P46 Management of autoimmune haemolytic anaemia in a paediatric patient

• Published in: BMJ paediatrics open 2024-05, Vol.8 (Suppl 3), p.A31-A32
• Main Authors: Yung, Ka Yu, Tsai, Shini, Rajani, Kalindi, Cheng, Iek
• Format: Article
• Language: English
• Subjects: Abstracts form the Neonatal and Paediatric Pharmacy Conference 2023; Anemia; Drug dosages; Drug interactions; Drug stores; Gene therapy; Immunotherapy; Inhibitor drugs; Pediatrics; Stem cell transplantation; Steroids
• ISSN: 2399-9772
• DOI: 10.1136/bmjpo-2024-NPPG.56

BackgroundAutoimmune haemolytic anaemia (AIHA) is a type of anaemia that develops when the antibodies of the immune system destroy some of the red blood cells,1 causing haemolysis. The aetiology remains uncertain, but an increase in autoantibodies and lymphocytes in the presence of decreased immune tolerance is thought to be involved.2 A 2-year-old patient with adenosine deaminase deficient severe combined immunodeficiency (ADA-SCID) was diagnosed with AIHA post-gene therapy, which was not responsive to intravenous immunoglobulins (IVIG), corticosteroids and rituximab, and was initiated on sirolimus as a steroid-sparing agent.One-year post-gene therapy, the patient continued to suffer from poor immune reconstitution. Due to multiple drug interactions, increasing hepato- and myelotoxicities and continuously fluctuating sirolimus levels, the patient was initiated on IV abatacept. The patient responded well to abatacept and sirolimus was gradually weaned off. However, on day 24 (D24), after completion of the initial loading course of abatacept, he went into an acute haemolytic crisis. The next schedule dose was rescheduled from D28 to D24, and IV bortezomib was initiated as a bridging agent and two doses given, while IV daratumumab was requested on a compassionate-use basis. Due to the difference in mechanisms of actions, these agents were pursued. However, the use of these drugs in paediatrics is limited.Pharmacy ContributionsThe immunology pharmacists were heavily involved in the discussion of treatment options at several multi-disciplinary team (MDT) meetings. Once a consensus was reached, the pharmacists performed a comprehensive literature search to determine appropriate dosing regimens and assess risks versus benefits. Daratumumab was requested from the manufacturer on a compassionate-use basis, where the patient’s medical background, the urgent clinical need and rationale for this therapy was explained. Subsequently, the manufacturer agreed that the patient may benefit from daratumumab. Pharmacists ensured adequate supply of daratumumab was provided for the duration of therapy and that local governance processes were adhered to. The pharmacists explained the options appraisal to the family, including counselling of the safety and practical aspects of the drugs, the unlicensed and off-label nature, side effect profile, monitoring and the aim of the treatment. Patient information leaflets were also provided. During treatment with abatacept, bortezomib an