OBJECTIVES

With the increasing variety of treatments for metastatic renal cell carcinoma (mRCC), understanding patient adherence to various agents will help illustrate products with better adherence and potentially better outcomes. This study sought to determine patient adherence to medical treatment of mRCC.

METHODS

This is a retrospective analysis of patients enrolled in commercial and Medicare plans covering the continental US using administrative claims from Magellan Rx incurred between 01/01/2013 – 06/30/2018. Patients were included if they were >18 years old on index date and had >1 medical claim with a diagnosis code for RCC, >2 medical claims for metastasis on or after initial RCC diagnosis date, evidence of any mRCC systemic therapy on or after initial mRCC diagnosis date, and continuous enrollment for >6 months prior to the index date until >6 months after the index date.

RESULTS

Various therapeutic classes (TCs) of anticancer agents were used among 903 mRCC patients treated. There were differences in adherence between each selected therapeutic class, which included mechanistic target of rapamycin (mTOR) inhibitors (n=185), tyrosine kinase inhibitors (TKI) (n=409), immune-oncology (IO) agents (n=140), and others (n=324). Using proportion of days covered methodology, which assesses the number of days of supplied therapy for the first 6 months of therapy, resulted in adherence of 0.50 for mTOR, 0.61 for TKI, and 0.71 for IO. Days supply information was taken directly from submitted ambulatory pharmacy claims and inferred from the labeling information for products billed via the medical benefit. Patients who switched classes in the first 6 months were counted in each class.

CONCLUSIONS

Differences in adherence exist between TCs used for the treatment of mRCC, and IO showed a 10%-21% greater adherence than other TCs. Understanding patient adherence may help to guide choice in therapy toward agents with better real world adherence and potentially better outcomes.