Sanofi, Regeneron ready to roll with $3B-plus Dupixent approval

Sanofi and Regeneron just scored their biggest new drug approval of the year—and for Sanofi, of the past several.

Dupixent, also known as dupilumab, is now the first approved drug to inhibit the IL-4 and IL-13 immune system pathways—and the first new treatment in years for atopic dermatitis, a form of eczema that can be debilitating for patients.

Set to launch at a price of $37,000, Dupixent can now embark on its path to expected sales of $3 billion-plus, not just in this disease, but potentially asthma, severe nasal allergies and more. Indeed, Regeneron CEO Len Schleifer has said he sees Dupixent (dupilumab), with its ability to target a variety of disorders, as the sort of multitasking med that drugmakers like to have in their stables.

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Dupixent’s success isn’t guaranteed; as several Big Pharmas have discovered in recent years, even a much-anticipated drug can be bedeviled by tight-fisted payers and threatened by intellectual property disputes. The development partners themselves have struggled with their PCSK9 cholesterol-fighter Praluent, which has been saddled with prior authorization requirements and high-tier copays since its 2015 debut—and is now the subject of a high-stakes patent lawsuit under appeal at the U.S. Federal Circuit Court.

Indeed, as the Dupixent approval neared, Sanofi and Regeneron preemptively sued Amgen, asking for a court order declaring that the drug did not infringe one of the California biotech’s patents. Amgen had been developing an IL-4 drug for asthma, but it failed a phase 2 study back in 2010.

Unlike Praluent, however, Dupixent wasn’t approved on a surrogate endpoint; its atopic dermatitis data shows direct symptom relief. That data—on skin clearance, itching, anxiety and more—suggest that, "for many patients with severe atopic dermatitis, dupilumab will be life transforming," Leerink Partners analyst Geoffrey Porges wrote to investors when two pivotal trials were unveiled last year. At the time Leerink estimated peak sales of about $5 billion.

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Plus, unlike Praluent with its direct rival from Amgen, Repatha, Dupixent will face little competition in the field, and no head-to-head rivals at all.

Available treatments, some of which are used off-label, now include topical corticosteroid therapy, which doesn’t work well for all patients, as well as cyclosporin and Rituxan. Those who do respond to current treatments often have to discontinue therapy periodically because of side effects, which creates a cycle of symptoms that surge whenever treatment is paused, according to Sanofi’s head of Dupixent development, Gianluca Pirozzi.

As for data, the Dupixent approval is based on two 16-week studies that showed it delivered clear or mostly clear skin in 36% to 38% of patients, compared with 8% to 10% of placebo patients. Half or almost half of dupilumab patients also saw 75% improvement on another scale that served as a secondary endpoint in the U.S. and co-primary in the E.U.

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Dupixent also reduced the severe itching that accompanies this disease by a median of four points on a scale of 1 to 10. In a longer-term trial, unveiled at the American Academy of Dermatology meeting in early March, Dupixent showed it could have a lasting effect on atopic dermatitis symptoms when used alongside topical steroids.

After 52 weeks of treatment, patients on a weekly dose saw an 80% improvement in their symptoms, while those on a biweekly dose saw a 78% improvement over the course of the trial, compared with 46% of those on steroid therapy plus placebo. Improvements after the therapy reached its maximum effect were 90% for the weekly patients, Pirozzi said ahead of the approval.

The companies have also been talking up anecdotal evidence from patients who’ve seen dramatic results while taking Dupixent. At an event at Sanofi Genzyme headquarters earlier this week, Pirozzi presented dramatic before-and-after photos of a woman who had traveled from Mexico to New York every two weeks to participate in a clinical trial. And a patient, Anne Warnock, described her own experiences taking Dupixent for the past three years, ever since she joined her first clinical trial.

“After two weeks my old skin started to shed and I had new, normal skin for the first time in my life,” she said, noting that she can now sleep—“I don’t think I slept a full night in my entire adolescence,” the 33-year-old said. “This medicine has totally changed my way of life. ... Every ability I had before has completely changed.”

Warnock said her asthma cleared up on Dupixent, too. “I can ride my bike in the winter as fast as I want now,” without having an asthma attack, she said.

Getting Dupixent to the right patients will be the challenge. Payers have been increasingly reluctant to grant unencumbered coverage for new drugs, even when they have strong data to back them up. Ahead of approval, the two companies were planning to strike deals with payers that would make it worthwhile to cover Dupixent in all appropriate patients, Schleifer said during a presentation at the J.P. Morgan Healthcare Conference in January.

About 3% of the general population suffers from atopic dermatitis, Pirozzi said in an interview, with 10% to 20% of that group classified as moderate-to-severe. Sanofi estimates that 300,000 patients would be eligible for the drug. A recently approved med from Pfizer, Eucrisa, is targeted at milder forms of the disease.

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With new indications, of course, the drug could expand to other broad patient populations. Sanofi and Regeneron are planning to go to the FDA later this year with their asthma data, generated in two pivotal studies, one a phase 2b study and the other a phase 3 trial. A second phase 3 is also underway. “We are preparing the filing as we speak,” Pirozzi said.

As for how Dupixent will fare with payers once the launch is underway, Pirozzi said he’s hopeful that the quality-of-life measures in the atopic dermatitis trials persuade them to offer favorable coverage.

“In reality, we are human beings, and how these patients have improved at the end of treatment makes it invaluable,” he said.