Researchers from the M.D. Anderson Cancer Center have reported that Tasigna® (nilotinib) produces rapid and complete cytogenetic response in patients with newly diagnosed chronic myeloid leukemia (CML). These data were presented at the 2008 meeting of the American Society of Clinical Oncology in Chicago May 30-June 2.¹ 

Gleevec® (imatinib mesylate) is the standard initial treatment of newly diagnosed CML. Gleevec produces high rates of complete cytogenetic responses (70-85%) and of major molecular responses (20-40%), and has improved progression-free and overall survival. However, Gleevec does not eradicate the BCR-ABL clones in most patients as detected by polymerase chain reaction (PCR) monitoring. Furthermore, a small but significant fraction of patients will develop Gleevec-resistance or are intolerant to the drug. Patients who fail or are intolerant to Gleevec now have treatment alternatives other than allogeneic stem cell transplantation.

Sprycel and Tasigna® (nilotinib) are two new agents that have been developed for the treatment of patients with BCR-ABL-positive CML and acute lymphoblastic leukemia (ALL) that appear to have great promise for the treatment of patients who fail Gleevec. Sprycel and Tasigna are both approved by the U.S. Food and Drug Administration for treatment of patients who fail or are intolerant to Gleevec. Other tyrosine kinases are under development and being tested in the clinic. Studies are beginning to determine if Sprycel or Tasigna may be superior to Gleevec for the initial treatment of patients with newly diagnosed CML.

Researchers presented data on 35 newly diagnosed patients with CML treated with nilotinib; patients had been treated for a median of 6.5 months. The median age of this group was 47 years, and 70% were low risk by Sokal criteria. Patients receiving Sprycel were compared with patients receiving Gleevec at a dose 400 or 800 mg/day for the initial treatment of CML. The following table summarizes the main findings of this trial to date.

The authors concluded that Tasigna produced rapid and complete cytogenetic responses within three months in all patients treated.

Comments: It would appear that Tasigna may more rapidly induce complete cytogenetic remission than Gleevec. Ultimately, only randomized trials will determine if Tasigna or Sprycel represents superior treatment for newly diagnosed patients with CML.

Related News:

Tasigna® Effective for CML Patients with Gleevec® Resistance or Intolerance (11/13/2007)

Tasigna® Approved for CML (10/30/2007)

Nilotinib Effective in Patients with CML Intolerant to Gleevec® (06/12/2007)

Nilotinib Effective in Newly Diagnosed Patients with CML (1/9/2007 5:48:16 AM)

Reference:

¹ Cortes JE, O’Brien SM, Ferrajoli A, et al. Efficacy of nilotinib (AMN107) in patients (pts) with newly diagnosed, previously untreated Philadelphia chromosome (Ph) + chronic myelogenous leukemia in early chronic phase (CML-CP). Journal of Clinical Oncology. 2008;26:abstract 7016.