One of the three observed SAE’s appears to be explainable by gallstones
That certainly is Idenix's take on the matter but not mine. Considering the small size of the study (total of twenty patients), and the fact two other healthy patients experienced SAE's, nothing can be ruled out.
but two of the three SAE’s cannot be explained by any hypothesis other than an intracellular drug-drug interaction between IDX184 and IDX320
If this was true why did the FDA halt individual testing on IDX184 and IDX320? As you stated the DDI study came up clean and at this point nobody knows. IDX184 had previously shown unexplained tox signals at higher doses and IDX320 had an AE in 3 day POC testing. I'm not sure if latter event was listed as an AE but it was spoken about during the c.c.