FDA grants breakthrough therapy designation to inotuzumab ozogamicin for ALL

The FDA granted breakthrough therapy designation to inotuzumab ozogamicin for treatment of patients with acute lymphoblastic leukemia.

Inotuzumab ozogamicin (Pfizer), an investigational antibody–drug conjugate, is comprised of a monoclonal antibody that targets CD22 — a cell surface antigen expressed on approximately 90% of B-cell malignancies — linked to the cytotoxic agent calicheamicin.

Inotuzumab ozogamicin binds to the CD22 antigen on malignant B cells, at which point it is internalized into the cell. Calicheamicin is then released to destroy the cell.

The FDA based its designation on results of the phase 3 INO-VATE ALL trial, which compared inotuzumab ozogamicin with standard-of-care chemotherapy in 326 adults with relapsed or refractory CD22-positive ALL.

Topline results presented at the European Hematology Association Annual Congress showed the study met its first primary endpoint of higher complete hematologic remission rate. OS is a second primary endpoint.

“Inotuzumab ozogamicin is the third Pfizer oncology medicine to be granted breakthrough therapy designation by the FDA, underscoring our commitment to innovative research and development that addresses significant unmet needs,” Mace Rothenberg, MD, senior vice president of clinical development and medical affairs and chief medical officer for Pfizer Oncology, said in a press release. “Breakthrough therapy designation will allow us to work more closely with the FDA to bring this important therapy to patients as rapidly as possible. Advancing therapies for patients with adult acute lymphoblastic leukemia is crucial, as only 10 percent of adults with ALL who relapse after first-line therapy survive five years or more with current treatment options.”