Novel Leukemia Drug Granted FDA Priority Review

Inotuzumab ozogamicin treats relapsed or refractory B-cell precursor acute lymphoblastic leukemia (ALL).

The FDA recently accepted a new biologics license application for inotuzumab ozogamicin, and also granted the drug priority review in patients with relapsed or refractory B-cell precursor acute lymphoblastic leukemia (ALL).

The novel treatment was previously granted breakthrough therapy designation for this indication in October 2015, according to a press release from Pfizer.

Priority review designation reduces review time from 10 months to approximately 6 months from the FDA’s acceptance of the application. This designation is granted to drugs for conditions that have a clinically unmet need in hopes of improving access to treatment.

The Prescription Drug User Fee Act goal date is August 2017, according to the press release. The marketing authorization application for inotuzumab ozogamicin is also currently being reviewed by the European Medicines Agency for the same indication.

The recent submissions were based on positive findings from the INO-VATE 1022 phase 3 clinical trial, which were previously published in the New England Journal of Medicine.

Included in the trial were 326 patients with relapsed or refractory B-cell ALL, who were either treated with inotuzumab ozogamicin or standard chemotherapy. The clinical trial included 2 primary endpoints: complete response with or without hematologic remission and overall survival.

The trial met its endpoint of complete response, with more patients responding to inotuzumab ozogamicin than chemotherapy, Pfizer reported. The investigators found that treatment with inotuzumab ozogamicin also extended progression-free survival more significantly than chemotherapy.

Overall survival was seen to increase among patients treated with inotuzumab ozogamicin compared with chemotherapy. However, those results were not found to be statistically significant, with a 23% overall survival rate at 2 years with inotuzumab ozogamicin and 10% with chemotherapy, according to Pfizer.

Patients treated with inotuzumab ozogamicin were also observed to have high rates of minimal residual disease negativity, and increased duration of response, compared with chemotherapy.

Common adverse events associated with both treatments were cytopenias, including febrile neutropenia. Treatment-emergent adverse events linked to inotuzumab ozogamicin included nausea, headache, and pyrexia, while chemotherapy was associated with nausea, pyrexia, and diarrhea, according to Pfizer.

Veno-occlusive liver disease also occurred more commonly among patients treated with inotuzumab ozogamicin compared with chemotherapy, according to the press release.

With current treatments, the 5-year survival rate is less than 10%, and only 20% to 40% of patients are disease-free after standard treatments. This highlights the need for additional, effective treatments that will improve the prognosis of these patients.

“ALL that has recurred after, or is refractory to, first-line therapy is a rapidly progressing and deadly disease,” said Mace Rothenberg, MD, chief development officer, Oncology, Pfizer Global Product Development. “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.”