Insurance and cost-related access barriers to specialty oral anticancer medications for blood cancers in a nationwide sample of Medicare and commercially insured patients.

11031 Background: Specialty oral anticancer medications improve survival across blood cancers but may have access challenges. This study examined approval and fill rates of specialty oral anticancer medication prescriptions indicated for blood cancers in a nationwide sample of Medicare and commercially insured patients. Methods: Using nationwide claims (Symphony Health Solutions Integrated Dataverse), we identified patients with ≥1 new specialty oral anticancer medication prescription during 2022. Outcomes were measured for the initial prescription as well as any prescription for the same drug within 90 days and were classified as: (i) rejected by insurer, (ii) approved by insurer but not filled by patient, or (iii) approved by insurer and filled by patient. Among rejected prescriptions, we examined rejection reasons, eventual approval rates, and time to approval. Among approved prescriptions, we compared fill rates across out-of-pocket cost levels. Adjusted outcomes were estimated using multivariable logistic regressions. Results: The study included 12, 134 patients (61. 0% Medicare, 39. 0% commercial) with a specialty oral anticancer medication prescription. Initially, very few prescriptions were both approved and filled (9. 6%, Medicare; 4. 0%, commercial). Insurers initially rejected most prescriptions (64. 9% for Medicare; 84. 0% for commercial), frequently due to prior authorization or formulary restrictions. By 90 days, approval rates rose to 85. 0% (Medicare) and 62. 9% (commercial), but many approved prescriptions were never filled; ultimately, only 54. 5% of Medicare patients and 45. 5% of commercial patients both received insurer approval and filled their prescription. Fill rates dropped sharply when out-of-pocket costs exceeded 175 per SOAM prescription. When out-of-pocket costs exceeded 2, 000 per prescription, only 31. 9% of Medicare patients and 26. 9% of commercial patients filled their prescriptions. Adjusted rates were similar to unadjusted rates. Conclusions: This study found substantial access barriers to specialty oral anticancer medications for blood cancer, particularly among commercially insured patients. Even after insurer approval, many patients never filled their prescription. This highlights the importance of addressing both payer-level restrictions and patient-level affordability challenges to ensure treatment access.