  We apply the similarity renormalization group (SRG) approach to evolve a
nucleon-nucleon ($NN$) interaction in leading-order (LO) chiral effective field
theory (ChEFT), renormalized within the framework of the subtracted kernel
method (SKM). We derive a fixed-point interaction and show the renormalization
group (RG) invariance in the SKM approach. We also compare the evolution of
$NN$ potentials with the subtraction scale through a SKM RG equation in the
form of a non-relativistic Callan-Symanzik (NRCS) equation and the evolution
with the similarity cutoff through the SRG transformation.
