I think they are likely much too late to the party as monotherapy.
Given the entirely different MoA from the existing PCa treatments, I would think there could be a monotherapy role in patients refractory to Xtandi/Zytiga or any of the other PCa drugs. As fantastic of a drug as Xtandi is, it's not a cure, unfortunately, and patients will ultimately need other options.
For combo therapy in patients refractory to Xtandi/Zytiga (where the expense would be a real issue), I suppose it might be interesting, but so would other combinations (like a PI3k inhibitor).
I agree that combo therapy is likely the best path forward for OGX-427. But, why does such a role have to be limited to patients refractory to the existing PCa treatments? Why couldn't there be a role in earlier-stage disease if OGXI can show that 427 meaningfully adds on to efficacy of the existing treatments? Again, and I know it's very early and limited data, but note the CR when 427 was combined with prednisone vs. none in prednisone arm in the Phase 2 trial. It will be interesting to see in what patient population 427 will be tested in the upcoming combo trial w/Zytiga.