Key points
- Samsung Biologics agreed July 20 to buy Swiss peptide manufacturer PolyPeptide Group for 2.7 trillion won ($1.8 billion), its biggest deal yet outside antibody manufacturing.
- SK Biotek finished its own peptide ingredient plant in Sejong ($260 million, 376 billion won) days later, setting up a direct fight with Samsung for peptide manufacturing contracts.
- Kosdaq's Peptron fell 29.76% in July after the market misread its own CEO's comments, then rose 29.97% on August 3 on separate news about its Eli Lilly obesity-drug plant.
- D&D Pharmatech fell as much as 21.6% Wednesday after Pfizer dropped a drug built on its technology, proof these stocks don't only move in one direction.
- The US and Korea are each tightening rules on GLP-1 obesity drugs this month, but both target how the drugs are sold to patients, not how much Korean companies can manufacture and export.
Samsung Biologics agreed July 20 to buy PolyPeptide Group, a Swiss peptide manufacturer, for 2.7 trillion won ($1.8 billion). It's the company's biggest deal outside antibody manufacturing, and the reason behind it is a shortage that's already making some Kosdaq stocks move 30% in a week.
Peptide drugs are the class that includes the GLP-1 obesity treatments Novo Nordisk and Eli Lilly sell around the world, and demand has outgrown the world's ability to manufacture them. Korean industry coverage puts it plainly, peptide raw material is something companies "can't sell because there isn't enough of it." The global peptide market was worth about $52.5 billion in 2025, heading to $83.7 billion by 2034. The obesity-drug slice alone is projected at $150 billion (200 trillion won) by 2035.
In the press release announcing the deal, Samsung Biologics chairman and chief executive John Rim wrote that it "reinforces our long-term growth strategy by not only broadening our service portfolio with modality expansion into peptides including GLP-1, but by also boosting our geographic reach and proximity further within the US, Europe, and India." The deal is expected to close by the end of 2026.
Samsung isn't alone. SK Biotek (SK바이오텍), a subsidiary of SK Pharmteco, finished its own peptide plant in Sejong days later, built for $260 million (376 billion won) with eight production lines. One Korean headline put it plainly, SK Pharmteco is now set to "clash with Samsung in peptide CDMO." Commercial production ramps up next year.
The stocks already making these drugs keep moving hard in both directions
Peptron (펩트론) shows what that shortage feels like day-to-day. On July 9, at a biotech forum in Daejeon, chief executive Choi Ho-il tried to clarify the company's joint research with Eli Lilly, referred to in the room as "Company L." "When we do joint research with Company L," he told the forum, "we're developing a completely different peptide formulation, and tirzepatide isn't included in it." The market read that as Peptron admitting it had nothing to do with Eli Lilly's obesity drug, and the stock lost about 1.11 trillion won of value within days. Peptron fell 29.76% on July 10, closing at 112,300 won.
Three weeks later, on August 3, Peptron rose 29.97% to 166,100 won, triggering a trading halt. This time the news was about something else entirely, reports that its Osong Plant 2 is being built at more than double its planned scale, a joint project with Eli Lilly for a once-monthly obesity drug. Short interest was already a record 1.35 million shares, 5.79% of the float, which likely added fuel too.
D&D Pharmatech (디앤디파마텍) fell as much as 21.6% two days later, after Pfizer discontinued MET-224o, an oral obesity-drug candidate built on D&D's ORALINK technology. Pfizer had listed the drug in Phase 1 trials as recently as May 5, before marking it discontinued on August 4. In a written statement, D&D Pharmatech said the decision reflects "Pfizer's R&D portfolio restructuring, with limited impact on other technology transfer candidates and the oral peptide platform OralLink's business viability." The stock's reaction says investors aren't convinced.
What the US and Korea are actually restricting
The US and Korea are each tightening rules on these drugs this month. What they're restricting is different from what's actually moving these stocks.
The FDA proposed in April removing semaglutide, tirzepatide and liraglutide from the list pharmacies can legally compound in bulk. Commissioner Marty Makary put it simply, "when FDA-approved drugs are available, outsourcing facilities cannot lawfully compound using bulk drug substances unless there is a clear clinical need." The comment period closed July 30, and the rule isn't final yet, but cheap compounded copies of these drugs are going away in the US. That's a restriction on generic-style copies, not on the branded supply chain Samsung and SK Biotek are building for. A separate FDA advisory committee voted in July to recommend legal compounding for six unrelated wellness peptides, including BPC-157, and Korean coverage tied that recommendation to the same group of CDMO makers, though it's still only a recommendation.
Korea's own rule works the other way. The Ministry of Food and Drug Safety plans to designate these same three drugs as drugs of "misuse concern" as soon as this month, adding warning labels and closing a loophole that let pharmacies in doctor-scarce areas sell the drugs without a prescription. Supply into Korea rose from 169.9 billion won in 2024 to 1.0709 trillion won in 2025, a 6.3 times increase, and regulators cited cases reaching underage patients and people using the drugs purely for cosmetic weight loss. It's a rule about how a Korean pharmacy sells to a Korean patient, and it says nothing about manufacturing, factories or exports, the business Samsung, SK Biotek, Peptron and D&D Pharmatech are actually in.
Meanwhile, Alteogen, ABL Bio and HLB were among the biotech leaders in the August 4 Kosdaq rally, though I wrote at the time that it looked more like Kosdaq-wide rotation than a peptide-specific move.
Sources
- 한국경제, 삼성바이오로직스, 2.7조원에 스위스 펩타이드 CDMO 기업 인수, on the Samsung Biologics-PolyPeptide Group deal terms
- 서울경제, SK팜테코, 비만약 원료공장 준공…삼성과 펩타이드 CDMO서 격돌, on the SK Biotek Sejong plant and its framing as competition with Samsung
- 머니투데이, on Peptron's August 3 trading halt and the Eli Lilly Osong Plant 2 reports
- 한국경제, 디앤디파마텍, 화이자 경구 비만약 1종 개발 중단…후속 영향 제한, on D&D Pharmatech's August 5 decline and the company's response
- 한국경제, on the Ministry of Food and Drug Safety's misuse-designation plan and the import supply figures
- Our earlier coverage: the August 4 Kosdaq biotech rally
Won figures are converted to US dollars at about 1,425 won to the dollar. This is general market commentary and not investment advice. Always do your own research and consider speaking with a licensed financial professional before making any investment decision.
