Been snapped in half? Hope you didn't buy it like that.
Cut the spike. It's already getting dehydrated, look at the leaves closely. You will struggle keeping it alive without roots. It should start dropping leaves within days.
Oh, poor orchid Cut the spike right away and try any rooting hormone you can find ASAP. I agree that the leaves will start falling very soon, try your best to get some roots and hopefully the poor thing will pull through. It is a beautiful vanda, though!