The impact of Daratumumab on transfusion service costs.

BACKGROUND: Daratumumab (DARA) is a human IgG1κ monoclonal antibody directed against CD38, approved for the treatment of multiple myeloma. As CD38 is expressed on RBCs, DARA can interfere with pretransfusion testing. DARA interference can be negated by denaturation of CD38 on RBCs with dithiothreitol (DTT) reagents. Because of this interference in pretransfusion testing, our hospital implemented a notification and testing/transfusion algorithm (NATTA) for pretransfusion testing and RBC product provision for DARA patients. This standardized approach combines DTT-based testing with selective genotyping and the provision of phenotypically similar RBCs for patients with clinically significant antibodies. STUDY DESIGN AND METHODS: We evaluated pretransfusion test results and transfusion requirements for 91 DARA patients in an academic medical center over 1 year to determine the incremental cost of pretransfusion testing and RBC selection. The actual costs for the NATTA approach were compared to a theoretical approach using universal genotyping with a provision of phenotypically similar RBC transfusions. RESULTS: The annual cost of testing related to DARA after NATTA implementation was $535.76 per patient. The simulated annual cost for the alternative genotyping with provision of phenotypically similar RBC transfusions approach was $934.83 per patient. CONCLUSION: In our entire cohort of DARA patients, a DTT-based testing algorithm with selective genotyping and provision of phenotypically similar RBCs only for patients with clinically significant antibodies was less expensive than a simulated model of universal genotyping and provision of phenotypically similar RBCs.

Therapy-related myelodysplastic syndrome and acute myeloid leukemia following initial treatment with chemotherapy plus radioimmunotherapy for indolent non-Hodgkin lymphoma.

Patients with indolent non-Hodgkin lymphoma (I-NHL) often receive multiple courses of cytotoxic chemotherapy over several years. Radioimmunotherapy (RIT) has become an important part of treatment for relapsed patients and tositumomab/lodine I-131 tositumomab is a promising regimen currently being incorporated into first-line therapy. While treatment-related myelodysplasia (tMDS) and acute myeloid leukemia (tAML) are well-known, poor-prognosis complications of conventional chemotherapy and radiation therapy, they have not been previously observed as a consequence of initial treatment with RIT-based regimens. We describe four patients with tMDS/tAML who received a sequential chemotherapy and tositumomab/lodine I-131 tositumomab program as their initial and only lymphoma treatment. Our findings suggest that the potential risk of these important complications must be considered in the development of this novel therapeutic strategy in the first-line setting.