The KamLAND-Zen experiment is searching for the 0$\nu\beta\beta$ decay of $^{136}$Xe using 320--380\,kg of enriched Xe, mounted in the KamLAND detector in the Kamioka mine in Japan. In this talk, we report on the results of 504\,kg$\cdot$yr of data collected during the second phase of data taking, which followed a purification program of the liquid scintillator and Xe. Using this data, we set a limit on the 0$\nu\beta\beta$ half-life of $T_{1/2}^{0\nu}(^{136}\mathrm{Xe})>9.2\times10^{25}$\,yr at 90\% C.L. Combined with the results of the first phase, this limit improves to $T_{1/2}^{0\nu}(^{136}\mathrm{Xe})>1.07\times10^{26}$\,yr at 90\% C.L. Finally, we report on the current status of the next phase of the experiment, KamLAND-Zen 800.