TARRYTOWN, N.., USA I July 30, 2012 I Regeneron Pharmaceuticals, Inc. (NASDAQ: REGN) today announced that the U.S. Food and Drug Administration (FDA) issued a Complete Response Letter for the supplemental biologics license application (sBLA) for ARCALYST® (rilonacept) Injection for Subcutaneous Use for the prevention of gout flares in patients initiating uric acid-lowering therapy.

The Complete Response Letter states that the FDA cannot approve the application in its current form. The agency has requested additional clinical data, as well as additional Chemistry, Manufacturing, and Controls (CMC) information related to a proposed new dosage form. The FDA’s action does not impact the approved indication of ARCALYST for the treatment of Cryopyrin-Associated Periodic Syndromes (CAPS), including Familial Cold Auto-inflammatory Syndrome (FCAS) and Muckle-Wells Syndrome (MWS) in adults and children 12 and older.

"Regeneron is reviewing the Complete Response Letter and will determine appropriate next steps," said George D. Yancopoulos, M.D., Ph.D., President of Regeneron Laboratories. "We remain committed to continuing to make ARCALYST available to the community of patients with CAPS including our comprehensive patient and caregiver educational and reimbursement services programs."

Important information about ARCALYST® (rilonacept) Injection

ARCALYST is currently indicated in the U.S. for the treatment of Cryopyrin-Associated Periodic Syndromes (CAPS), including Familial Cold Auto-inflammatory Syndrome (FCAS) and Muckle-Wells Syndrome (MWS) in adults and children 12 and older. Rilonacept is also approved, but not marketed, in the E.U. for the same patient population. IL-1 blockade may interfere with immune response to infections. Serious, life-threatening infections have been reported in patients taking rilonacept. Rilonacept should be discontinued if a patient develops a serious infection. Taking rilonacept with tumor necrosis factor inhibitors is not recommended because this may increase the risk of serious infections. Treatment with rilonacept should not be initiated in patients with active or chronic infections. Patients should not receive a live vaccine while taking rilonacept. It is recommended that patients receive all recommended vaccinations prior to initiation of treatment with rilonacept. Patients should be monitored for changes in their lipid profiles and provided with medical treatment if warranted. Hypersensitivity reactions associated with rilonacept administration have been rare. Please see the full Prescribing Information for ARCALYST® (rilonacept), available online at www.regeneron.com/ARCALYST-fpi.pdf.

About Regeneron Pharmaceuticals, Inc.

Regeneron is a fully integrated biopharmaceutical company that discovers, invents, develops, manufactures, and commercializes medicines for the treatment of serious medical conditions. Regeneron markets two products in the United States, EYLEA® (aflibercept) Injection and ARCALYST® (rilonacept) Injection for Subcutaneous Use. Regeneron has filed regulatory applications with the U.S. Food and Drug Administration (FDA) for a second indication for EYLEA and for the product candidate ZALTRAP® (aflibercept) Injection for Intravenous Infusion. Phase 3 studies are in progress with EYLEA in two additional indications and with product candidates sarilumab and REGN727. Regeneron has active research and development programs in many disease areas, including ophthalmology, inflammation, cancer, and hypercholesterolemia. Additional information and recent news releases are available on the Regeneron web site at www.regeneron.com.

SOURCE: Regeneron Pharmaceuticals