Comparison of Prescription Patterns of BCR-Abl Tyrosine Kinase Inhibitors Among Patients with Commercial Insurance, Medicare and Medicaid
Authors: Kim Myung Sun (Sunny) 
Published: December 2024

Background
Several BCR-Abl tyrosine kinase inhibitors (TKI) are approved for clinical use since the approval of imatinib (Gleevec, Novartis) in 2001. The relative prescription patterns of different BCR-Abl TKIs between different payers are unknown.
Methods
California's All Payer Claims Database is a publicly available research database that includes statewide pharmacy claims data reported by mandatory and voluntary submitters. Reporting entities include Commercial insurance plans, Medicare Advantage plans, Medicare Part D and Medicaid (Medi-Cal). The prescription counts for Gleevec (imatinib), generic imatinib, Sprycel (dasatinib), Tasigna (nilotinib), Bosulif (bosutinib), and Iclusig (ponatinib) were extracted by payer type for years 2018 to 2021. The total number of BCR-Abl TKI prescriptions were compared by payer type. Prescription count for each drug compared to total number of prescriptions for all BCR-Abl TKIs was calculated as a percentage for each year and compared between payer types. Generic imatinib prescriptions and Gleevec prescriptions as a proportion of total imatinib prescriptions were compared between payers.
Results
In 2018, pharmacy claims data within California was submitted for 15.7 million individuals with commercial health plans, 7 million individuals on Medicare Advantage plans or with Medicare Part D coverage, and 14 million individuals with Medi-Cal. There was a total of 65,061 prescriptions for BCR-Abl TKIs, 18,717 (28.5%) for commercial insurance, 36,393 (55.9%) for Medicare, and 9,951 (15.3%) for Medicaid. For commercial insurance, 57.1% of total BCR-Abl TKI prescriptions were for generic or brand imatinib, 30.1% for dasatinib, 11.9% for nilotinib, 0.9% for bosutinib and 0% for ponatinib. For Medicare, 64.6% of prescriptions were for imatinib, 17.8% for dasatinib, 13.7% for nilotinib, 2% for bosutinib, and 1.6% for ponatinib. For Medicaid, 48% of prescription were for imatinib, 35.2% for dasatinib, 11.8% for nilotinib, 0% for bosutinib, and 5% for ponatinib. From 2018 to 2021, prescriptions for Brand or generic imatinib decreased from 57.1% to 46% of all BCR-Abl TKI prescription for commercial insurance, 64.6% to 63.0% for Medicare and 48.0% to 38.5% for Medicaid. During the same period, prescriptions for dasatinib increased 30.1% to 37.6% for commercial insurance, 17.8% to 19.3% for Medicare and 35.2% to 38.9% for Medicaid. Nilotinib prescriptions changed from 11.9% to 11.2% for commercial insurance, 13.7% to 11.6% for Medicare and 11.8% to 12.3% for Medicaid. Bosutinib prescriptions increased from 0.9% to 2.6% for commercial insurance, 2.4% to 4.0% for Medicare and 0% to 1.9% for Medicaid. Ponatinib prescriptions increased 0% to 2.4% for commercial insurance, 1.6% to 2.1% for Medicare and 5.0% to 8.3% for Medicaid. The percentage of Gleevec prescriptions out of all imatinib prescriptions was 11.8% for commercial insurance, 14.9% for Medicare and 21.9% for Medicaid in 2018. The proportion of Gleevec prescriptions decreased from 11.8% to 9.7% for commercial insurance, 14.9% to 3.5% for Medicare and 21.9% to 4.9% for Medicaid between 2018 and 2021.
Limitations
Self-funded employers are not required to submit data to the California Health Care Payments Data (HPD) Program and participate on a voluntary basis. Fee for service Medicare data was not available for 2021 as data was not reported by July, 2024.
Conclusions
State pharmacy claims database allows comparison of prescriptions patterns between commercial insurance, Medicare and Medicaid that has not been previously reported. Comparing prescription patterns of BCR-Abl TKIs, Medicare had the highest proportion of generic or brand imatinib prescriptions that did not change significantly from 2018 to 2021. Commercial insurance and Medicaid had lower rates of imatinib prescriptions in 2018 and also had a 10% decrease in imatinib prescriptions during that period that translated to an increase in second and third generation BCR-Abl TKI prescriptions. Medicaid had the highest rate of prescriptions for ponatinib, the only third generation BCR-Abl TKI. These differences may reflect dissimilarities in comorbidities and treating diagnoses in the patient population covered by each insurance. All payers had a decrease in brand imatinib prescription out of all imatinib prescriptions with the greatest decrease seen in Medicaid.