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The Effect of STIOLTO™ RESPIMAT® on Fatigue in Chronic Obstructive Pulmonary Disease

A Randomized, Crossover, Placebo Controlled, Double-blind Trial of the Effect of STIOLTO™ RESPIMAT® on Central and Peripheral Components of Fatigue During Exercise in Chronic Obstructive Pulmonary Disease

Status
Completed
Phases
Phase 4
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT02845752
Enrollment
14
Registered
2016-07-27
Start date
2017-03-01
Completion date
2018-08-06
Last updated
2020-08-06

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

Conditions

Chronic Obstructive Pulmonary Disease

Brief summary

The purpose of this study is to determine whether exercise can be prolonged in COPD can by the inhaled bronchodilator Stiolto Respimat. The study will identify whether any endurance benefit is due to reduction in fatigue that originates within the skeletal muscles and/or from effects on neural activation of the skeletal muscles.

Detailed description

Patients with chronic obstructive pulmonary disease (COPD) have reduced exercise tolerance. One mechanism for this is thought to be due to dynamic hyperinflation during exercise (an increase in the end-expiratory lung volume) that contributes to the sensation of breathlessness. Whether this also contributes to inhibiting motor recruitment, and reduces the available power output (termed performance fatigue; PF), is not well understood. Preliminary data suggests that many COPD patients, unlike healthy subjects, stop exercise with a 'skeletal muscle power reserve' i.e. the ability to acutely increase muscle power output. This suggests that they are limited in the exercise task by mechanisms other than acute intramuscular limitations to power production (termed muscle fatigue; MF). Exercise tolerance is increased by treatment with the fixed-dose combination bronchodilator, STIOLTO™ RESPIMAT®. We hypothesize that increased exercise tolerance with STIOLTO™ RESPIMAT® (reduced performance fatigue; PF) will be mediated by a combination of: 1) reduced inhibition of muscle activation (termed activation fatigue; AF) allowing patients to drive their leg muscles harder, and thus; 2) increased muscle fatigue (MF).

Interventions

Oral inhalation spray

Oral inhalation spray

Sponsors

Boehringer Ingelheim
CollaboratorINDUSTRY
Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender
ALL
Age
45 Years to 90 Years
Healthy volunteers
No

Inclusion criteria

* All patients must have a diagnosis of chronic obstructive pulmonary disease and must meet the following criteria: (a) Patients must be in a stable state of their disease with no exacerbation within the previous 4 weeks; and (b) At visit 1 spirometric must demonstrate a post-bronchodilator FEV1 \<80% of predicted normal and a post-bronchodilator FEV1/FVC \<70%. * At visit 1, patients will demonstrate appreciable reversibility, defined as a 12% increase in FEV1 in response to albuterol administration. * Baseline dyspnea index focal score ≤ 9. * Male or female patients, between 45 and 90 years (inclusive) of age. * Patients must be current or ex-smokers with a smoking history of more than 10 pack-years * Patients must be able to perform technically acceptable pulmonary function tests must be able to complete multiple symptom-limited cycle ergometry tests. * Patients must be able to inhale medication in a competent manner from the inhalers used in the study.

Exclusion criteria

* Patients with a significant disease other than COPD; a significant disease is defined as a disease which, in the opinion of the investigator, may (i) put the patient at risk because of participation in the study, (ii) influence the results of the study, or (iii) cause concern regarding the patient's ability to participate in the study. * Patients with a documented history of asthma. For patients with allergic rhinitis or atopy, medical records will be required to verify that the patient does not have asthma. * Patients with any of the following conditions: 1. A history of myocardial infarction within 1 year of screening visit. 2. Unstable or life-threatening cardiac arrhythmia. 3. Hospitalized for heart failure within the past year. 4. Known active tuberculosis. 5. A malignancy for which patient has undergone resection, radiation therapy or chemotherapy within last two years (patients with treated basal cell carcinoma are allowed). 6. A history of life-threatening pulmonary obstruction within the past two years. 7. A history of cystic fibrosis. 8. Clinically evident bronchiectasis. 9. A history of significant alcohol or drug abuse within the past two years. 10. Any contraindications for exercise testing as outlined below (see contraindications to exercise). 11. Patients who have undergone thoracotomy with pulmonary resection. * Patients being treated with oral corticosteroid medication at unstable doses (i.e., less than six weeks on a stable dose) or at doses in excess of the equivalent of 10 mg of prednisone per day or 20 mg every other day. * Patients who regularly use daytime oxygen therapy for more than one hour per day and in the investigator's opinion will be unable to abstain from the use of oxygen therapy during clinic visits. * Patients who desaturate to SpO2 \<85% on screening incremental exercise testing. * Patients who have completed a pulmonary rehabilitation program in the six weeks prior to the screening visit or patients who are currently in a pulmonary rehabilitation program. * Patients who have a limitation of exercise performance as a result of factors other than fatigue or exertional dyspnea, such as arthritis in the leg, angina pectoris or claudication or morbid obesity. * Patients with a constant power cycle ergometry endurance time less than 4 or greater than 10 minutes after work rate adjustment procedures (described below). * Patients who have taken an investigational drug within one month or six half-lives (whichever is greater) prior to screening visit (Visit 1). * Pregnant or nursing women. * Women of childbearing who have the potential not to be using a highly effective method of birth control. Female patients will be considered to be of childbearing potential unless surgically sterilized by hysterectomy or bilateral tubal ligation, or post-menopausal for at least two years. * Patients who are currently participating in another interventional study. * Patients who are unable to comply with pulmonary medication restrictions prior to randomization.

Design outcomes

Primary

MeasureTime frameDescription
The Magnitude of Change in Isokinetic Power (Performance Fatigue, PF) Associated With Stiolto Respimat Compared With Placebo Respimat at Isotime During Constant Work Rate Exercise (CWR)Baseline and day 7 of each treatment periodConstant work rate (CWR) exercise causes fatigue. Fatigue is measured by the difference between pre-CWR and post-CWR maximal voluntary isokinetic power i.e. how much maximal voluntary isokinetic power declines during CWR. The magnitude of fatigue is measured in watts at the time of the shortest exercise duration in either study arm, which is termed isotime. A smaller value (in watts) of performance fatigue means that the intervention was associated with less fatigue after a given CWR exercise duration (i.e. at isotime).

Secondary

MeasureTime frameDescription
Exercise Endurance Time During CWR Cycling ExerciseBaseline and day 7 of each treatment periodThe duration in seconds for which constant work rate (CWR) cycling exercise could be tolerated prior to voluntary termination of exercise.
Change From Period Baseline in the Exercise-isotime Inspiratory Reserve Volume During CWRBaseline and day 7 of each treatment periodInspiratory reserve volume (IRV) measured during CWR cycling exercise at the time of the shortest duration of each intervention arm (isotime). A greater IRV would reflect a beneficial response to intervention.
Change From Period Baseline in the Exercise-isotime Inspiratory Capacity During CWRBaseline and day 7 of each treatment periodInspiratory capacity (IC) measured during constant work rate (CWR) cycling exercise at the time of the shortest duration of each intervention arm (isotime). A greater IC would reflect a beneficial response to the intervention.
Change From Period Baseline in the Forced Expiratory Volume in 1 Second (FEV1)Baseline and day 7 of each treatment periodThis outcome describes the the effect of the intervention on forced expiratory volume in 1 second (FEV1) during resting spirometry. A greater FEV1 would reflect a positive benefit of the intervention.
Change From Period Baseline in the Exercise-isotime in Pulse Oximeter Oxygen Saturation During CWRBaseline and day 7 of each treatment periodPercentage of arterial hemoglobin that is saturated with oxygen, measured using pulse oximetry during constant work rate (CWR) cycling exercise at the time of the shortest duration of each intervention arm (isotime). A greater pulse oximeter oxygen saturation would reflect a beneficial response to the intervention.
Change From Period Baseline in the Exercise-isotime Ventilation During CWRBaseline and day 7 of each treatment periodMinute ventilation (VE) measured during constant work rate (CWR) cycling exercise at the time of the shortest duration of each intervention arm (isotime). A lesser VE would reflect a beneficial response to the intervention.
The Magnitude of Change Electromyographic (EMG) Muscle Activity (Activation Fatigue, AF) Associated With Stiolto Respimat Compared With Placebo Respimat at Isotime During Constant Work Rate Exercise (CWR)Baseline and day 7 of each treatment periodConstant work rate (CWR) exercise causes fatigue and reduces muscle activation. The relationship between muscle activation and power is measured at baseline (unfatigued condition). Fatigue is measured by the difference between pre-CWR and post-CWR maximal voluntary isokinetic power i.e. how much maximal voluntary isokinetic power declines during CWR. The fraction of fatigue that is ascribed to reduced muscle activity is then calculated. The magnitude of activation fatigue is measured in EMG activity and expressed in watts at the time of the shortest exercise duration in either study arm, which is termed isotime. A smaller value (in watts) of activation fatigue means that the intervention was associated with a less reduction in EMG activity after a given CWR exercise duration (i.e. at isotime).
Change From Period Baseline in the Exercise-isotime Frontal Lobe Oxygen Saturation During CWRBaseline and day 7 of each treatment periodTissue saturation of hemoglobin with oxygen is measured by spatially resolved near-infrared spectroscopy from the frontal lobe during constant work rate (CWR) cycling exercise at the time of the shortest duration of each intervention arm (isotime). A greater frontal lobe oxygen saturation at isotime would reflect a beneficial response to the intervention.
Change From Period Baseline in the Exercise-isotime Muscle Oxygen Saturation During CWRBaseline and day 7 of each treatment periodTissue saturation of hemoglobin plus myoglobin with oxygen is measured by spatially resolved near-infrared spectroscopy from the vastus lateralis muscle during constant work rate (CWR) cycling exercise at the time of the shortest duration of each intervention arm (isotime). A greater muscle oxygen saturation at isotime would reflect a beneficial response to the intervention.
Change From Period Baseline in the Exercise-isotime Borg CR-10 Rating of Perceived Dyspnea During CWRBaseline and day 7 of each treatment periodBorg rating of perceived shortness of breath (dyspnea) were measured on a category-ratio scale from 0 to 10 (CR-10) during constant work rate (CWR) cycling exercise at the time of the shortest duration of each intervention arm (isotime). A lower CR-10 score for dyspnea at isotime would reflect a beneficial response to the intervention.
Change From Period Baseline in the Exercise-isotime Borg CR-10 Rating of Perceived Leg Fatigue During CWRBaseline and day 7 of each treatment periodBorg rating of perceived tiredness on the legs (leg fatigue) were measured on a category-ratio scale from 0 to 10 (CR-10) during constant work rate (CWR) cycling exercise at the time of the shortest duration of each intervention arm (isotime). A lower CR-10 score for leg fatigue at isotime would reflect a beneficial response to the intervention.
Change From Period Baseline in the Pre/Post Exercise-induced Decline in Peak Isokinetic Power Normalized to the Measured Muscle Activity (Muscle Fatigue, MF) During CWRBaseline and day 7 of each treatment periodConstant work rate (CWR) exercise causes muscle fatigue (MF) and reduces muscle activation (activation fatigue; AF). The relationship between muscle activity (using EMG) and power is measured at baseline (unfatigued condition). Fatigue is measured by the difference between pre-CWR and post-CWR maximal voluntary isokinetic power i.e. how much maximal voluntary isokinetic power declines during CWR. The fraction of the total fall in voluntary isokinetic power (total fatigue) that is ascribed to reduced muscle activity is then calculated from the reduction in EMG activity. The remainder is ascribed to muscle fatigue (MF) and expressed as a percentage of total fatigue. This measurement was made at peak exercise. A smaller value (%) of MF would be associated with a beneficial response to the intervention.
Change From Period Baseline in the Exercise-isotime Oxygen Uptake (VO2) During CWRBaseline and day 7 of each treatment periodPulmonary oxygen uptake (VO2) measured during constant work rate (CWR) cycling exercise at the time of the shortest duration of each intervention arm (isotime). A lesser VO2 would reflect a beneficial response to the intervention.

Countries

United States

Participant flow

Participants by arm

ArmCount
Stiolto Respimat, Then Placebo Respimat
Participants first received Stiolto Respimat inhaler (two actuations, once daily for 7 days). After a washout period of 14 days, participants will then received Placebo Respimat inhaler (two actuations, once daily for 7 days).
7
Placebo Respimat, Then Stiolto Respimat
Participants first received Placebo Respimat inhaler (two actuations, once daily for 7 days). After a washout period of 14 days, participants will then received Stiolto Respimat inhaler (two actuations, once daily for 7 days).
7
Total14

Baseline characteristics

CharacteristicStiolto Respimat, Then Placebo RespimatTotalPlacebo Respimat, Then Stiolto Respimat
Age, Continuous63 years64 years71 years
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Asian
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Black or African American
3 Participants7 Participants4 Participants
Race (NIH/OMB)
More than one race
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Unknown or Not Reported
0 Participants0 Participants0 Participants
Race (NIH/OMB)
White
4 Participants7 Participants3 Participants
Region of Enrollment
United States
7 participants14 participants7 participants
Sex: Female, Male
Female
2 Participants4 Participants2 Participants
Sex: Female, Male
Male
5 Participants10 Participants5 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
0 / 140 / 14
other
Total, other adverse events
0 / 140 / 14
serious
Total, serious adverse events
0 / 140 / 14

Outcome results

Primary

The Magnitude of Change in Isokinetic Power (Performance Fatigue, PF) Associated With Stiolto Respimat Compared With Placebo Respimat at Isotime During Constant Work Rate Exercise (CWR)

Constant work rate (CWR) exercise causes fatigue. Fatigue is measured by the difference between pre-CWR and post-CWR maximal voluntary isokinetic power i.e. how much maximal voluntary isokinetic power declines during CWR. The magnitude of fatigue is measured in watts at the time of the shortest exercise duration in either study arm, which is termed isotime. A smaller value (in watts) of performance fatigue means that the intervention was associated with less fatigue after a given CWR exercise duration (i.e. at isotime).

Time frame: Baseline and day 7 of each treatment period

ArmMeasureValue (MEDIAN)
Stiolto RespimatThe Magnitude of Change in Isokinetic Power (Performance Fatigue, PF) Associated With Stiolto Respimat Compared With Placebo Respimat at Isotime During Constant Work Rate Exercise (CWR)75 watts
Placebo RespimatThe Magnitude of Change in Isokinetic Power (Performance Fatigue, PF) Associated With Stiolto Respimat Compared With Placebo Respimat at Isotime During Constant Work Rate Exercise (CWR)77 watts
Secondary

Change From Period Baseline in the Exercise-isotime Borg CR-10 Rating of Perceived Dyspnea During CWR

Borg rating of perceived shortness of breath (dyspnea) were measured on a category-ratio scale from 0 to 10 (CR-10) during constant work rate (CWR) cycling exercise at the time of the shortest duration of each intervention arm (isotime). A lower CR-10 score for dyspnea at isotime would reflect a beneficial response to the intervention.

Time frame: Baseline and day 7 of each treatment period

ArmMeasureValue (MEDIAN)
Stiolto RespimatChange From Period Baseline in the Exercise-isotime Borg CR-10 Rating of Perceived Dyspnea During CWR3 scores on a scale
Placebo RespimatChange From Period Baseline in the Exercise-isotime Borg CR-10 Rating of Perceived Dyspnea During CWR2.5 scores on a scale
Secondary

Change From Period Baseline in the Exercise-isotime Borg CR-10 Rating of Perceived Leg Fatigue During CWR

Borg rating of perceived tiredness on the legs (leg fatigue) were measured on a category-ratio scale from 0 to 10 (CR-10) during constant work rate (CWR) cycling exercise at the time of the shortest duration of each intervention arm (isotime). A lower CR-10 score for leg fatigue at isotime would reflect a beneficial response to the intervention.

Time frame: Baseline and day 7 of each treatment period

ArmMeasureValue (MEDIAN)
Stiolto RespimatChange From Period Baseline in the Exercise-isotime Borg CR-10 Rating of Perceived Leg Fatigue During CWR3 scores on a scale
Placebo RespimatChange From Period Baseline in the Exercise-isotime Borg CR-10 Rating of Perceived Leg Fatigue During CWR2.5 scores on a scale
Secondary

Change From Period Baseline in the Exercise-isotime Frontal Lobe Oxygen Saturation During CWR

Tissue saturation of hemoglobin with oxygen is measured by spatially resolved near-infrared spectroscopy from the frontal lobe during constant work rate (CWR) cycling exercise at the time of the shortest duration of each intervention arm (isotime). A greater frontal lobe oxygen saturation at isotime would reflect a beneficial response to the intervention.

Time frame: Baseline and day 7 of each treatment period

ArmMeasureValue (MEDIAN)
Stiolto RespimatChange From Period Baseline in the Exercise-isotime Frontal Lobe Oxygen Saturation During CWR62.5 Percent of hemoglobin saturated with O2
Placebo RespimatChange From Period Baseline in the Exercise-isotime Frontal Lobe Oxygen Saturation During CWR62.8 Percent of hemoglobin saturated with O2
Secondary

Change From Period Baseline in the Exercise-isotime in Pulse Oximeter Oxygen Saturation During CWR

Percentage of arterial hemoglobin that is saturated with oxygen, measured using pulse oximetry during constant work rate (CWR) cycling exercise at the time of the shortest duration of each intervention arm (isotime). A greater pulse oximeter oxygen saturation would reflect a beneficial response to the intervention.

Time frame: Baseline and day 7 of each treatment period

ArmMeasureValue (MEDIAN)
Stiolto RespimatChange From Period Baseline in the Exercise-isotime in Pulse Oximeter Oxygen Saturation During CWR99.0 percent of hemoglobin saturated with O2
Placebo RespimatChange From Period Baseline in the Exercise-isotime in Pulse Oximeter Oxygen Saturation During CWR98.5 percent of hemoglobin saturated with O2
Secondary

Change From Period Baseline in the Exercise-isotime Inspiratory Capacity During CWR

Inspiratory capacity (IC) measured during constant work rate (CWR) cycling exercise at the time of the shortest duration of each intervention arm (isotime). A greater IC would reflect a beneficial response to the intervention.

Time frame: Baseline and day 7 of each treatment period

ArmMeasureValue (MEDIAN)
Stiolto RespimatChange From Period Baseline in the Exercise-isotime Inspiratory Capacity During CWR1.91 Liters
Placebo RespimatChange From Period Baseline in the Exercise-isotime Inspiratory Capacity During CWR1.88 Liters
Secondary

Change From Period Baseline in the Exercise-isotime Inspiratory Reserve Volume During CWR

Inspiratory reserve volume (IRV) measured during CWR cycling exercise at the time of the shortest duration of each intervention arm (isotime). A greater IRV would reflect a beneficial response to intervention.

Time frame: Baseline and day 7 of each treatment period

ArmMeasureValue (MEDIAN)
Stiolto RespimatChange From Period Baseline in the Exercise-isotime Inspiratory Reserve Volume During CWR0.54 Liters
Placebo RespimatChange From Period Baseline in the Exercise-isotime Inspiratory Reserve Volume During CWR0.46 Liters
Secondary

Change From Period Baseline in the Exercise-isotime Muscle Oxygen Saturation During CWR

Tissue saturation of hemoglobin plus myoglobin with oxygen is measured by spatially resolved near-infrared spectroscopy from the vastus lateralis muscle during constant work rate (CWR) cycling exercise at the time of the shortest duration of each intervention arm (isotime). A greater muscle oxygen saturation at isotime would reflect a beneficial response to the intervention.

Time frame: Baseline and day 7 of each treatment period

ArmMeasureValue (MEDIAN)
Stiolto RespimatChange From Period Baseline in the Exercise-isotime Muscle Oxygen Saturation During CWR54.5 % of O2 saturated hemoglobin+myoglobin
Placebo RespimatChange From Period Baseline in the Exercise-isotime Muscle Oxygen Saturation During CWR53.4 % of O2 saturated hemoglobin+myoglobin
Secondary

Change From Period Baseline in the Exercise-isotime Oxygen Uptake (VO2) During CWR

Pulmonary oxygen uptake (VO2) measured during constant work rate (CWR) cycling exercise at the time of the shortest duration of each intervention arm (isotime). A lesser VO2 would reflect a beneficial response to the intervention.

Time frame: Baseline and day 7 of each treatment period

ArmMeasureValue (MEDIAN)
Stiolto RespimatChange From Period Baseline in the Exercise-isotime Oxygen Uptake (VO2) During CWR1.279 Liters/minute
Placebo RespimatChange From Period Baseline in the Exercise-isotime Oxygen Uptake (VO2) During CWR1.219 Liters/minute
Secondary

Change From Period Baseline in the Exercise-isotime Ventilation During CWR

Minute ventilation (VE) measured during constant work rate (CWR) cycling exercise at the time of the shortest duration of each intervention arm (isotime). A lesser VE would reflect a beneficial response to the intervention.

Time frame: Baseline and day 7 of each treatment period

ArmMeasureValue (MEDIAN)
Stiolto RespimatChange From Period Baseline in the Exercise-isotime Ventilation During CWR50.20 Liters/minute
Placebo RespimatChange From Period Baseline in the Exercise-isotime Ventilation During CWR45.25 Liters/minute
Secondary

Change From Period Baseline in the Forced Expiratory Volume in 1 Second (FEV1)

This outcome describes the the effect of the intervention on forced expiratory volume in 1 second (FEV1) during resting spirometry. A greater FEV1 would reflect a positive benefit of the intervention.

Time frame: Baseline and day 7 of each treatment period

ArmMeasureValue (MEDIAN)
Stiolto RespimatChange From Period Baseline in the Forced Expiratory Volume in 1 Second (FEV1)1.81 Liters
Placebo RespimatChange From Period Baseline in the Forced Expiratory Volume in 1 Second (FEV1)1.72 Liters
Secondary

Change From Period Baseline in the Pre/Post Exercise-induced Decline in Peak Isokinetic Power Normalized to the Measured Muscle Activity (Muscle Fatigue, MF) During CWR

Constant work rate (CWR) exercise causes muscle fatigue (MF) and reduces muscle activation (activation fatigue; AF). The relationship between muscle activity (using EMG) and power is measured at baseline (unfatigued condition). Fatigue is measured by the difference between pre-CWR and post-CWR maximal voluntary isokinetic power i.e. how much maximal voluntary isokinetic power declines during CWR. The fraction of the total fall in voluntary isokinetic power (total fatigue) that is ascribed to reduced muscle activity is then calculated from the reduction in EMG activity. The remainder is ascribed to muscle fatigue (MF) and expressed as a percentage of total fatigue. This measurement was made at peak exercise. A smaller value (%) of MF would be associated with a beneficial response to the intervention.

Time frame: Baseline and day 7 of each treatment period

ArmMeasureValue (MEDIAN)
Stiolto RespimatChange From Period Baseline in the Pre/Post Exercise-induced Decline in Peak Isokinetic Power Normalized to the Measured Muscle Activity (Muscle Fatigue, MF) During CWR20.9 percentage of total fatigue
Placebo RespimatChange From Period Baseline in the Pre/Post Exercise-induced Decline in Peak Isokinetic Power Normalized to the Measured Muscle Activity (Muscle Fatigue, MF) During CWR25.4 percentage of total fatigue
Secondary

Exercise Endurance Time During CWR Cycling Exercise

The duration in seconds for which constant work rate (CWR) cycling exercise could be tolerated prior to voluntary termination of exercise.

Time frame: Baseline and day 7 of each treatment period

ArmMeasureValue (MEDIAN)
Stiolto RespimatExercise Endurance Time During CWR Cycling Exercise297 seconds
Placebo RespimatExercise Endurance Time During CWR Cycling Exercise274 seconds
Secondary

The Magnitude of Change Electromyographic (EMG) Muscle Activity (Activation Fatigue, AF) Associated With Stiolto Respimat Compared With Placebo Respimat at Isotime During Constant Work Rate Exercise (CWR)

Constant work rate (CWR) exercise causes fatigue and reduces muscle activation. The relationship between muscle activation and power is measured at baseline (unfatigued condition). Fatigue is measured by the difference between pre-CWR and post-CWR maximal voluntary isokinetic power i.e. how much maximal voluntary isokinetic power declines during CWR. The fraction of fatigue that is ascribed to reduced muscle activity is then calculated. The magnitude of activation fatigue is measured in EMG activity and expressed in watts at the time of the shortest exercise duration in either study arm, which is termed isotime. A smaller value (in watts) of activation fatigue means that the intervention was associated with a less reduction in EMG activity after a given CWR exercise duration (i.e. at isotime).

Time frame: Baseline and day 7 of each treatment period

ArmMeasureValue (MEDIAN)
Stiolto RespimatThe Magnitude of Change Electromyographic (EMG) Muscle Activity (Activation Fatigue, AF) Associated With Stiolto Respimat Compared With Placebo Respimat at Isotime During Constant Work Rate Exercise (CWR)58 watts
Placebo RespimatThe Magnitude of Change Electromyographic (EMG) Muscle Activity (Activation Fatigue, AF) Associated With Stiolto Respimat Compared With Placebo Respimat at Isotime During Constant Work Rate Exercise (CWR)50 watts

Source: ClinicalTrials.gov · Data processed: Feb 18, 2026