I think there is reason that this device doesn't have enable/disbale pin. Darlington Transitor is just a switch that has a trasistor pair instead of one. There is nothing to enable or disable a switch. The inputs (base terminal) acts as enable/disable pin for each pair. Here is a diagram of darlington transistor:
This transistor is useful when current at the base of the transistor is too weak to switch a normal switching transistor. Here, First transistor is turned on with small input current(~.82mA) which is then amplified and fed to the base of 2nd transistor.
So when you provide '0' at the Input, the switched is turned off and no current flows. Except some leakage current ICE within the transistors. But this is very small, practically around 100uA.
So this means to disable the IC from power consumption, just put 0V at the inputs. No current will be drained except some small leakage.
As for pin9(com), this doesn't 'disable' the device. It just shorts the output pins with the 'com' pin(see the schematic in datasheet). You'll still have power consumption through the IC.