re: ANDS -I tend to agree with you and also hope they're able to continue with ANA975 since it's a TLR-7 agonist , which has not received as much attention as , say , TLR-9. I think I mentioned here previously that the "extreme immune stimulation" observed was not so bad after all , since immune stimulation is the name of the game.
When they mentioned that they would be using the "new crystalline form " of ANA975 prepared by NVS it suggested to me that the adults at NVS figured the kids at ANDS needed help making clean drug.
I don't know anything about the synthesis of ANA975 except that it's a guanosine analog , but it seems at least theoretically possible that contaminating other-substituted analogs with high specific activity could be responsible for some of the activity(s) observed. My guess though, like yours , is that it's the 975.