There’s two ways. You can use the “HOLD” function in Live mode to trigger a note which will stay held. You can then use CC’s to play with the drone. The problem is hold mode can’t be sequenced. If you want your drone fully programmed then you’re going to have to use features of your synth to workaround the retrigger that happens when the pattern repeats. You can lessen the times this happens by changing the time signature of the track so it plays much slower but you’re still going to have to deal with the retrigger.
Slow attacks, portamento/legato can lessen retrigger effects.