What to do in case of recurrence?

I would appreciate your helpful insights for a friend I am assisting regarding what is thought to be the best treatment options in case of recurrence? What are the most promising clinical trials? Would it be better to consider compassionate use of drugs in late-stage trials? I realize everyone's situation is different, so here are a few details:

Full resection in Aug 2018 at age 48. GBM unmethylated, IDIH wild type. Full genetic testing done, which showed he may be sensitized to a PARP inhibitor due to being BRCA1 positive, perhaps niraparib. We read that SLFN11 expression can further indicate sensitization to PARP inhibitors and his SLFN11 expression is “normal” and there are no mutations – so if this gene is important in the response to PARP inhibitors, that should be positive.  However, NO and MO say there is not enough data to show dosages of the PARP inhibitor with TMZ so are holding off on using at this time as he has just completed third round of 5/23 TMZ. They believe BRCA1 sensitizes patients to TMZ even if unmethylated. 

Is consideration for a clinical trial a better option in case of recurrence? There was something suspicious on the last MRI in a new area of the brain, so they have moved up scans to check again. He is consulting with UCSF after each scan along with local doctors. 

His cocktail also includes Valcyte, Celebrex, Metformin, Mebednazole, Keppra, Atorvastatin, Doxycycline, Bosweillic acid, Omega 3, mushrooms, Vit D, Curcumin, Probiotic, Selenium, Magnesium, Green tea extract, Melatonin, Astragalus, Milk Thistle, Lysine, Cimetidine, MCT oil, keto diet, lots of exercise. He is also on Optune.

Thank you so much for your input!