FDA biosimilar approvals slow as K-biotech giants eye next frontier

The US Food and Drug Administration's pace of biosimilar (generic-equivalent biopharmaceutical) approvals has shifted into a lower gear. With approvals in the first half of this year falling to six — down sharply from 18 in each of the previous two years — analysts say the initial wave of competition tied to major originator drug patent expirations is largely winding down.

The FDA approved six biosimilars in the first half of this year. That compares with 18 approvals in each of 2024 and 2025, years that saw explosive growth in the sector.

The surge in 2024 and 2025 was driven largely by the concentrated patent expirations of blockbuster autoimmune drugs — Humira (adalimumab) and Stelara (ustekinumab), once the world's top-selling biologics. Major pharmaceutical companies and South Korean biotech firms had rushed to file approval applications ahead of those expirations to secure early footholds in the lucrative markets.

The first half of this year, by contrast, reflects a more diversified landscape. Among the new approvals was Imgolys, a biosimilar of Janssen's autoimmune drug Simponi (golimumab), marking the first biosimilar entry for that reference product and signaling a shift toward new therapeutic targets.

Since the FDA approved the first biosimilar in 2015, it has cleared a total of 87 products referencing 21 originator drugs. Biosimilars of Humira and of Prolia/Xgeva lead the count at 10 each, followed by Stelara and Neulasta at eight each, and Avastin, Eylea and Herceptin at six each.

By country of the approving company, the United States leads with 31 cumulative approvals, while South Korea holds a commanding second place with 19 — ahead of India (12), Germany (8), Switzerland (7) and China (4). The figures underscore how Samsung Bioepis and Celltrion have helped South Korean biotech firms outpace global rivals in the world's largest biopharmaceutical market.

Both companies are pushing ahead with additional US launches in the second half of this year. Celltrion is preparing to bring Omriclo (a biosimilar of Xolair, for asthma and chronic hives) and Idenzelt (a biosimilar of Eylea, for eye diseases) to the US market. Samsung Bioepis, meanwhile, has begun commercializing Ospomyb (a biosimilar of Prolia and Xgeva, for bone disease) and is advancing subsequent pipeline candidates through the US approval process.

The rapidly shifting biosimilar landscape, however, means South Korean firms face mounting pressure to act ahead of the curve. The established anti-TNF antibody market is shrinking under fierce price competition from biosimilars. Citing data from global market research firm La Merie, the Korea Bioindustry Association's Global Economic Research Center said total anti-TNF antibody sales fell 23 percent year-on-year as biosimilar competition intensified.

"As the first-generation biosimilar market becomes saturated, it is structurally difficult to avoid margin erosion through simple replication," an industry official said. "Only companies that rapidly diversify their pipelines — moving beyond autoimmune diseases into oncology and next-generation modality biosimilars — will survive."

Ultimately, the slowdown in FDA approvals signals not a market downturn but a shift in target markets. As antibody-drug conjugates (ADCs), bispecific antibodies, and cell and gene therapies such as CAR-T continue to grow as a share of the drug landscape, South Korean biotech firms will need to pursue a carefully calibrated strategic pivot — cutting costs on existing biosimilars while simultaneously developing next-generation pipelines — to maintain their competitive edge.