Part of the issue is that both Zytiga and Xtandi are firmly in the more than half-century old main line of PCa treatments. Drugs with innovative new MOAs have to overcome that by being significantly better in some way.
We haven't yet seen what Z or X can do in very early stage disease. That's going to be very interesting, although you paradoxically might see more side effects than in late stage patients that already have castrate levels of androgen from prior treatments.
I agree that neither Z or X is a cure, but that mostly only opens up patients that have already progressed on them for other treatments. That could be a combo with Z/X or monotherapy.
So I'm not dismissing the OXG drug - just pointing out that it is late to the party and so will have a tougher time finding a niche and enrolling trials.