Celltrion said it submitted an investigational new drug (IND) application to the U.S. FDA for a phase 3 clinical trial aimed at expanding the indication of its autoimmune disease treatment, Zympentra (ingredient: infliximab), to include rheumatoid arthritis (RA).

The clinical trial will involve 189 RA patients divided into two groups -- one receiving CT-P13 SC and the other receiving a placebo.

The study will focus on comparing the efficacy, safety, and pharmacokinetic characteristics of the treatment.

By adding RA to Zympentra's indications, Celltrion aims to bolster its influence in the global market, particularly in the U.S., where the drug has already secured approval for two inflammatory bowel disease (IBD) indications.

RA is a prevalent autoimmune disease that causes joint pain, swelling, stiffness, and loss of function as the immune system attacks healthy joint tissue. The RA market in the U.S. is approximately three times larger than the IBD market.

According to pharmaceutical IQVIA, the global RA market was valued at $42.3 billion in the previous year, with the U.S. market alone accounting for about 72 percent of this, or $30.4 billion.

Zympentra, under the brand name Remsima SC in Europe, has already demonstrated its efficacy, safety, and superiority in treating RA in several international studies. If approved for RA in the U.S., Zympentra's potential target market could expand significantly from $10.3 billion to $40.8 billion.

In Europe, where CT-P13 SC is already approved for RA, Remsima SC has shown strong growth, capturing a 21 percent market share in the EU5 countries —the U.K., Germany, France, Spain, and Italy— by the end of the last quarter.

Combined with its intravenous counterpart, Remsima, the product line holds a commanding 74 percent market share in these regions.

"The submission of the IND marks a pivotal moment in our efforts to expand Zympentra's market presence in the U.S," a Celltrion official said. "We are committed to ensuring the success of this clinical trial."

If the company secures the RA indication, it will significantly broaden Zympentra's target market in the U.S. and enhance the product's competitiveness, accelerating Celltrion's growth, he added.