ImmuCell Pivots from FDA Setback to Double Down on Star Product

PORTLAND, ME – December 24, 2025 – In a decisive strategic shift, animal health company ImmuCell Corporation announced it will halt further investment in its developmental drug Re-Tain® following a regulatory setback from the U.S. Food and Drug Administration. The company will instead channel its resources into an aggressive expansion of its flagship First Defense® product line, a market leader in preventing calf scours.

The pivot comes after ImmuCell received an “Incomplete Letter” from the FDA on December 23 regarding its New Animal Drug Application (NADA) for Re-Tain®, a novel treatment for mastitis in dairy cows. Rather than navigate further delays, the company is making a calculated bet on its proven revenue generator, signaling a new chapter focused on capitalizing on existing market dominance.

The High Cost of a Regulatory Roadblock

The FDA's decision was not a rejection of the drug's efficacy but stemmed from persistent compliance issues at a third-party contract manufacturer. ImmuCell had successfully navigated four of the five technical sections required for NADA approval, and its own manufacturing facility passed a rigorous FDA inspection in 2024. However, the final hurdle—the Chemistry, Manufacturing, and Controls (CMC) section related to the aseptic filling of syringes—proved insurmountable due to the contractor's failure to address inspectional deficiencies.

This marks the second time the contract manufacturer's issues have stalled the Re-Tain® application, following a similar incomplete letter in May 2024. With the company's contract with the manufacturer set to expire in March 2026, the prospect of continued delays and investment led to a strategic reassessment. The experience serves as a stark case study on the significant risks and dependencies inherent in pharmaceutical development, where the success of a promising product can be jeopardized by supply chain partners.

As a result of pausing the project, ImmuCell expects to record a non-cash impairment write-down of approximately $2.3 million in the fourth quarter. The charge is related to Re-Tain® assets, which carried a net book value of around $15.5 million as of September 30, 2025. However, the company plans to repurpose a large portion of the associated facilities and equipment, turning a potential write-off into a strategic asset for its new focus.

A Strategic Pivot to a Proven Winner

ImmuCell's leadership is framing the pivot not as a failure, but as a disciplined allocation of capital toward its highest-return opportunity. The company will now focus its full attention on the First Defense® franchise, which provides immediate immunity to newborn dairy and beef calves to prevent scours, a common and costly intestinal disease.

“While it is disappointing news that we will be unable to achieve NADA approval with this contract manufacturer, this has only strengthened our resolve to allocate our resources to our highest return opportunity, namely First Defense®,” said Olivier te Boekhorst, President and CEO of ImmuCell.

This confidence is built on a solid foundation of historical success. The First Defense® brand has been a powerful growth engine for ImmuCell for over a decade. David S. Tomsche, DVM, Chair of the company's Board of Directors, highlighted this track record.

“Fifteen years ago, ImmuCell established a small field team that grew First Defense® annual revenue from approximately $4.4 million then to approximately $27.8 million in the trailing twelve-month period ended September 30, 2025,” Tomsche commented. “First Defense®’s record of more than 13% compounded growth per year for more than a decade gives us confidence that focusing on and investing more in First Defense® can deliver strong shareholder value.”

Unleashing First Defense®'s Potential

ImmuCell is wasting no time in executing its new strategy. The company announced it is immediately increasing its First Defense® field sales force by 50%, creating two new sales territories in the U.S. to deepen its domestic penetration. It is also hiring a senior dairy executive to develop and lead its international expansion strategy, aiming to capture a larger piece of the estimated $900 million global market for preventing scours in calves.

First Defense® already holds a commanding position in the United States, where it enjoys a 29% market share and was ranked the #1 product for scour prevention in the 2025 Hoard’s Dairyman Continuing Market Study. The product works by providing a concentrated dose of bovine antibodies from hyper-immunized colostrum, offering immediate protection against key pathogens like E. coli, coronavirus, and rotavirus. This mechanism differentiates it from competitors, which primarily consist of vaccines administered to either the pregnant dam or the newborn calf. Major players in the vaccine space include Zoetis, Merck, Elanco, and Boehringer Ingelheim, which recently launched its Fencovis vaccine.

To support this commercial expansion, ImmuCell is launching a multi-year manufacturing improvement program. By repurposing the assets from the Re-Tain® project, the company aims to lower production costs, improve manufacturing yields, and execute its next phase of capacity expansion beyond its current capability of over $30 million in annual production.

Financial Realignment and Future Outlook

The strategic shift was met with a brief, mild dip in ImmuCell's stock (Nasdaq: ICCC), but the price quickly rebounded and saw gains in the following days. The positive investor reaction suggests the market views the move as a prudent de-risking of the company's strategy, trading the regulatory uncertainty of Re-Tain® for the predictable growth of First Defense®.

While the Re-Tain® project is paused, it is not being completely abandoned. ImmuCell will complete ongoing studies to potentially enhance the drug's claims for preventing and treating mastitis. The company will then seek to license the product or partner with a global manufacturer, a path that would allow it to potentially realize value from its research and development without further in-house capital investment or manufacturing risk.

With a strong liquidity position and a clear focus, ImmuCell is now poised to accelerate the growth of its core business. The company has moved decisively to extricate itself from a costly development quagmire, choosing instead to invest heavily in the product that has consistently delivered results for the company and its customers in the dairy and beef industries.