A Phase 3 interventional study of REGN-2Cat and Freneslerbart in Allergic Conjunctivitis, sponsored by Regeneron Pharmaceuticals. Recruiting at 2 sites in United States. Open to participants aged 8 Years and older. Per ClinicalTrials.gov, last updated 2026-11-05.
Sponsored by Regeneron Pharmaceuticals · Phase 3, Interventional, and Treatment
This study is researching two experimental medicines, freneslerbart and mevonlerbart. Freneslerbart and mevonlerbart can be given alone or together. When given together, the medicine is called "REGN-2Cat". These medicines are also known as the "study drugs".
The aim of the study is to see what side effects freneslerbart, mevonlerbart, and REGN-2Cat may have and if they help reduce eye allergy symptoms caused by cat hair/dander compared with a placebo.
The study is looking at several other research questions, including:
210 studies on the registry are indexed under Conjunctivitis, Allergic; 18 are open to participants now.
This study's planned enrollment of 570 is above the median of 87 across 174 interventional studies indexed under Conjunctivitis, Allergic.
Browse Conjunctivitis, Allergic studies →Regeneron Pharmaceuticals is the lead sponsor of 411 studies on the registry; 90 are open to participants now.
Of its 125 completed or terminated interventional studies of FDA-regulated products, 79 (63%) have results posted.
Counted across the registry records on this site, refreshed daily.
Key Inclusion Criteria:
Key Exclusion Criteria:
Note: Other Protocol Defined Inclusion/ Exclusion Criteria Apply
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Part A and B
Drug: REGN-2Cat
Part A and B
Drug: Freneslerbart
Part A
Drug: Mevonlerbart
Part A and B
Drug: Placebo
Administered per the protocol
Also known as: REGN1908-REGN1909
Administered per the protocol
Also known as: REGN1908
Administered per the protocol
Also known as: REGN1909
Administered per the protocol
Ocular itch score in participants receiving REGN-2Cat as compared to placebo
Time frame: At day 8, post-Conjunctival Allergen Challenge (CAC)
1. Ocular itch score in participants receiving REGN-2Cat as compared to placebo
Time frame: Up to day 85, post-CAC
2. Conjunctival redness score in participants receiving REGN-2Cat as compared to placebo
Time frame: Up to day 85, post-CAC
3. Achievement of at least a 1-point reduction from baseline in ocular itch score for at least 2 out of 3 post-CAC time points in participants receiving REGN-2Cat as compared to placebo
Time frame: Up to day 85, post-CAC
4. Achievement of at least a 1-point reduction from baseline in conjunctival redness score for at least 2 out of 3 post-CAC time points in participants receiving REGN-2Cat as compared to placebo
Time frame: Up to day 85, post-CAC
5. Percent change from baseline in cat titrated Skin Prick Test (tSPT) in participants receiving REGN-2Cat as compared to placebo
Time frame: Up to day 85
6. Ocular itch score in participants receiving freneslerbart as compared to placebo
Time frame: Up to day 85, post-CAC
7. Conjunctival redness score in participants receiving freneslerbart as compared to placebo
Time frame: Up to day 85, post-CAC
8. Achievement of at least a 1-point reduction from baseline in ocular itch score for at least 2 out of 3 post-CAC time points in participants receiving freneslerbart as compared to placebo
Time frame: Up to day 85, post-CAC
9. Achievement of at least a 1-point reduction from baseline in conjunctival redness score for at least 2 out of 3 post-CAC time points in participants receiving freneslerbart as compared to placebo
Time frame: Up to day 85, post-CAC
10. Percent change from baseline in cat tSPT in participants receiving freneslerbart as compared to placebo
Time frame: Up to day 85
11. Ocular itch score in participants receiving mevonlerbart as compared to placebo
Part A
Time frame: At day 8, post-CAC
12. Conjunctival redness score in participants receiving mevonlerbart as compared to placebo
Part A
Time frame: At day 8, post-CAC
13. Achievement of at least a 1-point reduction from baseline in ocular itch score for at least 2 out of 3 post-CAC time points in participants receiving mevonlerbart as compared to placebo
Part A
Time frame: At day 8, post-CAC
14. Achievement of at least a 1-point reduction from baseline in conjunctival redness score for at least 2 out of 3 post-CAC time points in participants receiving mevonlerbart as compared to placebo
Part A
Time frame: At day 8, post-CAC
15. Ocular itch score in participants receiving REGN-2Cat as compared to mevonlerbart
Part A
Time frame: At day 8, post-CAC
16. Ocular itch score in participants receiving REGN-2Cat as compared to freneslerbart
Time frame: At day 8, post-CAC
17. Achievements of different degrees of clinical response, as measured by change from baseline in ocular itch score among participants receiving REGN-2Cat, freneslerbart, mevonlerbart or placebo
Time frame: At day 8, post-CAC
18. Percent change from baseline in cat tSPT in participants receiving REGN-2Cat as compared to freneslerbart
Time frame: At day 8
19. Percent change from baseline in cat tSPT in participants receiving REGN-2Cat as compared to mevonlerbart
Part A
Time frame: At day 8
20. Ciliary redness score in participants receiving REGN-2Cat as compared to placebo
Time frame: Up to day 85, post-CAC
21. Episcleral redness score in participants receiving REGN-2Cat as compared to placebo
Time frame: Up to day 85, post-CAC
22. Total redness score in participants receiving REGN-2Cat as compared to placebo
Time frame: Up to day 85, post-CAC
23. Ciliary redness score in participants receiving freneslerbart as compared to placebo
Time frame: Up to day 85, post-CAC
24. Episcleral redness score in participants receiving freneslerbart as compared to placebo
Time frame: Up to day 85, post-CAC
25. Total redness score in participants receiving freneslerbart as compared to placebo
Time frame: Up to day 85, post-CAC
26. Percent change from baseline in cat tSPT in participants receiving mevonlerbart as compared to placebo
Part A
Time frame: Up to day 85
27. Occurrence of Treatment Emergent Adverse Events (TEAEs)
Time frame: Up to day 113
28. Severity of TEAEs
Time frame: Up to day 113
29. Occurrence of Treatment Emergent-Serious Adverse Events (TE-SAEs)
Time frame: Up to day 113
30. Concentrations of total freneslerbart in serum
Time frame: Up to day 113
31. Concentrations of total mevonlerbart in serum
Time frame: Up to day 113
32. Occurrence of Anti-Drug Antibodies (ADA) to freneslerbart
Time frame: Up to day 113
33. Magnitude of ADA to freneslerbart
Time frame: Up to day 113
34. Occurrence of ADA to mevonlerbart
Time frame: Up to day 113
35. Magnitude of ADA to mevonlerbart
Time frame: Up to day 113
Plan to share: Yes — All Individual Patient Data (IPD) that underlie publicly available results will be considered for sharing.
Supporting information: Study protocol, Statistical analysis plan, Informed consent form, Clinical study report, Analytic code
Time frame: When Regeneron has: received marketing authorization from major health authorities (e.g., FDA, European Medicines Agency (EMA), Pharmaceuticals and Medical Devices Agency (PMDA), etc.) for the product and indication or has globally discontinued development of the product for all indications on or after April 2020 and has no plans for future development made the study results publicly available (e.g., scientific publication, scientific conference, clinical trial registry) the legal authority to share the data, and ensured the ability to protect participant privacy
Access criteria: Qualified researchers can submit a proposal for access to individual patient or aggregate level data from a Regeneron-sponsored clinical trial through Vivli. Regeneron's Independent Research Request Evaluation Criteria can be found at: https://www.regeneron.com/sites/default/files/Regeneron-External-Data-Sharing-Policy-and-Independent-Research-Request-Evaluation-Criteria.pdf
Data sharing details ↗ · vivli.org
No publications or documents are linked to this record.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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