Feeling scared update

I posted back in November 2017, about my husband who has advanced prostate cancer. So much has happened since then. The oncologist discovered kieron's femor and hip were very close to fracturing due to disease spread so 13 weeks on a new femor and hip in place, one round of radiotherapy to the the femor and hip area, we are ready to start our next treatment. Kieron has hormone restraint prostate cancer. Kieron has recovered really well and his orthopaedic surgeon, is thrilled with kieron's ability to walk so well after the extent of his surgery. Our bubble was burst on Tuesday when we received kieron's latest PSA result it is 456. This is from 36 in November and 6 weeks post enzalutamide being withdrawn. We are on the experimental medicine waiting list at The Christie and we have our oncology appointment on Monday, since diagnosis in 2015 we have been on biclaclutamide, enzalutamide and had 1mg of docetaxol but unfortunately kieron is allergic to this. Any advice on next treatments we could be offered would be appreciated. We are very scared at the minute.