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Efficacy and Safety Study of RAGWITEK™ (MK-3641) in Children With Ragweed-Induced Rhinoconjunctivitis With or Without Asthma (MK-3641-008)

A Phase III, Randomized, Placebo-Controlled Clinical Trial to Study the Efficacy and Safety of MK-3641, a Ragweed (Ambrosia Artemisiifolia) Sublingual Immunotherapy Tablet, in Children With a History of Ragweed-Induced Rhinoconjunctivitis With or Without Asthma

Status
Completed
Phases
Phase 3
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT02478398
Enrollment
1025
Registered
2015-06-23
Start date
2015-07-20
Completion date
2018-11-19
Last updated
2019-09-06

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Rhinitis, Allergic, Seasonal

Brief summary

The purpose of this study is to assess the efficacy and safety of short ragweed pollen allergen extract (MK-3641, SCH 039641, RAGWITEK™) sublingual immunotherapy tablets in children aged 5 to 17 years with ragweed-induced allergic rhinitis/rhinoconjunctivitis with or without asthma. The primary hypothesis of this study is that administration of short ragweed pollen allergen extract sublingual immunotherapy tablets to children 5 to 17 years of age, compared with placebo, will result in a significant reduction in the combination of rhinoconjunctivitis symptoms and medication use over the peak ragweed season (RS).

Interventions

BIOLOGICALPlacebo

One placebo sublingual tablet, QD for up to 35 weeks.

BIOLOGICALShort ragweed pollen allergen extract

One sublingual tablet containing 12 units of Amb a 1-U, once daily (QD) for up to 35 weeks.

DRUGSelf-injectable epinephrine

Intramuscular (IM) injection with suggested doses of 0.15 mg for participants weighing 15-30 kg (33-66 pounds) or 0.3 mg for participants weighing ≥30 kg (≥66 pounds), as needed for severe allergic reactions. Epinephrine was only provided in countries/study sites where it was a regulatory requirement.

DRUGAlbuterol/Salbutamol

Inhalation of albuterol 90 mcg/puff or salbutamol 100 mcg/puff metered dose inhaler (MDI), as needed as asthma rescue medication for those participants with asthma

DRUGLoratadine

5 mg (1 mg/mL syrup or 5 mg tablet) for participants 5 years old or 10 mg (1 mg/mL syrup or 10 mg tablet) for participants 6 to 17 years old, as needed for rhinoconjunctivitis symptoms

Opthalmic solution, 1 drop (0.1%) per affected eye twice daily (BID), as needed for rhinoconjunctivitis symptoms

Intranasal spray, at doses of 1 spray (50 mcg/ spray) per nostril for participants 5 to 11 years old or 2 sprays (50 mcg/spray) per nostril for participants 12 to 17 years old, as needed for rhinoconjunctivitis symptoms

Sponsors

Merck Sharp & Dohme LLC
Lead SponsorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Caregiver, Investigator)

Eligibility

Sex/Gender
ALL
Age
4 Years to 17 Years
Healthy volunteers
No

Inclusion criteria

* Is between the ages of 4 and 17 years (inclusive) at enrollment in this study and is at least 5 years old at randomization * Has a clinical history of significant ragweed pollen-induced allergic rhinitis/rhinoconjunctivitis of ≥1 year (at least 1 season for ages 4 to 6 years) or ≥2 years (at least 2 seasons for ages 7 to 17 years) duration diagnosed by a physician (with or without asthma) and have received treatment for the condition during the previous ragweed season * If female, agrees to remain abstinent or use (or have their partner use) an acceptable method of birth control within the projected duration of the study.

Exclusion criteria

* Has a clinical history of symptomatic seasonal allergic rhinitis (and/or asthma) due to another allergen, which has required regular medication during, or potentially overlapping, the ragweed season * Has a clinical history of significant symptomatic perennial allergic rhinitis and/or asthma due to an allergen to which the subject is regularly exposed during the ragweed season which would interfere with assessment of the treatment effect * Has any nasal condition that could confound the efficacy or safety assessments (e.g., nasal polyposis). * Has asthma requiring high daily doses of inhaled corticosteroids within the 6 months prior to the Screening visit * Is either \>7 years old and cannot perform reproducible FEV1 maneuvers despite coaching; OR is ≤7 years old and cannot perform reproducible FEV1 maneuvers despite coaching and has current symptoms of asthma characterized by recurrent episodes of wheezing, or episodes of cough, wheeze, difficulty in breathing, or chest tightness * Has severe, unstable, or uncontrolled asthma, as judged by the clinical investigator, or has experienced a life-threatening asthma attack or an occurrence of any clinical deterioration of asthma that resulted in emergency treatment, hospitalization due to asthma, or treatment with systemic corticosteroids (but allowing short-acting beta agonists) at any time within the last 3 months prior to the Screening or Randomization visits * Has a history of anaphylaxis with cardiorespiratory symptoms with prior immunotherapy, unknown cause, or inhalant allergen * Has a diagnosis of eosinophilic esophagitis * Has a history of chronic urticaria and/or chronic angioedema * Has a clinical history of chronic sinusitis during the 2 years prior to the Screening or Randomization visits * Has current severe atopic dermatitis * Has a history of allergy, hypersensitivity, or intolerance to the ingredients of the study drug (except for Ambrosia artemisiifolia), rescue medications, or self-injectable epinephrine * Has previously received short ragweed pollen allergen extract * Has previously been randomized into this study * Is participating in any other clinical study or plans to participate in another clinical study during the duration of this study

Design outcomes

Primary

MeasureTime frameDescription
Total Combined Score (TCS) During the Peak Ragweed Season (RS)The 15-day period during the ragweed season with the highest moving pollen averageTCS is daily symptom score (DSS) plus daily medication score (DMS), assessed in the peak RS (15 consecutive RS days with the highest 15-day average pollen count). The rhinoconjunctivitis (RC) DSS assesses 6 allergy symptoms measured on a scale of 0 to 3 (0=no symptoms, 3=severe symptoms; score range: 0-18). Lower DSS indicates less RC symptoms. The RC DMS is based on use of RC rescue medications (loratadine, olopatadine, mometasone), with different rescue medications being assigned different scores/dose unit (score range: 0-20). Lower DMS indicates less RC medication use. Summed RC DSS+DMS could range from 0 to 38; a lower score indicates less RC symptoms and medication use. Components that contribute to DSS and DMS endpoints are collected in an electronic diary (e-diary) completed by the participant/parent/guardian. Evaluation is based on average TCS during peak RS.

Secondary

MeasureTime frameDescription
Average Rhinoconjunctivitis (RC) DSS During the Peak RSThe 15-day period during the ragweed season with the highest moving pollen averageThe DSS consists of a total of 6 rhinoconjunctivitis symptoms: 4 rhinitis symptoms (runny nose, stuffy nose, sneezing, itchy nose) and 2 conjunctivitis symptoms (itchy eyes, watery eyes). The components that contribute to the DSS endpoint are collected in an e-diary completed by the participant/parent/guardian. The RC DSS is measured on a 4-point scale from 0 to 3 as follows: 0 (no sign/symptom evident) to 3 (sign/symptom that is hard to tolerate; may cause interference with activities of daily living and/or sleeping). The maximum DSS is 18 points if a participant experiences all 6 symptoms with an intensity of 3 for each symptom. The minimum DSS is 0 points if a participant experiences no symptoms. A lower DSS means symptoms are less severe. The evaluation is based on the average DSS during the peak RS.
Average Rhinoconjunctivitis (RC) DMS During the Peak RSThe 15-day period during the ragweed season with the highest moving pollen averageThis DMS endpoint consists of a total of scores for use of RC medications: loratadine syrup or tablets (6 points), olopatadine (6 points), and mometasone (8 points). The score range of the RC DMS is 0-20 points, and a lower DMS means that less medication is used. The method used for analysis of the RC DMS is a zero-inflated log-normal model, which takes the average RC DMS during the peak RS as the response and adjusts for the same terms as in the ANOVA model. The components that contribute to the DMS endpoint are collected in an e-diary completed by the participant/parent/guardian.
Average TCS During the Entire RSUp to 13 weeksTCS is DSS plus DMS, assessed here during the entire RS. This starts from the first day of 3 consecutive days with ragweed pollen counts ≥10 grains/m\^3 through the last day of the last occurrence of 3 consecutive days with ragweed pollen counts ≥10 grains/m\^3. The duration of the entire RS is up to 13 weeks; this duration varies by site/region. The RC DSS assesses 6 allergy symptoms measured on a scale of 0 to 3 (score range: 0-18). A lower DSS indicates less RC symptoms. The RC DMS is based on use of RC rescue medications (loratadine, olopatadine, mometasone) with different scores/dose unit (score range: 0-20). A lower DMS indicates less RC medication use. The sum of RC DSS+DMS ranges from 0 to 38, with a lower score indicating less RC symptoms and medication use. Components contributing to the TCS for the entire RS are collected in an e-diary completed by the participant/parent/guardian.
Percentage of Participants Reporting Anaphylaxis and/or Systemic Allergic ReactionsUp to 35 weeksFor the purposes of this study, systemic allergic reactions are allergic reactions that occur away from the site of study drug application (allergic reactions other than local application site reactions). Anaphylaxis is a severe allergic reaction that typically involves more than one body system.
Percentage of Participants Treated With EpinephrineUp to 35 weeksSelf-injectable epinephrine was provided to each participant/parent/guardian at randomization in countries where it is a regulatory requirement, and was to be available around the time treatment is administered at home. Self-injectable epinephrine was intended for immediate self-administration for an anaphylactic reaction, including symptoms/signs of upper airway obstruction. Instances of treatment with forms of epinephrine other than systemic epinephrine (e.g., inhaled racepinephrine) were counted as use of epinephrine.
Percentage of Participants Reporting Pre-specified Local Application Site ReactionsUp to 35 weeksPre-specified local application site reactions, irrespective of causality, included AEs related to lip swelling/edema, mouth swelling/edema, palatal swelling/edema, swollen tongue/edema, oropharyngeal swelling/edema, pharyngeal edema/throat tightness, oral pruritus, throat irritation, tongue pruritus, and ear pruritus.

Participant flow

Participants by arm

ArmCount
Short Ragweed Pollen Allergen Extract
Participants received one short ragweed pollen allergen extract sublingual tablet containing 12 units of Amb a 1-U, QD for up to 35 weeks.
512
Placebo
Participants received one placebo sublingual tablet, QD for up to 35 weeks.
510
Total1,022

Withdrawals & dropouts

PeriodReasonFG000FG001
Overall StudyAdverse Event205
Overall StudyLost to Follow-up54
Overall StudyNon-Compliance With Study Drug51
Overall StudyProtocol Violation31
Overall StudyWithdrawal By Parent/Guardian96
Overall StudyWithdrawal By Participant104

Baseline characteristics

CharacteristicShort Ragweed Pollen Allergen ExtractPlaceboTotal
Age, Continuous12.1 years
STANDARD_DEVIATION 3.2
12.2 years
STANDARD_DEVIATION 3.1
12.1 years
STANDARD_DEVIATION 3.1
Age, Customized
< 12 years
206 Participants204 Participants410 Participants
Age, Customized
≥ 12 years
306 Participants306 Participants612 Participants
Baseline Asthma Status
No
293 Participants293 Participants586 Participants
Baseline Asthma Status
Yes
219 Participants217 Participants436 Participants
Race/Ethnicity, Customized
Hispanic or Latino
15 Participants21 Participants36 Participants
Race/Ethnicity, Customized
Not Hispanic or Latino
490 Participants483 Participants973 Participants
Race/Ethnicity, Customized
Not Reported
4 Participants5 Participants9 Participants
Race/Ethnicity, Customized
Unknown
3 Participants1 Participants4 Participants
Race (NIH/OMB)
American Indian or Alaska Native
1 Participants0 Participants1 Participants
Race (NIH/OMB)
Asian
4 Participants6 Participants10 Participants
Race (NIH/OMB)
Black or African American
18 Participants14 Participants32 Participants
Race (NIH/OMB)
More than one race
13 Participants11 Participants24 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
3 Participants2 Participants5 Participants
Race (NIH/OMB)
Unknown or Not Reported
0 Participants0 Participants0 Participants
Race (NIH/OMB)
White
473 Participants477 Participants950 Participants
Sex: Female, Male
Female
188 Participants191 Participants379 Participants
Sex: Female, Male
Male
324 Participants319 Participants643 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
0 / 5130 / 509
other
Total, other adverse events
370 / 513233 / 509
serious
Total, serious adverse events
7 / 5139 / 509

Outcome results

Primary

Total Combined Score (TCS) During the Peak Ragweed Season (RS)

TCS is daily symptom score (DSS) plus daily medication score (DMS), assessed in the peak RS (15 consecutive RS days with the highest 15-day average pollen count). The rhinoconjunctivitis (RC) DSS assesses 6 allergy symptoms measured on a scale of 0 to 3 (0=no symptoms, 3=severe symptoms; score range: 0-18). Lower DSS indicates less RC symptoms. The RC DMS is based on use of RC rescue medications (loratadine, olopatadine, mometasone), with different rescue medications being assigned different scores/dose unit (score range: 0-20). Lower DMS indicates less RC medication use. Summed RC DSS+DMS could range from 0 to 38; a lower score indicates less RC symptoms and medication use. Components that contribute to DSS and DMS endpoints are collected in an electronic diary (e-diary) completed by the participant/parent/guardian. Evaluation is based on average TCS during peak RS.

Time frame: The 15-day period during the ragweed season with the highest moving pollen average

Population: The analysis population includes all treated participants w/ ≥1 e-diary entry for the specified measurement and timeframe.

ArmMeasureValue (LEAST_SQUARES_MEAN)Dispersion
Short Ragweed Pollen Allergen ExtractTotal Combined Score (TCS) During the Peak Ragweed Season (RS)4.39 Score on a scale95% Confidence Interval 3.85
PlaceboTotal Combined Score (TCS) During the Peak Ragweed Season (RS)7.12 Score on a scale95% Confidence Interval 6.57
p-value: <0.00195% CI: [-3.45, -2]ANOVA
Secondary

Average Rhinoconjunctivitis (RC) DMS During the Peak RS

This DMS endpoint consists of a total of scores for use of RC medications: loratadine syrup or tablets (6 points), olopatadine (6 points), and mometasone (8 points). The score range of the RC DMS is 0-20 points, and a lower DMS means that less medication is used. The method used for analysis of the RC DMS is a zero-inflated log-normal model, which takes the average RC DMS during the peak RS as the response and adjusts for the same terms as in the ANOVA model. The components that contribute to the DMS endpoint are collected in an e-diary completed by the participant/parent/guardian.

Time frame: The 15-day period during the ragweed season with the highest moving pollen average

Population: The analysis population includes all treated participants w/ ≥1 e-diary entry for the specified measurement and timeframe.

ArmMeasureValue (MEAN)Dispersion
Short Ragweed Pollen Allergen ExtractAverage Rhinoconjunctivitis (RC) DMS During the Peak RS2.01 Score on a scale95% Confidence Interval 1.57
PlaceboAverage Rhinoconjunctivitis (RC) DMS During the Peak RS3.85 Score on a scale95% Confidence Interval 3.14
p-value: <0.00195% CI: [-2.6, -1.08]Zero-Inflated Log-Normal Model
Secondary

Average Rhinoconjunctivitis (RC) DSS During the Peak RS

The DSS consists of a total of 6 rhinoconjunctivitis symptoms: 4 rhinitis symptoms (runny nose, stuffy nose, sneezing, itchy nose) and 2 conjunctivitis symptoms (itchy eyes, watery eyes). The components that contribute to the DSS endpoint are collected in an e-diary completed by the participant/parent/guardian. The RC DSS is measured on a 4-point scale from 0 to 3 as follows: 0 (no sign/symptom evident) to 3 (sign/symptom that is hard to tolerate; may cause interference with activities of daily living and/or sleeping). The maximum DSS is 18 points if a participant experiences all 6 symptoms with an intensity of 3 for each symptom. The minimum DSS is 0 points if a participant experiences no symptoms. A lower DSS means symptoms are less severe. The evaluation is based on the average DSS during the peak RS.

Time frame: The 15-day period during the ragweed season with the highest moving pollen average

Population: The analysis population includes all treated participants w/ ≥1 e-diary entry for the specified measurement and timeframe.

ArmMeasureValue (LEAST_SQUARES_MEAN)Dispersion
Short Ragweed Pollen Allergen ExtractAverage Rhinoconjunctivitis (RC) DSS During the Peak RS2.55 Score on a scale95% Confidence Interval 2.24
PlaceboAverage Rhinoconjunctivitis (RC) DSS During the Peak RS3.95 Score on a scale95% Confidence Interval 3.63
p-value: <0.00195% CI: [-1.81, -0.99]ANOVA
Secondary

Average TCS During the Entire RS

TCS is DSS plus DMS, assessed here during the entire RS. This starts from the first day of 3 consecutive days with ragweed pollen counts ≥10 grains/m\^3 through the last day of the last occurrence of 3 consecutive days with ragweed pollen counts ≥10 grains/m\^3. The duration of the entire RS is up to 13 weeks; this duration varies by site/region. The RC DSS assesses 6 allergy symptoms measured on a scale of 0 to 3 (score range: 0-18). A lower DSS indicates less RC symptoms. The RC DMS is based on use of RC rescue medications (loratadine, olopatadine, mometasone) with different scores/dose unit (score range: 0-20). A lower DMS indicates less RC medication use. The sum of RC DSS+DMS ranges from 0 to 38, with a lower score indicating less RC symptoms and medication use. Components contributing to the TCS for the entire RS are collected in an e-diary completed by the participant/parent/guardian.

Time frame: Up to 13 weeks

Population: The analysis population includes all treated participants w/ ≥1 e-diary entry for the specified measurement and timeframe.

ArmMeasureValue (LEAST_SQUARES_MEAN)Dispersion
Short Ragweed Pollen Allergen ExtractAverage TCS During the Entire RS3.88 Score on a scale95% Confidence Interval 3.44
PlaceboAverage TCS During the Entire RS5.75 Score on a scale95% Confidence Interval 5.3
p-value: <0.00195% CI: [-2.46, -1.27]ANOVA
Secondary

Percentage of Participants Reporting Anaphylaxis and/or Systemic Allergic Reactions

For the purposes of this study, systemic allergic reactions are allergic reactions that occur away from the site of study drug application (allergic reactions other than local application site reactions). Anaphylaxis is a severe allergic reaction that typically involves more than one body system.

Time frame: Up to 35 weeks

Population: The safety population was all participants as treated. One participant was randomized to placebo but received short ragweed pollen allergen extract for one day and is included in the short ragweed pollen allergen extract arm.

ArmMeasureValue (NUMBER)
Short Ragweed Pollen Allergen ExtractPercentage of Participants Reporting Anaphylaxis and/or Systemic Allergic Reactions0.58 Percentage of Participants
PlaceboPercentage of Participants Reporting Anaphylaxis and/or Systemic Allergic Reactions0.20 Percentage of Participants
p-value: =0.3295% CI: [-0.57, 1.53]Miettinen & Nurminen
Secondary

Percentage of Participants Reporting Pre-specified Local Application Site Reactions

Pre-specified local application site reactions, irrespective of causality, included AEs related to lip swelling/edema, mouth swelling/edema, palatal swelling/edema, swollen tongue/edema, oropharyngeal swelling/edema, pharyngeal edema/throat tightness, oral pruritus, throat irritation, tongue pruritus, and ear pruritus.

Time frame: Up to 35 weeks

Population: The safety population was all participants as treated. One participant was randomized to placebo but received short ragweed pollen allergen extract for one day and is included in the short ragweed pollen allergen extract arm.

ArmMeasureValue (NUMBER)
Short Ragweed Pollen Allergen ExtractPercentage of Participants Reporting Pre-specified Local Application Site Reactions64.52 Percentage of Participants
PlaceboPercentage of Participants Reporting Pre-specified Local Application Site Reactions26.92 Percentage of Participants
p-value: <0.00195% CI: [31.82, 43.12]Miettinen & Nurminen
Secondary

Percentage of Participants Treated With Epinephrine

Self-injectable epinephrine was provided to each participant/parent/guardian at randomization in countries where it is a regulatory requirement, and was to be available around the time treatment is administered at home. Self-injectable epinephrine was intended for immediate self-administration for an anaphylactic reaction, including symptoms/signs of upper airway obstruction. Instances of treatment with forms of epinephrine other than systemic epinephrine (e.g., inhaled racepinephrine) were counted as use of epinephrine.

Time frame: Up to 35 weeks

Population: The safety population was all participants as treated. One participant was randomized to placebo but received short ragweed pollen allergen extract for one day and is included in the short ragweed pollen allergen extract arm.

ArmMeasureValue (NUMBER)
Short Ragweed Pollen Allergen ExtractPercentage of Participants Treated With Epinephrine0.19 Percentage of Participants
PlaceboPercentage of Participants Treated With Epinephrine0.20 Percentage of Participants
p-value: =0.99695% CI: [-0.92, 0.92]Miettinen & Nurminen

Source: ClinicalTrials.gov · Data processed: Feb 27, 2026