Estimates of Medicaid and Non-Medicaid Net Prices of Top-Selling Brand-name Drugs Incorporating Best Price Rebates, 2015 to 2019.

Importance: The US spends far more on brand-name prescription drugs than other comparable countries. However, studies of prescription drug spending in the US are often limited because there can be substantial differences in the confidential rebates that drug manufacturers pay to Medicaid vs other payers. Objectives: To demonstrate an approach for improved estimation of Medicaid rebates through case studies of 18 top-selling drugs to better understand trends in net Medicaid and non-Medicaid spending and prices for brand-name drugs. Design, Settings, and Participants: This was a cross-sectional study of US pricing data from 2015 to 2019 derived from Medicaid State Drug Utilization data SSR Health, Medi-Span, the Federal Supply Schedule, and IQVIA. Pricing data for 18 top-selling brand-name drugs measured consistently in both SSR Health, which captures US sales reported by publicly traded companies, and IQVIA's top US prescription drugs by nondiscounted spending in 2015 to 2019. Data were accessed and analyzed from January 2019 to June 2021. Main Outcomes and Measures: Gross and net Medicaid and non-Medicaid drug spending for the sample of 18 drugs and prices corresponding to a 30-day supply of medication. Results: Medicaid aggregate gross spending for the 18 drugs in the sample increased 173%, from $3.6 billion in 2015 to $9.9 billion in 2019, and estimated net spending after discounts increased by 119%, from $1.4 billion to $3.0 billion. Medicaid inflation-linked rebates reduced average gross price per 30-day supply by an estimated 43% in 2019, and up to 67% for individual drugs. In addition to the basic rebate, the best price provision reduced the average gross price per 30-day supply by an estimated 3% in 2019 and up to 54% for individual drugs. Between 2015 and 2019 across all study drugs, estimated average non-Medicaid net 30-day prices were between 1.9 and 2.6 times higher than Medicaid net prices. Excluding adalimumab-a spending anomaly because of the entry of a new high-cost formulation-net prices weighted by average gross spending decreased annually by 1% from 2015 through 2019 for Medicaid, while increasing by 2% for non-Medicaid payers. Conclusions and Relevance: In this cross-sectional study of 18 top-selling brand-name drugs, excluding 1 anomaly, Medicaid average net prices declined from 2015 to 2019. Simultaneously, for non-Medicaid payers, net price increased more than previously published marketwide growth rates, raising the importance of restraining drug price growth in non-Medicaid markets. Rigorous and transparent methods to estimate Medicaid discounts are imperative to understand patterns in Medicaid and non-Medicaid prices and develop policies that better align drug prices with clinical benefits.