B^0_(s) -> h^+h'^- at LHCb

LHCb will collect very large samples of B-mesons decaying to charmless two-body final states. The combined measurement of the $B^0 \to \pi^+ \pi^-$ and $B^0_s \to K^+K^-$ time-dependent CP asymmetries allows to determine the Unitarity Triangle angle $\gamma$, up to U-spin flavour symmetry breaking corrections. Here the status of the analysis of the charged two-body charmless modes is presented. The study of the LHCb sensitivity on the direct and mixing-induced CP-violating parameters $A_{CP}^{dir}$ and $A_{CP}^{mix}$ is then performed and the final LHCb sensitivity to the $\gamma$ angle measurement using these decay modes is estimated.