Previous studies have shown improvements in life expectancy for patients with CML increasing over time, thanks to evolving treatment strategies. A 2002 study reported that “Interferon-α (IFN-α) has significantly prolonged survival in CML, but some patients do not respond and many responses are not durable.”2

Results improved by combining interferon with low-dose arabinosyl cytosine or cytarabine.


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The greatest improvements, however, came after the development of TKIs. The FDA approved the first, imatinib mesylate (marketed as Gleevac or Glivec), in 2001. This discovery and use in the treatment of CML earned 3 of the men behind it the Lasker-DeBakey Clinical Medical Research Award in 2009.

One of the researchers, Dr Brian J. Druker, of the Oregon Health and Science University in Portland, reported in a follow-up study 5 years after the approval of imatinib that “the 5-year estimated overall survival rate for patients who received imatinib as initial therapy (89%) is higher than that reported in any previously published prospective study of the treatment of CML.”3

Since this drug’s approval, researchers have discovered other kinase inhibitors, such as dasatinib and nilotinib, which “showed high response rates in patients who had had a relapse during imatinib therapy,” Druker reported.

According to the American Cancer Society, “in large part due to the discovery of targeted drugs, the 5-year survival rate for CML has doubled over the past two decades, from 31% in the early 1990s to 63% for patients diagnosed from 2005 to 2011.”4

The increase in life expectancy, however, comes at a price, Dr Bower and her co-authors conclude: “notwithstanding that a small subgroup of patients with an excellent response to treatment have been able to stop taking TKI agents,” they wrote, “most patients with CML will take the drug for life, which along with the increasing prevalence of CML, has high cost implications.”

They said, however, in an e-mail to Cancer Therapy Advisor that “as time progresses we will get more refined information about which patients can stop treatments for varying periods of time without jeopardizing their overall outcome, which will reduce the amount of medication, and thus the costs.”

References

  1. Bower M, Bjorkholm M, Dickman PW, Hoglund M, Lambert PC, Andersson TM. Life expectancy of patients with chronic myeloid leukemia approaches the life expectancy of the general population. J Clin Oncol. 20 Jun 2016. doi: 10.1200/JCO.2015.66.2866 [Epub ahead of print]
  2. Baccarani M, Rosti G, de Vivo A, et al. A randomized study of interferon-alpha versus interferon-alpha and low-dose arabinosyl cytosine in chronic myeloid leukemia. Blood. 2002 Mar 1;99(5):1527-35.
  3. Druker BJ, Guilhot F, O’Brien SG, et al. Five-year follow-up of patients receiving imatinib for chronic myeloid leukemia. N Engl J Med. 2006 Dec 7;355(23):2408-17.
  4. Cancer Facts & Figures 2016. American Cancer Society. http://www.cancer.org/acs/groups/content/@research/ documents/document/acspc-047079.pdf Updated 2016.