Global Impact of Tyrosine Kinase Inhibitors on Chronic Myeloid Leukemia Epidemiology Over the Next Ten Years

Background: The advent of tyrosine kinase inhibitors (TKIs) has transformed the prognosis of CML. Prolonged survival has already been achieved in most patients with access to these drugs, and as access improves in more resource-constrained settings, it should be expected that this improvement will become more common, thus increasing the prevalence of CML. Aim: Through this analysis, we aim to understand the global impact of targeted therapy on CML prevalence over the next ten years. Methods: Using a critically appraised set of country-specific cancer registries, CML incidence was estimated for 45 countries, representing approximately 90% of the world population in 2018. An assumptions-based 10-year forecast model was used to incorporate the effects of improving access to TKIs in developing countries using an observed correlation between gross domestic product per capita, CML risk, and survival ( Fig 1 ). To represent the continuing optimization of TKI-based treatments, survival was further trended based on an attenuated historical trend. Prevalence was estimated as cumulative incidence over 20 years from diagnosis, with deductions for all-cause mortality. To estimate prevalent CML globally, countries were grouped into economically- and geographically-defined regions. Regional totals were projected upwards to account for the countries for whom direct estimates were not made. A control forecast was also developed where no improved survival attributed to improved access to TKIs in resource-constrained settings was assumed. The results between the two models were then compared with measure the difference attributable to the effects of improved TKI access. Results: In 2018, there will be an estimated 503,000 prevalent cases of CML globally with 267,000 of these estimated to be living in resource-constrained settings. When assuming no improvements in survival across developing countries due to TKI access, we expect this number would have been 221,000 cases. That is, 46,000 people are living with CML in resource-constrained settings now who would not be alive had it not been for access to TKIs. Conclusion: The prevalence of CML is expected to rise globally which can be primarily attributed to prolonged survival and improved access to TKIs. [Figure: see text]