Blockbuster sanofi & Regeneron Drug Dupixent Notches FDA Nods Inflammatory Skin Disease
Sanofi and Regeneron Pharmaceuticals DumenceDixent have been approved by the FDA for chronic spontaneous urticaria, introducing a new approach to treating this inflammatory skin disease. This is the seventh FDA approval instruction for Blockbuster products.
The regulatory decision announced Friday covers treatment for patients aged 12 and older, whose chronic spontaneous urticaria (CSU) symptoms continue despite having standard antihistamine treatment.
CSU is partially driven by type 2 inflammation, which is an overactive immune response. This reaction causes beehives and itching. CSU is defined as a disease that lasts for more than six weeks. Sanofi estimates that 1.7 million people in the United States are affected by CSU. Although antihistamines are available, the company says about half of CSU patients suffer from diseases that are not adequately controlled by these standard treatments.
Antihistamines target H1 receptors, immune cell receptors that play a role in immune responses and inflammation. The second-line treatment option for CSU is Genentech's Xolair, an asthma drug that expands approval for inflammatory skin diseases in 2014. Xolair is an antibody designed to block immunoglobulin E receptors, involving allergic reactions and immune responses. But other avenues play a role in CSU. Dupixent, a biweekly injection of the drug, is a monoclonal antibody designed to block signaling pathways IL-13 and IL-4.
FDA approval of Dupixent in CSU is based on the results of a two-stage 3 test that evaluates the adnex of the drug as an antihistamine compared to placebo and antihistamines. The results showed that dupixent met the primary and secondary goals of itching severity as well as itching and hive activity compared with the control group. The study drug group also showed an increased likelihood of good disease control or a complete response at 24 weeks. In terms of security, the results are consistent with Dupixent's known security in its approval instructions. The most common adverse event reported is injection site reaction.
Dupixent first approved as a treatment for atopic dermatitis in 2017. It is Sanofi's best-selling product, accounting for more than 13 billion euros (about 14.7 billion US dollars) in 2024. Sanofi's inflammatory and immunologic strategies include expanding drug use to other signs. Last year, the European Medicines Commission and the FDA approved dupixent for chronic obstructive pulmonary disease.
“This FDA approval provides a new treatment option to help address potential drivers of these severe and recurring signs and symptoms,” said Alyssa Johnsen, head of Sanofi Global Treatment Zone, in a prepared statement. “Dupixent has the potential to improve the prognosis of CSU patients with limited previous treatment options.”
In 2023, the FDA rejected Sanofi's preliminary application for the drug in CSU, requesting more clinical data to show efficacy. The submission is based on two phase 3 studies, one of which failed to meet the main trial objectives. Resubmit data including the third phase of the test. Dupixent received CSU approval in Japan, the United Arab Emirates and Brazil. The drug is still under review in such signs that other markets in Europe and the world are being reviewed.
There are other companies trying to provide new ways to CSU. Celldex Therapeutics with Barzovolimab is an antibody drug designed to bind to kit receptors on mast cells. Evommune aims to solve mast cell activation using oral small molecule EVO756. When the startup launched a $115 million Series C funding last October, it said it expects preliminary 2B data for CSU in the first half of 2025.
But CSU drug research has also led to failure. In 2022, the third harmonic discontinued the development of oral small molecule kits after the Phase 1 data, showing potential signs of hepatotoxicity. The company shifted its focus to a different box-sealed small molecule THB335, which is currently preparing for a second phase of development. But last week, Third Harmonic announced plans to disband the company and sell its assets, including 333 THB335, to return cash to shareholders.
Meanwhile, Allakos has less than twice as much effort in developing antibodies that inhibit mast cells. Last year, Allakos reported that its drug lirentelimab did not beat the placebo in the second phase of the CSU test. Biotech shifted its focus to another drug, AK006. But the drug's first phase failure in January triggered the second corporate restructuring of the biotech in the past year.
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