The effects of daratumumab on red blood cells can last up to 6 months; therefore, type and crossmatch are recommended prior to starting daratumumab to prevent delays in transfusion crossmatching. But crossmatch is typically only good for a number of days — certainly not 6 months. If type and crossmatch is obtained before initiating treatment, what good would that do if a transfusion is required a month later? — Name withheld on request

Crossmatch prior to daratumumab administration should not supersede any local policies your blood bank or institution have regarding timelines for crossmatching.

Recommendations are that crossmatch, with or without additional testing such as red blood cell phenotyping, should be obtained prior to initiating daratumumab to serve as a reference. When requesting a unit of blood for a patient receiving daratumumab, the blood bank should be advised of the patient’s therapy as well as any information on file (eg, the baseline type and crossmatch or other testing) to facilitate timely results and blood products.

For more information on this subject, the manufacturer has made the following available: www.darzalexhcp.com/shared/product/darzalex/darzalex-information-on-assay-interference.pdf.

See also: Type and Crossmatch Needed Before Initiating Treatment With Daratumumab