TKI introduction improves French CML patient survival

By Lynda Williams, Senior medwireNews Reporter

Real-world study findings from France show the significant impact tyrosine kinase inhibitor (TKI) treatment has had on the survival of patients with Philadelphia chromosome-positive (Ph+) chronic myeloid leukaemia (CML).

Amélie Penot, from CHU de Limoges in France, and co-workers identified 781 patients, aged an average of 57.4 years at CML diagnosis, who were included in five population-based French registries and were followed-up for a median of 51 months.

The 5-year relative survival (RS) rate of French patients with CML increased from 40.2% between 1980 and 1986 to 59.4% between 1987 and 1999 after the introduction of interferon α to the traditional CML armamentarium of chemotherapy, bone marrow transplant and hydroxyurea, the researchers explain.

A second significant increase in 5-year RS to 82.6% then occurred between 2000 and 2009 when TKIs became available and were given to 96.3% of patients, the team reports in Leukemia & Lymphoma.

The corresponding 5-year RS rates for patients with confirmed Ph+ CML in these time periods were 43.7%, 63.8% and 88.7%, with 8-year RS rates of 30.6%, 47.0% and 73.3%, respectively.

Of note, both Ph+ CML patients aged less than 65 years and their older counterparts experienced a significant increase in the 8-year RS over the study period, say Penot et al.

Medical records of 424 patients also revealed a significant reduction in the rate of transformation to acute leukaemia, from 51.8% of patients treated between 1980 and 1986 to just 7.4% of patients treated in the TKI era.

Noting that their results are in line with changes in survival of patients in Japan and the USA following the introduction of TKI therapy, the team writes that “TKIs have thus dramatically improved the prognosis of all patients with Ph+ CML, not only those included in clinical trials.”

Nevertheless, the researchers observe that CML patients still have poorer survival rates than age- and gender-matched healthy individuals.

“This could be explained by the occurrence of blast crisis before an optimal therapeutic response is achieved, and also by the onset of mutations conferring resistance to [imatinib]”, they write.

“Second-generation TKIs may reduce mortality related to these factors.”

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