Moving to monthly on the popeye juice... any issues?

Yes, I have done this with nivo with no issue.  

Following the initial 4 cycles of the combined ipi/nivo doses I developed inflammation in the kidney, and as a result an impaired eGR (kidney function).  Treatment was stopped for about 6-8 weeks whilst I went on a small steroid dose to reverse the situation.  Monotherapy nivo then re-introduced at a half dose every 2 weeks as a gradual introduction.  Although eGFR decreased again it wasn't low enough to stop treatment.  We continued with this approach every 2 weeks for a bit, then reverted to the "normal" dose and frequency of 4 weeks.  Nothing adverse happened. 

I actually think there's an admin problem with nivo every 2 weeks.  When I looked at my treatment sheet, there wasn't an "option" for nivo every 2 weeks.  It always said "nivo 4 weekly" with an exception note.  Minor point.  

Edit:  I just remembered when we changed the frequency to 4 weekly, we kept the bloods at 2 weekly.  Then after a couple  of months cancelled them because everything had stabilised (and I got fed up asking for "extra" bloods and having to explain why!

Useful information - thanks very much, appreciated.