As oncology drugs advance, they are met with rising costs, potentially posing financial risk, and limiting access to patients who need them.

Historically, oncology drugs have been chemotherapy infusions delivered in a clinical setting and covered under a patient’s medical benefit, Medicare Part B. In recent decades, orally administered anticancer drugs have emerged; these drugs are covered under outpatient prescription benefits, Medicare Part D. However, as oncology drugs evolve, their rising cost threatens to place beneficiaries in financial distress.

A recent study in JAMA Network Open, by HCPpostdoctoral fellow Michael Anne Kyle, PhD, Professor of Health Care Policy, Nancy Keating, MD, PhD, and colleagues, analyzed Medicare Parts B and D to determine the share of total use and spending attributed to oncology drugs within each Medicare program.

The cross-sectional study incorporated data from the 2016-2020 Medicare Parts B and D Drug Spending Dashboard Public Use Files and used the Oncology Care Model drug lists to identify oncology drugs.

For each Medicare program and year, they calculated measures of drug utilization and spending for all drugs, oncology drugs, and non-oncology drugs. Part B data was adjusted using Medicare enrollment percentages to account for missing Medicare Advantage beneficiaries, whose utilization patterns and cancer prevalence are consistent with those of traditional Medicare beneficiaries. Using the total number of oncology drugs in Parts B and D as the denominator, the allocation of oncology drugs, claims, and spending was calculated across each program.

Comparative findings revealed that from 2016 to 2020, the share of Part B and Part D drugs used for oncology increased slightly. While the proportion of beneficiaries receiving oncology drugs remained stable, median annual per-beneficiary oncology drug spending in both programs nearly doubled over five years. Between 2016 and 2020, median annual per-beneficiary oncology drug spending increased from $9,325 to $18,761 in Part B and from $27,761 to $52,016 in Part D.

The proportion of oncology drugs covered by Part D vs B increased slightly over time, from 46.4% in 2016 to 50.9% in 2020.

Failure to address rapidly rising costs of anticancer drugs could result in diminished access and financial toxicity for patients. The (un)affordability of outpatient prescription drugs in Medicare is the subject of considerable policy attention. Efforts to cap patient out-of-pocket spending may disproportionately benefit people with cancer given the rising number of oncology drugs covered under Part D.