Celltrion, a South Korea–based biopharmaceutical company best known for biosimilar drugs, is gaining measurable traction in the U.S. pharmaceutical market as prescriptions for Zymfentra, its subcutaneous infliximab treatment, climb to record levels less than a year after launch, signaling that the company is moving beyond early market entry and into a more established phase of commercial execution.
According to the company, weekly total prescriptions in mid-January reached their highest point since Zymfentra was introduced in the U.S. in March last year. Data compiled by IQVIA show prescriptions rose roughly 27% from the prior month and more than quadrupled from a year earlier, a pace of growth that is drawing attention in a market where uptake of new biologics is often slow and uneven.
Zymfentra is the only subcutaneous formulation of infliximab currently available in the U.S., positioning Celltrion differently from competitors that rely on intravenous administration. The company has paired that product profile with a marketing strategy modeled closely on U.S. industry practices, combining broad television and digital advertising with targeted promotion inside clinics and hospitals aimed at physicians and patients involved in prescribing decisions.
Access, rather than awareness alone, has been a central constraint for many specialty drugs, and Celltrion has focused heavily on reimbursement. The company said it has secured rebate agreements covering more than 90% of the reimbursable market by negotiating with major pharmacy benefit managers, insurers and regional PBMs, reducing cost-related friction that can limit adoption even after regulatory approval.
That effort gained additional momentum with Zymfentra’s recent inclusion as a preferred drug on the formulary of Evernorth Health Services, a healthcare services arm of Cigna Group. Evernorth manages pharmacy benefits across a broad range of plans, including those administered by Express Scripts, one of the largest PBMs in the U.S. market. Preferred status typically eases administrative requirements tied to prescribing, accelerating uptake once a drug is written into treatment pathways.
For Celltrion, the prescription data suggest that its U.S. strategy is beginning to clear the structural hurdles that often limit foreign drugmakers to niche positions. Rather than relying solely on price competition, the company has emphasized coverage, formulary positioning and sustained promotion, placing Zymfentra within the mainstream mechanics of the U.S. healthcare system.
The recent rise in prescriptions does not yet place Zymfentra among top-selling autoimmune therapies, but it does indicate that Celltrion has progressed beyond proof of concept. With broader coverage now in place and marketing intensity set to increase, the company appears positioned to test whether its foothold in the U.S. can translate into durable scale in one of the world’s most competitive drug markets.
