  A class of exact, anisotropic cosmological solutions to the vacuum
Brans-Dicke theory of gravity is considered within the context of the pre-big
bang scenario. Included in this class are the Bianchi type III, V and VI_h
models and the spatially isotropic, negatively curved
Friedmann-Robertson-Walker universe. The effects of large anisotropy and
spatial curvature are determined. In contrast to negatively curved
Friedmann-Robertson-Walker model, there exist regions of the parameter space in
which the combined effects of curvature and anisotropy prevent the occurrence
of inflation. When inflation is possible, the necessary and sufficient
conditions for successful pre-big bang inflation are more stringent than in the
isotropic models. The initial state for these models is established and
corresponds in general to a gravitational plane wave.
