A Study to Investigate the Efficacy and Safety of Tezepelumab Compared With Placebo in Children 5 to < 12 Years Old With Severe Asthma
Asthma
What this study involves
The registry says this study is recruiting. Individual locations may have different availability.
- Study type
- Interventional
- Phase
- Phase 3
- Age range
- 5 years - 11 years
- Sex eligible
- All sexes
- Healthy volunteers
- Not accepted
- Participants
- 231 Estimated
These are starting points, not an eligibility decision. The research team must review the full requirements.
About the research
To assess the efficacy and safety of tezepelumab in pediatric participants with severe uncontrolled asthma on medium to high-dose inhaled corticosteroids (ICS) and at least one additional asthma controller medication with or without oral corticosteroids.
Read the full description
This is a phase-3 multicentre, double-blind, parallel-group placebo-controlled, randomised study.
The study will comprise of:
1. Screening/Run-in period of 4 to 6 weeks,
2. 52-week double-blind Treatment period,
3. Post-treatment Follow-up period of 12 weeks.
Participants will be randomised 2:1 to receive either tezepelumab or placebo administered by (SC) Subcutaneous injections for 52 weeks (double-blind Treatment period).
There will then be a 12-week off-treatment Follow-up period for participants who do not continue in the optional open-label Active Treatment Extension period.
An optional open-label Active Treatment Extension will allow all eligible participants the opportunity to receive active treatment with tezepelumab. The Active Treatment Extension period of the study will start following the 52-week double-blind Treatment period and will consist of a 104-week open-label Treatment period prior to the 12-week post-treatment Follow-up period.
Who may be able to participate?
The list below is the sponsor’s full registry wording. It can include conditions, prior treatment, test results and other requirements. A match in search does not mean you qualify.
Inclusion Criteria:
1. Written informed consent from (ICF) at least one parent/caregiver (as per local guidelines) and accompanying informed assent from the participant (where the participant is able to provide assent) prior to admission to the study.
2. Participants must be 5 to \< 12 years of age, at the time of signing the assent form (as applicable per local guidelines) and their caregivers signing the ICF and at Visit 3.
3. Documented physician diagnosis of severe asthma confirmed and evaluated for at least 6 months prior to Visit 1.
4. Documented physician-prescribed treatment with a total daily dose of either medium or high dose, for at least 3 months with stable dose ≥ 1 month prior to Visit 1.
5. Documented treatment with at least one additional maintenance asthma controller medication is required according to local guidelines and standard of care; (long-acting beta agonist, leukotriene receptor antagonist, long-acting muscarinic antagonist) for at least 3 months with stable dose ≥ 1 month prior to Visit 1.
6. Supportive evidence of asthma as documented by one of the following:
1. Post-BD (albuterol/salbutamol) responsiveness of FEV1 ≥ 10% during Screening (15 to 30 min after administration of 4 puffs of albuterol/salbutamol with a maximum of 12 puffs of reliever medication only if tolerated by the participant) at either Visit 1 or Visit 2.
If (a) is not achieved at Visit 1 or Visit 2, historical documentation by any of the below prior to Visit 1:
2. Post-BD responsiveness of FEV1 ≥ 10%.
3. Positive methacholine challenge defined as provocative concentration (PC20) of ≤ 16 mg/mL.
4. PEF average daily diurnal variability \> 13% over a 2-week period.
5. Variability of FEV1 ≥ 12% between any two clinical visits.
6. Positive exercise challenge test (defined as a fall in FEV1 of \> 12%).
7. FeNO ≥ 20 ppb despite confirmed ICS maintenance therapy.
7. History of at least 2 severe asthma exacerbation events OR 1 severe asthma exacerbation event resulting in hospitalisation within 12 months prior to Visit 1.
8. Pre-BD FEV1 \>50% and ≤ 95%PN OR FEV1/forced vital capacity (FVC) ratio ≤ 0.85 at either Visit 1 or Visit 2.
9. Evidence of uncontrolled asthma, with at least 1 of the below criteria:
1. ACQ-IA score ≥ 1.5 at least once during Screening/Run-in, including Visit 3 (prior to Randomisation) for participants ≥ 6 years old at Screening.
2. Use of reliever medication, other than as a preventive for exercise induced bronchospasm, on 3 or more days per week for at least 1 week during the Screening/Run-in period.
3. Sleep awakening due to asthma symptoms requiring use of reliever medication at least once during the Screening/Run-in period.
4. Asthma symptoms 3 or more days per week in at least 1 week during the Screening/Run-in period.
10. Body weight ≥ 16 kg at Visit 1 (Screening) and Visit 3 (Randomisation).
Exclusion Criteria:
1. History of vocal cord dysfunction, cystic fibrosis, primary ciliary dyskinesia, or chronic rhinosinusitis with nasal polyposis.
2. History of any clinically significant disease or disorder other than asthma which, in the opinion of the investigator, may either put the participant at risk because of participation in the study, or influence the results or the participant's ability to participate in the study.
3. History of a clinically significant deterioration in asthma or asthma exacerbation including those requiring use of systemic corticosteroids or increase in the maintenance dose of oral corticosteroids within 30 days prior to Visit 1.
4. Change in ICS dose within 1 month prior to Visit 1.
5. History of a life-threatening asthma exacerbation resulting in a hypoxic seizure or requiring intubation.
Treatment, groups and participation
The registry may describe treatments and study duration without a complete visit calendar. Ask the study team for the exact schedule, procedures, risks, costs and alternatives. Keep your usual care plan unless your treating clinician tells you otherwise.
- Assignment
- Random assignment
- Masking
- Triple masked
Tezepelumab
Participants will be receiving tezepelumab subcutaneous injection
Biological: Tezepelumab
Placebo
Participants will be receiving placebo through a subcutaneous injection
Other: Placebo
Tezepelumab BIOLOGICAL
Participants will be receiving subcutaneous injection of tezepelumab
Placebo OTHER
Participants will be receiving subcutaneous injection of matching placebo
What researchers are measuring
Outcome measures describe what is being studied. They are not proof that a treatment works.
Primary measures
Annualized severe asthma exacerbation rate (AAER)
Time frame: From Baseline to Week 52
To assess the effect of tezepelumab on severe asthma exacerbations in children 5 to \< 12 years old with severe uncontrolled asthma compared with placebo.
Secondary measures
Change from baseline in pre-bronchodilator (pre-BD) forced expiratory volume in 1 second (FEV1) percent predicted normal (PN)
Time frame: From Baseline to Week 52
To assess the effect of tezepelumab on pulmonary function (FEV1) in children with severe uncontrolled asthma compared with placebo. Pre-bronchodilator FEV1% PN will be determined by spirometry at the clinic visit.
AAER associated with allergic asthma
Time frame: From Baseline to Week 52
AAER will be assessed in association with both allergic asthma (defined by a positive perennial allergen using serum specific IgE \[FEIA\]).
Time to first severe asthma exacerbation
Time frame: From Baseline to Week 52
Time to first severe asthma exacerbation will be assessed.
Proportion of participants with ≥ 1 severe asthma exacerbation
Time frame: From Baseline to Week 52
Proportion of participants with ≥ 1 severe asthma exacerbation will be assessed.
AAER associated with ER visit or hospitalisation
Time frame: From Baseline to Week 52
AAER will be assessed in association with ER visits or hospitalisations.
Cumulative exposure to systemic corticosteroids for treatment of severe asthma exacerbations
Time frame: From Baseline to Week 52
Cumulative exposure to systemic corticosteroids for treatment of severe asthma exacerbations over the 52 week double-blind treatment period
Change from baseline in Paediatric Asthma Quality of Life Questionnaire (PAQLQ-(S)-IA) total score
Time frame: From Baseline to Week 52
Change from baseline of PAQLQ-(S)-IA total score will be assessed. The PAQLQ was developed to measure the functional problems (physical, emotional, and social) that are most troublesome to children with asthma. The PAQLQ-(S)-IA has 23 questions in 3 domains (symptoms, activity limitation, and emotional function). Participants are asked to think about how they have been during the previous week and respond to each question on a 7-point scale (1 = extremely bothered to 7 = not bothered at all or 1 = all of the time to 7 = none of the time). There are 2 coloured cards (green and blue), which list sets of response options appropriate to different questions. The appropriate card should be used by the participant during completion of each question and then taken back when it is no longer required. The overall PAQLQ-(S)-IA score is the mean of all 23 responses, and the individual domain scores are the means of the items in those domains.
Change from baseline in weekly mean daily Paediatric Asthma Symptom Observer (PASO) score
Time frame: From Baseline to Week 52
Change from baseline in PASO score will be assessed. The PASO questionnaire will be completed by the caregiver each day from the evening of Treatment period. Caregivers in this study will complete 4 items from the morning assessment capturing night-time asthma symptoms, rescue medication use, night-time awakenings, and maintenance asthma medication use. The evening assessment will capture daytime asthma symptoms, rescue medication use, activity limitation and change in asthma.
Change from baseline in Asthma Control Questionnaire - Interviewer Administered (ACQ-IA) score
Time frame: From Baseline to Week 52
Change from baseline in ACQ-IA score will be assessed. The ACQ-IA will only be completed for participants ≥ 6 years old at Screening. The ACQ-IA is administered by trained individuals according to standardised instructions to help the child understand concepts like symptoms (night-time waking, symptoms on waking, activity limitation, shortness of breath, and wheezing) and use of SABA during the past week using a 7-point scale. The ACQ-IA score is calculated by taking the mean of the 6 equally weighted items and ranges from 0 (well controlled) to 6 (extremely poorly controlled). The estimated minimal clinically important difference is 0.5
Change from baseline in weekly mean rescue medication use
Time frame: From Baseline to Week 52
Change from baseline in weekly mean rescue medication use will be assessed.
Change from baseline in weekly mean number of night-time awakenings
Time frame: From Baseline to Week 52
Change from baseline in weekly mean number of night-time awakenings will be assessed.
Change from baseline in blood eosinophil count
Time frame: From Baseline to Week 52
Change from baseline in blood eosinophil count will be assessed.
Change from baseline in fractional exhaled nitric oxide (FeNO)
Time frame: From Baseline to Week 52
Change from baseline in FeNO will be assessed.
Change from baseline in total serum IgE
Time frame: From Baseline to Week 52
Change from baseline in total serum IgE will be assessed.
Change from baseline in pre-bronchodilator (pre-BD) peak expiratory flow (PEF)
Time frame: From Baseline to Week 52
The effect of tezepelumab on pulmonary function compared with placebo will be assessed using spirometry.
Number of asthma--related healthcare resource utilization (HRU)
Time frame: From Baseline to Week 52
Mean number and type of Asthma specific HRU (eg, unscheduled physician visits, unscheduled phone calls to physicians, use of other asthma medications) will be assessed.
Number of participant/caregiver health-related absences
Time frame: From Baseline to Week 52
Mean number of participant/caregiver health-related absences from work/school due to asthma will be assessed.
Serum concentrations of tezepelumab
Time frame: At Baseline, Week 4, Week 24, and Week 52
To evaluate the pharmacokinetics of tezepelumab.
Incidence of anti-drug antibodies (ADAs)
Time frame: At Baseline, and from time of first dose at Week 0 to end of study at week 64
To evaluate the immunogenicity of tezepelumab.
Incidence of neutralising antibodies (nAbs)
Time frame: At Baseline, and from time of first dose at Week 0 to end of study at week 64
To evaluate the immunogenicity of tezepelumab.
Review the complete result tables and limitations in the official record.
Open official results ↗Research locations (147)
The overall study status and a local site’s status can differ. Confirm that location’s availability before traveling.
147 locations
Research SiteMontgomery, Alabama, United StatesRecruiting
Research SitePhoenix, Arizona, United StatesRecruiting
Research SiteLittle Rock, Arkansas, United StatesWithdrawn
Research SiteLa Jolla, California, United StatesActive, not recruiting
Research SiteLong Beach, California, United StatesRecruiting
Research SiteOrange, California, United StatesWithdrawn
Research SiteSan Diego, California, United StatesRecruiting
Research SiteAtlanta, Georgia, United StatesRecruiting
Research SiteSavannah, Georgia, United StatesTerminated
Research SiteBaltimore, Maryland, United StatesRecruiting
Research SiteBoston, Massachusetts, United StatesRecruiting
Research SiteBoston, Massachusetts, United StatesRecruiting
Research SiteAnn Arbor, Michigan, United StatesTerminated
Research SiteDetroit, Michigan, United StatesRecruiting
Research SiteNorthfield, New Jersey, United StatesRecruiting
Research SiteHawthorne, New York, United StatesRecruiting
Research SiteSchenectady, New York, United StatesWithdrawn
Research SiteStaten Island, New York, United StatesRecruiting
Research SiteChapel Hill, North Carolina, United StatesRecruiting
Research SiteCincinnati, Ohio, United StatesRecruiting
Research SiteCleveland, Ohio, United StatesRecruiting
Research SiteToledo, Ohio, United StatesRecruiting
Research SiteOklahoma City, Oklahoma, United StatesRecruiting
Research SiteColumbia, South Carolina, United StatesWithdrawn
Research SiteCoppell, Texas, United StatesTerminated
Research SiteDallas, Texas, United StatesRecruiting
Research SiteFrisco, Texas, United StatesWithdrawn
Research SiteHouston, Texas, United StatesRecruiting
Research SiteSan Antonio, Texas, United StatesRecruiting
Research SiteTemple, Texas, United StatesWithdrawn
Research SiteBuenos Aires, ArgentinaRecruiting
Research SiteBuenos Aires, ArgentinaRecruiting
Research SiteBuenos Aires, ArgentinaRecruiting
Research SiteCABA, ArgentinaTerminated
Research SiteFlorida, ArgentinaRecruiting
Research SiteLanus, ArgentinaRecruiting
Research SiteLobos, ArgentinaRecruiting
Research SiteMendoza, ArgentinaRecruiting
Research SiteQuilmes, ArgentinaTerminated
Research SiteRosario, ArgentinaRecruiting
Research SiteBlumenau, BrazilRecruiting
Research SiteCuritiba, BrazilRecruiting
Research SiteSalvador, BrazilWithdrawn
Research SiteSão Paulo, BrazilActive, not recruiting
Research SiteSão Paulo, BrazilRecruiting
Research SiteSão Paulo, BrazilRecruiting
Research SiteSorocaba, BrazilRecruiting
Research SiteEdmonton, Alberta, CanadaRecruiting
Research SiteBurlington, Ontario, CanadaRecruiting
Research SiteHamilton, Ontario, CanadaRecruiting
Research SiteWindsor, Ontario, CanadaRecruiting
Research SiteMontreal, Quebec, CanadaRecruiting
Research SiteBeijing, ChinaRecruiting
Research SiteChangchun, ChinaRecruiting
Research SiteHohhot, ChinaRecruiting
Research SiteLanzhou, ChinaRecruiting
Research SiteNanjing, ChinaRecruiting
Research SiteShanghai, ChinaRecruiting
Research SiteShanghai, ChinaWithdrawn
Research SiteShenyang, ChinaRecruiting
Research SiteShenzhen, ChinaRecruiting
Research SiteTianjin, ChinaRecruiting
Research SiteWuxi, ChinaRecruiting
Research SiteZhanjiang, ChinaNot yet recruiting
Research SiteZhongshan, ChinaNot yet recruiting
Research SiteBogotá, ColombiaWithdrawn
Research SiteBogotá, ColombiaWithdrawn
Research SiteMedellín, ColombiaWithdrawn
Research SiteBrest, FranceRecruiting
Research SiteBron, FranceSuspended
Research SiteCréteil, FranceRecruiting
Research SiteMarseille, FranceRecruiting
Research SiteParis, FranceActive, not recruiting
Research SiteParis, FranceRecruiting
Research SiteParis, FranceRecruiting
Research SiteRouen, FranceRecruiting
Research SiteVandœuvre-lès-Nancy, FranceRecruiting
Research SiteDebrecen, HungaryCompleted
Research SiteSzeged, HungaryRecruiting
Research SiteSzigetvár, HungaryRecruiting
Research SiteGenova, ItalyRecruiting
Research SitePavia, ItalyRecruiting
Research SiteRoma, ItalyRecruiting
Research SiteFukuoka, JapanRecruiting
Research SiteFukuoka, JapanRecruiting
Research SiteFukuyama, JapanRecruiting
Research SiteFunabashi-shi, JapanRecruiting
Research SiteNara, JapanRecruiting
Research SiteOdawara, JapanRecruiting
Research SiteŌtsu, JapanRecruiting
Research SiteSaga, JapanRecruiting
Research SiteShimotsuga-gun, JapanRecruiting
Research SiteYokohama, JapanWithdrawn
Research SiteChihuahua City, MexicoRecruiting
Research SiteGuadalajara, MexicoRecruiting
Research SiteMexico City, MexicoWithdrawn
Research SiteVeracruz, MexicoRecruiting
Research SiteAmsterdam, NetherlandsRecruiting
Research SiteRotterdam, NetherlandsRecruiting
Research SiteIloilo City, PhilippinesRecruiting
Research SiteLas Piñas, PhilippinesRecruiting
Research SiteQuezon, PhilippinesRecruiting
Research SiteSanta Rosa, PhilippinesRecruiting
Research SiteLodz, PolandRecruiting
Research SiteTarnów, PolandRecruiting
Research SiteBucharest, RomaniaRecruiting
Research SiteBucharest, RomaniaRecruiting
Research SiteBellville, South AfricaRecruiting
Research SiteCape Town, South AfricaRecruiting
Research SiteDurban, South AfricaActive, not recruiting
Research SiteDurban, South AfricaRecruiting
Research SiteMiddelburg, South AfricaRecruiting
Research SiteThabazimbi, South AfricaWithdrawn
Research SiteVereeniging, South AfricaRecruiting
Research SiteWelkom, South AfricaRecruiting
Research SiteSeongnam-si, South KoreaWithdrawn
Research SiteSeongnam-si, South KoreaRecruiting
Research SiteSeoul, South KoreaRecruiting
Research SiteSeoul, South KoreaRecruiting
Research SiteBadalona, SpainRecruiting
Research SiteBarcelona, SpainRecruiting
Research SiteEsplugues de Llobregat (Barc), SpainRecruiting
Research SiteMadrid, SpainRecruiting
Research SiteSabadell, SpainRecruiting
Research SiteValencia, SpainRecruiting
Research SiteValencia, SpainWithdrawn
Research SiteVillarreal, SpainRecruiting
Research SiteBangkok, ThailandRecruiting
Research SiteBangkoknoi, ThailandRecruiting
Research SiteChiang Mai, ThailandRecruiting
Research SiteMuang, ThailandRecruiting
Research SiteBursa, Turkey (Türkiye)Recruiting
Research SiteIstanbul, Turkey (Türkiye)Recruiting
Research SiteIzmir, Turkey (Türkiye)Recruiting
Research SiteYenimahalle, Turkey (Türkiye)Recruiting
Research SiteChernivtsi, UkraineRecruiting
Research SiteIvano-Frankivsk, UkraineRecruiting
Research SiteKyiv, UkraineRecruiting
Research SiteKyiv, UkraineRecruiting
Research SiteBirmingham, United KingdomRecruiting
Research SiteBradford, United KingdomRecruiting
Research SiteBristol, United KingdomRecruiting
Research SiteGlasgow, United KingdomWithdrawn
Research SiteLeicester, United KingdomRecruiting
Research SiteLondon, United KingdomRecruiting
Research SiteNottingham, United KingdomRecruiting
Research SiteStoke-on-Trent, United KingdomRecruiting
Study team and timeline
- Lead sponsor
- AstraZeneca
- Study start
- Aug 24, 2023 Actual
- Primary completion
- May 31, 2028 Estimated
- Study completion
- Aug 23, 2030 Estimated
- First posted
- Sep 5, 2023 Actual
- Last updated
- Nov 10, 2026 Actual
Official study contacts
Official study title
A Multicentre, Randomised, Double-Blind, Parallel-Group Placebo-Controlled, Phase 3, Efficacy and Safety Study of Tezepelumab in 5 to < 12 Year Old Children With Severe Uncontrolled Asthma (HORIZON)
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Source: ClinicalTrials.gov API v2. Information is submitted by sponsors and investigators. NLM does not approve the safety or science of all listed studies. Registry disclaimer.
Retrieved: Nov 12, 2026 · Last registry update: Nov 10, 2026
