Treatment Options for Chronic Myeloid Leukemia

Chronic myeloid leukemia responds well to bosutinib in trial

(RxWiki News) Chronic myeloid leukemia (CML) has a number of treatment options. And those options may be expanding in the near future. A drug still being investigated shows positive results in treating newly diagnosed CML patients.

The drug bosutinib delivered superior results to Gleevec (imatinib) in the phase III BELA trial.

While both drugs produced the same complete cytogenetic response (CCyR), bosutinib resulted in significantly better major molecular response (MMR), as compared to Gleevec.

These responses indicate how well the disease is being controlled. CCyR indicates normal blood cells with no evidence of disease, and MMR means there are no signs of abnormal genes created by the Philadelphia Chromosome that causes CML.

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The BELA study is being led by Jorge E. Cortes, M.D., Chair of the CML Section at The University of Texas MD Anderson Cancer Center.

Study participants include 250 CML patients who were randomly assigned to receive 500 mg of bosutinib per day and 252 patients receiving 400 mg/day of Gleevec. These patients have been followed for about 26 months.

At 24 months, 37 percent of the bosutinib patients had to stop the therapy due to adverse effects, which included gastrointestinal problems and liver toxicity.

Here's what the study found:

  • Both groups achieved the same CCyR responses.
  • MMR rates - 67 percent for patients taking the bosutinib vs. 52 percent for those on Gleevec
  • Fewer patients taking bosutinib saw their disease worsen (5 vs. 9)
  • Bosutinib also resulted in fewer treatment failures than did Gleevec (4 vs. 13 percent)
  • Fewer people died of CML while on bosutinib (6 vs. 13)

Dr. Cortes told HemOnc Today, "Complete cytogenic response rates were significantly higher for bosutinib at 3 months and 6 months, but after that, they became very similar. By cumulative measures, the two treatments had almost the same outcomes by 24 months.”

He also reported that bosutinib resulted in faster major molecular responses, a difference that remained unchanged for up to 12 months.

“By 24 months, we saw a 61 percent response rate with bosutinib and a 50 percent response rate in imatinib,” Dr. Cortes said.

Bosutinib also outperformed Gleevec in event-free survival rate at 24 months: 92 vs 88 percent.

Dr. Cortes concludes that "these results indicate that bosutinib presents a new therapeutic option for patients with newly diagnosed CML.”

Results from this trial were presented at the 2011 Annual Meeting of the American Society of Hematology (ASH)

Dr. Cortes has disclosed that he has received consultancy and research funding from CML drug manufactures - Pfizer, Bristol-Myers Squibb and Novartis.

Review Date: 
January 12, 2012