Mepolizumab Injection Intervals Can Safely Be Extended in Eosinophilic Asthma

Patients with well-controlled eosinophilic asthma can reduce their therapy burden by extending their interval of mepolizumab injections from every 4 weeks to every 6 to 8 weeks, according to study findings published in World Allergy Organization Journal.

Current guidelines recommend patients with severe eosinophilic asthma receive lifelong therapy with mepolizumab, a humanized monoclonal antibody and interleukin-5 (IL-5) inhibitor that has proved safe and effective in improving pulmonary function, disease control, and exacerbation rates. Investigators sought to explore how extending administration intervals for mepolizumab affected asthma symptoms in patients who had attained good disease control following mepolizumab initiation.

The current retrospective study utilized data obtained from an outpatient clinic in Germany between 2016 and 2020. Participants had initiated mepolizumab treatment for uncontrolled severe eosinophilic asthma after high-dose inhaled corticosteroids/long-acting beta-2-agonist therapy had not effectively controlled their condition.  The initiation of mepolizumab treatment for these patients had 3 goals: elimination of exacerbations, discontinuations of oral corticosteroids, and reaching a stable symptom status, defined an Asthma Control Test (ACT) score of at least 20.

Of the 64 patients who had initiated mepolizumab treatment, researcher identified 18 patients for the current analysis who had extended their injection interval from every 4 weeks to every 6 to 8 weeks after attaining a stable symptom status. Notably, these patients gave written informed consent to follow the off-label extended dosing interval.

The study analysis assessed differences in disease control and lung function over time, with time points including the initiation of mepolizumab treatment, the initiation of extended injection intervals, and 3-month follow-up visits that occurred during the 1-year observation period. Disease control was evaluated via ACT scores; pulmonary function was assessed by spirometry measurements of forced expiratory volume in 1 second (FEV₁) and forced vital capacity (FVC). Daily oral corticosteroid (OCS) intake for control of asthma was registered at each patient visit.

Analysis results showed significant improvements in both ACT scores (P <.001) and pulmonary function values (FEV₁ [P <.001] and FVC [P =.01]) after mepolizumab was initiated on a regular 4-weekly injection interval. Following extension of dosing intervals, both ACT scores and pulmonary function remained on stable levels without any significant changes observed during the follow-up visits for 1 year. Notably, blood eosinophil levels never reached baseline levels for any patient during the study period.

The median dosage of the OCS prednisolone decreased significantly in the study group receiving mepolizumab treatment (P =.012) and remained at a low level during all follow-up visits, with only 1 patient requiring the use of prednisolone after 1 year.

This study had several limitations, including: a treatment cohort of only 18 patients; the lack of a matched control group of patients who maintained the regular 4-week injection interval; and the inability to assess the effects of the extended treatment interval on asthma exacerbations due to the relatively short study period.

The authors concluded that “In patients with fully or well controlled eosinophilic asthma treated with mepolizumab extending the dosage intervals between the injections up to 8 weeks bears the potential to save costs for the health care system.”

Disclosure: Some of the study authors have declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.