Targeted ADC therapy moves closer to approval.

With a nearly unanimous (6 to 1) vote, the FDA’s Oncologic Drug Advisory Committee (ODAC) found the results of trial ALFA-0701 demonstrated the efficacy of Pfizer Inc.’s MYLOTARG (gemtuzumab ozogamicin), earning a “favorable” risk: benefit profile as a combination chemotherapy for patients with newly-diagnosed CD33-positive acute myeloid leukemia (AML). 

Mace Rothenberg, Chief Development Officer for Pfizer Global Product Development’s Oncology group was upbeat in his appraisal of the committees’ vote of confidence, “We are extremely pleased with the Committee’s recommendation and believe this is an important step toward our goal of making MYLOTARG available to patients with newly-diagnosed AML.” Noting that Pfizer was looking forward to “working closely” with regulators on the path to approval.

Included for committee review, along with the BLA, were Pfizer-sponsored studies from MYLOTARG’s original New Drug Application (NDA) and meta-analysis of individual patient data from five randomized Phase III studies (~3,000 patients) including ALFA-0701. Pfizer said these studies cover 10 years of research across more than 4,300 patients.

Jorge Cortes, a doctor at the University of Texas’ MD Anderson Cancer Center highlighted the depth of the research so far, explaining, “Clinical studies investigating MYLOTARG have provided a significant body of evidence supporting the risk: benefit profile of MYLOTARG in AML,” he said. “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.”

Although the ODAC discussed MYLOTARG for newly diagnosed CD33-positive AML in its review and vote, Pfizer said it is seeking FDA approval for two indications: one, as a combination with standard chemotherapy treating previously untreated “de novo” CD33-positve AML patients and two, as a monotherapy for first-relapse patients 60 or older who aren’t candidates for cytotoxic chemotherapy.