COLUMBA results support long-term use of mepolizumab in patients with severe asthma
medwireNews: The anti-interleukin (IL)-5 monoclonal antibody mepolizumab has durable safety and efficacy profiles over an average 3.5 years of follow-up in patients with severe eosinophilic asthma, indicate findings from the COLUMBA open-label extension study.
“This study represents the longest clinical experience to date with an anti-IL-5 monoclonal therapy in severe asthma”, write the investigators in the Journal of Allergy and Clinical Immunology.
The COLUMBA study included 347 patients who completed the placebo-controlled DREAM trial, which demonstrated “strong and consistent exacerbation reductions” among patients treated with intravenous mepolizumab, say Hector Ortega (GSK, La Jolla, California, USA) and study co-authors. They explain that following an “off-treatment period” of 12–28 months (median 17.8 months) after completion of DREAM, all patients were treated with subcutaneous mepolizumab 100 mg every 4 weeks alongside standard care in COLUMBA.
In all, 94% of patients experienced adverse events (AEs) over a total mepolizumab exposure time of 1201 patient–years in the extension study, giving an exposure-adjusted rate of 3688 AEs per 1000 patient–years. The most commonly reported treatment-emergent AE was respiratory tract infection (67%), followed by headache (29%), asthma worsening (27%) and bronchitis (21%).
Serious adverse events occurred in 23% of patients, and there were six deaths during the study period, none of which were considered by the investigators to be related to mepolizumab.
Overall, the safety profile of subcutaneous mepolizumab “was similar to that seen in previous randomized, placebo-controlled trials of mepolizumab with [intravenous] and [subcutaneous] administration”, and “no new safety concerns were identified in this study following long-term exposure”, summarise Ortega and team.
The rate of asthma exacerbations during treatment with mepolizumab was 0.68 events/year, which represented a 61% reduction from the rate of 1.74 events/year during the off-treatment period between DREAM and COLUMBA, report the researchers.
For the 286 patients with at least 156 weeks of follow-up in COLUMBA, the exacerbation rate was 0.74 events/year, equating to a 56% reduction in exacerbation rates from the off-treatment period.
Participants also experienced improvements in asthma control from baseline to week 12, with an average reduction in Asthma Control Questionnaire-5 score of 0.47 points, and these improvements were maintained for the duration of follow-up.
Ortega and colleagues note that the immunogenicity profile of mepolizumab “was consistent with previous studies”, with 8% of patients testing positive for antidrug antibodies at any time during the study.
And the team concludes that taken together, “these results support the use of mepolizumab as a long-term treatment choice” for individuals with severe eosinophilic asthma.
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