General information. Class/mechanism: Antibody targeting CD22, conjugated with a cytotoxic, antitumor antibiotic (calicheamicin). Inotuzumab demonstrates a dose-dependent cytotoxicity both in vitro and in vivo.. Acute lymphoblastic leukemia (ALL) is a cancer of the lymphoid line of blood cells characterized by the development of large numbers of immature lymphocytes. Symptoms may include feeling tired, pale skin color, fever, easy bleeding or bruising, enlarged lymph nodes, or bone pain. . Besponsa official prescribing information for healthcare professionals. Includes: indications, dosage, adverse reactions, pharmacology and more.. Pfizer Inc. announced that the FDA has approved Besponsa (inotuzumab ozogamicin) for treatment of adults with relapsed or refractory B-cell precursor acute lymphoblastic leukemia (ALL).. The National Institute for Health and Care Excellence has today published draft guidance not recommending Pfizer’s Besponsa to treat some patients with leukaemia on the NHS in England and Wales.. Pfizer’s antibody drug conjugate Besponsa has become the first to be approved by regulators in Europe to treat some adults with the rare, aggressive cancer acute lymphoblastic leukaemia (ALL)..