Historically RC has better outcomes. More recent trials show EVP (padcev + pembro) can be medium term effective. Data is still maturing for long term. Pembro alone is not as common and therefore complicated. Case reports on Inspire/BCAN show occasional good outcomes with ICI (usually nivo instead of pembro but both are very similar) with subsequent RC. You did not specify if this is UC or prostate malignancy. Plus adding ctdna tracking can further inform status.

There are also case reports with atezo being effective long term but IMVIGOR led to discontinuation. Ave is another ICI sometimes indicated as salvage treatment after successful re-challenge with chemotherapy upon recurrence.

Same with balversa for egfr positive disease. Highly toxic unfortunately.