Manufacturing problems in France threaten to delay the release of Sanofi SA (NYSE:SNY) and Regeneron Pharmaceuticals Inc (NASDAQ:REGN) blockbuster drug, dupilumab, according to analysts at Leerink.  The drug, which has already won priority review from the FDA for the treatment of eczema, now faces the risk of losing its PDUFA date slated for early next year.

Inspectors’ Concerns

It has emerged that after an inspection in July, inspectors made 13 observations, which also included problems that the company had not addressed that were raised on a previous inspection. Concerns over the proliferation of mold and bacteria are one of the deficiencies that could affect manufacturing works at the plant.

Form 483 seen by analysts also suggests that the FDA raised concerns about airflow in the Le Trait plant. Sanofi was also taken to task to explain the design of certain equipment, which according to the inspectors did not meet standards.

Sanofi has since refuted claims that the deficiencies raised by the inspectors could have an effect on dupilumab as well as sarilumab.  In a bid to address some of the issues raised by the FDA, the drug maker says it has started to work on an action plan to fix the issues.

Second Facility Option

There are also indications that Sanofi and Regeneron might use another facility for the manufacturing of dupilumab should the need arise in a bid to ensure current problems do not interfere with the launch date. The last thing that Sanofi needs now is a delay on its two new blockbuster drugs that could help it offset a decline in sales in other drugs.

“The lack of specific product quality observations by the FDA provides some assurance that with skill, resources and a healthy dose of contrition, Sanofi could address these issues to the satisfaction of the FDA, and thus secure the approval of sarilumab and provide assurances about the timeline for dupilumab,” said the analysts in a research note to investors.

Sanofi SA (ADR) (NYSE:SNY) stock was up by 1.79% in Tuesday’s trading session consequently closing the day at highs of $40.44 a share.