Fills of oral blood cancer drugs fall as out-of-pocket costs rise

Clinical takeaway: Watch for unfilled prescriptions when patients on oral blood cancer drugs face high out-of-pocket costs, which were tied to fill rates as low as about one in five among commercially insured patients even after insurer approval. 

Oral anticancer drugs let patients with leukemia, lymphoma, and multiple myeloma receive treatment at home. But prior authorization (PA) and high cost-sharing can make accessing these drugs difficult for patients. 

Earlier work tied high out-of-pocket costs to abandonment of new oral cancer prescriptions. The authors say no nationwide study had followed these prescriptions through each stage, from prescribing to fill. This claims analysis traces these prescriptions from the pharmacy to the patient, quantifying how often insurers reject them and how often approved ones go unfilled. 

Among approved prescriptions, fill rates within 90 days tracked out-of-pocket cost, staying above 70% through $175, then dropping. Medicare patients filled 84.9% at $15 or less and 29.2% at $500.01 to $2,000. Commercial fills ran 80% and 30.9% in the same tiers, falling to 21.6% above $2,000. Fills through manufacturer free-drug programs wouldn't show up in the claims. 

Insurers rejected 84% of commercial and 64.9% of Medicare prescriptions at first submission. Approval within 90 days reached 85% for Medicare but only 62.8% for commercial, so commercially insured patients had the higher first-pass rejection rate and the lower final approval rate. Once fills were counted, 54.5% of Medicare and 45.5% of commercial prescriptions were approved and filled within 90 days. After adjustment, commercial and Medicare patients had similar odds of leaving an approved prescription unfilled. 

Most prior authorization rejections ended in approval within 90 days, 85.9% for Medicare and 71.3% for commercial. Among commercially insured patients, off-formulary rejections fared worse, with 48.5% approved by 90 days. The researchers couldn't determine whether individual rejections were clinically appropriate, and some may reflect safety considerations. 

The researchers analyzed prescription and medical claims for 12,134 Medicare Part D and commercially insured patients newly prescribed specialty oral anticancer drugs for leukemia, lymphoma, or multiple myeloma in 2022. They followed each patient's first prescription from initial pharmacy submission through insurer approval and whether it was filled within 90 days. 

For Medicare patients, the annual out-of-pocket cap that took effect in 2025 and the Medicare Prescription Payment Plan may help spread high costs across the year, though the authors note that awareness of and enrollment in the plan stayed low in its first year. Commercially insured patients faced more rejections and fewer final approvals. The authors say changes to prior authorization, drug coverage rules, and cost-sharing may be needed so that plan design doesn't decide who gets oral cancer drugs. 

"PA continues to place undue administrative and logistical barriers on cancer patients receiving medically warranted treatment, as shown in this study focused on access to oral medications to treat blood cancers," wrote Stephanie Wheeler, MPH, PhD, associate editor of the Journal of Clinical Oncology and distinguished professor of cancer health policy at the University of North Carolina at Chapel Hill. "Policies to restrict use of PA by payers should be developed and implemented to improve access." 

Source: Doshi JA, et al. (2026 Sep 30) J Clin Oncol. Insurance and Cost-Related Access Barriers to Specialty Oral Anticancer Medications for Blood Cancers in a Nationwide Sample of Medicare and Commercially Insured Patients