General AML

The FDA advisory committee recommends approval of Mylotarg® (gemtuzumab ozogamicin) for AML

The U.S Food and Drug Administration’s (FDA) Oncologic Drug Advisory Committee (ODAC) have unanimously voted 6 to 1 in favor of allowing Mylotarg® to be approved for the treatment of newly diagnosed adult patients with de novo CD33-positive Acute Myeloid Leukemia (AML).1

Mylotarg® (gemtuzumab ozogamicin), an Antibody Drug Conjugate (ADC), is an antibody-targeted chemotherapeutic agent consisting of a humanized murine CD33 antibody. Since it is a humanized anti-CD33 monoclonal antibody, it is highly specific for targeting leukemic blasts. Mylotarg® binds to, and is internalized by tumor cells expressing CD33. As a result, this ADC can then dispense the anti-tumor antibiotic calicheamicin to CD33-expressing tumor cells.2

Mylotarg® was previously approved by the FDA via accelerated review in May 2000 for monotherapy of elderly individuals with relapsed AML but it was voluntarily withdrawn by the company , Pfizer, from market on October 15 2010 for the treatment of AML patients.  However, in February 2017, the AGP reported on the resubmission of a Biologics License Application (BLA), that sought approval of gemtuzumab ozogamicin in combination with daunorubicin and cytarabine for the treatment of adults with treatment-naive CD33–positive AML.

The ODAC discussions were based on the BLA which is currently under review by the FDA. The BLA for Mylotarg® was based on results obtained from the phase III ALFA-701 study. Data from the ALFA-701 study showed that combination of Mylotarg® with standard chemotherapy regimen in adult AML patients significantly improved 3-year Event Free Survival (EFS) and Relapse Free Survival (RFS) compared to chemotherapy alone.3  The ODAC said that the combination of Mylotarg®  added to chemotherapy in patients with newly diagnosed CD33+ AML “demonstrated a favorable risk–benefit profile”.1

The role of the ODAC is to provide recommendations to the FDA. The FDA is scheduled to make a decision on the BLA application by September 2017.

References
  1. Business Wire: FDA Advisory Committee Votes in Favor of Pfizer’s MYLOTARG (gemtuzumab ozogamicin) for Acute Myeloid Leukemia. 2017 Jul 11. http://www.businesswire.com/news/home/20170711006589/en/FDA-Advisory-Committee-Votes-Favor-Pfizer%E2%80%99s-MYLOTARG [Accessed 2017 Jul 12].
  2. Ricart A. D. Antibody-drug conjugates of calicheamicin derivative: gemtuzumab ozogamicin and inotuzumab ozogamicin. Clin Cancer Res. 2011 Oct 15; 17(20): 6417-27. DOI: 10.1158/1078-0432.CCR-11-0486.
  3. Castaigne S. et al. Final Analysis of the ALFA 0701 Study. Blood. 2014; 124: 376.