Is Dupixent now the gold standard for asthma with nasal polyps? Inside Sanofi and Regeneron’s big study win

Why are Sanofi and Regeneron doubling down on Dupixent’s respiratory dominance?

In a major clinical milestone, Sanofi (EPA: SAN) and Regeneron Pharmaceuticals Inc. (NASDAQ: REGN) have secured a significant win in the competitive respiratory biologics space. Their flagship drug Dupixent (dupilumab) has outperformed Roche and Novartis’ long-standing therapy Xolair (omalizumab) in the EVEREST Phase 4 head-to-head study targeting chronic rhinosinusitis with nasal polyps and coexisting asthma. The findings, presented at the 2025 European Academy of Allergy and Clinical Immunology (EAACI) Congress in Glasgow, add further credibility to Dupixent’s platform potential and clinical superiority in type 2 inflammatory diseases.

This latest data comes at a time when the global immunology market is becoming increasingly crowded and differentiated clinical outcomes are essential to sustaining both reimbursement traction and physician loyalty. Sanofi and Regeneron appear to be positioning Dupixent not just as a therapy, but as a cross-indication biologic engine.

What did the EVEREST study demonstrate about Dupixent’s efficacy and superiority?

The EVEREST trial enrolled 360 adult patients suffering from severe uncontrolled chronic rhinosinusitis with nasal polyps and coexisting asthma, a dual-disease cohort associated with higher symptom burden, frequent relapses, and limited therapeutic options. The trial compared 300 mg Dupixent administered every two weeks against weight- and IgE-level-based doses of omalizumab, both in conjunction with daily intranasal mometasone furoate.

Dupixent achieved superior outcomes across all prespecified primary and secondary endpoints. This included a 1.60-point greater reduction in nasal polyp size and an 8-point higher improvement in patients’ ability to smell compared to Xolair. Importantly, these improvements were observed as early as week four and were sustained through week 52. Additional improvements were recorded in overall symptom scores, nasal congestion severity, disease burden, and asthma control.

In lung function metrics, Dupixent delivered a 150 mL greater improvement in pre-bronchodilator FEV1 versus Xolair. The therapy also scored 0.48 points higher on the Asthma Control Questionnaire, underscoring its dual utility in upper and lower airway inflammation. These findings validate Dupixent’s interleukin-4 and interleukin-13 inhibition mechanism as a more broadly effective strategy compared to IgE inhibition, particularly in patients with overlapping airway diseases.

How does Dupixent’s success fit into broader trends in the biologics market?

The results of the EVEREST study reinforce an increasingly dominant strategy among top-tier pharmaceutical companies: develop platform biologics with high-efficacy targets across multiple inflammatory conditions. Dupixent is already approved for diseases such as atopic dermatitis, eosinophilic esophagitis, chronic spontaneous urticaria, and asthma. Its safety profile, consistent efficacy, and broad biomarker-driven applicability have made it a cornerstone of Sanofi and Regeneron’s immunology franchise.

With more than one million patients treated globally, Dupixent’s market footprint is growing rapidly. The EVEREST study marks another milestone in the companies’ effort to entrench the drug further into the respiratory care continuum. The head-to-head trial design adds additional weight, especially given Xolair’s entrenched use as a standard of care in allergic asthma and nasal polyposis.

The ongoing transformation of the respiratory biologics market includes next-generation competition targeting IL-5, TSLP, and IL-33, making this success even more crucial for Dupixent’s longevity. Sanofi and Regeneron are moving quickly to translate clinical superiority into regulatory and commercial advantage before biosimilar threats emerge closer to the 2030 window.

What are analysts and investors saying about Regeneron Pharmaceuticals and Sanofi?

Following the EVEREST presentation, shares of Regeneron Pharmaceuticals Inc. showed a modest uptick, reflecting investor recognition of another de-risked growth opportunity for Dupixent. Analyst sentiment remains broadly positive, with continued conviction in the company’s late-stage pipeline strategy and biologics execution track record. Sanofi, while seeing less immediate volatility in its stock price, is receiving favorable mention among healthcare-focused institutional investors who value durable immunology revenue streams.

The trial results are being viewed not just as another data point, but as a signal of market leadership in type 2 inflammation. Buy-side and sell-side analysts have noted that Dupixent’s ability to treat multiple coexisting conditions with one therapy creates a strategic moat and justifies its premium pricing structure.

Key opinion leaders in immunology and respiratory medicine have also echoed optimism, noting the 8-point improvement in smell and 92 percent reduction in corticosteroid or surgical intervention risk observed in earlier CRSwNP trials. These effects could drive a shift in treatment paradigms and guidelines, positioning Dupixent earlier in the care continuum.

What future developments could impact Dupixent’s trajectory after this trial?

The immediate next step is expected to be a supplemental Biologics License Application for Dupixent’s label expansion, targeting approval in 2026. If successful, this will provide Sanofi and Regeneron with a new marketing claim that could further boost physician adoption and payer acceptance. Expanded access would also support broader formulary coverage and drive deeper penetration into allergy and ENT networks.

The companies may additionally explore long-acting formulations, combination therapies, or new delivery devices to extend the product life cycle. As real-world data begins to accumulate from this new patient segment, it will be important to track metrics such as time to symptom control, reduction in healthcare utilization, and patient-reported quality of life improvements.

The competitive landscape is also evolving, with AstraZeneca, Amgen, and other biopharma majors advancing rival candidates. This makes Dupixent’s early and consistent success critical for retaining category leadership.

In parallel, Sanofi and Regeneron are expanding Dupixent into other inflammatory indications, including bullous pemphigoid and prurigo nodularis. Each successful readout strengthens the company’s case to regulators and payers that Dupixent is a portfolio asset, not just a one-indication biologic.

Key takeaways: What the EVEREST trial reveals about Dupixent’s next chapter in respiratory care

• Sanofi and Regeneron’s Dupixent achieved clinical superiority over Xolair in a head-to-head Phase 4 trial for chronic rhinosinusitis with nasal polyps and asthma.
• The study met all primary and secondary endpoints, with statistically significant improvements in nasal symptoms, asthma control, and lung function.
• Dupixent’s mechanism of IL-4 and IL-13 inhibition continues to demonstrate broader efficacy across type 2 inflammatory diseases.
• The trial data supports a likely label expansion and greater commercial adoption in respiratory comorbidity markets.
• Investor sentiment for Regeneron Pharmaceuticals and Sanofi remains positive, driven by confidence in pipeline execution and biologics life cycle management.
• The biologic’s expanding footprint, consistent performance, and high real-world impact position it as a platform asset in immunology.