  We analyze the stability of sessile filaments (ridges) of nonvolatile liquids
versus pearling in the case of externally driven flow along a chemical stripe
within the framework of the thin film approximation. The ridges can be stable
with respect to pearling even if the contact line is not completely pinned. A
generalized stability criterion for moving contact lines is provided. For large
wavelengths and no drive, within perturbation theory, an analytical expression
of the growth rate of pearling instabilities is derived. A numerical analysis
shows that drive further stabilizes the ridge by reducing the growth rate of
unstable perturbations, even though there is no complete stabilization. Hence
the stability criteria established without drive ensure overall stability.
