On a Wednesday afternoon in February 2026, Costco shoppers in suburban California walked past a quiet pharmacy display and saw something that would have been unthinkable five years ago. A Korean-made biologic drug, Steqeyma, was being sold at one of America’s largest retailers — directly competing with Johnson & Johnson’s blockbuster Stelara. Furthermore, the same week, Samsung Bioepis announced its Stelara biosimilar Pyzchiva had become a top-three player in the U.S. ustekinumab market within a single year. In short, the Korea biosimilar market 2026 had quietly arrived at a tipping point.

For foreign investors and pharmaceutical executives watching Asia, this was not a story about clever marketing. Instead, it was a structural shift in who controls the next phase of global drug pricing. In particular, two Korean companies — Celltrion and Samsung Bioepis — now hold a combined 53.5% share of Europe’s six largest biosimilar categories. As a result, Korea has become the first country outside the United States and Switzerland to lead a major segment of global biopharma.

The Korea biosimilar market 2026 sits at the convergence of three powerful forces. First, a $200 billion patent cliff is unfolding between 2025 and 2030. Second, the U.S. Inflation Reduction Act is forcing Medicare to negotiate prices on top biologics. Third, the FDA quietly relaxed biosimilar approval requirements in 2025 and 2026. Consequently, the cost and time barriers that protected innovator drugs for decades are collapsing. Meanwhile, Korean biosimilar firms are positioned to harvest the opportunity faster than any rival nation.

This is not the same story Seoulz has covered before. In particular, our recent analysis of Korea’s K-Bio CDMO industry examined contract manufacturing infrastructure. Meanwhile, our overview of the three Korean startups Big Pharma can’t ignore focused on novel drug platforms. By contrast, this piece covers something different: the Korean biosimilar industry’s direct assault on global pharma’s most valuable franchises. Specifically, it covers the war for Stelara, Soliris, Eylea, Prolia, and beyond.

The $33 Billion Battle: How the Korean Biosimilar Industry Took Half of Europe

To understand why the Korea biosimilar market 2026 matters globally, start with the numbers. According to a recent KIS Korea report, the global biosimilar market grew from $2.2 billion in 2016 to $32.7 billion in 2024. Furthermore, between 2025 and 2030, biologic drugs with combined annual sales of roughly $127.6 billion will lose patent protection. As a result, the addressable market for biosimilar entrants is multiplying year over year.

In particular, Korean firms have already proven they can win in the most demanding regulatory environment on Earth — Europe. According to IQVIA data published in January 2025, Celltrion and Samsung Bioepis together held 53.5% of the European market across the six biggest biosimilar molecules: infliximab, rituximab, adalimumab, trastuzumab, bevacizumab, and etanercept. Meanwhile, that figure climbed steadily from 45.0% in 2022 to 48.9% in 2023 before crossing the majority threshold in 2024. In short, this was not a one-quarter spike. It was a structural takeover.

Some of the individual category numbers are even more striking. For instance, Korean firms control 84.2% of Europe’s infliximab market when including Celltrion’s subcutaneous Remsima SC. Additionally, Samsung Bioepis alone holds 49.2% of the European etanercept market — significantly outpacing both Pfizer (26.9%) and Sandoz (22.2%). Meanwhile, in the adalimumab category — the world’s largest autoimmune treatment market with annual sales near $18 billion — the combined Korean share of 26.5% has already overtaken AbbVie’s original Humira franchise at 21.9%.

For comparison, the global biosimilars market is projected to grow from $40.87 billion in 2025 to $206.75 billion by 2035, according to recent industry research. Furthermore, the U.S. Congressional Budget Office estimates Medicare alone will save $51 billion from biosimilars between 2026 and 2035. Consequently, the policy tailwinds favor Korean execution capacity over almost any other geography.

Two Songdo Towers, Two Strategies: Celltrion Samsung Bioepis Compared

Both Celltrion and Samsung Bioepis are headquartered in Songdo, Incheon — the master-planned biotech cluster about an hour west of Seoul. Specifically, Celltrion sits at one end of the campus, Samsung Bioepis at the other. However, despite their physical proximity, the two companies pursue almost opposite commercial strategies. As a result, understanding that split is essential for any investor evaluating the Korean biosimilar industry.

Celltrion: The Vertically Integrated Brand Builder

Celltrion has gone direct. In particular, the company runs its own sales networks across major markets, manages pricing strategy in-house, and builds its own brand alongside its biosimilars. Furthermore, this structure allows aggressive pricing decisions and faster market response. However, it also carries the cost of a global commercial footprint and inventory pressure across dozens of countries.

The financial results validate the approach. In 2025, Celltrion posted record annual revenue of 4.16 trillion won ($2.84 billion), up 17% year over year. Meanwhile, operating profit soared 137.5% to 1.69 trillion won, lifting the operating margin to 28.1%. Additionally, the company has set a 2026 revenue target of 5.3 trillion won — a milestone that would push it firmly into the top tier of global biosimilar companies.

The growth came from a wave of new launches. Specifically, drugs like Yuflyma (a Humira biosimilar), Vegzelma (Avastin biosimilar), Steqeyma (Stelara biosimilar), Omlyclo (Xolair biosimilar), and Stoboclo-Osenvelt (Prolia/Xgeva biosimilars) gained traction across the U.S. and Europe in 2025. Furthermore, five products either launched or pre-launched in the second half of 2025 generated combined annual sales of more than 300 billion won. As a result, newer products now account for roughly 54% of Celltrion’s biosimilar revenue. Older anchors like Remsima, Truxima, and Herzuma still maintain market leadership in their respective categories.

In addition, Celltrion has taken a direct-to-consumer approach unusual for biologic drugs. For instance, in March 2026, the company began selling Steqeyma at Costco — leveraging the warehouse retailer’s pricing power to capture U.S. ustekinumab share. Meanwhile, Celltrion’s “select and focus” strategy for 2026 emphasizes higher-margin newer products and tendering for premium contracts. The company expects revenue contribution from these products to expand to roughly 70% of total sales.

Samsung Bioepis: The Partner-Led Platform

Samsung Bioepis has chosen the opposite path. Specifically, the company sells most of its products through partner distribution networks. As a result, it gains faster market entry, lower selling and marketing expenses, and access to established commercial relationships. However, it also surrenders pricing control and brand-building leverage to its partners. Its commercial relationships span Sandoz, Biogen, Organon, Teva, and Harrow across various molecules.

The strategy delivered record results in 2025. In particular, Samsung Bioepis posted 1.67 trillion won in revenue — its highest ever. Furthermore, operating profit excluding milestone payments more than doubled year over year. Meanwhile, in the U.S. market, the company runs a “two-track” approach: collaborating with local marketing partners while securing supply channels with private insurance pharmacy benefit managers (PBMs). For instance, Samsung Bioepis launched Stelara and Soliris biosimilars in the U.S. through partnerships, with the Stelara biosimilar Pyzchiva securing private-label PBM contracts that have rapidly expanded its share.

In Europe, Samsung Bioepis has grown its on-sale product count to 10 within a decade of its first launch in 2016. Specifically, four of those — Soliris, Prolia, Xgeva, and Lucentis biosimilars — are now sold directly through the company’s local sales network. By contrast, the rest go through distribution partners. As a result, the company has built optionality. It can switch between partner-led and direct sales depending on the market and molecule.

In November 2025, Samsung Biologics completed a corporate spin-off of its biosimilar investment business into a new entity called Samsung Epis Holdings. Consequently, Samsung Biologics is now a pure-play CDMO. The structural change removes any conflict of interest with potential pharma clients. Meanwhile, Samsung Bioepis has new room to expand its biosimilar portfolio to 20 products by 2030, including biosimilars in development for Keytruda, Dupixent, and Enhertu.

The 2026 Catalyst: Stelara, Soliris, and the Patent Cliff Wave

What makes the Korea biosimilar market 2026 different from prior years is timing. In particular, 2026 sits at the front edge of what industry analysts call the “super-cliff.” For instance, between 2026 and 2030, roughly 70 high-revenue biologic and pharmaceutical products will face patent expiration, putting an estimated $236 billion in annual revenue at risk.

The first major test is already underway. Specifically, Stelara (ustekinumab) — Johnson & Johnson’s autoimmune blockbuster with $10 billion in 2024 sales — lost its U.S. patent protection in early 2025. As a result, both Celltrion’s Steqeyma and Samsung Bioepis’s Pyzchiva entered the U.S. market in February 2025 alongside biosimilars from Amgen and Alvotech-Teva. Meanwhile, the FDA granted provisional interchangeability designations to both Korean products. That status allows pharmacists to substitute the biosimilar without explicit physician approval in many states.

The Stelara dynamics are illustrative of the broader battle. Specifically, the original drug generated billions per year for J&J, treating millions of patients with psoriasis, Crohn’s disease, ulcerative colitis, and psoriatic arthritis. Furthermore, Korean biosimilars priced 30% to 80% below the reference drug have rapidly captured share. As of February 2026, U.S. ustekinumab biosimilar adoption reached approximately 60%, according to Samsung Bioepis’s quarterly market report. In particular, that level of penetration within roughly 12 months of launch is unprecedented historically.

Beyond Stelara, the 2026 to 2028 window includes several more landmark expirations. For example, Eylea (aflibercept) for age-related macular degeneration faces biosimilar entry in the United States. Additionally, Prolia and Xgeva (denosumab) for osteoporosis and bone metastases are in active competition. Meanwhile, Soliris (eculizumab) for rare blood disorders has multiple Korean entrants. Furthermore, looking out to 2028, Keytruda — Merck’s $29 billion oncology drug — will lose composition-of-matter patent protection. As a result, Samsung Bioepis already has a Keytruda biosimilar in development. Celltrion’s pipeline also targets the molecule.

In addition, the GLP-1 patent cliff is a wild card. Specifically, Novo Nordisk’s semaglutide (Ozempic, Wegovy) loses Chinese patent protection as early as 2026 and global protection by 2031. As a result, Korean firms are evaluating biosimilar opportunities even as the originator continues to dominate. Indeed, Samsung Biologics is reportedly reviewing the acquisition of a U.S. facility capable of producing GLP-1-based medicines for obesity. The move signals how Korean players are positioning across the entire forward patent cliff.

Costco, PBMs, and the American Distribution Game

The most overlooked element of the Korea biosimilar market 2026 story is U.S. distribution. In particular, biosimilars do not sell themselves. They depend on three gatekeepers: pharmacy benefit managers (PBMs), hospital formularies, and increasingly, retail channels. As a result, the playbooks Celltrion and Samsung Bioepis use to navigate these gatekeepers determine commercial outcomes far more than clinical data does.

Celltrion’s Costco deal for Steqeyma is the boldest example to date. Specifically, by placing a Stelara biosimilar in a major retail chain, the company bypassed parts of the traditional specialty pharmacy channel. Furthermore, the move pressured PBMs to include Steqeyma on preferred formulary tiers. Meanwhile, this kind of channel innovation is rare in immunology. For comparison, most biologics still flow through specialty pharmacies and hospital infusion centers because of cold-chain handling and patient education requirements.

Samsung Bioepis has taken a different but equally aggressive approach with PBMs. In particular, the company secured private-label contracts with major PBMs for its Stelara biosimilar Pyzchiva. As a result, the drug appears under the PBM’s own brand on formulary listings. Meanwhile, this private-label strategy has been a key driver of the company’s rapid Pyzchiva market share gains. In addition, Samsung Bioepis was the first biosimilar maker to publicly track quarterly U.S. biosimilar adoption metrics. Its Q2 2026 Biosimilar Market Report confirmed that 92 biosimilars across 20 unique molecules had been FDA-approved by March 2026, with 67 (73%) launched commercially.

The U.S. policy backdrop is also shifting. Specifically, the Trump administration has pushed PBM reform, including reducing rebates and shifting toward fixed-fee structures. As a result, PBMs may have weakened incentives to favor originator drugs over lower-priced biosimilars. Meanwhile, the Inflation Reduction Act adds another tailwind. Medicare price negotiations for top-spend drugs, alongside measures encouraging biosimilar uptake, create structural support for biosimilar adoption. However, the U.S. system remains complex. For instance, Medicare Part B reimburses providers based on average sales price, which can paradoxically reduce financial incentives to switch from a high-priced reference drug to a lower-priced biosimilar. As a result, biosimilar uptake in the U.S. still trails Europe — where countries like Germany and Sweden see Humira biosimilar adoption above 70%.

The Regulatory Tailwind: FDA’s Quiet 2026 Shift

The biggest tailwind for the Korea biosimilar market 2026 is regulatory. In October 2025, the FDA issued a draft guidance indicating that comparative efficacy studies (CES) may no longer be routinely expected for biosimilar approval. Furthermore, in March 2026, the agency revised the guidance again, introducing additional flexibility in the use of non-U.S.-licensed comparator data. Together, these updates reflect a broader shift toward greater emphasis on analytical and pharmacokinetic evidence in demonstrating biosimilarity.

The practical impact is significant. Specifically, biosimilar development typically takes five to seven years and costs between $100 million and $300 million. In short, this makes biosimilars more like mid-stage novel drugs than cheap generics. However, if comparative efficacy trials become optional, both timelines and capital requirements shrink meaningfully. Meanwhile, the European Medicines Agency has been moving in parallel. The EMA is also weighing waivers for comparative efficacy studies when “high similarity” is already established.

In Korea, the Ministry of Food and Drug Safety (MFDS) has matched the global trend. Specifically, MFDS plans to introduce a streamlined biosimilar approval pathway from 2026, reducing review timelines from 420 days to 295 days. Additionally, the agency will introduce product-specific review teams, expedite GMP and GCP inspections, and increase direct consultations with sponsors. As a result, Korean firms can now run faster development programs domestically before pursuing FDA and EMA approvals abroad.

The combined effect is a structural acceleration. Specifically, every six months saved in development translates to earlier launches and longer market exclusivity windows. Meanwhile, the cost reductions improve project economics across the industry. However, regulatory flexibility cuts both ways. In particular, lower barriers to entry mean more competitors. Already, the Humira (adalimumab) biosimilar market has 10 FDA-approved entrants. As a result, Korean firms cannot rely on regulatory advantages alone. Instead, they must continue to invest in manufacturing scale, distribution relationships, and pipeline depth.

Manufacturing and Capacity: Songdo’s Hidden Advantage

Korean biosimilar dominance is built on physical infrastructure most foreign investors never see. In particular, the Songdo Bio Cluster in Incheon hosts the world’s largest concentration of biopharmaceutical manufacturing capacity. Furthermore, Samsung Biologics holds three campuses spanning roughly half a million square meters in the cluster. Celltrion runs its corporate headquarters and original biosimilar plants there. Meanwhile, Lotte Biologics is expanding its Korean footprint while operating a U.S. facility acquired from Bristol-Myers Squibb.

For Celltrion specifically, capacity expansion has accelerated dramatically. In December 2025, the company announced a 700 billion won ($478 million) investment to expand a former Eli Lilly active pharmaceutical ingredient manufacturing facility. Furthermore, in March 2026, Celltrion committed an additional 1.2 trillion won ($805 million) to expand its Incheon facility. As a result, total annual capacity is expected to reach 570,000 liters when both projects complete. Meanwhile, the company also acquired a plant in Branchburg, New Jersey, adding 66,000 liters of U.S.-based capacity with plans to double that figure to 132,000 liters.

Why does manufacturing scale matter so much? Because biosimilars are not generics. Specifically, biologic drugs are produced by living cells in carefully controlled bioreactors. Furthermore, replicating manufacturing yields — and meeting strict FDA and EMA quality standards — requires years of process optimization. As a result, only a handful of facilities globally can produce biosimilars at the scale required to compete in major markets. In short, Songdo is one of three global biomanufacturing capitals, alongside the U.S. Northeast corridor and Switzerland.

The geographic concentration also creates supply chain advantages. For instance, Korean biosimilar firms can move clinical samples, manufacturing materials, and regulatory documents between sites in a single business day. Meanwhile, suppliers of single-use bioreactors, chromatography media, and analytical instruments cluster in the same region. As a result, the time from process development to commercial production is typically shorter in Korea than in comparable U.S. or European facilities. Furthermore, this is one of the underappreciated reasons the Korea biosimilar market 2026 has been able to scale so quickly.

Risk Factors: Margin Compression, Chinese Entrants, and the Korean Biosimilar Industry’s Vulnerabilities

The Korea biosimilar market 2026 narrative is bullish, but the risks are real. In particular, three specific concerns deserve careful attention from foreign investors.

First, margin compression. According to KIS, the more biosimilars approved per molecule, the lower the achievable price. For instance, Humira now has 10 FDA-approved biosimilars. Meanwhile, denosumab biosimilars showed wholesale acquisition cost discounts ranging from 6% to 86% across different products. As a result, late entrants face brutal pricing dynamics. In short, the question for both Celltrion and Samsung Bioepis is whether the speed of new launches outpaces the speed of margin erosion on existing products. Meanwhile, KIS notes that even modestly cheaper development timelines can intensify competition rather than improve project economics.

Second, Chinese competition. Specifically, Chinese biosimilar firms are scaling rapidly. For example, Hangzhou Jiuyuan Gene Engineering filed for marketing approval of a semaglutide biosimilar with China’s National Medical Products Administration in April 2024. Furthermore, the company is anticipated to be the first domestic manufacturer to receive regulatory approval once the patent expires in 2026 in mainland China. As a result, Chinese players are likely to emerge as serious global competitors in the GLP-1 segment. In particular, that segment is forecast to grow from $15 billion to potentially $150 billion by 2035.

Third, U.S. policy volatility. In particular, the political environment around drug pricing has shifted multiple times in the past three years. Furthermore, while the Inflation Reduction Act and PBM reform have created tailwinds for biosimilars, regulatory pendulum swings can quickly change competitive dynamics. Meanwhile, the FDA’s 2026 guidance updates were viewed positively by industry analysts. However, future shifts could go in the opposite direction. In addition, U.S.-Korea trade dynamics remain a wild card. For instance, any escalation in pharmaceutical tariffs could disproportionately impact Korean biosimilar imports.

Investor Playbook: How to Get Exposure to the Korea Biosimilar Market 2026

For foreign investors evaluating the Korea biosimilar market 2026, the practical entry points are limited but meaningful.

The most direct play is Celltrion (KS:068270), listed on KOSPI. The company offers vertically integrated exposure to global biosimilar sales, growing CDMO revenue from its Branchburg facility, and a deep pipeline of pre-launched biosimilars. Furthermore, the 2026 revenue target of 5.3 trillion won — combined with margin expansion to 28%-plus — gives the stock a clear forward earnings narrative. Meanwhile, Celltrion holds public float available to non-Korean institutional investors through KOSPI and Korean depositary receipts.

The second play is Samsung Biologics (KS:207940), the parent CDMO of Samsung Bioepis-related operations following the November 2025 corporate restructuring. Specifically, Samsung Biologics now operates as a pure-play contract manufacturer. Furthermore, it ranks among the world’s three largest biomanufacturing CDMOs by capacity. As of January 2026, Samsung Biologics reached the third position in global biotech market capitalization at roughly $60.69 billion, according to research firm Bulfincha. Meanwhile, Samsung Epis Holdings is the more direct biosimilar-pure-play vehicle, though its trading liquidity remains lower.

For broader exposure, investors can consider Alteogen (KQ:196170), the largest biotech company by market cap on KOSDAQ. Specifically, Alteogen’s ALT-B4 hyaluronidase platform has attracted partnerships from AstraZeneca and Daiichi Sankyo. While not a pure biosimilar story, the company’s technology underpins subcutaneous formulations that biosimilar firms are increasingly licensing. As a result, Alteogen offers indirect exposure to the broader Korean biopharma export thesis.

For investors who prefer ETF-style exposure, options remain limited. In particular, no major U.S.-listed ETF specifically targets Korean biosimilars. However, broader Korea equity ETFs like iShares MSCI Korea (EWY) include both Celltrion and Samsung Biologics as significant constituents. Meanwhile, several Asian healthcare ETFs include Korean biosimilar names as part of their portfolios.

For more on how foreign capital is flowing into Korean biopharma, see Seoulz’s coverage of Korea’s top scale-ups for 2026, which includes detailed analysis of investor syndicates and IPO pipelines. Additionally, our earlier piece on the Korea National Pension Fund explains how Korea’s largest institutional investor is positioning across domestic biotech equities.

What Comes Next

The Korea biosimilar market 2026 is not a temporary peak. Rather, it is the visible surface of a decade-long structural shift. In particular, the global pharmaceutical industry is entering its largest patent cliff in history. Furthermore, the regulatory environment is becoming meaningfully easier for biosimilar developers. Meanwhile, the manufacturing infrastructure required to capture the opportunity sits disproportionately in Korea. As a result, three or four winners are likely to emerge from the next five years of competition. Korean firms are explicitly engineered to be among them.

For pharma executives, the takeaway is clear. Specifically, biosimilar partnerships with Korean firms are no longer a regional Asia play. They are core to global product strategy. Furthermore, for foreign investors, the question is no longer whether Korea matters in biosimilars. It is how to structure exposure given limited public market vehicles. Meanwhile, for policymakers in the United States and Europe, the rise of Korean biosimilars validates a decade of FDA and EMA decisions to lower barriers for biosimilar entry. In short, more competition has indeed produced more affordable biologics.

In the 2010s, Korea exported its pop music. Throughout the early 2020s, it exported its dramas, cosmetics, and food. Now, in the late 2020s, Korea may be remembered as the country that exported its biosimilar playbook to the world — and forced Big Pharma to rethink its most valuable franchises in the process.