Nearly a third of Medicare beneficiaries with chronic myeloid leukemia (CML) did not initiate tyrosine kinase inhibitor therapy within 6 months of diagnosis, according to a review of SEER-Medicare data.
The findings suggest that out-of-pocket costs might be a barrier to timely initiation of tyrosine kinase inhibitor (TKI) therapy in CML patients, Aaron N. Winn of the University of North Carolina at Chapel Hill and his colleagues reported online ahead of print in the Journal of Clinical Oncology.
Of 393 individuals diagnosed with CML between 2007 and 2011, only 68% initiated TKI therapy within 180 days (median, 75 days), and 61% of those patients were adherent. Earlier treatment initiation was associated with receipt of cost-sharing subsidies (hazard ratio, 1.35), more-recent diagnosis (HR, 1.14), and living in a big metropolitan area (HR, 1.80) or metropolitan area vs. an urban area (HR, 1.84), while later treatment initiation was associated with higher levels of comorbidity (HR, 0.81) and age older than 80 years vs. age younger than 70 years (HR, 0.53)
Multivariate analysis showed that therapy initiation within 180 days was significantly more likely among those with more-recent diagnosis (relative risk, 1.06) and those living in a large metropolitan area vs. an urban area (RR, 1.57), and was significantly less likely among those older than age 80 years vs. those younger than age 70 years (RR, 0.71). Adherence within 180 days of therapy initiation was higher for those diagnosed in more-recent years (RR, 1.07) and lower for patients aged 80 years or older vs. 66-69 years (RR, 0.74), the investigators found (J Clin Oncol. 2016 Oct 3. doi: 10/1200/JCO.2016.67.4184).
“Our findings highlight important gaps in TKI use among Medicare beneficiaries with CML and suggest that high cost sharing may result in delays in initiation of these life-saving medications,” they concluded.
This study was supported by a University of North Carolina Clinical and Translational Science award, the UNC School of Medicine, the Royster Society of Fellows at UNC Chapel Hill, and by grants from the National Institutes of Health, North Carolina Translational and Clinical Sciences Institute, and the National Cancer Institute. The authors reported having no disclosures.