OT:RR:NC:N3:138
Daejin Song
Celltrion
19, Academy-ro, 51 Beon-gil, Yeonsu-gu
Incheon 22014
South Korea
RE: The country of origin of ZYMFENTRA™ (Infliximab-dyyb) Injection
Dear Mr. Song:
In your letter dated May 28, 2026, you requested a country of origin ruling on ZYMFENTRA
(Infliximab-dyyb) Injection.
ZYMFENTRA (Infliximab-dyyb) Injection, contains Infliximab-dyyb, a chimeric IgG1 monoclonal
antibody, as the active pharmaceutical ingredient (API). Zymfentra is a tumor necrosis factor (TNF) blocker
indicated for adult patients with moderately to severely active ulcerative colitis or Crohn’s disease. It is
administered subcutaneously (under the skin) following an induction period with infliximab delivered via
intravenous (IV) infusion. Zymfentra will be imported in 120 mg/mL in single-dose prefilled auto-injector
pens and in single-dose prefilled syringes.
In your letter, you indicated that the active pharmaceutical ingredient (API) is made in South Korea. In South
Korea, the API is mixed with inactive ingredients to produce the final drug substance (DS) in bulk form. The
DS is then exported to Germany where it undergoes filtering and filling operations. In Germany, the DS is
filled into vials and aliquoted into 120 mg/mL dosage form called the unlabeled drug product (uDP). Next,
the uDP is imported into South Korea to be assembled into autoinjector pens and prefilled syringes called the
assembled drug product (aDP). In South Korea, the aDP is labeled and packaged to produce the final drug
product (fDP) in dosage form prior to export to the United States.
Please note that we already issued you NY Ruling Letter N352591 (dated September 18, 2025) on the exact
same product with the API made in Singapore. However, in this case the API is made in South Korea instead
of Singapore. In your letter, you stated that Celltrion manufactures the API for Zymfentra in both Singapore
and South Korea.
When determining the country of origin, the substantial transformation analysis is applicable. See, e.g.,
Headquarters Ruling Letter (“HQ”) H301619, dated November 6, 2018. The test for determining whether a
substantial transformation will occur is whether an article emerges from a process with a new name,
character, or use different from that possessed by the article prior to processing. See Texas Instruments Inc. v.
United States, 681 F.2d 778 (C.C.P.A. 1982). This determination is based on the totality of the evidence. See
National Hand Tool Corp. v. United States, 16 C.I.T. 308 (1992), aff’d, 989 F.2d 1201 (Fed. Cir. 1993).
In this case, we find the country of origin of ZMFENTRA (Infliximab-dyyb) Injection will be South Korea,
where the API is made.
This merchandise may be subject to the Federal Food, Drug, and Cosmetic Act and/or The Public Health
Security and Bioterrorism Preparedness and Response Act of 2002 (The Bioterrorism Act), which are
administered by the U.S. Food and Drug Administration (FDA). Information on the Federal Food, Drug, and
Cosmetic Act, as well as The Bioterrorism Act, can be obtained by calling the FDA at 1-888-463-6332, or by
visiting their website at www.fda.gov.
The holding set forth above applies only to the specific factual situation and merchandise description as
identified in the ruling request. This position is clearly set forth in Title 19, Code of Federal Regulations
(CFR), Section 177.9(b)(1). This section states that a ruling letter is issued on the assumption that all of the
information furnished in the ruling letter, whether directly, by reference, or by implication, is accurate and
complete in every material respect. In the event that the facts are modified in any way, or if the goods do not
conform to these facts at time of importation, you should bring this to the attention of U.S. Customs and
Border Protection (CBP) and submit a request for a new ruling in accordance with 19 CFR 177.2.
Additionally, we note that the material facts described in the foregoing ruling may be subject to periodic
verification by CBP.
This ruling is being issued under the provisions of Part 177 of the Customs and Border Protection
Regulations (19 C.F.R. 177).
A copy of the ruling or the control number indicated above should be provided with the entry documents
filed at the time this merchandise is imported. If you have any questions regarding the ruling, please contact
National Import Specialist Judy Lee at [email protected].
Sincerely,
(for)
James P. Forkan
Director
National Commodity Specialist Division