A study in people with Cystic Fibrosis ( a rare hereditary lung disease) to assess the efficacy and safety of a combination of two experimental drugs

A Phase 3, Randomized, Double-Blind, Ivacaftor-Controlled, Parallel-Group Study to Evaluate the Efficacy and Safety of VX-661 in Combination With Ivacaftor in Subjects Aged 12 Years and Older With Cystic Fibrosis, Heterozygous for the F508del-CFTR Mutation and a Second CFTR Allele With a Gating Defect That Is Clinically Demonstrated to be Ivacaftor Responsive

Status

Active, not recruiting

Phases

Phase 3

Study type

Interventional

Source

EU CTR

Registry ID

EUCTR2014-004838-25-IT

Enrollment

200

Registered

2015-03-30

Start date

2015-05-20

Completion date

Unknown

Last updated

2018-02-19

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

Conditions

Cystic Fibrosis MedDRA version: 17.1 Level: PT Classification code 10011762 Term: Cystic fibrosis System Organ Class: 10010331 - Congenital, familial and genetic disorders

Interventions

Product Name: VX-661/ivacaftor 100mg/150mg Product Code: VX-661/VX-770 Pharmaceutical Form: Film-coated tablet INN or Proposed INN: Not yet assigned CAS Number: 1152311-62-0 Current Sponsor code: VX-6

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: • Heterozygous for F508del-CFTR mutation and a second CFTR allele with a gating defect that is clinically demonstrated to be ivacaftor responsive • FEV1 =40% and =90% of predicted normal for age, sex, and height during screening • Stable CF disease as judged by the investigator. Are the trial subjects under 18? yes Number of subjects for this age range: 100 F.1.2 Adults (18-64 years) yes F.1.2.1 Number of subjects for this age range 100 F.1.3 Elderly (>=65 years) no F.1.3.1 Number of subjects for this age range

Exclusion criteria

Exclusion criteria: • History of any comorbidity that, in the opinion of the investigator, might confound the results of the study or pose an additional risk in administering study drug to the subject. • Pregnant and nursing females (females of childbearing potential must have a negative pregnancy test at Screening and Week -4 Visits). • Sexually active subjects of reproductive potential who are not willing to follow the contraception requirements

Design outcomes

Primary

Measure	Time frame
Main Objective: To evaluate the efficacy of VX-661 in combination with ivacaftor in subjects with CF who are heterozygous for the F508del mutation on the CFTR gene and a second CFTR allele with a gating defect that is clinically demonstrated to be ivacaftor responsive ;Secondary Objective: To evaluate the safety of VX-661 in combination with ivacaftor To investigate the pharmacokinetics (PK) of VX-661 and its metabolites, M1 and M2 (M1-661 and M2-661, respectively) and ivacaftor and its metabolite M1 (M1 ivacaftor) ;Primary end point(s): Absolute change in percent predicted forced expiratory volume in 1 second (FEV1) from baseline;Timepoint(s) of evaluation of this end point: Week 8	—

Measure

Time frame

Main Objective: To evaluate the efficacy of VX-661 in combination with ivacaftor in subjects with CF who are heterozygous for the F508del mutation on the CFTR gene and a second CFTR allele with a gating defect that is clinically demonstrated to be ivacaftor responsive ;Secondary Objective: To evaluate the safety of VX-661 in combination with ivacaftor To investigate the pharmacokinetics (PK) of VX-661 and its metabolites, M1 and M2 (M1-661 and M2-661, respectively) and ivacaftor and its metabolite M1 (M1 ivacaftor) ;Primary end point(s): Absolute change in percent predicted forced expiratory volume in 1 second (FEV1) from baseline;Timepoint(s) of evaluation of this end point: Week 8

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Secondary

Measure	Time frame
Secondary end point(s): • Relative change in percent predicted FEV1 from baseline through Week 8 • Absolute change in sweat chloride from baseline through Week 8 • Absolute change in Cystic Fibrosis Questionnaire – Revised (CFQ-R) respiratory domain score from baseline through Week 8 • Safety and tolerability assessments based on adverse events (AEs), clinical laboratory values, standard 12-lead electrocardiograms (ECGs), vital signs, and pulse oximetry; from screening through 4 weeks after receiving last dose • PK parameters of VX-661, M1-661, M2-661, ivacaftor, and M1 ivacaftor through Week 8;Timepoint(s) of evaluation of this end point: Weeks 8 and 12	—

Measure

Time frame

Secondary end point(s): • Relative change in percent predicted FEV1 from baseline through Week 8 • Absolute change in sweat chloride from baseline through Week 8 • Absolute change in Cystic Fibrosis Questionnaire – Revised (CFQ-R) respiratory domain score from baseline through Week 8 • Safety and tolerability assessments based on adverse events (AEs), clinical laboratory values, standard 12-lead electrocardiograms (ECGs), vital signs, and pulse oximetry; from screening through 4 weeks after receiving last dose • PK parameters of VX-661, M1-661, M2-661, ivacaftor, and M1 ivacaftor through Week 8;Timepoint(s) of evaluation of this end point: Weeks 8 and 12

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Countries

Austria, Belgium, Canada, France, Germany, Ireland, Italy, United Kingdom, United States

Contacts

Public ContactClinical Trials and Medical Info

Vertex Pharmaceuticals Incorporated

medical_info@vrtx.com1877634-8789

Outcome results

None listed

Source: EU CTR (via WHO ICTRP) · Data processed: Feb 4, 2026