D1.400 - Omalizumab premedication improves ferric carboxymaltose desensitization outcomes: A Case Report

Background: Ferric carboxymaltose (FCM) can be used in cases of intolerance/non-response to oral iron therapy and may cause hypersensitivity reactions, including anaphylaxis. This report presents successful FCM desensitization with omalizumab premedication in a patient with a history of recurrent hypersensitivity reactions during FCM desensitization.

Case Presentation: A 39-year-old female patient developed pruritus, erythema, dyspnea, and bradycardia approximately 5 minutes after the start of FCM infusion.Similar symptoms also developed 5 minutes after oral administration of ferrous fumarate. The patient, who had an absolute indication for FCM replacement, was evaluated at our clinic. A 10-step desensitization protocol with FCM, which we had previously administered successfully, was planned.(Table-1) We obtained consent and permission to publish the case report from the patient.During the first desensitization administered, the patient developed pruritus, erythema, nasal congestion and dyspnea at an infusion rate of 4 mL/hour. The patient was administered antihistamines, systemic steroids and epinephrine. Following improvement in clinical findings, the protocol was reduced by one step and an intermediate step was added. The desensitization procedure was successfully completed. The next day, desensitization was initiated to continue treatment. Upon the development of similar reactions at a rate of 16 mL/hour, antihistamines, steroids, and epinephrine were administered. As the symptoms subsided, the protocol was reduced by one step and an intermediate step was added. However, when pruritus and erythema developed again at a rate of 12 mL/hour, the infusion was stopped, desensitization was deemed unsuccessful.One year later, the patient was re-consulted.FCM desensitization was planned again. During desensitization antihistamines, steroids, and intramuscular epinephrine were administered at a rate of 32 mL/hour. After clinical improvement, the protocol was stepped back one level and the procedure continued with an intermediate step added. Antihistamines and steroids were administered when urticaria developed at a rate of 64 mL/hour. After the general condition improved, the desensitization procedure was completed without any problems. Nine months later, iron replacement was required again. Due to the previous occurrence of anaphylaxis during three desensitization procedures, it was decided to perform the procedure with omalizumab premedication.An omalizumab provocation test was performed on day 1.On day 15, omalizumab 300 mg was administered.On day 16, desensitization FCM was completed without any reaction.On day 29, omalizumab 300 mg was again administered.On day 30, desensitization with FCM was successfully completed without any hypersensitivity reaction.

Conclusion:Omalizumab premedication may be a safe and effective approach in patients who develop systemic reactions during desensitization.This case demonstrates that anti-IgE therapy can improve FCM desensitization outcomes in high-risk patients who absolutely require iron replacement.