The US Food and Drug Administration (FDA) has granted breakthrough therapy designation for Pfizer’s investigational antibody-drug conjugate (ADC) inotuzumab ozogamicin to treat acute lymphoblastic leukaemia (ALL).
The breakthrough status was based on data from the Phase III INO-VATE ALL trial, which enrolled 326 adult patients with relapsed or refractory CD22-positive ALL and compared inotuzumab ozogamicin to standard of care chemotherapy.
Inotuzumab ozogamicin is an investigational antibody-drug conjugate (ADC), which includes a monoclonal antibody (mAb) targeting CD22, a cell surface antigen expressed in around 90% of B-cell malignancies linked to a cytotoxic agent.
The company said that when inotuzumab ozogamicin binds to the CD22 antigen on malignant B-cells, it is internalised into the cell, where the cytotoxic agent calicheamicin is released to destroy it from within.
Pfizer is responsible for all manufacturing, clinical development and commercialisation activities of inotuzumab ozogamicin, which has been developed as part of its collaboration with Celltech, now UCB.
Pfizer Oncology Clinical Development and Medical Affairs senior vice-president and chief medical officer Dr Mace Rothenberg said: "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.
"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 leukaemia is crucial as only 10% of adults with ALL who relapse after first-line therapy survive five years or more with current treatment options."
ALL is an aggressive type of leukaemia with high unmet need and a poor prognosis in adults and intensive, with long-term chemotherapy the current standard treatment for this disease.
It is estimated that around 6,250 cases of ALL will be diagnosed this year in the US, with one in three cases in adults.
Earlier this month, FDA granted fast-track designation for Merck and Pfizer’s investigational anti-PD-L1 IgG1 monoclonal antibody, avelumab to treat metastatic Merkel cell carcinoma (MCC).
In September, avelumab was granted FDA orphan drug designation to treat MCC, a rare and aggressive type of skin cancer.
Image: Pfizer world headquarters. Photo: courtesy of Jim.henderson.