The present disclosure relates to compounds of formula (IVA) which are modulators of ATP-Binding Cassette ("ABC") transporters or fragments thereof, including Cystic Fibrosis Transmembrane Conductance Regulator, compositions thereof, and methods therewith, wherein the variables shown in formula (IVA) are as defined in the specification. The disclosure also relates to methods of treating ABC transporter mediated diseases using such modulators.