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

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.).

• VX-581 (Drug): Tablet and Suspension for Oral Administration.

Primary outcomes

• 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

• 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)]

Sex: Male, ages: 18 Years to 55 Years, accepts healthy volunteers

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.