A combination of measurements sensitive to the CKM angle $gamma$ from LHCb is performed. The inputs are from analyses of time-integrated $B^{+}rightarrow DK^+$, $B^{0} rightarrow D K^{*0}$, $B^{0} rightarrow D K^+ pi^-$ and $B^{+} rightarrow D K^+pi^+pi^-$ tree-level decays. In addition, results from a time-dependent analysis of $B_{s}^{0} rightarrow D_{s}^{mp}K^{pm}$ decays are included. The combination yields $gamma = (72.2^{+6.8}_{-7.3})^circ$, where the uncertainty includes systematic effects. The 95.5% confidence level interval is determined to be $gamma in [55.9,85.2]^circ$. A second combination is investigated, also including measurements from $B^{+} rightarrow D pi^+$ and $B^{+} rightarrow D pi^+pi^-pi^+$ decays, which yields compatible results.