In a single-institution study reported in JCO Oncology Practice, Bernardo H.L. Goulart, MD, and colleagues found that higher out-of-pocket costs for tyrosine kinase inhibitors (TKIs) were associated with reduced adherence to and increased discontinuation of TKI therapy—as well as poorer overall survival—among patients with EGFR- and ALK-positive stage IV non–small cell lung cancer (NSCLC).
Bernardo H.L. Goulart, MD
The study involved data from 105 eligible patients with TKI claims from the Hutchinson Institute for Cancer Outcomes Research database; the database provides patient-level data from the Cancer Surveillance System registry linked to claims from Medicare and two commercial insurance plans (Regence Blue Shield and Premera Blue Cross).
Patients were categorized into quartiles (Qs) of TKI out-of-pocket costs based on average monthly costs per patient up to 3 months from therapy initiation. A landmark analysis at 3 months from TKI initiation was performed to assess the Q1–3 vs Q4 TKI out-of-pocket cost associations with overall survival, as well as TKI duration of therapy, adherence, and discontinuation. Multivariate models were adjusted for age at diagnosis, sex, insurance type at the month of TKI initiation (Medicare vs commercial), mutation type (EGFR vs ALK), receipt of intravenous chemotherapy or immune checkpoint inhibitors at any time, and time from diagnosis to date of first TKI claim. Overall, 53.9% of patients in Q1–3 and 92.6% of those in Q4 had Medicare.
The median average monthly TKI out-of-pocket costs were $1,431 for 78 patients in Q1–3 and $2,888 for 27 patients in Q4.
With median follow-up of 23.8 months, 87.6% patients had died.
After the 3-month landmark, median overall survival was 22.4 months in Q1–3 vs 9.1 months in Q4, with an adjusted hazard ratio (HR) on multivariate analysis of 1.85 (P =.019). When Q1 was used as the reference category, no significant increase in mortality risk was observed for each higher quartile (adjusted HR = 1.16, P = .241).
Median duration of TKI therapy was 6.0 months vs 7.0 months (adjusted HR = 1.06, P = .862). The likelihood of being TKI-adherent was 65.4% vs 33.3% (adjusted odds ratio [OR] = 0.28, P = .012). Within 3 months of TKI initiation, 10.3% vs 48.2% discontinued TKI therapy (adjusted OR = 8.75, P < .001).
As noted by the investigators, “The [large] Medicare subgroup drove all the observed associations of higher TKI out-of-pocket costs with decreased survival, lower TKI adherence, and an increased likelihood of early TKI discontinuation [as evident in unadjusted analyses]…Compared with [those insured with] Medicare, commercially insured patients incurred lower TKI out-of-pocket costs and probably had access to financial assistance programs from drug manufacturers, whereas federal legislation prohibits Medicare beneficiaries from applying for such assistance. Further studies are necessary to elucidate the impact of insurance type on the association of TKI out-of-pocket costs with patient outcomes.”
They concluded, “Among patients with advanced EGFR- and ALK-positive NSCLC, higher TKI out-of-pocket costs are associated with decreased TKI adherence, a higher likelihood of TKI discontinuation, and inferior survival.”
Dr. Goulart, of the Fred Hutchinson Cancer Research Center, is the corresponding author for the JCO Oncology Practice article.
Disclosure: The study was supported by a grant from the National Cancer Institute. For full disclosures of the study authors, visit ascopubs.org.The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.