Regeneron's Eylea HD Faces Setbacks, but Company Remains Optimistic

Regeneron Pharmaceuticals has encountered another obstacle in its quest to bring the high-dose (HD) version of its blockbuster drug Eylea to market. The U.S. Food and Drug Administration (FDA) has issued a complete response letter (CRL) for the prefilled syringe formulation of Eylea HD, citing manufacturing issues at a third-party facility. Despite this setback, the company is actively pursuing solutions and remains confident in the drug's future.

Manufacturing Challenges and FDA Rejection

The rejection stems from unresolved issues at a Novo Nordisk manufacturing plant in Bloomington, Indiana, which Novo acquired from Catalent in late 2024. Earlier this month, Novo informed Regeneron that the FDA had classified the facility with an Official Action Indicated (OAI) status, the most severe of the agency's inspection classifications. This designation suggests that the facility is in an "unacceptable state of compliance," with violations including persistent contamination issues and lack of preventive mechanisms.

Regeneron's Response and Alternative Strategies

Despite the setback, Regeneron CEO Leonard Schleifer struck an optimistic note during the company's Q3 earnings call. The pharmaceutical giant is pursuing several strategies to overcome the manufacturing hurdles:

1. Alternate Prefilled Syringe Filler: Regeneron plans to submit an application in January 2026 to add an alternate prefilled syringe filler. This would trigger a four-month FDA review, which the company expects to result in a favorable outcome.

2. Alternate Vial Filler: The company is tapping an alternate vial filler for an ongoing review, with the FDA having a target action date in late December. This could provide an additional opportunity for the agency to approve supplemental biologics license applications (sBLAs) for Eylea HD's every-four-week dosing and for the treatment of macular edema following retinal vein occlusion.

3. Long-term Manufacturing Plans: Regeneron is considering business development deals to gain the ability to manufacture all of its products in-house. The company is expanding its campus in Tarrytown, New York, and building a new fill-finish facility in Rensselaer, New York.

Financial Performance and Market Impact

Despite the regulatory challenges, Regeneron's financial performance remains strong. In the third quarter, the company posted a 1% year-on-year growth, reaching $3.75 billion in revenues. This growth was primarily driven by its Sanofi-partnered blockbuster drug Dupixent, which brought in $4.86 billion.

The Eylea franchise, however, experienced a 28% decline in total sales, hitting $1.11 billion for the quarter. Nonetheless, Eylea HD sales in the United States have trended positively, reaching an all-time high of $431 million in Q3, up from $307 million in Q1 and $393 million in Q2.

Investors seem to share analysts' positive outlook on Regeneron's ability to overcome these challenges. Shares of the company rose 11.8% to $654.48 at the close of trading following the earnings call.