Use of antithymocyte globulin (rabbit) in a patient with known alpha-gal syndrome undergoing allogenic stem cell transplantation.

INTRODUCTION: Alpha-gal syndrome (AGS) is a hypersensitivity disorder in which tick bites-most commonly from the lone star tick (Ambylomma americanum)-trigger immunoglobulin E-mediated hypersensitivity reaction upon exposure to oligosaccharide galactosse-alpha-1,3-galactose (α-gal). α-gal is most notorious for being found in "red meat" products but is present in mammalian meats such as beef, pork, lamb, rabbit, and others. Manifestations of AGS hypersensitivity are variable. There is currently no in vivo data describing allergic reactions against rabbit products in patients with AGS. CASE REPORT: Here, we describe a case of a 44-year-old male with myelodysplastic syndrome and a known history of AGS undergoing allogeneic hematopoietic cell transplantation (allo-HSCT) with the use of rabbit antithymocyte globulin (rATG) for graft-versus-host disease (GVHD) prophylaxis. MANAGEMENT AND OUTCOME: The risk of cross-reactivity against rATG in our patient with AGS could not be ruled out and, therefore, a test dose was administered. The patient tolerated the test dose with no signs of anaphylaxis. After demonstrating tolerance to the test dose, rATG was utilized for GVHD prophylaxis. DISCUSSION: Due to the heterogeneity of AGS manifestations in patients, the use of rATG in patients with known AGS should be considered on a case-by-case basis. The administration of a test dose may help predict the occurrence of severe hypersensitivity reactions. The limited data surrounding the risk of AGS with rabbit-containing products and the various indications for the use of rATG warrants more in-depth study of the reactivity of this medication in this population.

The efficacy and cost-impact of rasburicase 3†mg versus 6†mg for the management of tumor lysis syndrome: A multicenter analysis.

Purpose: Hyperuricemia is a complication arising from tumor lysis syndrome (TLS). Literature has shown that a single 3 mg dose was just as efficacious as a single 6 mg dose when the uric acid (UA) levels were ≤12 mg/dL. Here, we present a multi-center analysis rasburicase utilization and its effect on healthcare costs. Methods: This is a multi-center, retrospective analysis of adult cancer patients who were admitted to Methodist Le Bonheur Healthcare hospitals and received rasburicase from February 2020 to February 2021. The primary endpoint was to test whether rasburicase 3 mg had similar rates of uric acid normalization (defined as uric acid ≤7.5 mg/dL) within 24 h as a dose of 6 mg. Results: Seventy-nine patients were included in the study. While the baseline uric acid was lower in the 3 mg arm compared to the 6 mg arms, there was no difference in the uric acid normalization at 24 h between the 3 mg arm (95%) and 6 mg arm (82%) (p = 0.134). A cost-savings of over $300,000 annually can be achieved with the proposed protocol. Conclusion: A single, fixed rasburicase dose of 3 mg was effective in normalizing uric acid levels within 24 h, and is associated with significant cost-savings.

Voxelotor: A Hemoglobin S Polymerization Inhibitor for the Treatment of Sickle Cell Disease.

Sickle cell disease (SCD) affects millions of people throughout the world. Hemoglobin S (HbS) polymerization is the fundamental cause of SCD pathophysiology, which leads to hemolysis, increased viscosity, and acute vaso-occlusive episodes. Novel agents have been developed to target the pathophysiology of SCD and decrease the frequency of SCD complications. Voxelotor (Oxbryta) is an HbS polymerization inhibitor that is approved by the U.S. Food & Drug Administration for the treatment of SCD in adults and pediatric patients 12 years and older.

Gilteritinib: A Novel FLT3 Inhibitor for Relapsed/Refractory Acute Myeloid Leukemia.

Acute myeloid leukemia (AML) is the most common adult leukemia, with an overall poor prognosis. New agents targeting various receptors may improve treatment outcomes and overall survival. FMS-like tyrosine kinase 3 (FLT3) is a targetable mutation occurring in one third of AML patients. It contributes to increased tumor proliferation and decreased cellular differentiation, ultimately conferring a poor overall prognosis. Among patients with FLT3-positive relapsed/refractory AML, outcomes are particularly dismal. Gilteritinib is a novel, second-generation FLT3 inhibitor approved by the U.S. Food & Drug Administration (FDA) for the treatment of relapsed/refractory AML with an FLT3 mutation as detected by an FDA-approved test.