The FDA advisory panel voted 6:1 in favor of the investigational antibody-drug conjugate. ODAC with its voting affirmed that the results of the phase 3 ALFA-0701 trial showed a favorable risk:benefit profile for Mylotarg 3 mg/m2 on days 1, 4 and 7 in combination of chemotherapy in newly-diagnosed CD33-positive AML patients.
The discussions of the advisory committee were based on the Biologics License Application (BLA) which is presently being reviewed by the FDA.
FDA is now expected to take a call on Mylotarg’s approval following the recommendation from ODAC with a decision likely to be made by September.
Pfizer global product development oncology chief development officer Mace Rothenberg noted ODAC’s recommendation as a major step towards the company’s goal of making Mylotarg available to newly-diagnosed AML patients.
Rothenberg added: “We look forward to working closely with the FDA as we continue the regulatory process. We are grateful to both the investigators who led MYLOTARG clinical trials and the patients who participated.”
According to Pfizer, Mylotarg comprises of calicheamicin, a cytotoxic agent which attaches to a monoclonal antibody (mAB) to target CD33. In more than 90% of patients suffering from AML, CD33 has been recognized to be the antigen expressed on the surface of myeloblasts.
By binding to the CD33 antigen on the cell surface, Mylotarg is absorbed into the cell following which calicheamicin is released thereby causing death to the cancer cell.
University of Texas MD Anderson Cancer Center MD Jorge Cortes said: “Clinical studies investigating Mylotarg have provided a significant body of evidence supporting the risk:benefit profile of Mylotarg in AML.
“Based on the totality of the efficacy and safety data, Mylotarg, if approved, has the potential to be an important treatment option for adult patients with AML.”
In 2000, Mylotarg was approved by the FDA originally under its accelerated approval program for use as a single agent in CD33-positive AML patients who had their first relapse of the disease and were of 60 years or above.
Pfizer voluntarily withdrew the drug in 2010 following a confirmatory phase 3 trial showed that Mylotarg did not demonstrate a clinical benefit. In the same trial dubbed SWOG S0106, the rate of fatalities was significantly higher in the Mylotarg arm as a result of treatment-related toxicity.