P2241 - Don’t Give up on Infliximab Too Early! Successful Medication Desensitization to Infliximab in a Patient With Crohn’s Disease

Yuting Huang, MBBS, PhD¹, Jacqueline D. Squire, MD¹, Francis A. Farraye, MD, MSc, MACG², Jana G.. Hashash, MD, MSc, FACG^2
1Mayo Clinic Florida, Jacksonville, FL; ²Mayo Clinic, Jacksonville, FL

Introduction: Infliximab (IFX), an effective TNF monoclonal antibody, is used in several gastrointestinal, rheumatologic, and dermatologic diseases. Its large protein structure leads to high immunogenicity, with as many as 9.7% of patients having acute infusion reactions and 1% severe enough to require a switch to alternative therapy. IFX desensitization has been used as early as 2001, but its use in patients with inflammatory bowel disease (IBD) has been mostly reserved when running out of therapeutic options.

Case Description/Methods: A 17-year-old male with newly diagnosed fistulizing ileocolonic Crohn's disease and no known allergies, was initiated on IFX 5mg/kg and weekly methotrexate 12.5 mg. During his first IFX infusion, he experienced hives and severe itching 1.5 hours into the infusion. The infusion was completed after diphenhydramine and acetaminophen were given. Prior to the second infusion, he was premedicated with diphenhydramine and IV methylprednisolone. Fifteen minutes into the infusion, he developed itching, red welts/streaks on his chest, eyelid swelling and tearing, so the infusion was stopped. A week after his incomplete infusion, an IFX level was 31mcg/ml without anti-drug antibodies. Given the efficacy of IFX in fistulizing disease, a shared decision was made to explore desensitization instead of switching agent.

An allergy consult was obtained. The patient had a negative IFX skin test but had mild itching and flushing of the chest during the test. Allergy to IFX components was unlikely since he previously received vaccines containing polysorbate 80 (influenza and HPV). IFX desensitization was performed and on each subsequent visit, he received montelukast, loratadine, IV diphenhydramine, famotidine, and methylprednisolone. The patient has received a total of 4 IFX infusions via desensitization uneventfully. Clinically he has improved on IFX with a trough level of 13 mcg/ml 4 months later.

Discussion: Desensitization involves gradually increasing doses under direct supervision in a controlled setting. If symptoms occur, desensitization is temporarily halted and medications are administered to alleviate the symptoms. Once symptoms subside, the desensitization process resumes until the desired dose is tolerated. Successful desensitization has been reported in other biologics including ustekinumab and adalimumab. Although multiple other advanced therapies are available to treat patients with IBD, desensitization should remain an option in select cases.


Disclosures:


Yuting Huang, MBBS, PhD¹, Jacqueline D. Squire, MD¹, Francis A. Farraye, MD, MSc, MACG², Jana G.. Hashash, MD, MSc, FACG². P2241 - Don’t Give up on Infliximab Too Early! Successful Medication Desensitization to Infliximab in a Patient With Crohn’s Disease, ACG 2023 Annual Scientific Meeting Abstracts. Vancouver, BC, Canada: American College of Gastroenterology.