Most specialty oral blood cancer prescriptions submitted to US insurers are rejected on first attempt, and even when approved, a substantial share are never filled because the out-of-pocket cost is too high. That is the finding of a nationwide claims study published in the Journal of Clinical Oncology by researchers at the Perelman School of Medicine at the University of Pennsylvania, in collaboration with teams at MD Anderson Cancer Center, Yale, and Columbia.
The study, funded by Blood Cancer United (formerly the Leukemia & Lymphoma Society), tracked 12,134 Medicare and commercially insured patients who received a new prescription for a specialty oral anticancer drug for a blood cancer in 2022. Drugs included Bruton tyrosine kinase (BTK) inhibitors, B-cell lymphoma 2 (BCL2) inhibitors, and immunomodulatory agents used to treat leukemias, lymphomas, and myeloma, with list prices that commonly exceed $10,000 per month.
At first submission, insurers rejected 64.9% of Medicare prescriptions and 84% of those under commercial plans. Prior authorization and formulary restrictions accounted for most initial rejections in both groups. By 90 days, approval rates reached 85% for Medicare and 62.8% for commercial patients, meaning the administrative work of appeals and documentation eventually unlocked coverage for most but not all.
Commercially insured patients faced more than three times the adjusted odds of rejection compared to Medicare beneficiaries, and more than eight times the odds of formulary exclusion at both submission and 90 days. That gap reflects a structural difference: Medicare Part D treats anticancer drugs as a protected class, requiring plans to cover all or substantially all, while commercial insurers operate under no equivalent federal mandate and can exclude drugs or apply preferred-drug arrangements.
Approval did not guarantee treatment. Within 90 days, 30.5% of Medicare and 17.4% of commercial patients had approved prescriptions that were never filled. Fill rates tracked closely with what patients owed. Medicare patients filled at rates between 76.7% and 84.9% when out-of-pocket costs stayed at or below $175, but that rate fell to 38% between $175 and $500, and to about 29% above $500. Commercial patients showed a similar gradient, dropping to roughly 22% above $2,000 per prescription.
Average first-fill out-of-pocket costs were $933 for Medicare patients and $775 for commercial patients in the study. Specialty oral cancer drugs fall under the pharmacy benefit, where cost-sharing structures, tier placements, and specialty deductibles are active plan design choices, and where cancer claims and specialty drug costs are already reshaping stop-loss exposure for self-insured employer plans.
The study’s data predate two notable policy developments. Medicare’s 2026 annual out-of-pocket cap of $2,100 under the Inflation Reduction Act may improve fill rates for Part D beneficiaries, though the authors note limited awareness and uptake during early rollout. Commercial plans have no equivalent federal cap. The study also relied on 2022 claims and could not link delays or non-fills to clinical outcomes, so the research does not establish whether rejections drove disease progression.
The authors identify two intervention points. Before approval, electronic prior authorization and gold-carding arrangements that exempt high-performing prescribers from routine authorization. After approval, early out-of-pocket estimates and financial assistance enrollment.
Gold-carding has gained traction in several states, including Texas, Colorado, Arkansas, and West Virginia. UnitedHealthcare launched its own voluntary program for medical procedures in late 2024. However, the Centers for Medicare & Medicaid Services (CMS) prior authorization rule that took effect in 2026, which introduced response-time requirements and electronic standards, excludes prescription drugs and applies only to Medicare Advantage and Medicaid. That leaves ERISA self-insured employer plans, the predominant form of commercial coverage in this study’s cohort, outside its scope.
