Pfizer’s inotuzumab ozogamicin gains FDA priority review in acute lymphoblastic leukemia

Pfizer Inc. has received a priority review designation from the U.S. Food and Drug Administration (FDA) for its innovative blood cancer drug, inotuzumab ozogamicin. This critical status will expedite the review process, potentially bringing this new treatment option to patients with acute lymphoblastic leukemia (ALL) sooner.

FDA Priority Review Accelerates Approval Process

Inotuzumab ozogamicin, an anti-CD22 antibody-drug conjugate developed by Pfizer, targets patients suffering from acute lymphoblastic leukemia, particularly those in whom the disease has recurred or remains refractory despite prior treatments. Thanks to the priority review, the FDA will complete its evaluation within a shortened six-month window, compared to the standard ten-month period.

The FDA grants priority review to drugs that offer significant improvements in treatment efficacy or provide a therapy where none adequately exists. The anticipation builds as the Prescription Drug User Fee Act (PDUFA) goal date for a decision is set for August this year.

Clinical Trials and Regulatory Pathway

The decision by the FDA was influenced by the results from the Phase 3 INO-VATE 1022 trial, where inotuzumab ozogamicin was pitted against standard care chemotherapy. According to Mace Rothenberg, MD, chief development officer of Oncology at Pfizer Global Product Development, “ALL that has recurred after, or is refractory to, first-line therapy is a rapidly progressing and deadly disease. Based on the positive results of the INO-VATE 1022 Phase 3 trial, we believe inotuzumab ozogamicin, if approved, represents a new treatment option for adult patients with relapsed or refractory B-cell precursor ALL.”

Inotuzumab ozogamicin also received the FDA’s Breakthrough Therapy designation in October 2015, underscoring its potential to address critical needs in blood cancer treatment. Concurrently, Pfizer has submitted a Marketing Authorization Application (MAA) to the European Medicines Agency (EMA) for review in the same patient demographic.

Mechanism and Impact

Inotuzumab ozogamicin operates as an investigational antibody-drug conjugate. It consists of a monoclonal antibody targeting CD22, a cell surface antigen prevalent in nearly all B-cell tumors linked to the cytotoxic agent. This specific approach could significantly advance the treatment landscape for blood cancers.

The expedited review of inotuzumab ozogamicin by the FDA signifies a potentially transformative advancement in the treatment of acute lymphoblastic leukemia. With its targeted approach and the backing of substantial clinical data, Pfizer’s drug could become a crucial addition to the arsenal against this aggressive form of cancer.