Cancer Treatment Today

According to Claudiani, S., & Apperley, J. F. (2018), “June 2018 was the 20th anniversary of the clinical use of the first tyrosine kinase inhibitor (TKI), imatinib, for chronic myeloid leukemia. Since then, the change in prognosis for patients with this disease is one of the major success stories of modern cancer medicine. The dilemmas that face physicians and patients are no longer only those concerned with delaying inevitable progression to the terminal blastic phase or selecting the individuals most likely to benefit from allogeneic stem-cell transplantation; rather, they are now focused also on the choice of TKI, the management of comorbidities and adverse effects, strategies to improve quality of life, and the appropriateness of a trial of therapy discontinuation. Interestingly, with 4 TKIs approved for frontline use, the choice of initial therapy continues to cause controversy, a situation made more complicated by the tantalizing prospect of treatment-free remission.”

According to Gómez-Almaguer, D., et al. (2016), “With the start of the new millennium, the International Randomized Study of Interferon- plus cytarabine versus STI571 (IRIS) trial demonstrated a dramatic improvement in survival by comparing imatinib versus interferon alpha plus cytarabine. The Food and Drug Administration (FDA) approved imatinib as first-line treatment for newly diagnosed CML in 2001 due to its outstanding effectiveness. Years later, three second-generation (dasatinib, nilotinib, bosutinib) and one third-generation (ponatinib) tyrosine-kinase inhibitors (TKIs) were developed and approved. These highly effective treatment options, however, are not affordable for many low-income patients. Additionally, the use of drugs that effectively treat but do not cure the disease has resulted in an important economic impact for patients and health care systems worldwide, especially those in developing countries. Imatinib is the least expensive and a very effective TKI in many low-income countries. Early allogeneic stem cell transplantation must be considered in the management of selected patients before CML transformation.”

Per Kota, V.K., et al, (2017), “The second-generation tyrosine kinase inhibitors (TKIs) (2G-TKIs) dasatinib (DAS) and nilotinib (NIL) yield faster responses in newly diagnosed chronic phase (CP) chronic myeloid leukemia (CML) as compared with imatinib (IM); however, long-term safety of these agents is a growing concern. We identified 20 patients with CP-CML diagnosed between August 2013 and October 2016 who initiated 2G-TKIs and were then switched after optimal response at 3 months to IM. Second-generation TKIs initiated were DAS (n = 15), NIL (n = 3), or both sequentially due to intolerance (n = 1). One other patient initiated therapy with ponatinib on trial. Response was assessed by quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) for BCR-ABL1 levels every 3 months and in patients with qRT-PCR values less than 10% at 3 months, IM was started at 400 mg/d. IM was well tolerated except in 2 patients who required dose-reduction and discontinuation due to grade 2 skin rash (1) and grade 2 anxiety (1). After initiation of IM therapy, the BCR-ABL1 qRT-PCR levels trended down as expected. At 12 months 16 (84.2%) of 19 evaluable patients showed a 3 log (major molecular remission) or better reduction in their PCR levels. In conclusion, this retrospective analysis shows that IM can be safely and effectively administered following optimal response to 2G-TKIs. A prospective trial exploring this approach is currently enrolling and will be needed to confirm the safety and efficacy of this therapeutic approach.”  

  Claudiani, S., & Apperley, J. F. (2018). The argument for using imatinib in CML. Hematology Am Soc Hematol Educ Program. 2018 Nov 30;2018(1):161-167. doi: 10.1182/asheducation-2018.1.161.

Gómez-Almaguer, D., et al. (2016). The treatment of CML at an environment with limited resources. Hematology. 2016 Dec;21(10):576-582. Epub 2016 May 24.

Kota, V.K., et al. (2017). Outcomes of Newly Diagnosed Chronic Phase Chronic Myeloid Leukemia Following an Elective Switch From Second-Generation Tyrosine Kinase Inhibitor to Imatinib. Clin Lymphoma Myeloma Leuk. 2017 Dec;17(12):e71-e73. doi: 10.1016/j.clml.2017.09.004. Epub 2017 Sep 19