WARNINGS AND PRECAUTIONS

• • Allergic-type hypersensitivity reactions, including anaphylaxis, have occurred with ALTUVIIIO. Discontinue use of ALTUVIIIO if hypersensitivity reaction occurs and manage symptoms as appropriate.
• • Formation of neutralizing antibodies (inhibitors) to Factor VIII are possible following administration of ALTUVIIIO. Neutralizing antibodies were not reported in the clinical trials. Monitor all patients for the development of Factor VIII inhibitors by appropriate clinical observations and laboratory tests.
• • If assessment of plasma Factor VIII activity is needed, it is recommended to use a validated one-stage clotting assay. The ALTUVIIIO Factor VIII activity level is overestimated by the chromogenic assay and a specific ellagic acid-based aPTT reagent in one-stage clotting assay by approximately 2.5-fold. If these assays are used, divide the result by 2.5 to approximate the patient's ALTUVIIIO Factor VIII activity level.