Immunogenicity and safety of omalizumab in pre-filled syringes in patients with allergic (IgE-mediated) asthma

Background:Omalizumab, a humanised anti-immunoglobulin E monoclonal antibody for treatment of uncontrolled moderate-to-severe or severe persistent allergic asthma, was developed as a lyophilised powder for reconstitution. A liquid formulation in pre-filled syringes has now been developed. The purpose of this study was to assess the immunogenicity and safety of this liquid formulation.Methods:In this multinational, open-label, single-arm study, patients (≥12 years) with moderate-to-severe allergic asthma were treated for 24 weeks with the liquid formulation of omalizumab (75 or 150 mg in a pre-filled syringe) at 2 or 4 week intervals. Immunogenicity was assessed by measurement of human anti-therapeutic antibody (ATA) levels. Safety was assessed by monitoring adverse events (AEs), haematology, blood chemistry, urine analysis and vital signs.Results:A total of 155 patients were enrolled in the study. No patient had a confirmed positive ATA test result. Most frequent individual AEs were asthma (17.4%), sinusitis (17.4%) and upper respiratory tract infection (11.6%). Fourteen patients (9.0%) had serious AEs and there was one death (not treatment related). There were no cases of anaphylaxis according to Sampson criteria. Most patients remained within normal ranges for haematology and biochemistry laboratory variables.Conclusions:Omalizumab in pre-filled syringes was not associated with immunogenicity. This novel formulation, which does not require reconstitution, had a safety profile consistent with the lyophilised formulation. A limitation of this study is that efficacy of omalizumab in the treatment of asthma was not specifically addressed herein.Clinicaltrials.gov identifier:NCT00500539.