BESPONSA can cause liver problems that can be severe, life-threatening, or fatal, including a condition called veno-occlusive disease (VOD). This condition can occur during treatment with BESPONSA or following subsequent treatment with a stem cell transplant. This condition was more common in patients who had elevated liver tests or who received dual alkylating agents in preparation for their stem cell transplant. Patients may be at a higher risk of VOD if they: . 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.. “Besponsa will help address a significant need for new treatment options in B-cell acute lymphoblastic leukemia, and may help more patients reach stem cell transplant, which provides the best chance for long term remission,” said president of Pfizer Oncology, Liz Barrett..