Infusion-Related Reactions: Infusion-related reactions (all Grade 2) were reported in 4/164 patients (2%). Premedicate with a corticosteroid, antipyretic, and antihistamine prior to dosing. Monitor patients closely during and for at least 1 hour after the end of the infusion for the potential onset of infusion-related reactions including symptoms such as fever, chills, rash, or breathing problems. Interrupt the infusion and institute appropriate medical management if an infusion-related reaction occurs. Depending on the severity, consider discontinuation of the infusion or administration of steroids and antihistamines. For severe or life-threatening infusion reactions, permanently discontinue BESPONSA.. Learn about the risks & benefits of BESPONSA™, an Rx treatment for adults with relapsed or refractory B-cell precursor acute lymphoblastic leukemia.. BESPONSA is a prescription medicine used to treat adults with relapsed or refractory B-cell acute lymphoblastic leukemia (ALL). It is not known if BESPONSA is safe and effective in children under 18 years of age..