Trial Outcomes & Findings for Trikafta in Cystic Fibrosis Patients (NCT NCT03506061)

Last Updated: 2025-09-11

Results Overview

FEV1 provides a direct measurement of patient health among individuals with cystic fibrosis and declines in FEV1 are associated with poor outcomes among those with CF. FEV1 is measured by spirometry and is the maximum amount of air the participant can blow out in one second.

Recruitment status

COMPLETED

Study phase

PHASE2

Target enrollment

42 participants

Primary outcome timeframe

Baseline, Day 28

Results posted on

2025-09-11

Participant Flow

Participants were enrolled at two sites in the United States: The Emory Children's Center in Atlanta, Georgia, and The University of Alabama Cystic Fibrosis Center in Birmingham, Alabama. Participant enrollment began September 4, 2019 and all follow-up assessments were completed by February 13, 2024.

Participant milestones

Participant milestones
Measure	Participants With Evidence of Partial Function (Sweat Chloride < 80 mEq/L or Pancreatic Sufficiency) Substudy 1 - Participants with cystic fibrosis (CF) with evidence of partial function (sweat chloride \< 80 milliequivalents per liter (mEq/L) or pancreatic sufficiency) receiving Trikafta for 28 days. Trikafta: Participants take Trikafta which is a combination tablet comprised of 100 milligrams (mg) of elexacaftor, 50 mg of tezacaftor and 75 mg of ivacaftor (2 tablets taken in the morning), and 150 mg of ivacaftor taken in the evening.	Participants Who Encode the N1303K Variant Substudy 2 - Participants with cystic fibrosis (CF) who encode the N1303K variant receiving Trikafta for 28 days. Trikafta: Participants take Trikafta which is a combination tablet comprised of 100 milligrams (mg) of elexacaftor, 50 mg of tezacaftor and 75 mg of ivacaftor (2 tablets taken in the morning), and 150 mg of ivacaftor taken in the evening.
Overall Study STARTED	22	20
Overall Study COMPLETED	20	20
Overall Study NOT COMPLETED	2	0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Trikafta in Cystic Fibrosis Patients

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Participants With Evidence of Partial Function (Sweat Chloride < 80 mEq/L or Pancreatic Sufficiency) n=22 Participants Participants with cystic fibrosis (CF) with evidence of partial function (sweat chloride \< 80 milliequivalents per liter (mEq/L) or pancreatic sufficiency) receiving Trikafta for 28 days.	Participants Who Encode the N1303K Variant n=20 Participants Participants with cystic fibrosis (CF) who encode the N1303K variant receiving Trikafta for 28 days.	Total n=42 Participants Total of all reporting groups
Age, Customized 12 to <18 years old	4 Participants n=5 Participants	8 Participants n=7 Participants	12 Participants n=5 Participants
Age, Customized 18 or more years old	18 Participants n=5 Participants	12 Participants n=7 Participants	30 Participants n=5 Participants
Sex: Female, Male Female	11 Participants n=5 Participants	10 Participants n=7 Participants	21 Participants n=5 Participants
Sex: Female, Male Male	11 Participants n=5 Participants	10 Participants n=7 Participants	21 Participants n=5 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	0 Participants n=5 Participants	2 Participants n=7 Participants	2 Participants n=5 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	22 Participants n=5 Participants	18 Participants n=7 Participants	40 Participants n=5 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Race/Ethnicity, Customized Southeast Asian	2 Participants n=5 Participants	0 Participants n=7 Participants	2 Participants n=5 Participants
Race/Ethnicity, Customized Black or African American	3 Participants n=5 Participants	0 Participants n=7 Participants	3 Participants n=5 Participants
Race/Ethnicity, Customized White or Caucasian	17 Participants n=5 Participants	18 Participants n=7 Participants	35 Participants n=5 Participants
Race/Ethnicity, Customized More than one race	0 Participants n=5 Participants	1 Participants n=7 Participants	1 Participants n=5 Participants
Race/Ethnicity, Customized Other	0 Participants n=5 Participants	1 Participants n=7 Participants	1 Participants n=5 Participants
Region of Enrollment United States	22 Participants n=5 Participants	20 Participants n=7 Participants	42 Participants n=5 Participants
CF Medical History Pancreatic Insufficiency	3 Participants n=5 Participants	20 Participants n=7 Participants	23 Participants n=5 Participants
CF Medical History CF-related Diabetes	3 Participants n=5 Participants	4 Participants n=7 Participants	7 Participants n=5 Participants
CF Medical History Chronic Sinusitis	12 Participants n=5 Participants	12 Participants n=7 Participants	24 Participants n=5 Participants
Percent of Predicted FEV1 Less than 50%	6 Participants n=5 Participants	4 Participants n=7 Participants	10 Participants n=5 Participants
Percent of Predicted FEV1 50% up to 75%	4 Participants n=5 Participants	3 Participants n=7 Participants	7 Participants n=5 Participants
Percent of Predicted FEV1 75% up to 100%	8 Participants n=5 Participants	13 Participants n=7 Participants	21 Participants n=5 Participants
Percent of Predicted FEV1 100% or More	4 Participants n=5 Participants	0 Participants n=7 Participants	4 Participants n=5 Participants

PRIMARY outcome

Timeframe: Baseline, Day 28

Population: The Analysis Population includes the intended use population. Two participants with evidence of partial function were found to have cystic fibrosis transmembrane conductance regulator (CFTR) genotypes that were approved by the FDA to use elexacaftor-tezacaftor-ivacaftor while the study was ongoing; these participants were removed from data analysis.

Outcome measures

Outcome measures
Measure	Participants With Evidence of Partial Function (Sweat Chloride < 80 mEq/L or Pancreatic Sufficiency) n=20 Participants Participants with cystic fibrosis (CF) with evidence of partial function (sweat chloride \< 80 milliequivalents per liter (mEq/L) or pancreatic sufficiency) receiving Trikafta for 28 days.	Participants Who Encode the N1303K Variant Participants with cystic fibrosis (CF) who encode the N1303K variant receiving Trikafta for 28 days.
Percent Predicted Forced Expiratory Volume in One Second (FEV1) Among Participants With Evidence of Partial Function Baseline	74.8 percent of predicted FEV1 Interval 72.4 to 77.2	—
Percent Predicted Forced Expiratory Volume in One Second (FEV1) Among Participants With Evidence of Partial Function Day 28	76 percent of predicted FEV1 Interval 73.6 to 78.5	—

PRIMARY outcome

Timeframe: Baseline, Day 28

Population: The Analysis Population includes the intended use population.

Persons with CF have higher levels of chloride in their sweat. Sweat chloride concentrations of less than or equal to 29 mmol/L are considered normal, concentrations of 30-59 mmol/L are considered intermediate and indicate that the individual may have CF. Concentrations of 60 mmol/L and greater mean that a diagnosis of CF is likely.

Outcome measures

Outcome measures
Measure	Participants With Evidence of Partial Function (Sweat Chloride < 80 mEq/L or Pancreatic Sufficiency) n=20 Participants Participants with cystic fibrosis (CF) with evidence of partial function (sweat chloride \< 80 milliequivalents per liter (mEq/L) or pancreatic sufficiency) receiving Trikafta for 28 days.	Participants Who Encode the N1303K Variant Participants with cystic fibrosis (CF) who encode the N1303K variant receiving Trikafta for 28 days.
Sweat Chloride Among Participants Who Encode the N1303K Variant Baseline	109 mmol/liter Interval 105.6 to 112.4	—
Sweat Chloride Among Participants Who Encode the N1303K Variant Day 28	107.9 mmol/liter Interval 104.5 to 111.3	—

PRIMARY outcome

Timeframe: Baseline

Population: Participants with evidence of partial function were included for the primary outcome measure of examining response of iPS cell derived epithelial monolayers. This analysis includes participants from which samples were successfully obtained, differentiated, and examined using bioelectric measurements.

Response of iPS cells (iPSc) to treatment among participants with evidence of partial function was examined to determine whether iPS derived monolayers could predict "personalized" clinical benefit. Cutaneous punch biopsy material was collected from each participant so that iPS cells could be differentiated into airway epithelial monolayers and tested for response to treatment in vitro - as a potential way to predict improvement from Trikafta in vivo.

Outcome measures

Outcome measures
Measure	Participants With Evidence of Partial Function (Sweat Chloride < 80 mEq/L or Pancreatic Sufficiency) n=8 Participants Participants with cystic fibrosis (CF) with evidence of partial function (sweat chloride \< 80 milliequivalents per liter (mEq/L) or pancreatic sufficiency) receiving Trikafta for 28 days.	Participants Who Encode the N1303K Variant Participants with cystic fibrosis (CF) who encode the N1303K variant receiving Trikafta for 28 days.
Number of Participants With Induced Pluripotent Stem (iPS) Cells Predicting Response to Treatment Among Participants With Evidence of Partial Function	0 Participants	—

SECONDARY outcome

Timeframe: Baseline, Day 28

Population: The Analysis Population includes the intended use population.

Outcome measures

Outcome measures
Measure	Participants With Evidence of Partial Function (Sweat Chloride < 80 mEq/L or Pancreatic Sufficiency) n=20 Participants Participants with cystic fibrosis (CF) with evidence of partial function (sweat chloride \< 80 milliequivalents per liter (mEq/L) or pancreatic sufficiency) receiving Trikafta for 28 days.	Participants Who Encode the N1303K Variant Participants with cystic fibrosis (CF) who encode the N1303K variant receiving Trikafta for 28 days.
Percent Predicted Forced Expiratory Volume in One Second (FEV1) Among Participants Who Encode the N1303K Variant Baseline	75.8 percent predicted FEV1 Interval 73.3 to 78.3	—
Percent Predicted Forced Expiratory Volume in One Second (FEV1) Among Participants Who Encode the N1303K Variant Day 28	85.3 percent predicted FEV1 Interval 82.8 to 87.8	—

SECONDARY outcome

Timeframe: Baseline, Day 28

Outcome measures

Outcome measures
Measure	Participants With Evidence of Partial Function (Sweat Chloride < 80 mEq/L or Pancreatic Sufficiency) n=20 Participants Participants with cystic fibrosis (CF) with evidence of partial function (sweat chloride \< 80 milliequivalents per liter (mEq/L) or pancreatic sufficiency) receiving Trikafta for 28 days.	Participants Who Encode the N1303K Variant Participants with cystic fibrosis (CF) who encode the N1303K variant receiving Trikafta for 28 days.
Sweat Chloride Among Participants With Evidence of Partial Function Baseline	66.9 mmol/liter Interval 63.8 to 70.1	—
Sweat Chloride Among Participants With Evidence of Partial Function Day 28	57.8 mmol/liter Interval 54.7 to 60.9	—

SECONDARY outcome

Timeframe: Baseline, Day 28

Participants take the CFQ-R corresponding to their age for assessing quality of life. Responses to questions are coded as 1 = very true or always, 2 = mostly true or often, 3 = somewhat true or sometimes, and 4 = not at all true or never. Some items are reverse scored so that higher scores indicate increased ability and higher quality of life. Scores for items in the respiratory domain are summed and standardized and the standardized score ranges from 1 to 100. A minimum clinically important difference (MCID) of 4 or more points represents improved respiratory-related quality of life.

Outcome measures

Outcome measures
Measure	Participants With Evidence of Partial Function (Sweat Chloride < 80 mEq/L or Pancreatic Sufficiency) n=20 Participants Participants with cystic fibrosis (CF) with evidence of partial function (sweat chloride \< 80 milliequivalents per liter (mEq/L) or pancreatic sufficiency) receiving Trikafta for 28 days.	Participants Who Encode the N1303K Variant n=20 Participants Participants with cystic fibrosis (CF) who encode the N1303K variant receiving Trikafta for 28 days.
Cystic Fibrosis Questionnaire - Revised (CFQ-R) Respiratory Domain Score Baseline	66.4 score on a scale Interval 59.8 to 73.1	60.6 score on a scale Interval 54.6 to 66.5
Cystic Fibrosis Questionnaire - Revised (CFQ-R) Respiratory Domain Score Day 28	74.1 score on a scale Interval 67.5 to 80.7	81.4 score on a scale Interval 75.5 to 87.3

SECONDARY outcome

Timeframe: Baseline, Day 28

Weight is measured in kilograms.

Outcome measures

Outcome measures
Measure	Participants With Evidence of Partial Function (Sweat Chloride < 80 mEq/L or Pancreatic Sufficiency) n=20 Participants Participants with cystic fibrosis (CF) with evidence of partial function (sweat chloride \< 80 milliequivalents per liter (mEq/L) or pancreatic sufficiency) receiving Trikafta for 28 days.	Participants Who Encode the N1303K Variant n=20 Participants Participants with cystic fibrosis (CF) who encode the N1303K variant receiving Trikafta for 28 days.
Weight Baseline	75 kilograms Interval 74.5 to 75.6	57.5 kilograms Interval 57.0 to 58.0
Weight Day 28	75.8 kilograms Interval 75.3 to 76.4	58.5 kilograms Interval 58.0 to 59.1

SECONDARY outcome

Timeframe: Baseline, Day 28

Body mass index is calculated as weight in kilograms divided by height in meters squared.

Outcome measures

Outcome measures
Measure	Participants With Evidence of Partial Function (Sweat Chloride < 80 mEq/L or Pancreatic Sufficiency) n=20 Participants Participants with cystic fibrosis (CF) with evidence of partial function (sweat chloride \< 80 milliequivalents per liter (mEq/L) or pancreatic sufficiency) receiving Trikafta for 28 days.	Participants Who Encode the N1303K Variant n=20 Participants Participants with cystic fibrosis (CF) who encode the N1303K variant receiving Trikafta for 28 days.
Body Mass Index (BMI) Baseline	25.4 kg/m^2 Interval 25.3 to 25.6	22.1 kg/m^2 Interval 21.9 to 22.3
Body Mass Index (BMI) Day 28	25.7 kg/m^2 Interval 25.5 to 25.9	22.5 kg/m^2 Interval 22.3 to 22.7

SECONDARY outcome

Timeframe: Baseline

Cutaneous punch biopsy material was collected from each participant so that iPS cells could be differentiated into airway epithelial monolayers and tested for response to treatment in vitro - i.e., as a potential way to predict benefit from Trikafta in vivo. By using iPS cells differentiated to exhibit a respiratory epithelial phenotype, the study aims to determine whether iPScs can be used to predict clinical improvement due to Trikafta.

Outcome measures

Outcome data not reported

Adverse Events

Participants With Evidence of Partial Function (Sweat Chloride < 80 mEq/L or Pancreatic Sufficiency)

Serious events: 0 serious events

Other events: 17 other events

Deaths: 0 deaths

Participants Who Encode the N1303K Variant

Serious events: 1 serious events

Other events: 14 other events

Deaths: 0 deaths

Serious adverse events

Serious adverse events
Measure	Participants With Evidence of Partial Function (Sweat Chloride < 80 mEq/L or Pancreatic Sufficiency) n=22 participants at risk Participants with cystic fibrosis (CF) with evidence of partial function (sweat chloride \< 80 milliequivalents per liter (mEq/L) or pancreatic sufficiency) receiving Trikafta for 28 days.	Participants Who Encode the N1303K Variant n=20 participants at risk Participants with cystic fibrosis (CF) who encode the N1303K variant receiving Trikafta for 28 days.
Respiratory, thoracic and mediastinal disorders Hospitalization due to cystic fibrosis pulmonary exacerbation caused by pneumonia	0.00% 0/22 • Information about adverse events was collected from the time of consent through Day 56.	5.0% 1/20 • Information about adverse events was collected from the time of consent through Day 56.

Other adverse events

Additional Information

Eric Sorscher, MD

Emory University

Phone: 205-612-1327

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place

Measure	Participants With Evidence of Partial Function (Sweat Chloride < 80 mEq/L or Pancreatic Sufficiency) n=22 participants at risk Participants with cystic fibrosis (CF) with evidence of partial function (sweat chloride \< 80 milliequivalents per liter (mEq/L) or pancreatic sufficiency) receiving Trikafta for 28 days.	Participants Who Encode the N1303K Variant n=20 participants at risk Participants with cystic fibrosis (CF) who encode the N1303K variant receiving Trikafta for 28 days.
Respiratory, thoracic and mediastinal disorders Increased coughing	31.8% 7/22 • Information about adverse events was collected from the time of consent through Day 56.	10.0% 2/20 • Information about adverse events was collected from the time of consent through Day 56.
Skin and subcutaneous tissue disorders Rash	27.3% 6/22 • Information about adverse events was collected from the time of consent through Day 56.	0.00% 0/20 • Information about adverse events was collected from the time of consent through Day 56.
Respiratory, thoracic and mediastinal disorders Increased sputum production	22.7% 5/22 • Information about adverse events was collected from the time of consent through Day 56.	10.0% 2/20 • Information about adverse events was collected from the time of consent through Day 56.
Gastrointestinal disorders Diarrhea	22.7% 5/22 • Information about adverse events was collected from the time of consent through Day 56.	0.00% 0/20 • Information about adverse events was collected from the time of consent through Day 56.
General disorders Fatigue	18.2% 4/22 • Information about adverse events was collected from the time of consent through Day 56.	10.0% 2/20 • Information about adverse events was collected from the time of consent through Day 56.
Infections and infestations Infective pulmonary exacerbation of cystic fibrosis	13.6% 3/22 • Information about adverse events was collected from the time of consent through Day 56.	0.00% 0/20 • Information about adverse events was collected from the time of consent through Day 56.
Infections and infestations Upper respiratory infection	13.6% 3/22 • Information about adverse events was collected from the time of consent through Day 56.	20.0% 4/20 • Information about adverse events was collected from the time of consent through Day 56.
General disorders Body aches	9.1% 2/22 • Information about adverse events was collected from the time of consent through Day 56.	10.0% 2/20 • Information about adverse events was collected from the time of consent through Day 56.
Respiratory, thoracic and mediastinal disorders Increased wheezing	9.1% 2/22 • Information about adverse events was collected from the time of consent through Day 56.	0.00% 0/20 • Information about adverse events was collected from the time of consent through Day 56.
Reproductive system and breast disorders Testicular pain	9.1% 2/22 • Information about adverse events was collected from the time of consent through Day 56.	0.00% 0/20 • Information about adverse events was collected from the time of consent through Day 56.
General disorders Headache	0.00% 0/22 • Information about adverse events was collected from the time of consent through Day 56.	15.0% 3/20 • Information about adverse events was collected from the time of consent through Day 56.
Respiratory, thoracic and mediastinal disorders Nasal congestion	0.00% 0/22 • Information about adverse events was collected from the time of consent through Day 56.	10.0% 2/20 • Information about adverse events was collected from the time of consent through Day 56.
Musculoskeletal and connective tissue disorders Joint pain	0.00% 0/22 • Information about adverse events was collected from the time of consent through Day 56.	10.0% 2/20 • Information about adverse events was collected from the time of consent through Day 56.
Ear and labyrinth disorders Ear pain	0.00% 0/22 • Information about adverse events was collected from the time of consent through Day 56.	5.0% 1/20 • Information about adverse events was collected from the time of consent through Day 56.
Respiratory, thoracic and mediastinal disorders Sinus congestion	0.00% 0/22 • Information about adverse events was collected from the time of consent through Day 56.	5.0% 1/20 • Information about adverse events was collected from the time of consent through Day 56.
General disorders Eosinophilia	0.00% 0/22 • Information about adverse events was collected from the time of consent through Day 56.	5.0% 1/20 • Information about adverse events was collected from the time of consent through Day 56.
Infections and infestations Pneumonia	0.00% 0/22 • Information about adverse events was collected from the time of consent through Day 56.	5.0% 1/20 • Information about adverse events was collected from the time of consent through Day 56.
Respiratory, thoracic and mediastinal disorders Decreased forced expiratory volume in one second (FEV1)	0.00% 0/22 • Information about adverse events was collected from the time of consent through Day 56.	5.0% 1/20 • Information about adverse events was collected from the time of consent through Day 56.
General disorders Decreased appetite	0.00% 0/22 • Information about adverse events was collected from the time of consent through Day 56.	5.0% 1/20 • Information about adverse events was collected from the time of consent through Day 56.
Infections and infestations Coronavirus disease 2019 (COVID-19)	0.00% 0/22 • Information about adverse events was collected from the time of consent through Day 56.	5.0% 1/20 • Information about adverse events was collected from the time of consent through Day 56.
Skin and subcutaneous tissue disorders Acne	0.00% 0/22 • Information about adverse events was collected from the time of consent through Day 56.	5.0% 1/20 • Information about adverse events was collected from the time of consent through Day 56.
Psychiatric disorders Increased anxiety	0.00% 0/22 • Information about adverse events was collected from the time of consent through Day 56.	5.0% 1/20 • Information about adverse events was collected from the time of consent through Day 56.
Infections and infestations Lower respiratory infection	0.00% 0/22 • Information about adverse events was collected from the time of consent through Day 56.	5.0% 1/20 • Information about adverse events was collected from the time of consent through Day 56.
Gastrointestinal disorders Constipation	0.00% 0/22 • Information about adverse events was collected from the time of consent through Day 56.	5.0% 1/20 • Information about adverse events was collected from the time of consent through Day 56.
Eye disorders Vision changes	0.00% 0/22 • Information about adverse events was collected from the time of consent through Day 56.	5.0% 1/20 • Information about adverse events was collected from the time of consent through Day 56.
General disorders Insomnia	0.00% 0/22 • Information about adverse events was collected from the time of consent through Day 56.	5.0% 1/20 • Information about adverse events was collected from the time of consent through Day 56.
General disorders Dry mouth	0.00% 0/22 • Information about adverse events was collected from the time of consent through Day 56.	5.0% 1/20 • Information about adverse events was collected from the time of consent through Day 56.