Concerns Potentially Halt Sarilumab FDA Approval

The experimental IL-6 inhibitor sarilumab is expected to compete with adalimumab for treatment of rheumatoid arthritis.

Manufacturing deficiencies found during a routine US Food and Drug Administration (FDA) inspection of a fill-finish facility may delay the approval of experimental interleukin (IL)-6 inhibitor sarilumab for the treatment of rheumatoid arthritis (RA).

Sanofi CEO Olivier Brandicourt said in a phone call that the deficiencies were “not specifically related to sarilumab.”1 An October 28th Securities and Exchange Commission (SEC) filing by Regeneron Pharmaceuticals—Sanofi’s research and development partner—noted that “given that the CGMP [Current Good Manufacturing Practice] status of this facility is under review by the FDA, it is unclear whether or how this situation may impact the timing of the potential approval of sarilumab.”2

Regeneron also noted that no Form 483 was issued to the company in connection with the facility inspection. The form is issued by the FDA “at the conclusion of an inspection when in investigator(s) has observed any conditions that in their judgment may constitute violations of the Food Drug and Cosmetic (FD&C) Act.”

Sarilumab monotherapy met the primary outcome measure as defined by change from baseline in disease activity score 28 (DAS28) erythrocyte sedimentation rate (ESR) vs adalimumab (Humira®, AbbVie) monotherapy in the phase 3 clinical trial SARIL-RA-MONARCH ( NCT02332590). 

The sarilumab treatment group showed significantly more change at -3.25 compared to -2.22 for adalimumab. Patients also displayed improvements in signs and symptoms by 20% according to the American College of Rheumatology (ACR) criteria (72% vs. 58% for sarilumab and adalimumab, respectively). 

Sarilimab is expected to reach sales of $1.8 billion by 2020. The biologics license application for sarilumab remains under active review; Regeneron anticipates an FDA action date of October 30, 2016. 

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  1. Palmer E. Sanofi and Regeneron’s expected blockbuster runs into FDA manufacturing concerns. Published October 28, 2016. Accessed October 28, 2016. 

  2. Regeneron Pharmaceuticals, Inc. US Securities and Exchange Commission Filing.
    Filed on October 28, 2016. Accessed October 28, 2016. 

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