total of 140 patients with EGPA received either subcutaneous benralizumab 30 mg or mepolizumab 300 mg every 4 weeks for 52 weeks. The trial, which began recruitment in late 2019, was limited to patients at least 18 years of age with relapsing/refractory EGPA that required stable use of oral glucocorticoids (OGCs) and immunosuppressive therapy for at least 4 weeks prior to randomization, and the primary endpoint was the proportion of patients who achieved remission at weeks 36 and 48. Remission was defined as a Birmingham Vasculitis Activity Score (BVAS) of 0 plus an OGC dose of no more than 4 mg/day. Secondary endpoints included rates of accrued and maintained remission, OGC use, clinical benefit and complete response, blood eosinophil counts, total BVAS, and Vascular Damage Index scores. The mean age of the 140 patients was 52 years, and 60% were women.
Dr. Merkel and colleagues reported that the adjusted remission rate at both weeks 36 and 48 was 59.2% for those in the benralizumab arm and 56.5% for those in the mepolizumab arm (P = .7278). The percentage of patients who achieved a BVAS of 0 was similar between the two arms (83% in the benralizumab arm vs. 84.2% for those in the mepolizumab arm; P = .8502), as was the percentage of patients on an OGC dose of up to 4 mg/day (62.1% vs. 57.9%; P = .5942). At 48-52 weeks, 86.1% of patients in the benralizumab arm achieved up to a 50% reduction in OGC use, compared with 73.9% of those in the mepolizumab arm (P = .0611), and 41.4% of patients in the benralizumab arm achieved a 100% reduction in OGC use, compared with 25.8% of those in the mepolizumab arm (P = .0406).
In findings related to safety, the top three adverse events were COVID-19 (21.4% in the benralizumab arm vs. 27.1% in the mepolizumab arm, respectively), headache (17.1% vs. 15.7%), and arthralgia (17.1% vs. 11.4%).
“We were pleased with the findings because they met our expectations,” Dr. Merkel, chief of rheumatology and professor of medicine and epidemiology at the University of Pennsylvania, Philadelphia, said in an interview. “The hypothesis was that these two drugs would be equivalent and safe. The implication for patients is that they’ll have another treatment option for EGPA, which is an underrecognized disease with need for more effective treatments. I anticipate that the drug will be approved for use in EGPA, providing another option for treating this complicated multisystem eosinophilic-associated disease. Having more options for our biologic therapies is good.”
He characterized the retention of patients in MANDARA as “remarkable, despite the COVID-19 pandemic. Patients with rare diseases are quite dedicated to helping conduct research. They know that their disease is not common and that they could help others.”
The study was sponsored and funded by AstraZeneca. Dr. Merkel disclosed that he has received consulting fees and research support from many pharmaceutical companies, including AstraZeneca.