A Study to Investigate the Efficacy and Safety of GSK5784283 Compared With Placebo in Participants With Uncontrolled Asthma (PERSIST ASTHMA-1)

A Phase 3, Multicenter, Randomized, Double-Blind, Placebo-Controlled, Parallel-Group Study to Evaluate the Efficacy and Safety of GSK5784283 (Felcorekibart) as an Add-On Therapy in Adults and Adolescents With Uncontrolled Asthma (PERSIST ASTHMA-1)

The study aims to demonstrate the superiority of GSK5784283 compared to placebo in reducing the annualized rate of clinically meaningful asthma exacerbations.

Study Overview

• Status: Not yet recruiting
• Conditions: Asthma
• Intervention / Treatment: Drug: Placebo; Drug: GSK5784283; Drug: Standard of care

• Study Type: Interventional
• Enrollment (Estimated): 514
• Phase: Phase 3

Contacts and Locations

• Study Contact: Name: US GSK Clinical Trials Call Center; Phone Number: 877-379-3718; Email: GSKClinicalSupportHD@gsk.com
• Study Contact Backup: Name: EU GSK Clinical Trials Call Center; Phone Number: +44 (0) 20 89904466; Email: GSKClinicalSupportHD@gsk.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Participants capable of giving signed informed consent, which includes compliance with the requirements and restrictions listed in Informed consent form (ICF). For participants aged 12 to 17 years, signed assent must be obtained from the participant in addition to signed consent from their Legally acceptable representative (LAR).
• Participants aged 12 to 80 years at the time of signing the informed consent.

• Male or eligible female participants:

  • Female participants:

    • A female participant is eligible to participate if she is not pregnant, not breastfeeding, and at least 1 of the following conditions applies:

      i. Is a Participant of non-childbearing potential (PONCBP) or ii. Is a Participant of childbearing potential (POCBP) and using a contraceptive method that is highly effective, with a failure rate of less than (<) 1 percent (%), 28 days prior to the first dose of the study drug, and during the study intervention period and follow-up period for at least 60 weeks after the last dose of study intervention. The investigator should evaluate potential for contraceptive method failure (e.g., non-compliance, recently initiated) in relationship to the first dose of study intervention.

• A POCBP must have a negative serum pregnancy test at screening and a highly sensitive pregnancy test (urine or serum, as required by local regulations) within 24 hours before each dose of study intervention.
• If a urine test cannot be confirmed as negative (e.g., an ambiguous result), a serum pregnancy test is required. In such cases, the participant must be excluded from participation if the serum pregnancy result is positive.
• The investigator is responsible for review of medical history, menstrual history, and recent sexual activity to decrease the risk for inclusion of a woman with an early undetected pregnancy.
• Contraceptive use by women should be consistent with local regulations regarding the methods of highly effective contraception for those participating in clinical trials.
• A documented physician diagnosis of asthma for at least 12 months prior to Visit 1, according to the Global Initiative for Asthma (GINA) 2026 guidelines.
• Evidence of variable airflow obstruction consistent with asthma.
• Documented history of asthma exacerbation within 12 months prior to Visit 1.
• A well-documented requirement for regular treatment with medium or high dose Inhaled corticosteroid (ICS) for at least 3 months prior to screening with or without maintenance oral corticosteroids (OCS).
• At least 1 additional maintenance asthma controller medication is required according to standard practice of care (e.g., Long-acting beta-2 agonist [LABA], Leukotriene receptor antagonists [LTRA], theophylline, Long-acting muscarinic agonists [LAMA], chromones, etc.). Use of additional asthma controller medications must be documented for at least 3 months prior to screening.
• Uncontrolled asthma based on ACQ-5 score.

Exclusion Criteria:

• Any concomitant respiratory disease that in the opinion of the investigator and/or medical monitor will interfere with the evaluation of the investigational product or interpretation of participant safety or study results.
• History of malignant neoplasm within the last 5 years (except definitively treated non-melanoma skin cancer or carcinoma in situ of the uterine cervix).
• Myocardial infarction, unstable angina or stroke within 6 months of screening, unstable arrhythmia.
• New York Heart Association (NYHA) class III or IV heart failure.
• Other significant medical conditions that could impact participants' safety or study outcomes.
• History of an unresolved clinically significant infection within 30 days prior to Visit 1.
• A known immunodeficiency, other than that explained by the use of corticosteroids taken as therapy for asthma.
• Receipt of any marketed or investigational biologic agent or investigational non-biologic agent, prior to Visit 1.
• Use of systemic immunosuppressive medication within 3 months prior to Visit 1 (other than systemic corticosteroid burst or stable maintenance OCS for treatment of asthma).
• Current smokers (tobacco and/or marijuana), current users of vaping products/electronic-cigarettes or participants with a smoking history >=10 pack-years.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Participants receiving GSK5784283 plus standard of care	Drug: GSK5784283; GSK5784283 will be administered.; Drug: Standard of care; Standard of care will be administered.
Placebo Comparator: Participants receiving matching placebo plus standard of care	Drug: Placebo; Placebo will be administered.; Drug: Standard of care; Standard of care will be administered.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Annualized rate of clinically significant asthma exacerbations	A clinically significant exacerbation is defined as a worsening of asthma symptoms requiring the use of systemic corticosteroids or in-patient hospitalization (that is greater than or equal to [>=] 24 hours) due to asthma.	Up to Week 52

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change from Baseline in pre-Bronchodilator Forced expiratory volume in 1 second (FEV1)	FEV1 is defined as the volume of air that can be forced out in first second after taking a deep breath by a person and will be measured by spirometry.	Baseline and at Week 52
Time to first clinically significant asthma exacerbation		Up to Week 52
Change from Baseline in Asthma Control Questionnaire-5 (ACQ-5) score	The ACQ-5 is a five-item questionnaire . designed to be self-completed by the . participants to assess the most common asthma symptoms. The scores range from 0 to 6. Higher scores indicated more impairment/limitations.	Baseline and at Week 52
Change from Baseline in Asthma Quality of Life Questionnaire (AQLQ) score	The AQLQ is a 32-item self-administered questionnaire designed to measure the impact of asthma on participants daily life. The score ranges from 1.0 to 7.0. Higher scores indicate better quality of life (QoL).	Baseline and at Week 52
Annualized rate of clinically significant exacerbations requiring emergency department (EmD) visit or hospitalization	Annualized rate of exacerbations requiring EmD visit or hospitalization (For pooled analysis across studies 300742 and 300743) will be assessed.	Up to Week 52

Collaborators and Investigators

• Sponsor: GlaxoSmithKline
• Investigators: Study Director: GSK Clinical Trials, GlaxoSmithKline

Study record dates

Study Major Dates

• Study Start (Estimated): August 31, 2026
• Primary Completion (Estimated): February 15, 2029
• Study Completion (Estimated): October 11, 2029

Study Registration Dates

• First Submitted: August 19, 2026
• First Submitted That Met QC Criteria: August 19, 2026
• First Posted (Actual): August 21, 2026

Study Record Updates

• Last Update Posted (Actual): August 21, 2026
• Last Update Submitted That Met QC Criteria: August 19, 2026
• Last Verified: August 1, 2026

More Information

Terms related to this study

• Keywords: Asthma; Placebo; Standard of care; GSK5784283; Felcorekibart
• Additional Relevant MeSH Terms: Immune System Diseases; Respiratory Tract Diseases; Lung Diseases; Bronchial Diseases; Lung Diseases, Obstructive; Respiratory Hypersensitivity; Hypersensitivity, Immediate; Hypersensitivity; Asthma; Health Services Administration; Health Care Quality, Access, and Evaluation; Quality of Health Care; Quality Indicators, Health Care; Standard of Care
• Other Study ID Numbers: 300742; 2026-526964-19 (Registry Identifier: EU CT Number)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Study Sponsor will assess requests from qualified researchers for anonymized individual patient-level data and related study documents. Data sharing is subject to certain criteria, conditions, and exceptions. For further information, refer to https://www.gsk-studyregister.com/gsk-patient-level-data-sharing-july2025.pdf
• IPD Sharing Time Frame: Anonymized IPD will be made available within 6 months of publication of primary, key secondary and safety results for studies in product with approved indication(s) or terminated asset(s) across all indications.
• IPD Sharing Access Criteria: Anonymized IPD is shared with researchers whose proposals are approved by an Independent Review Panel and after a Data Sharing Agreement is in place. Access is provided for an initial period of 12 months but an extension may be granted, when justified, for up to 6 months.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF; CSR

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No