After a site visit by FDA inspectors yielded a Form 483 for Genzyme Ireland in early 2026, the Sanofi subsidiary is facing further reprimand from the U.S. regulator.
Sanofi’s long-held Genzyme unit has now received the more serious wrist slap of a warning letter from the FDA, after agency officials visited the Sanofi site in Waterford, Ireland, between Jan. 12 and Jan. 20 this year.
The site inspection uncovered what the FDA has branded “significant” manufacturing violations tied to Sanofi’s Thymoglobulin (Anti-thymocyte Globulin [Rabbit]) product—indicated to prevent and treat acute rejection in kidney transplant patients—as well as its Sobi-partnered hemophilia A drug Altuviiio.
In an emailed statement, a Sanofi spokesperson stressed to Fierce that “patient safety and the quality of our products are our highest priorities.”
“We take the FDA Warning Letter issued to the Waterford facility with the utmost seriousness,” the spokesperson continued. “We are taking immediate actions and are committed to fully addressing each of the Agency’s observations, robustly and sustainably.”
Following receipt of the Form 483 at the Ireland site earlier this year, Sanofi responded to the FDA’s concerns in February, again following up in April.
The FDA conceded in its warning letter that Sanofi’s responses pointed to “corrective actions to address each individual Form-483 observation.” However, the agency argued that the reply still neglected to address the “underlying failure” of the site’s quality unit to meet current manufacturing standards.
The FDA also suggested that several responses Sanofi proposed may be inadequate, with the crux of its argument suggesting that the site fumbles to “demonstrate a pattern in which your quality unit failed to exercise proper oversight, including oversight of your data integrity practices.”
In the warning letter, the FDA noted that the Genzyme Ireland site’s quality unit didn’t make sure lab records included complete data from all necessary tests, failing to document multiple non-viable particulate excursion tests for review and investigation, among other missteps.
The FDA further asserted that the Waterford facility’s laboratory records “were incomplete because quality control personnel used uncontrolled Review Checklists to unofficially document laboratory record reviews, which were subsequently discarded.”
Record updates weren’t always traceable or attributable to a specific worker, either, the FDA pointed out.
The agency also chided the site for failure to properly investigate manufacturing batch discrepancies or failures, including “whether or not the batch has already been distributed.”
Sanofi plans to work in tandem with the FDA to meet its requirements, the company spokesperson told Fierce on Wednesday, adding that all products released from the Ireland site “meet established quality and safety specifications.”
The company does “not anticipate any impact on our ability to supply medicines at this time,” per the spokesperson.
The FDA reprimand comes more than a year after Sanofi's Genzyme unit received a separate warning letter at its facility in Framingham, Massachusetts, in that instance focused on subpar manufacturing error investigations and inconsistent drug ingredient production, among other problems.
Sanofi acquired Genzyme way back in 2011, spending a little more than $20 billion for the company historically focused on inherited disorders, kidney diseases, cancer and transplant and immune diseases.
The company was more holistically absorbed into the Sanofi corporate scheme during the French pharma’s branding overhaul in 2022.