Provenge seems to have some rough side effects. That is the sort of thing that makes the FDA reluctant to approve early stage use.
It’s been a while, but as I recall the side effects were fairly minimal and transient. Certainly less than chemo, and roughly the same as hormonal treatments. A few days of flu like symptoms resulting from the immune system being supercharged with prostate specific antigens.
It’s expensive and an involved process. There is no practical reason it couldn’t be given earlier, except that with the label for late stage cancer, insurance won’t pay for it. But it stands to reason as a immunotherapy that it would work better if given earlier, and the evidence shows that it works better when given to patients with low Gleason scores.
FDA took a long time to approve it, which is the main reason I thought of it here, contrasting with how they rushed the Covid mRNA shots. I am not a fan of calling those “vaccines”. It seems they have changed the definition of vaccine and I wish they didn’t. Just call them therapies. It would be great if they could generate patient specific treatments. NantHealth, which is owned by Patrick Soon-Shiong (biotech billionaire and owner of the LA Times and San Diego Tribune) has been developing genetic sequencing databases of cancer tumors with the idea that those specific sequences could be treated with targeted therapies. They may not need to be patient specific but rather gene sequence specific. I wonder if there is some connection there between NantHealth to these mRNA cancer gene therapies.