The use of intravenous versus subcutaneous monoclonal antibodies in the treatment of severe asthma: a review

Monoclonal antibodies (mAbs) approved for use as add-on therapy in patients with severe asthma target the underlying pathogenesis of asthma. Omalizumab binds immunoglobulin E (IgE), thereby inhibiting its interaction with the high-affinity IgE receptor and reducing the quantity of free IgE available to trigger the allergic cascade. Anti-interleukin (IL)-5 mAbs mepolizumab, benralizumab and reslizumab block the interaction between IL-5 and its receptor on eosinophils, thus targeting the eosinophilic pathway in asthma. Most mAbs are available as intravenous (IV) or subcutaneous (SC) formulations, as their high molecular weight and gastric degradation preclude oral administration. This review compares the pharmacology, efficacy, immunogenicity, injection- and infusion-related adverse drug reactions of subcutaneously administered omalizumab and mepolizumab with the intravenously administered reslizumab. In terms of pharmacokinetics, IV route of administration appears to be superior to the SC route due to quicker absorption, greater bioavailability, shorter time to maximum serum concentration and similar elimination half-life. Route of administration does not appear to translate into striking differences in efficacy and safety of mAbs used for the treatment of severe asthma, as all are generally considered to be effective and well tolerated. Hypersensitivity and administration-related reactions have been described with both IV and SC mAbs. mABs are effective and have low immunogenicity due to their nature as humanised antibodies. Evidence on the use of mAbs in indications other than severe asthma suggest that both the SC and the IV routes of administrations have their respective advantages and disadvantages; but their full utility remains to be elucidated.