No, you do not need to prune off all the old growth. And that in fact may be what is delaying or eliminating the flowering, as the vine is devoting all its energy on regrowing rather than producing flowers. I have not grown that particular variety myself but I have grown numerous other species and hybrids and never had reason to do any regular hard pruning. Just a light clean up/trim (you can remove all the dead foliage) in late winter or early spring and the occasional more severe rejuvenation pruning if the vine gets too woody and unwieldy. New growth should appear on the previous season's stems.