A Phase 1 Relative Bioavailability Study of a VX-581 Tablet Formulation

NCT07813039 | Not Yet Recruiting Phase 1 FDA Drug

• 1 other identifier: VX25-581-002
• Study Type: interventional
• Target: 16
• Locations: 0 countries
• Sites: N/A

Brief Summary

The purpose of this study is to evaluate the relative bioavailability of VX-581 tablet formulation compared to a suspension formulation along with its safety and tolerability.

Conditions

Cystic Fibrosis

Outcome Measures

Primary Outcomes (2)

• Maximum Observed Plasma Concentration (Cmax) of VX-581

  Period 1 and Period 2: From Day 1 up to Day 21

• Area Under the Concentration Versus Time Curve (AUC) of VX-581

  Period 1 and Period 2: From Day 1 up to Day 21

Secondary Outcomes (1)

• Safety and Tolerability as Assessed by Number of Participants With Adverse Events (AEs) and Serious Adverse Events (SAEs)

  From Signing of Informed Consent Form (ICF) up to Safety Follow Up (Up to Day 21)

Study Arms (2)

Sequence 1

EXPERIMENTAL

Participants will be randomized to receive VX-581 suspension in dosing period 1 followed by VX-581 tablet in dosing period 2. A washout period of 10 days will be maintained between the 2 dosing periods.

Drug: VX-581

Sequence 2

EXPERIMENTAL

Participants will be randomized to receive VX-581 tablet in dosing period 1 followed by VX-581 suspension in dosing period 2. A washout period of 10 days will be maintained between the 2 dosing periods.

Drug: VX-581

Interventions

VX-581 DRUG

Tablet and Suspension for Oral Administration.

Sequence 1; Sequence 2

Eligibility Criteria

• Age: 18 Years - 55 Years
• Sex: male
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Body mass index (BMI) of 18.0 to 32.0 kilogram per meter square (kg/m\^2), inclusive
• Total body weight of greater than (\>) 50 kg
• Nonsmoker or ex-smoker for at least 3 months before screening with current nonsmoking status confirmed by urine or blood cotinine at screening

You may not qualify if:

• 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

Sponsors & Collaborators

• Vertex Pharmaceuticals Incorporated: lead

MeSH Terms

Conditions

Cystic Fibrosis

Condition Hierarchy (Ancestors)

Pancreatic Diseases; Digestive System Diseases; Lung Diseases; Respiratory Tract Diseases; Genetic Diseases, Inborn; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Infant, Newborn, Diseases

Central Study Contacts

Medical Information

CONTACT

617-341-6777; medicalinfo@vrtx.com

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: CROSSOVER
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: September 4, 2026
• First Posted: September 10, 2026
• Study Start: September 7, 2026
• Primary Completion (Estimated): October 27, 2026
• Study Completion (Estimated): October 27, 2026
• Last Updated: September 10, 2026

Record last verified: 2026-09

Data Sharing

• IPD Sharing: Will not share