It is a bit early to prune now, it will be just about to flower. As soon as it finishes flowering you can cut it right back, very hard. So long as there is a bit of green it will have time to put on a bit of growth before winter and it will be a new plant next year.
In the mean time turn the prunings into cuttings. Most sizes pieces will have a good chance of rooting in a mix with some sharp sand in, I stand them out side the North face of the greenhouse, of course the larger the cutting the quicker it turns into a decent size plant, up to the point where the foliage is losing water faster than the stem can absorb it. Have patience, they can take months and months to strike sometimes, but keep an eye on the bottom of the pot, sometimes they go quickly and get pot bound.
I have a nice hedge of 16 plants between one of my veg patches and the lawn that originated from pruning.