How would you sequence therapies for a patient with chemotherapy-naive metastatic castration-resistant prostate cancer who is MSI-H on tissue-based NGS?  

Yes, I absolutely would use Pembrolizumab (200 mg IV q3wk, or 400 mg IV q6wk) in a MSI-high patient with mCRPC who has not yet received chemotherapy. However, I would probably postpone this until after the patient has progressed on one novel AR-directed therapy. I think that the "sweet spot" for usi...