Medicare beneficiaries face unique circumstances that might make medication adherence challenging, and research suggests that many are nonadherent between their first and last fill of their prescriptions for newly initiated oral anticancer agents.

A retrospective claims analysis was conducted to identify oral anticancer treatment utilization patterns among a national sample of Medicare beneficiaries. The findings were published in the Journal of Managed Care + Specialty Pharmacy.

The researchers selected beneficiaries who were treated for chronic myeloid leukemia (CML), multiple myeloma (MM), metastatic prostate cancer (mPC), metastatic renal cell carcinoma (mRCC), or metastatic breast cancer (mBC). The analysis used 100% data from Medicare Chronic Condition Data Warehouse Parts A, B, and D files from 2011 to 2014 for the patients with CML, MM, mPC, or mRCC and a 5% random fee-for-service sample from 2011 to 2013 for the patients with mBC.

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Reviewed measures included number of 30-day prescription fills for the newly initiated (index) oral anticancer agent, adherence to the index oral anticancer agent, and discontinuation of the index agent.

A key finding was that a meaningful proportion of patients only filled their prescription for the index oral anticancer agent one time, with more than 1 in 5 patients with mRCC, 1 in 6 patients with MM, and 1 in 10 patients with mPC and CML only filling their prescription for the index agent one time. When they looked forward to determine which patients were alive during the entire 12-month follow-up period, the average number of prescriptions ranged from 6 to almost 9. 

“In some cases, the high rates of single fills and low numbers of prescription fills could be due to toxicities of certain oral agents,” they noted. “Other factors such as social determinants of health may also be at play.”

Rates of discontinuation tended to be lowest in patients with CML (32%), followed by patients with mPC (38%) and mRCC (42%). Meanwhile, discontinuation rates among patients with MM or mBC were 48% and 58% respectively.

Clinicians can use this kind of information to focus clinical attention on adherence and toxicity management.

For example, oncology practices could ask their patients about adherence in a nonjudgmental way to get a better sense of barriers such as cost or side effects that might be factors. “Early and aggressive toxicity management (eg, hand foot syndrome with sorafenib) may also help improve adherence and persistence to effective medications,” the researchers stated.

“As the proliferation of innovative oral anticancer therapies is likely to continue unabated, further research is urgently needed to examine factors associated with non-adherence to oral anticancer agents in Medicare patients and develop and test interventions to address these barriers,” they concluded.

Because the study was conducted as a retrospective study with insurance claims data, the researchers didn’t have access to nonadherence and discontinuation information. Another limitation was the outcomes do not fully capture if a medication was taken as prescribed or not. There also may be possible coding errors within the data. The Medicare data was only updated as recently as 2014, and several promising oral anticancer agents have entered the market since then.

Disclosure: Multiple authors declared an affiliation with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.


Doshi JA, Jahnke J, Raman S, et al. Treatment utilization patterns of newly initiated oral anticancer agents in a national sample of Medicare beneficiaries. J Manag Care Spec Pharm. 2021;27(10):1457-1468. doi:10.18553/jmcp.2021.27.10.1457

This article originally appeared on Oncology Nurse Advisor