Regeneron Advances Allergy Pipeline with Two Positive Phase 3 Trials Evaluating First-in-Class Antibody-Blockers of Cat and Birch Allergies
Regeneron Pharmaceuticals (NASDAQ: REGN) announced positive Phase 3 trial results for its first-in-class allergen-blocking antibodies targeting cat and birch allergies. The trials demonstrated significant symptom reduction compared to placebo.
In the cat allergy trial, a single dose of REGN1908/REGN1909 reduced itch by 52%, conjunctival redness by 39%, and skin prick reactivity by 44%. For birch allergy, REGN5713/REGN5715 showed similar efficacy with 51% itch reduction, 46% conjunctival redness reduction, and 44% decrease in skin prick reactivity.
Both treatments showed rapid onset within 8 days and durability lasting over 3 months. The company plans additional Phase 3 development, with cat allergy trials starting in H1 2026 and birch allergy trials by year-end.
Regeneron Pharmaceuticals (NASDAQ: REGN) ha comunicato risultati positivi in fase 3 per i suoi anticorpi di prima classe che bloccano gli allergeni responsabili delle allergie al gatto e alla betulla. Gli studi hanno mostrato una riduzione significativa dei sintomi rispetto al placebo.
Nel trial sull’allergia al gatto, una singola somministrazione di REGN1908/REGN1909 ha ridotto il prurito del 52%, il rossore congiuntivale del 39% e la reattività al prick test cutaneo del 44%. Per l’allergia alla betulla, REGN5713/REGN5715 ha ottenuto risultati analoghi: -51% di prurito, -46% di rossore congiuntivale e -44% nella reattività al prick test.
Entrambi i trattamenti hanno mostrato un’insorgenza rapida entro 8 giorni e un’efficacia che si è mantenuta per oltre 3 mesi. L’azienda prevede ulteriori sviluppi in fase 3, con l’avvio dei trial per l’allergia al gatto nella prima metà del 2026 e quelli per la betulla entro la fine dell’anno.
Regeneron Pharmaceuticals (NASDAQ: REGN) anunció resultados positivos de fase 3 para sus anticuerpos de primera clase que bloquean alérgenos responsables de las alergias a gatos y abedules. Los ensayos mostraron una reducción significativa de los síntomas frente a placebo.
En el ensayo de alergia a gatos, una dosis única de REGN1908/REGN1909 redujo el picor en un 52%, el enrojecimiento conjuntival en un 39% y la reactividad en el prick test cutáneo en un 44%. Para la alergia al abedul, REGN5713/REGN5715 mostró eficacia similar: 51% menos picor, 46% menos enrojecimiento conjuntival y 44% menos reactividad en el prick test.
Ambos tratamientos presentaron un inicio rápido en 8 días y una duración de efecto superior a 3 meses. La compañía planea más desarrollos de fase 3, con ensayos para la alergia a gatos que comenzarán en la primera mitad de 2026 y los de abedul antes de que termine el año.
Regeneron Pharmaceuticals (NASDAQ: REGN)는 고양이 및 자작나무(베치) 알레르기를 표적으로 하는 선구적 알레르겐 차단 항체의 3상 임상에서 긍정적인 결과를 발표했습니다. 시험은 위약 대비 증상 유의한 감소를 보여주었습니다.
고양이 알레르기 시험에서 단회 투여한 REGN1908/REGN1909는 가려움증을 52% 감소시켰고, 결막 충혈은 39%, 피부 프릭 검사 반응성은 44% 감소했습니다. 자작나무 알레르기에 대해서는 REGN5713/REGN5715가 유사한 효능을 보이며 가려움증 51% 감소, 결막 충혈 46% 감소, 프릭 검사 반응성 44% 감소를 기록했습니다.
두 치료제 모두 8일 이내 빠른 효과 발현을 보였고 3개월 이상 지속되는 내구성을 확인했습니다. 회사는 추가 3상 개발을 계획하고 있으며, 고양이 알레르기 시험은 2026년 상반기 시작, 자작나무 시험은 연말까지 시작할 예정입니다.
Regeneron Pharmaceuticals (NASDAQ: REGN) a annoncé des résultats positifs en phase 3 pour ses anticorps innovants bloquant les allergènes responsables des allergies aux chats et au bouleau. Les essais ont montré une réduction significative des symptômes par rapport au placebo.
Dans l’essai sur l’allergie aux chats, une unique dose de REGN1908/REGN1909 a réduit les démangeaisons de 52 %, les rougeurs conjonctivales de 39 % et la réactivité au test cutané par prick de 44 %. Pour l’allergie au bouleau, REGN5713/REGN5715 a obtenu des résultats comparables : −51 % de démangeaisons, −46 % de rougeurs conjonctivales et −44 % de réactivité au prick test.
Les deux traitements ont montré un effet rapide en 8 jours et une durabilité supérieure à 3 mois. La société prévoit des développements supplémentaires en phase 3, avec le démarrage des essais pour l’allergie aux chats au premier semestre 2026 et ceux pour le bouleau d’ici la fin de l’année.
Regeneron Pharmaceuticals (NASDAQ: REGN) meldete positive Phase‑3‑Ergebnisse für seine neuartigen, allergenblockierenden Antikörper gegen Katzen‑ und Birkenallergien. Die Studien zeigten im Vergleich zu Placebo eine deutliche Symptomreduktion.
Im Katzenallergie‑Studie führte eine Einzeldosis REGN1908/REGN1909 zu einer Verringerung des Juckreizes um 52%, der konjunktivalen Rötung um 39% und der Haut‑Prick‑Reaktivität um 44%. Bei der Birkenallergie erzielte REGN5713/REGN5715 vergleichbare Ergebnisse: 51% weniger Juckreiz, 46% weniger konjunktivale Rötung und 44% weniger Prick‑Reaktivität.
Beide Behandlungen zeigten einen schnellen Wirkungseintritt innerhalb von 8 Tagen und eine Wirkdauer von über 3 Monaten. Das Unternehmen plant weitere Phase‑3‑Studien: Die Katzenallergie‑Studien sollen in H1 2026 beginnen, die Studien zur Birke bis Jahresende.
- Both cat and birch allergy treatments achieved all primary and secondary endpoints with high statistical significance
- Single-dose treatment showed rapid efficacy within 8 days and lasted over 3 months
- Cat allergy antibody reduced symptoms by up to 64% in target patient population
- Both treatments demonstrated strong safety profiles with no serious adverse events
- Addresses large market opportunities: 20M+ cat allergy and 10M+ birch allergy patients in U.S.
- Additional Phase 3 trials still required before potential regulatory approval
- Treatments not yet evaluated by regulatory authorities
- Limited trial sizes: only 64 participants for cat allergy and 54 for birch allergy studies
Insights
Regeneron's allergen-blocking antibodies show remarkable efficacy in Phase 3 trials, potentially transforming allergy treatment with single-dose administration.
Regeneron's announcement represents a significant breakthrough in allergy treatment. The company's first-in-class allergen-blocking antibodies demonstrated impressive efficacy in Phase 3 trials for both cat and birch allergies, meeting all primary and secondary endpoints with high statistical significance.
The cat allergy treatment (REGN1908/REGN1909 combination) reduced ocular itch by
Similarly, the birch allergy antibody combination (REGN5713/REGN5715) reduced itch by
What's particularly groundbreaking is the single-dose administration with rapid onset (benefits observed by day 8) and durable response (lasting at least 3 months) in both programs. This represents a paradigm shift from traditional immunotherapy requiring years of frequent injections.
The market opportunity is substantial, with over 20 million Americans suffering from cat allergies and 10 million from birch allergies. With Phase 3 development planned to begin in H1 2026 for cat allergy and by year-end for birch allergy, Regeneron is poised to potentially capture significant market share in the allergy treatment space.
Beyond these programs, Regeneron's mention of promising early results in severe food allergies using a combination approach (BCMAxCD3 bispecific antibody plus Dupixent) suggests the company is building a comprehensive allergy franchise that could represent a meaningful future revenue stream.
In separate cat and birch allergen-challenge trials, single doses of allergen-specific antibody blockers significantly reduced allergy symptoms compared to placebo
Data from these trials will support further Phase 3 development
TARRYTOWN, N.Y., Sept. 08, 2025 (GLOBE NEWSWIRE) -- Regeneron Pharmaceuticals, Inc. (NASDAQ: REGN) today announced results evaluating its first-in-class investigational allergen-blocking antibodies in allergen-challenge Phase 3 trials in adults with moderate-to-severe cat or birch allergies. Both trials met their respective primary and key secondary endpoints. Data from the Phase 3 trials will be presented at an upcoming medical conference and will inform confirmatory Phase 3 trials.
“Millions suffer from the debilitating effects of allergies, which can cause severe symptoms in the eyes, nose, skin and even trigger asthma. To try to alleviate this suffering, millions undergo allergy desensitization shots, often several times a week for several years, and often with disappointing results. The purpose of these burdensome allergy shots is to try to build up allergen-blocking antibodies in the body. We wondered whether we could instead manufacture and directly provide allergen-blocking antibodies,” said George D. Yancopoulos, M.D., Ph.D., Board co-Chair, President and Chief Scientific Officer at Regeneron, and a co-inventor of this new approach to allergy. “These recent Phase 3 allergen challenge trials, together with our earlier Phase 2 trials, provide compelling evidence that our first-in-class approach can have the potential to provide profound allergy relief – rapidly and durably after a single treatment – decreasing ocular, nasal and even asthma measures. We see significant relief at the earliest assessment timepoint, and lasting for over three months, in both our cat and birch allergy programs.”
In these “ocular allergen challenge” Phase 3 trials, patients received direct ocular instillation of the allergen (either cat dander or birch pollen) at day 8 following a single subcutaneous administration of the allergen-blocking antibodies. Trial endpoints assessed signs and symptoms of ocular allergy measured after instillation of allergen in the eye.a Earlier Regeneron trials evaluated “nasal allergen challenges” and “environmental exposure unit (EEU) allergen challenges.”
Allergen-blocking antibody treatment in Cat-allergen “Ocular Challenge” Trial:
Cat allergy is one of the most common indoor allergens, affecting more than 20 million patients in the U.S. alone, often resulting in severe ocular, nasal and respiratory symptoms despite standard of care therapies (ranging from topical and systemic antihistamines to allergy-desensitization shots; about a million patients in the U.S. initiate cat allergy desensitization shots each year). REGN1908 and REGN1909 are two fully human monoclonal antibodies (mAbs) targeting and blocking FelD1 – the most dominant cat allergen – which “doggedly” clings to clothes, shoes and furniture, making it challenging to avoid even in cat-free indoor environments.
In the Phase 3 trial, cat-allergic participants were randomized to receive a single dose of the FelD1-blocking antibody combination therapy (REGN1908 and REGN1909, n=33) or placebo (n=31).
- The primary endpoint of ocular itch and both key secondary endpoints of conjunctival redness and skin prick testing – assessed one week after the single treatment with FelD1-blocking antibodies – were met with high degree of statistical significance in the overall population. Itch was reduced by
52% (p<0.0001), conjunctival redness by39% (p<0.0001) and skin prick reactivity by44% (p<0.0001). - In a post-hoc exploratory analysis of patients whose cat allergy was more specifically driven by FelD1 (the majority of the population, and the target patients for the confirmatory trial), reductions in ocular itch and conjunctival redness were greater compared to the overall population (ocular itch reduction of
64% and conjunctival redness reduction of49% ). - The combination therapy was generally well-tolerated, with no serious treatment-related adverse events or adverse events leading to trial discontinuation reported; the trial is ongoing for further safety follow-up. Additional Phase 3 development is planned to begin in the first half of 2026.
- The results in this "ocular challenge" trial are similar to earlier trials using “nasal allergen challenge” and “EEU allergen challenge,” which evaluated nasal and respiratory symptoms including asthma induction in those trials. In those earlier trials, statistically and clinically meaningful improvement was also seen at the earliest assessment done at 8 days following administration of REGN1908 and REGN1909, with durable benefit maintained for at least 3 months.
Allergen-blocking antibody treatment in Birch-allergen “Ocular Challenge” Trial:
Birch pollen is one of the most common seasonal allergens in the U.S., affecting more than 10 million people. About
In the Phase 3 trial, participants were randomized to receive a single dose of the BetV1-blocking antibody combination (REGN5713 and REGN5715, n=27) or placebo (n=27).
- The primary endpoint of ocular itch and both key secondary endpoints of conjunctival redness and skin prick testing – assessed one week after the single treatment with BetV1-blocking antibodies – were met with high degree of statistical significance. Itch was reduced by
51% (p<0.0001), conjunctival redness by46% (p<0.0001), and skin prick reactivity by44% (p<0.0001). - The combination therapy was generally well-tolerated, with no serious adverse events or adverse events leading to trial discontinuation. Additional Phase 3 development is planned to begin by the end of the year.
- Prior “nasal allergen challenge” and “EEU allergen challenge”b trials of REGN5713 and REGN5715 in patients with birch-induced allergic rhinitis revealed similarly rapid and profound benefit at the first assessment timepoint, with durable reduction of allergic rhinitis and conjunctivitis symptoms up to 3 months following a single subcutaneous administration of the allergen-blocking antibodies.
The cat and birch allergy programs are part of a broader allergy pipeline, which also includes an ongoing proof-of-concept trial in adults with severe food allergy. This latter trial involves ablating the cells making the IgE antibodies that initiate the allergen response (with a short-course treatment with Regeneron’s BCMAxCD3 bispecific antibody), followed by ongoing treatment with Dupixent to prevent the return of these cells. Initial results from the food allergy trial have been encouraging, showing the promise of this novel approach, and is expected to complete enrollment by the end of the year.
The safety and efficacy of these investigational medicines have not been fully evaluated by any regulatory authority.
About Regeneron’s VelocImmune Technology
Regeneron's VelocImmune technology utilizes a proprietary genetically-engineered mouse platform endowed with a genetically-humanized immune system to produce optimized fully human antibodies. When Regeneron's co-Founder, President and Chief Scientific Officer George D. Yancopoulos was a graduate student with his mentor Frederick W. Alt in 1985, they were the first to envision making such a genetically-humanized mouse, and Regeneron has spent decades inventing and developing VelocImmune and related VelociSuite® technologies. Dr. Yancopoulos and his team have used VelocImmune technology to create a substantial proportion of all original, FDA-approved fully human monoclonal antibodies. This includes Dupixent® (dupilumab), Libtayo® (cemiplimab-rwlc), Praluent® (alirocumab), Kevzara® (sarilumab), Evkeeza® (evinacumab-dgnb), Inmazeb® (atoltivimab, maftivimab and odesivimab-ebgn) and Veopoz® (pozelimab-bbfg). In addition, REGEN-COV® (casirivimab and imdevimab) had been authorized by the FDA during the COVID-19 pandemic until 2024. The REGN1908 and REGN1909 cat allergen-blocking antibodies, as well as the REGN5713 and REGN5715 birch allergen-blocking antibodies, were also created using Regeneron's VelocImmune technology.
About Regeneron
Regeneron (NASDAQ: REGN) is a leading biotechnology company that invents, develops and commercializes life-transforming medicines for people with serious diseases. Founded and led by physician-scientists, our unique ability to repeatedly and consistently translate science into medicine has led to numerous approved treatments and product candidates in development, most of which were homegrown in our laboratories. Our medicines and pipeline are designed to help patients with eye diseases, allergic and inflammatory diseases, cancer, cardiovascular and metabolic diseases, neurological diseases, hematologic conditions, infectious diseases, and rare diseases.
Regeneron pushes the boundaries of scientific discovery and accelerates drug development using our proprietary technologies, such as VelociSuite, which produces optimized fully human antibodies and new classes of bispecific antibodies. We are shaping the next frontier of medicine with data-powered insights from the Regeneron Genetics Center® and pioneering genetic medicine platforms, enabling us to identify innovative targets and complementary approaches to potentially treat or cure diseases.
For more information, please visit www.Regeneron.com or follow Regeneron on LinkedIn, Instagram, Facebook or X.
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This press release includes forward-looking statements that involve risks and uncertainties relating to future events and the future performance of Regeneron Pharmaceuticals, Inc. (“Regeneron” or the “Company”), and actual events or results may differ materially from these forward-looking statements. Words such as “anticipate,” “expect,” “intend,” “plan,” “believe,” “seek,” “estimate,” variations of such words, and similar expressions are intended to identify such forward-looking statements, although not all forward-looking statements contain these identifying words. 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a The conjunctival allergen challenge was conducted with the Ora Conjunctival Challenge Model (Ora-CAC®.) Ocular itch was assessed on a 0-4 point Ora® Calibra Conjunctival Allergen Challenge Ocular Itching Scale. Conjunctival redness was assessed on a 0-4 point Ora® Calibra Ocular Hyperemia Scale.
b E. A. Couroux P. Abstract of “A single dose of a combination of Bet v 1 antibodies provides durable efficacy in reducing allergic rhinitis symptoms for up to 3 months in patients with moderate-severe birch pollen allergy.” EAACI Congress. May 2024.
FAQ
What were the key results of Regeneron's Phase 3 trials for cat and birch allergies?
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When will Regeneron's REGN cat and birch allergy treatments be available?
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