New Chronic Myeloid Leukemia Drug

Bosulif receives FDA approval to treat resistant chronic myelogenous leukemia

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) Chronic myeloid leukemia often responds to first-line treatment. Gleevec (imatinib) is the standard first-line medication. The disease usually quiets for a time, then comes back. A new drug has been approved to treat this blood and bone marrow cancer.

The U.S. Food and Drug Administration has approved Bosulif (bosutinib) to treat patients with chronic myelogenous leukemia (CML) who no longer respond to other therapies.

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Bosulif is designed to treat patients with all phases (chronic, accelerated and blast) of Philadelphia chromosome positive CML. These patients will have already been treated with other CML medications, including Gleevec.

“With the approval of tyrosine kinase inhibitors, we are seeing improvements in the treatment of CML based on a better understanding of the molecular basis of the disease,” said Richard Pazdur, MD, director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research.

“These improvements have been observed in chronic and accelerated phases of CML.”

Other drugs approved by the FDA to treat various forms of CML include Gleevec (2001), Sprycel (dasatinib) in 2006 and Tasigna (nilotinib) in 2007.

The safety and effectiveness of Bosulif was evaluated in a single clinical trial involving 546 adult patients who had chronic, accelerated or blast phase CML.

All participants had CML that had gotten worse after treatment with Gleevec, or Gleevec followed by Sprycel and/or Tasigna, or who couldn’t tolerate the side effects of one of the medicines.

The trial members were all treated with Bosulif.

In patients with chronic phase CML, effectiveness was judged by the number of patients who experienced a major cytogenetic response (MCyR) within the first 24 weeks of treatment. This response means that 65 percent of the cells tested are normal.

In patients with chronic phase CML, the study found:

  • Among the patients who had received Gleevec, 34 percent achieved MCyR after 24 weeks. Of those who had this response at any time, 52.8 saw the response last at least 18 months. 
  • About 27 percent of the patients treated with Gleevec followed by Sprycel and/or Tasigna achieved MCyR within 24 weeks. Of those, 51.4 percent had major responses that lasted at least nine months.

For patients with accelerated phase CML, this research showed:

  • Of those previously treated with at least Gleevec, 33 percent had their blood counts that returned to normal range (complete hematologic response) and 55 percent achieved normal blood counts with no evidence of leukemia (overall hematologic response) within the first 48 weeks of treatment.

Among patients with blast phase CML, 15 percent and 28 percent of patients achieved complete hematologic response and overall hematologic response, respectively.

The most common side effects seen in those taking Bosulif were diarrhea, nausea, a low level of platelets in the blood (thrombocytopenia), vomiting, abdominal pain, rash, low red blood cell count (anemia), fever and fatigue.

Bosulif is marketed by Pfizer. FierceBiotech reported that a Pfizer spokesperson said that the drug will cost less than $8,200 a month.

Reviewed by: 
Review Date: 
September 5, 2012
Last Updated:
September 7, 2012