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

September 4, 2026 updated by: Vertex Pharmaceuticals Incorporated

A Phase 1, Open-label, Randomized, Crossover Study to Evaluate the Relative Bioavailability of a Tablet Formulation of VX-581 in Healthy Adult Subjects

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.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

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 in healthy human participants. Note: This clinical trial information was submitted voluntarily under the applicable law and, therefore, certain submission deadlines may not apply. (That is, clinical trial information for this applicable clinical trial was submitted under section 402(j)(4)(A) of the Public Health Service Act and 42 CFR 11.60 and is not subject to the deadlines established by sections 402(j)(2) and (3) of the Public Health Service Act or 42 CFR 11.24 and 11.44.).

Study Type

Interventional

Enrollment (Estimated)

16

Phase

  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

Yes

Description

Key Inclusion Criteria:

  • 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

Key Exclusion Criteria:

  • 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

Other protocol defined Inclusion/Exclusion criteria may apply.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Sequence 1
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
Tablet and Suspension for Oral Administration.
Experimental: Sequence 2
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
Tablet and Suspension for Oral Administration.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Maximum Observed Plasma Concentration (Cmax) of VX-581
Time Frame: Period 1 and Period 2: From Day 1 up to Day 21
Period 1 and Period 2: From Day 1 up to Day 21
Area Under the Concentration Versus Time Curve (AUC) of VX-581
Time Frame: Period 1 and Period 2: From Day 1 up to Day 21
Period 1 and Period 2: From Day 1 up to Day 21

Secondary Outcome Measures

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

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Vertex Pharmaceuticals Incorporated

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

September 7, 2026

Primary Completion (Estimated)

October 27, 2026

Study Completion (Estimated)

October 27, 2026

Study Registration Dates

First Submitted

September 4, 2026

First Submitted That Met QC Criteria

September 4, 2026

First Posted (Actual)

September 10, 2026

Study Record Updates

Last Update Posted (Actual)

September 10, 2026

Last Update Submitted That Met QC Criteria

September 4, 2026

Last Verified

September 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • VX25-581-002

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Details on Vertex data sharing criteria and process for requesting access can be found at: https://www.vrtx.com/our-science/clinical-trials-data-sharing/

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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