Recruiting
Phase 1

VX-581

Sponsor:

Vertex Pharmaceuticals Incorporated

Code:

NCT07283770

Conditions

Cystic Fibrosis

Eligibility Criteria

Sex: All

Age: 18 - 55

Healthy Volunteers: Accepted

Interventions

VX-581

Placebo

D-IVA

TEZ

ELX/TEZ/IVA

Study Details

Brief summary:

The purpose of this study is to evaluate the safety, tolerability, and pharmacokinetics of single dose of VX-581 and multiple ascending doses of VX-581 alone and in combination with tezacaftor (TEZ)/deutivacaftor (D-IVA) or D-IVA in healthy participants. The study will also evaluate the safety, tolerability, and pharmacokinetics of VX-581 administered in combination with D-IVA with or without TEZ in participants with cystic fibrosis (CF).

Conditions

Cystic Fibrosis

Study ID

NCT07283770

Start date

Dec 9, 2025

Status verified date

Oct, 2026

Completion date

Jul 12, 2027

Anticipated

Primary completion date

Jul 12, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 55

Healthy Volunteers: Accepted

Key Inclusion Criteria:

  • Parts A, B, C:

  • Body mass index (BMI) of 18.0 to 32.0 kilogram per meter square (kg/m\^2)
  • A total body weight of more than (>) 50 kg
  • Part D:

  • Confirmed diagnosis of CF

Key Exclusion Criteria:

  • Parts A, B, C:

  • History of febrile illness or other acute illness that has not fully resolved within 14 days before the first dose of study drug
  • Any condition possibly affecting drug absorption
  • Part D:

  • History of clinically significant cirrhosis with or without portal hypertension.

Other protocol defined Inclusion/Exclusion criteria may apply.

Study Design

Enrollment

152 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Part A: Single Ascending Dose

Participants will be randomized to receive a single dose of VX-581.

placebo comparator: Placebo: Part A

Participants will be randomized to receive a single dose of placebo matched to VX-581.

experimental: Part B: Multiple Ascending Dose

Participants will be randomized to receive multiple doses of VX-581.

placebo comparator: Placebo: Part B

Participants will be randomized to receive multiple doses of placebo matched to VX-581.

experimental: Part C: VX-581 with TEZ/D-IVA or D-IVA

Participants will be randomized to receive multiple doses VX-581 in combination with TEZ/D-IVA or D-IVA.

placebo comparator: Placebo: Part C

Participants will be randomized to receive placebo matched to VX-581 in combination with TEZ/D-IVA or D-IVA.

experimental: Part D: VX-581 with TEZ/D-IVA or D-IVA in CF

Participants with CF will enter a run-in period and receive ELX/TEZ/IVA. Following the run-in period participants will receive VX-581 in combination with TEZ/D-IVA or D-IVA in the treatment period. Following the treatment period, participants will enter a 14-day Washout Period and receive ELX/TEZ/IVA. (Part D will be open-label)

Interventions

VX-581

Suspension for Oral Administration.

Placebo

Suspension for Oral Administration.

D-IVA

Tablet for Oral Administration.

TEZ

Tablet for Oral Administration.

ELX/TEZ/IVA

Fixed dose combination (FDC) Tablets for Oral Administration.

VX-581

Tablets for Oral Administration.

IVA

Tablet for Oral Administration.

Primary outcome measure

  • Part A: Safety and Tolerability as Assessed by Number of Participants With Adverse Events (AEs) and Serious Adverse Events (SAEs) [ Time Frame: From Day -1 up to Day 8 ]
  • Part B: Safety and Tolerability as Assessed by Number of Participants With Adverse Events (AEs) and Serious Adverse Events (SAEs) [ Time Frame: From Day -1 up to Day 17 ]
  • Part C: Safety and Tolerability as Assessed by Number of Participants With Adverse Events (AEs) and Serious Adverse Events (SAEs) [ Time Frame: From Day -1 up to Day 17 ]
  • Part D: Safety and Tolerability as Assessed by Number of Participants With Adverse Events (AEs) and Serious Adverse Events (SAEs) [ Time Frame: From Signing of Informed Consent up to Day 105 ]

Central Contacts and Locations

Central contacts

Medical Information

617-341-6777medicalinfo@vrtx.com

Locations

Altasciences - Kansas City

Recruiting

Overland Park, Kansas, United States, 66212

More Information

Sponsor

Vertex Pharmaceuticals Incorporated

Last update posted

Oct 19, 2026

Last verified

Oct, 2026

Trial information was received from ClinicalTrials.gov and was last updated on 2026-10-23. This information was provided to ClinicalTrials.gov by Vertex Pharmaceuticals Incorporated on 2026-10-19. Recruitment status is synced daily from ClinicalTrials.gov and may not reflect the sponsor's current status. Confirm during your call.