Despite deep discounts, Humira biosimilars are priced higher than the originator’s original price

Despite significant discounts from the current price of Humira (adalimumab), introductory prices of the biosimilars adalimumab are still double the originator’s introductory price, according to a study published in JAMA network open.

Humira can be administered with a pre-filled syringe or an auto-injector pen.

Throughout 2023, 9 FDA-approved adalimumab biosimilars are expected to enter the US market. As of the second week of July 2023, 8 had entered the market, starting with Amgens Amjevita (adalimumab-atto) in January. Amjevita was launched with a dual pricing strategy, where 2 versions of the drug would be launched at 2 different prices (5% and 55% less than Humira’s current price) to entice both pharmacy benefit managers (PBMs) to add the product to their formulary lists and to ensure that uninsured patients have access to the product.

The researchers said that, despite the long waiting period for these products to enter, no studies quantified the net prices payers faced after discounts for Humira. The current analysis is the first to contextualize the prices of biosimilars and allow the estimation of the savings associated with their entry.

For the period 2013 to 2020, the authors estimated several factors:

• Annual gross sales as a product of list price and units sold
• The difference between the company’s reported gross sales and net sales from SSR Health
• Medicaid discounts and 340B, which is the best Medicaid price
• Coverage gap discounts from Medicare’s 5% sample

Government rebates through Medicaid, 340B programs, and the coverage gap were subtracted and attributed to PBM rebates. Medicaid inflation rebates, which reimburse Medicaid for price increases above inflation, were also estimated separately for citrate-containing and citrate-free Humira, the latter of which was introduced to the market in 2018.

Between 2013 and 2020, the list price of Humira went from $1153 to $2784, an increase of 141%. PBM rates for the drug also increased from $28 (2.4% of list price) to $973 (34.9% of list price). The median net price for commercial floors and Part D increased from $1125 to $1906, a jump of 69%, between 2013 and 2018 before declining in 2020 to $1812 (65.1% of list price ).

From 2013 to 2018, the base discount for Medicaid was 23.1% of Humira’s list price. After 2019, PBM discounts grew, setting a new best price. Medicaid inflation discounts for citrate-containing Humira increased from 38.6% of list price in 2013 to 69.6% in 2019. Medicaid net price for citrate-containing Humira decreased from 38.3% of list price at 8.3% to 0% in 2013, 2018 and 2019, respectively. Inflation discounts were lower for Humira without citrate, resulting in a significantly higher Medicaid net price.

While there is 1 biosimilar interchangeable adalimumab (Cyltezo) on the market so far, more are expected to come, including Amjevita. The authors noted that while interchangeable biosimilars of adalimumab present new opportunities for market competition, the ease with which one interchangeable product can be substituted for another biosimilar may depend on the concentration and citrate content of the product.

These formulations can compete more directly on list price, marketing to pharmacies looking to source the product cheaply to generate a margin when reimbursed by an insurer at a predetermined amount for interchangeable formulations. However, interchangeable biosimilars expected in 2023 will only be interchangeable with original Humira, but not the citrate-free version, they wrote.

The researchers said their main limitations were only the ability to analyze price changes through 2020 and the lack of data to estimate discounts for federal buyers.

Reference

Calip GS, Altomare IP, Guadamuz JS. Evaluation of the external validity of studies on the safety of biosimilars in oncology.JAMA network open.2023;6(4):e235776. doi:10.1001/jamannetworkopen.2023.5776