It has been approved for use for patients who have favourable or intermediate cytogenetics, or those who do not know their cytogenetic status.
Gemtuzumab ozogamicin is an antibody-drug conjugate (an antibody joined to a drug). This means the drug (ozogamicin) is targeted to the leukaemia cells with the CD33 protein on their surface, to which the antibody (gemtuzumab) matches. The brand name for this treatment is Mylotarg and it is manufactured by Pfizer. AML patients undergo several stages of the chemotherapy in order to induce and sustain remission; NICE have approved gemtuzumab ozogamicin for both induction (the first stage) and consolidation (subsequent stages) chemotherapy.
The decision was made following a clinical trial called ALFA-0701, conducted in France. The trial was conducted in adults aged between 50 and 70, who had de novo AML (i.e. not developed as a result of treatment for another condition) which had not yet been treated. Patients receiving gemtuzumab ozogamicin alongside the standard treatment of daunorubicin and cytarabine were shown to have increased event free and relapse free survival times when compared with patients receiving just daunoribicin and cytarabine.
AML patients are classified as favourable, intermediate or unfavourable in terms of their cytogenetics. This means that different AML patients have different mutations within their leukemic cells, which can correlate to a different response to treatment; i.e. someone with unfavourable cytogenetics is less likely to respond to the standard treatment. Further analysis of the efficacy of gemtuzumab ozogamicin showed that it was only effective at increasing event-free and relapse-free survival in those patients with favourable or intermediate cytogenetics. NICE have indicated that treatment of those with unknown cytogenetics, such as those who need treatment too urgently to wait for the cytogenetic test results, can also be treated with gemtuzumab ozogamicin until such a time as they know the cytogenetic status.
“We welcome NICE’s decision to allow individuals diagnosed with this particular type of AML access to gemtuzumab ozogamicin,” said Zack Pemberton-Whiteley, Patient Advocacy Director at Leukaemia Care. “Today’s approval provides people with an important new treatment, where options have previously been limited.”