For approval the authorities were submitted a trail results that included 326 patients with relapsed or refractory B-cell ALL.
B-cell precursor acute lymphoblastic leukemia (ALL) is a form of leukemia, in which too many B-cell lymphoblasts (immature white blood cells) are found in the blood and bone marrow.
Dr. Richard Pazdur, the FDA's director for cancer drugs, said the drug's approval provides a targeted option for patients with few available treatments. This new treatment could be a targeted treatment that could benefit this group of patients.
Inotuzumab ozogamicin (Besponsa; Wyeth Pharmaceuticals, Pfizer) is an investigational antibody-drug conjugate comprised of a monoclonal antibody that targets CD22 - an antigen expressed on cancer cells in most patients with B-cell ALL - linked to a cytotoxic agent.
The approval of Responsa was based on a Phase 3 study of patients with relapsed or refractory B-cell ALL who were randomized to receive treatment with Besponsa (n=109) or an alternative chemotherapy regimen (fludarabine plus cytarabine with G-CSF, high-dose cytarabine, or cytarabine plus mitoxantrone; n=109).
"The approval of Besponsa is an important step forward for adult patients with relapsed or refractory B-cell acute lymphoblastic leukemia, a rare disease that can be fatal within a matter of months if left untreated", Liz Barrett, global president of Pfizer Oncology, said in a company-issued press release. The trial measured the percentage of patients with no evidence of disease and full recovery of blood counts after treatment. More than 35 percent of people evaluated achieved complete remission for about eight months after taking Besponsa, compared with about 17 percent of those who took a different chemotherapy drug.
Common side effects ( 20% of patients) associated with Besponsa include thrombocytopenia, neutropenia, leukopenia, infection, anemia, fatigue, hemorrhage, pyrexia, nausea, headache, febrile neutropenia, liver damage (transaminases and/or gamma-glutamyltransferase increased), abdominal pain and hyperbilirubinemia. The warning also states that the drug could cause blockage of veins in the liver or VOD or sinusoidal obstruction syndrome which could be problematic. Women who are pregnant or breastfeeding are not to be prescribed Besponsa because it may harm the developing fetus or the newborn breastfeeding baby.