The Biologics License Application for inotuzumab ozogamicin has been accepted for filing and granted Priority Review by the FDA. Inotuzumab ozogamicin is being evaluated for the treatment of adult patients with relapsed or refractory B-cell precursor acute lymphoblastic leukemia (ALL).
Inotuzumab ozogamicin is an investigational antibody-drug conjugate comprised of a monoclonal antibody targeting CD22, a cell surface antigen expressed on approximately 90 percent of B-cell malignancies, linked to a cytotoxic agent. When inotuzumab ozogamicin binds to the CD22 antigen on B cells, it is internalized into the cell, where the cytotoxic agent calicheamicin is released to destroy the cell.
Inotuzumab ozogamicin received Breakthrough Therapy designation from the FDA in October 2015 for ALL. Priority Review status accelerates FDA review time from 10 months to a goal of 6 months from the day of acceptance of filing, and it is given to drugs that may offer major advances in treatment or may provide a treatment for which no adequate therapy exists. The Prescription Drug User Fee Act goal date for a decision by the FDA is August 2017.
The submission is based on results from the phase III INO-VATE 1022 trial, which enrolled 326 adult patients with relapsed or refractory B-cell ALL and compared inotuzumab ozogamicin to standard-of-care chemotherapy. The INO-VATE 1022 study had two independent primary endpoints, complete response with or without hematologic remission and overall survival.
The most common adverse events (AEs) observed in clinical trials for inotuzumab ozogamicin were cytopenias, including febrile neutropenia. Common nonhematologic treatment-emergent AEs included nausea, headache, and pyrexia. Additionally, veno-occlusive liver disease was observed more frequently in patients treated with inotuzumab ozogamicin, especially those who went on to receive hematopoietic stem cell transplantation.