Comparison of Immune Profiles in Chronic Rhinosinusitis Patients After Mepolizumab Treatment

Comparison of Immune Profiles in Chronic Rhinosinusitis Patients After Mepolizumab Treatment (NCT05642806) is a Phase 4 interventional studying Chronic Rhinosinusitis With Nasal Polyps and Asthma, sponsored by St. Paul's Sinus Centre. RECRUITING as of the most recent ClinicalTrials.gov update. Talk to your doctor before contacting the trial site.

About This Trial

What Stage of Research Is This?

Phase 4 studies happen after a treatment has been approved by the FDA. They monitor long-term safety, real-world effectiveness, and any rare side effects that only emerge in larger populations over longer periods. Phase 4 results sometimes lead to label changes, additional warnings, or — rarely — withdrawal of approval.

This trial is currently recruiting participants. The sponsor has registered the study with ClinicalTrials.gov as actively enrolling, which means new applicants who meet the eligibility criteria can be considered for screening. Trial status can change between updates — confirm current recruiting status with the study contact before traveling for a screening visit.

Target enrollment of 90 participants puts this in the typical range for a Phase 2-style efficacy study or a moderate Phase 3 trial in a focused Chronic Rhinosinusitis With Nasal Polyps subpopulation. At this scale, the study has enough statistical power to detect a clear treatment effect but is not the largest cohort in the field.

Who May Be Eligible (Plain English)

Who May Qualify: 1. Are over the age of 19. 2. Patients with CRSwNP with or without asthma: - Asthma confirmed with a spirometry and assessment on previous history of asthma (a methacholine challenge test and atopy testing to document positive or negative history of asthma will be performed if there is no clinical record). - Presence or absence of nasal polyps. This can be based on formal exam at Baseline Visit or historical assessment. 3. Patients with CRSsNP with asthma: - These patients will not take the study treatment and they will only complete screening and baseline visits. 4. Females of childbearing potential must commit to using an acceptable method of birth control for the duration of the study and they must have a negative urine pregnancy test at each study visit. Who Should NOT Join This Trial: 1. Current or past sinonasal or bronchial tumours 2. Subjects who have been treated with oral antibiotics in the past month prior to surgery. 3. Subjects with known weakened immune system 4. Subjects with known autoimmune conditions (where your immune system attacks your own body) 5. Smoking history; current or former smokers. 6. Prior lung transplants 7. Subjects with parasitic (helmintic) infection 8. Subjects with hypersensitivity; with allergy/intolerance to a monoclonal antibody or biologic 9. Female participants who are pregnant or breastfeeding Always talk to your doctor about whether this trial is right for you.

These are translations of the protocol\'s inclusion and exclusion criteria, simplified for patients and caregivers. The original clinical text appears below. Eligibility is ultimately confirmed by the trial site\'s screening process — this summary is a starting point for a conversation with your doctor, not a final determination.

Original Eligibility Criteria

View original clinical language

Inclusion Criteria: 1. Are over the age of 19. 2. Patients with CRSwNP with or without asthma: * Asthma confirmed with a spirometry and assessment on previous history of asthma (a methacholine challenge test and atopy testing to document positive or negative history of asthma will be performed if there is no clinical record). * Presence or absence of nasal polyps. This can be based on formal exam at Baseline Visit or historical assessment. 3. Patients with CRSsNP with asthma: * These patients will not take the study treatment and they will only complete screening and baseline visits. 4. Females of childbearing potential must commit to using an acceptable method of birth control for the duration of the study and they must have a negative urine pregnancy test at each study visit. Exclusion Criteria: 1. Current or past sinonasal or bronchial tumours 2. Subjects who have been treated with oral antibiotics in the past month prior to surgery. 3. Subjects with known immunodeficiency 4. Subjects with known autoimmune disease 5. Smoking history; current or former smokers. 6. Prior lung transplants 7. Subjects with parasitic (helmintic) infection 8. Subjects with hypersensitivity; with allergy/intolerance to a monoclonal antibody or biologic 9. Female participants who are pregnant or breastfeeding

Treatments Being Tested

BIOLOGICAL

Mepolizumab

Mepolizumab will be administered subcutaneously (SC) every 4 weeks for a total of 24 weeks

OTHER

Placebo

Placebo will be administered subcutaneously (SC) every 4 weeks for a total of 24 weeks

Locations (1)

Trial sites listed on ClinicalTrials.gov for this study. Site activation status can vary — confirm with the specific site before traveling for a screening visit.

St. Pual's Sinus Centre

Vancouver, British Columbia, Canada

How to Talk to Your Doctor About This Trial

Bring the printable summary of this trial — including the NCT ID (NCT05642806), the sponsor (St. Paul's Sinus Centre), and the key eligibility criteria — to your next appointment. Your doctor can review the inclusion and exclusion criteria against your medical history, lab values, and current treatments to assess whether you are likely to qualify. They can also help you weigh whether trial participation makes sense alongside your existing care plan.

Useful questions to walk through together: What does the trial protocol require beyond standard care? How long is the active treatment phase, and how long is follow-up? Are there study visits at sites I can reach? Who pays for the trial-specific procedures, and who pays for standard-of-care portions? See our 25 questions to ask about clinical trials guide for a more complete checklist.

Authoritative Sources

The official record for this trial lives on ClinicalTrials.gov — the federal registry maintained by the National Library of Medicine at NIH. For background on how this trial fits into the FDA approval pathway, see the FDA drug approval process. For oncology-specific guidance for patients considering trials, the National Cancer Institute publishes patient-oriented overviews. International trial registries are aggregated by the WHO ICTRP.

Frequently Asked Questions

What is the NCT05642806 clinical trial studying?

This study aims to analyze the immune profiles of patients with Chronic Rhinosinusitis with Nasal polyps (CRSwNP) with and without asthma before and after Mepolizumab. A group of participants with CRS without nasal polyps (CRSsNP) with asthma will be included to compare their immune profiles to CRSwNP. The full protocol is registered on ClinicalTrials.gov and includes the primary outcome measures, eligibility criteria, and study endpoints.

Who can participate in NCT05642806?

Eligibility for this trial depends on the specific inclusion and exclusion criteria set by the sponsor. The plain-English summary above translates the most important criteria into accessible language; the official clinical text is preserved in the collapsible section underneath. Whether you fit any specific trial is a medical decision your doctor needs to confirm — bring the trial information to your treating physician for a full review against your medical history.

How do I contact the trial site for NCT05642806?

Contact information registered with ClinicalTrials.gov is shown in the sidebar of this page. Before reaching out, confirm with your treating physician that this trial is appropriate for your situation. The trial site will then walk you through the screening process to determine final eligibility.

Is participating in a clinical trial safe?

Clinical trials in the United States are regulated by the FDA and overseen by Institutional Review Boards (IRBs) that review the protocol for safety. Risk varies by trial — Phase 1 studies test new treatments in humans for the first time, while Phase 3 trials use treatments that have already passed earlier safety screening. The informed consent document for any specific trial details the known risks and what to expect. Discuss those risks with your physician before deciding whether to participate.

Where can I verify the data on this page?

Every detail on this page comes directly from the ClinicalTrials.gov API. Click "View on ClinicalTrials.gov" in the sidebar to see the official, unmodified record. The federal record is always authoritative; this page is a structured presentation with a plain-English eligibility translation. For background on how clinical trials are regulated, see the FDA drug approval process documentation.

How This Page Is Built

Every field on this page is pulled directly from the ClinicalTrials.gov API v2 — no estimates, no proxies. The plain-English eligibility translation is generated from the original protocol text and reviewed for fidelity to the underlying clinical criteria. The original clinical text remains visible in the collapsible section above so users and clinicians can verify the translation. Read the full methodology for the data pipeline and known limitations.

Source: ClinicalTrials.gov API v2 record for NCT05642806. Maintained by the National Library of Medicine at NIH. Public domain. Cite as: "TrialFinderData. NCT05642806. Data: ClinicalTrials.gov."

Medical disclaimer: This page is informational, not medical advice. Talk to your doctor about whether a clinical trial is right for you.

Last updated 2026-05-08 · Data from ClinicalTrials.gov.