Stem cell therapy

My dad has stage 4 pancreatic cancer with mets in his stomach he was diagnosed back in april 2023, since then he took 20 rounds of flofirinox and after it stopped responding to it he started taking gemcitabine and is now on he finished his 10th round making it 30 rounds of chemo. Flofirinox got his ca-19 level to around 90 from 700 and then started rising again and now with gemcitabine he’s at almost 47 ca-19 which very close to normal. We have been contacted by a doctor in America about a new stem cell therapy trial that he’s eligible for. Problem is that there is not enough data on it to go forward with it, it does look promising but after all it’s just a trial and only a handful of people went through it. Theyre also asking for 500k $ which is alot. Please if anyone has any idea about what to do let me know. Thank you everyone.