Seasonal asthma exacerbation prevention with depemokimab

ISRCTN ISRCTN11308300
DOI https://doi.org/10.1186/ISRCTN11308300
IRAS number 1012131
Secondary identifying numbers 3645 ASCEND
Submission date
15/05/2025
Registration date
15/07/2025
Last edited
15/07/2025
Recruitment status
Not yet recruiting
Overall study status
Ongoing
Condition category
Respiratory
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data
Record updated in last year

Plain English summary of protocol

Background and study aims
People with asthma can take medication to control their symptoms. Despite this, asthma attacks (exacerbations) can still happen, particularly in the autumn and winter months. People may need to visit emergency departments for treatment, and sometimes stay in hospital. During autumn and winter, hospitals in the UK are under high pressure to provide care for seasonal illnesses (also referred to as winter pressures) and research is needed to reduce this.
The aim of this study is to see if a new medicine called depemokimab can prevent asthma attacks over the autumn/winter period, when taken alongside current asthma medication. Depemokimab is a monoclonal antibody (also known as a biologic) and one dose can be given to treat people for up to six months. It is an unlicensed drug, which means trials are being conducted to collect the information needed to become a licensed medicine in the UK. All the studies conducted so far have shown that it is safe to be given at this dose. To see if the medicine works in this group of patients, it will be compared with a placebo (dummy medicine).

Who can participate?
Adults (aged 18 years and above) who have suffered from seasonal asthma exacerbations will be invited to take part in the study around September 2025.

What does the study involve?
Participants will be checked to make sure it is safe & suitable for them to take part. This involves tests/assessments at a hospital. A computer program is then used to decide which group they will enter. Half of the participants will receive one dose of the drug; the other half will be given one dose of a placebo. The drug/placebo will be injected under the skin. The study is blinded, which means neither the participants or the study team will know which group they are in.
They will attend follow-up visits over eight months (some at hospital, others via telephone) to check how they are feeling and if they have experienced any asthma attacks. The study will recruit 170 participants from eight hospitals across England and Scotland.

What are the possible benefits and risks of participating?
It is possible that depemokimab will reduce the asthma attacks experienced by participants during the autumn and winter time. However, we cannot say this for certain until we have completed this study and future research. Participants receiving the placebo injection will not be given a medicine that could potentially help with asthma attacks. Participants may not directly benefit from taking part in this study, but the information gained will help to improve the treatment of patients with this condition in the future.

Where is the study run from?
Guy’s Hospital (UK)

When is the study starting and how long is it expected to run for?
May 2025 to June 2026

Who is funding the study?
GlaxoSmithKline (UK)

Who is the main contact?
Prof. David Jackson, david.jackson@nhs.net

Contact information

Prof David Jackson
Principal Investigator

School of Immunology & Microbial Sciences
5th Floor, Guy’s Hospital
London
SE1 9RT
United Kingdom

Phone +44 (0)7737152154
Email david.jackson@nhs.net

Study information

Study designRandomized placebo-controlled double-blind study
Primary study designInterventional
Secondary study designRandomised controlled trial
Study setting(s)Hospital
Study typeSafety, Efficacy
Scientific titleSeASonal asthma exaCErbation preveNtion with Depemokimab (ASCEND)
Study acronymASCEND
Study objectivesPrimary objective:
To evaluate the efficacy of a single dose of depemokimab compared to placebo on preventing seasonal (autumn/winter) asthma exacerbations in participants with moderate-to-severe asthma.

Secondary objectives:
1. To evaluate the efficacy of depemokimab on patient-reported asthma control.
2. To evaluate the efficacy of depemokimab on preventing seasonal asthma exacerbations resulting in visits to the emergency department and/or hospitalisations.
3. To evaluate the effect of depemokimab on clinic visit post-bronchodilator FEV1.
4. To evaluate the efficacy of depemokimab on patient-reported quality of life.
5. To evaluate the efficacy of depemokimab on preventing asthma exacerbations in participants with blood eosinophil count ≥300 cells/µL at randomisation.
6. To evaluate the efficacy of depemokimab on preventing asthma exacerbations in participants with FeNO ≥50 ppb at randomisation.
Ethics approval(s)Pending approval; ref: 25/EM/0126
Health condition(s) or problem(s) studiedModerate-to-severe asthma
InterventionParticipants will be randomized at baseline in a 1:1 ratio, in addition to standard of care therapy, to receive:
1. Depemokimab 100 mg dose administered as a single subcutaneous injection
2. Matching placebo administered as a single subcutaneous injection

All participants will be followed up at weeks 4, 10, 18, 26 and 35 post-dosing.

Randomisation will take place using the online MedSciNet system upon confirmation of eligibility. All site team members – PI, research fellows, research nurses and pharmacy teams – will be blinded to allocation.
Intervention typeDrug
Pharmaceutical study type(s)Prophylaxis
PhasePhase III
Drug / device / biological / vaccine name(s)Depemokimab
Primary outcome measureAsthma exacerbations – annualised rate (AER) – measured at week 26
Secondary outcome measures1. Patient reported asthma control measured using Asthma Control Questionnaire (ACQ-5) at week 26
2. Asthma-related emergency department visits and/or hospitalisations measured at week 26
3. Forced expiratory volume (FEV1) (severity and reversibility of airflow obstruction) – post bronchodilator – measured at week 26
4. Patient-reported quality of life related to asthma measured using the Asthma Quality OF Life Questionnaire (AQLQ (S)=12) at week 26
5. Asthma exacerbations in participants with blood eosinophil count ≥300 cells/µL at randomisation – annualised rate (AER) – measured at week 26
6. Asthma exacerbations in participants with FeNO ≥50 ppb at randomisation – annualised rate (AER) – measured at week 26
Overall study start date13/05/2025
Completion date30/06/2026

Eligibility

Participant type(s)Patient
Age groupAdult
Lower age limit18 Years
SexBoth
Target number of participants170
Key inclusion criteria1. Ability to provide written informed consent
2. Adults (≥18 years at the time of randomisation)
3. Physician-diagnosed asthma with duration of ≥12 months (based on the BTS/NICE 2024 Guidelines) at the time of randomisation)
4. Treatment with medium or high-dose ICS/LABA therapy (MART is permitted)
5. Documented history of ≥1 asthma exacerbation requiring the use of systemic corticosteroids (oral or parenteral) during each of the previous 2 autumn/winter seasons (i.e. autumn/winter 2023-24 and 2024-25) or 1 asthma-related hospitalisation in the previous autumn/winter (2024-25). The autumn and winter seasons extend from 15th September to 15th March.
6. The most recent exacerbation must have been whilst the patient was prescribed medium or high dose ICS/LABA
7. Post-bronchodilator FEV1 ≥60% predicted at randomisation
Key exclusion criteria1. Known history of systemic hypersensitivity or anaphylaxis to any biologic therapy
2. Regular use of immunosuppressive medication (including but not limited to maintenance daily prednisolone, hydrocortisone, azathioprine, or weekly methotrexate)
3. Receipt of any licensed biologic drug (eg, omalizumab, mepolizumab, benralizumab, reslizumab, dupilumab, tezepelumab, or other monoclonal antibody) or any investigational biologic for asthma within 24 months prior to randomization
4. Scheduled elective surgery or other procedures requiring general anaesthesia during the trial
5. Any unstable or significant other medical condition which, in the opinion of the Investigator, may either put the participant at risk because of participation in the trial, or may influence the result of the trial, or the participant's ability to participate in the trial
Date of first enrolment22/08/2025
Date of final enrolment10/10/2025

Locations

Countries of recruitment

  • United Kingdom

Study participating centre

Not provided at time of registration
-
United Kingdom

Sponsor information

King's College London
University/education

KHP CTO, Floor 16
Tower Wing
Guy's Hospital
Great Maze Pond
London
SE1 9RT
England
United Kingdom

Phone +44 (0)207 1885732
Email Qm.khpcto@kcl.ac.uk
Website https://www.kcl.ac.uk/index
ROR logo "ROR" https://ror.org/0220mzb33
Guy's and St Thomas' NHS Foundation Trust
Hospital/treatment centre

Guy’s Hospital
Great Maze Pond
London
SE1 9RT
England
United Kingdom

Phone +44 (0)207 1885732
Email Qm.khpcto@kcl.ac.uk
Website https://www.guysandstthomas.nhs.uk/
ROR logo "ROR" https://ror.org/00j161312

Funders

Funder type

Industry

GlaxoSmithKline
Government organisation / For-profit companies (industry)
Alternative name(s)
GlaxoSmithKline plc., GSK plc., GSK
Location
United Kingdom

Results and Publications

Intention to publish date30/06/2027
Individual participant data (IPD) Intention to shareNo
IPD sharing plan summaryData sharing statement to be made available at a later date
Publication and dissemination plan1. Peer-reviewed scientific journals
2. Internal report
3. Conference presentation
4. Publication on website
5. Submission to regulatory authorities
5. Anonymised data may be shared with external collaborators, subject to any commercial IP sensitivities with the IMP.

Anonymised study results will be disseminated through the publication of journal articles, presentation at relevant conferences, and submission of the Final Study Report to the relevant regulatory bodies.
IPD sharing planThe data-sharing plans for the current study are unknown and will be made available at a later date

Editorial Notes

15/05/2025: Study's existence confirmed by Health Research Authority (HRA) (UK)