Evaluating patient adherence and persistence to first-line tyrosine-kinase inhibitors for metastatic renal cell carcinoma.

person Zhaohui Arter UCI Medical Center, Orange, CA info_outline Zhaohui Arter, David Joseph Benjamin, Yen Cao, Michael Forsyth, Ranjit Thirumaran, Jorge Farias, Arash Rezazadeh

Authors person Zhaohui Arter UCI Medical Center, Orange, CA info_outline Zhaohui Arter, David Joseph Benjamin, Yen Cao, Michael Forsyth, Ranjit Thirumaran, Jorge Farias, Arash Rezazadeh Organizations UCI Medical Center, Orange, CA, Hoag Family Cancer Institute, Newport Beach, CA, University of California, Irvine, Irvine, CA, Pfizer, Inc., Littleton, CO, Pfizer Inc., Aliso Viejo, CA, Pfizer, Inc., Irvine, CA, University of California Irvine Medical Center, Orange, CA Abstract Disclosures Research Funding No funding received None. Background: Tyrosine kinase inhibitors (TKIs) have been approved in treating advanced renal cell carcinoma (RCC) since 2005. More recently, combination therapy with an immune checkpoint inhibitor (ICI) and a kinase inhibitor (TKI) is considered standard of care in the first-line setting of metastatic RCC. While oral neoplastic therapies such as TKIs promote patient autonomy, these therapies pose unique challenges including ensuring patients take medications as indicated (i.e., adherence) and for the recommended duration (i.e., persistence). Persistence and adherence data from prescription dispensing and refill patterns are important to health care providers, systems, and payers in order to assess and/or optimize the therapeutic goal(s) of anticancer treatment. Therefore, we sought to explore adherence and persistence of first-line TKIs when used in combination with ICIs for treating metastatic RCC. Methods: Adults with metastatic RCC who received at least two prescriptions for FDA-approved TKIs used in combination with ICIs between April 29, 2019 and August 29,2022 were identified at University of California Irvine Medical Center. Adherence was determined by calculating the Medication Possession Ratio (MPR) and the Proportion of Days Covered (PDC). TKI persistence was evaluated using the Kaplan-Meier method. Also evaluated was the average length of therapy. We examined additional dispensing and refill pattern indicators, including the monthly total number of prescriptions filled. Results: A total of 66 individuals and 849 prescriptions were discovered. The mean duration of treatment for all patients was 237 days, and the median duration was 201 days (Table 1). The mean persistence was 303 days, whereas the median persistence was 233 days. Over 180 days, the median MPR was 83%, whereas the median PDC was 72%. The median variable PDC was 86%, while the median variable MPR was 105%. September was historically the month with the lowest prescription counts (16 +/- 2). Conclusions: We observed a significantly longer median duration of oral TKIs therapy (201 days) in an academic medical center than the national average ( < 100 days). This analysis of real-world data reveals that lengthier treatment durations for TKI+ICI combinations are feasible. Further research is warranted to identify possible factors such as clinical monitoring or adverse effect management that may prolong adherence and persistence. Data summary. Data Start 29-Apr-2019 Data End 29-Aug-2022 Number of Patients 66 Number of Prescriptions 849 Number of Episodes 94 Discontinued Patients 41 Average TKI Fills 13 All Patients Duration of Therapy Mean 237.0 All Patients Duration of Therapy Median 201.0