Successful use of anti IL5 targeted therapy (Mepolizumab) in two cases of hypereosinophilic syndrome from India

Background: Anti IL5 targeted therapy is being explored for indications beyond severe eosinophilic asthma, especially hypereosinophilic syndrome (HES). We herein report our experience of managing 02 cases of HES at a tertiary care chest center of Indian Armed Forces.

Aim and objectives: To assess response of long term use of Anti IL5 targeted therapy in HES.

Materials & Methods : Two F1P1L1?PDGFRA fusion gene negative HES patients, who had been having recurrent worsening of HES related symptoms (>2 times in past 01 year) requiring escalation of oral corticosteroids (OCS), despite being on optimum anti HES therapy were managed with anti IL5 targeted therapy Inj Mepolizumab 300mg subcutaneous (sc) injection every 04 weeks for 03 doses followed by 100 mg sc every 4 weeks, and are under follow-up for past 2 years.

Results: Both patients have remained exacerbations free, OCS could be tapered & stopped and their eosinophil levels are within normal limits.

Conclusion: Anti IL5 targeted therapies is an effective therapeutic options for HES patients preventing exacerbations and long term OCS use with their inherent side effects. The study shows that dose of mepolizumab can be tapered to 100 mg sc maintenance dose after initial 3 doses of 300mg, paving way for safe and economical alternative especially in developing country like India.