A Study Evaluating the Long-term Safety and Efficacy of VX-121 Combination Therapy

Key Inclusion Criteria:

• Part A: Completed study drug treatment in a parent study VX20-121-102 (NCT05033080)and VX20-121-103 (NCT05076149); or had study drug interruption(s) in a parent studybut did not permanently discontinue study drug, and completed study visits up to thelast scheduled visit of the Treatment Period in the parent study

• Part B: Completed study drug treatment in Part A; or had study drug interruption(s)in Part A, but did not permanently discontinue study drug, and completed studyvisits up to the last scheduled visit of the Treatment Period of Part A

Key Exclusion Criteria:

• History of drug intolerance in a parent study

• Pregnant or breast-feeding females at the time of enrollment in Part A

Other protocol defined Inclusion/Exclusion criteria may apply.