Tezspire gains FDA approval for CRSwNP, expanding AstraZeneca and Amgen’s reach in inflammatory airway diseases

AstraZeneca PLC (LSE: AZN) and Amgen Inc. (NASDAQ: AMGN) have received regulatory approval from the U.S. Food and Drug Administration (FDA) for Tezspire (tezepelumab) as an add-on maintenance therapy for adults and adolescents aged 12 years and older with chronic rhinosinusitis with nasal polyps (CRSwNP) that remains inadequately controlled. This decision marks a major milestone in the evolution of airway inflammation treatments and strengthens the therapeutic footprint of both pharmaceutical companies across upper and lower respiratory conditions.

This new indication represents the second approved use for Tezspire and expands the drug’s presence beyond severe asthma into the realm of epithelial-driven inflammation of the upper airways. Notably, Tezspire is now the first and only biologic targeting thymic stromal lymphopoietin (TSLP) to receive FDA approval for CRSwNP, offering a new pathway for patients where corticosteroids and sinus surgeries have historically provided inconsistent and short-lived relief.

The biologic’s approval was driven by positive outcomes in the WAYPOINT Phase III clinical trial, with results presented earlier this year at the 2025 American Academy of Allergy Asthma & Immunology and World Allergy Organization Joint Congress and published simultaneously in The New England Journal of Medicine. Trial data demonstrated rapid and sustained symptom relief, near-elimination of the need for surgical intervention, and a meaningful reduction in systemic corticosteroid use.

How does the Tezspire CRSwNP approval reinforce AstraZeneca and Amgen’s long-term respiratory strategy?

The FDA’s latest decision provides validation for the shared inflammatory mechanisms between diseases like severe asthma and chronic rhinosinusitis with nasal polyps. AstraZeneca PLC and Amgen Inc. have both highlighted the potential for TSLP inhibition as a unified approach across comorbid respiratory conditions.

For AstraZeneca PLC, this regulatory milestone reinforces its 50-year heritage in respiratory care and supports its ambition to reshape treatment paradigms for chronic inflammation and immune-mediated diseases. The British biopharmaceutical company has been consistently investing in its respiratory and immunology pipeline, with Tezspire forming a cornerstone of that strategy. The approval also strengthens Amgen Inc.’s commercial presence in the respiratory space, where it continues to expand beyond oncology and autoimmune diseases.

What efficacy data supported the FDA approval and what endpoints were met in the Phase III trial?

The WAYPOINT Phase III trial enrolled patients with uncontrolled CRSwNP and evaluated Tezspire’s efficacy and safety over a 52-week treatment period followed by 12 to 24 weeks of follow-up. Participants received either Tezspire or placebo via subcutaneous injection. The trial’s co-primary endpoints focused on changes in total nasal polyp score (TNPS) based on endoscopic assessments and bi-weekly nasal congestion scores recorded in daily symptom diaries.

Results showed that patients receiving Tezspire experienced statistically significant reductions in polyp size and nasal congestion compared to placebo. Additionally, the biologic demonstrated clinically meaningful secondary outcomes, including improvements in sense of smell, quality of life as measured by SNOT-22 scores, and lower reliance on systemic corticosteroids. Time to surgical decision-making was notably extended, further supporting the biologic’s disease-modifying potential.

The drug’s safety profile in CRSwNP remained consistent with its existing asthma label. The most common adverse events reported during the trial included COVID-19 infections, nasopharyngitis, and upper respiratory tract infections, but none led to discontinuation at a concerning rate.

Why is TSLP inhibition emerging as a differentiated strategy in respiratory biologics?

Unlike other biologics that act on downstream inflammatory targets such as interleukins IL-4, IL-5, or IL-13, tezepelumab blocks TSLP, an upstream epithelial cytokine released in response to environmental triggers like allergens, viruses, and pollutants. This upstream targeting allows Tezspire to modulate multiple inflammatory pathways simultaneously, positioning it as a first-in-class therapy capable of addressing both eosinophilic and non-eosinophilic disease types.

The dual benefit of upper and lower airway coverage makes Tezspire an attractive choice for clinicians treating patients with overlapping asthma and CRSwNP. Furthermore, by targeting the epithelial source of inflammation, Tezspire holds promise in addressing disease persistence and recurrence—a persistent challenge in nasal polyposis management.

What are the implications of this approval for patients with chronic rhinosinusitis with nasal polyps?

CRSwNP affects an estimated 320 million individuals worldwide and presents as a persistent inflammatory condition marked by benign nasal polyps, airflow obstruction, congestion, and loss of smell. While intranasal corticosteroids, systemic steroids, and endoscopic sinus surgeries have long served as standard of care, they often fail to provide lasting relief, and many patients endure recurring symptoms and multiple interventions.

With the approval of Tezspire, patients now have access to a non-surgical, biologic treatment option that has demonstrated the ability to reduce symptom burden, extend time between surgical interventions, and reduce the need for systemic steroid use. Experts believe this could represent a paradigm shift for patients and providers alike.

Where does Tezspire stand in terms of global regulatory status and future approvals?

While the latest approval covers the U.S. market, Tezspire is already under regulatory review for CRSwNP in the European Union, China, Japan, and several other geographies. In the EU, the Committee for Medicinal Products for Human Use (CHMP) has issued a positive opinion, indicating that marketing authorisation is likely to follow within months.

Tezspire is already approved for severe asthma in more than 60 countries, including the U.S., EU, and Japan. With the addition of CRSwNP and ongoing trials for chronic obstructive pulmonary disease (COPD) and eosinophilic esophagitis (EoE), the drug could evolve into a multi-indication respiratory and immunology franchise.

What does the collaboration structure between AstraZeneca and Amgen mean for commercialisation?

Under the revised 2012 collaboration agreement, AstraZeneca PLC and Amgen Inc. share development and commercialisation responsibilities for Tezspire, with profits and costs split equally. AstraZeneca leads global development and commercialisation outside the U.S., while Amgen is responsible for U.S.-based manufacturing and commercial sales.

In the U.S., Amgen records product sales directly and AstraZeneca recognizes its share of profits under “Collaboration Revenue.” For ex-U.S. markets, AstraZeneca records sales, while Amgen reports its share as “Other/Collaboration Revenue.” This structure has enabled both companies to align operational and financial incentives in advancing Tezspire globally.

How are institutional investors reacting to Tezspire’s FDA approval for CRSwNP and what does it signal for AstraZeneca and Amgen?

Following the announcement, shares of AstraZeneca PLC edged higher on the London Stock Exchange, though broader market conditions kept gains modest. Analysts have remained bullish on the company’s respiratory and oncology portfolios, with Tezspire seen as a valuable growth asset as it scales beyond asthma.

Amgen Inc., listed on the NASDAQ, also saw a marginal lift in pre-market trading. The move comes amid a broader rotation into large-cap biotech names with durable pipelines and favourable regulatory momentum. Analysts continue to issue “Buy” or “Outperform” ratings, citing Tezspire’s pipeline expansion and its first-in-class TSLP targeting approach as long-term catalysts.

What upcoming milestones should investors and clinicians monitor for Tezspire?

With regulatory reviews underway in Asia-Pacific and Europe, the next major milestone will be final marketing authorisation decisions in those jurisdictions. Simultaneously, two late-stage trials are evaluating Tezspire’s use in COPD and EoE, both areas where unmet clinical need remains high.

Tezspire also holds Orphan Drug Designation from the FDA for EoE, which could accelerate its path to approval and provide commercial exclusivity incentives. If these trials yield positive data, Tezspire could become a flagship molecule in airway inflammation, spanning multiple diseases with a single mechanism.

Longer-term, the real-world durability of Tezspire in CRSwNP will be closely watched, particularly its ability to reduce surgery rates and long-term corticosteroid use in larger and more diverse patient populations. Payers and clinical guideline bodies may update recommendations based on post-approval data, influencing adoption trends.

What are the key takeaways investors, clinicians and payers should know about Tezspire’s FDA approval and its commercial implications?

• The U.S. Food and Drug Administration approved Tezspire (tezepelumab) as an add‑on maintenance therapy for adults and adolescents (12+) with inadequately controlled chronic rhinosinusitis with nasal polyps (CRSwNP), marking the drug’s second indication after severe asthma and validating the thymic stromal lymphopoietin (TSLP) approach.
• The approval was supported by positive Phase III WAYPOINT data showing statistically significant reductions in total nasal polyp size, clinically meaningful relief in nasal congestion, improved sense of smell and SNOT‑22 scores, near‑elimination of the need for surgery, and materially lower systemic corticosteroid use versus placebo.
• Tezspire is now the first and only biologic targeting TSLP approved for CRSwNP, differentiating it from downstream interleukin‑targeting biologics and positioning it as a unified upstream option for overlapping upper and lower airway disease.
• AstraZeneca PLC and Amgen Inc. share development and profits under their collaboration; Amgen records U.S. sales with AstraZeneca recognising collaboration revenue, while AstraZeneca records ex‑U.S. sales with Amgen reporting profit share—this split preserves upside for both parties as the franchise expands.
• Commercial adoption is likely to be strongest in ENT and allergy specialty clinics and among patients with comorbid severe asthma and CRSwNP, aided by Tezspire’s self‑administered pre‑filled syringe and auto‑injector formats that support outpatient and home use.
• The Committee for Medicinal Products for Human Use has issued a positive opinion in the European Union and regulatory reviews are underway in China, Japan and other markets; outcomes in those jurisdictions will materially influence global revenue trajectory.
• Key upcoming clinical and commercial milestones to watch include final marketing authorisations in major markets, post‑marketing durability data on surgery avoidance and steroid‑sparing effects, and Phase III readouts in chronic obstructive pulmonary disease and eosinophilic esophagitis that could further broaden the label.
• Institutional sentiment has been constructively positive with modest share price uplift for both AstraZeneca PLC and Amgen Inc.; analysts view multi‑indication potential and the upstream TSLP mechanism as meaningful longer‑term growth drivers, subject to uptake, payer decisions and real‑world durability.