Despite global sales for Amjevita (adalimumab-atto) growing by 29% year-over-year and the agent being the first adalimumab biosimilar on the US market, sales in the United States dropped 63% from the first quarter to the second quarter of 2023.
In Amgen’s earnings report for the second quarter of 2023 (Q2), the company revealed that while global sales for Amjevita/Amgevita (adalimumab-atto) were up year-over-year (YoY), sales within in United States dropped significantly from Q1 to Q2.
Overall product sales for the company were up 6% for Q2 2023 vs Q2 2022, totaling $7.0 billion. Unit volumes went up by 11%, which was offset by 2% lower net selling price, 1% lower inventory levels, and a 1% negative impact from foreign exchange.
Amjevita is a biosimilar referencing Humira. It is a citrate-free, low-concentration product offered in either a prefilled syringe or autoinjector device. The product launched in January 2023 at 2 wholesale acquisition costs, where one version of the product was priced at 5% lower than the reference product and another version was priced at 55% lower than Humira. It was the first adalimumab biosimilar to enter the US market. In July 2023, 7 more adalimumab biosimilars launched.
From Q2 2022 to Q2 2023, sales around the world increased by 29% YoY, driven by 60% volume growth that was partially offset by lower inventory levels and net selling price. In the United States, sales for the product dropped 63% quarter-over-quarter, driven by a drawdown in inventory levels following the inventory build-up to support the launch in Q1.
Product sales excluding the United States increased 13% YoY due to a 25% volume growth that was partially offset by lower net selling price.
Revenues for Other Amgen Products
In addition to Amjevita, Mvasi (bevacizumab-awwb) and Kanjinti (trastuzumab-anns) experienced some sales decreases. Mvasi sales went down 19% YoY for the second quarter, primarily driven by a lower net selling price that was offset by 7% volume growth. The average selling price (ASP) for the product decreased 28% YoY and 12% quarter-over-quarter.
Amgen is also working on biosimilars referencing Opdivo (nivolumab), Stelara (ustekinumab), Eylea (aflibercept), and Soliris (eculizumab). A phase 1 study evaluating pharmacokinetic (PK) similarity of ABP 206 compared to reference nivolumab in patients with stage 3 or 4 melanoma is enrolling patients. A phase 3 switching study to support interchangeability in the United States for ABP 654 has met primary PK endpoints in patients with moderate-to-severe plaque psoriasis.
The final analysis from a phase 3 study evaluating the safety and efficacy profiles of ABP 938 compared with Eylea in patients with neovascular age-related macular degeneration confirmed no clinically meaningful differences in safety, efficacy, and immunogenicity between the products. Lastly, the FDA accepted the biologics license application for ABP 959 (eculizumab biosimilar).
Amgen is the manufacturer of Epogen (reference epoetin alfa) and Neulasta/Neulasta Onpro (pegfilgrastim/pegfilgrastim with on-body injector), which are reference products that currently face biosimilar competition. Sales for Epogen increased by 55% YoY and sales for Neulasta were up 24% YoY.
The company is also the maker of several reference biologics that are projected to face biosimilar competition in the next few years, including Enbrel (etanercept), Nplate (romiplostim), and Xgeva/Prolia (denosumab). Xgeva sales decreased 1% YoY, Nplate increased 9% YoY, and Enbrel increased 2% YoY.