The only issue regarding safety that I am aware of is that it...

The only issue regarding safety that I am aware of is that it has only been tested for a maximum of three months, which was in HCV patients.
The Australian trial is running for exactly that time, (three months of dosing), However the other trial is dosing for double that time, so safety does not seem to be a problem.
They did a series of tests fairly recently to assertain the levels that could be tolerated. Maybe that is what you are remembering.
Note: At the wrong volume, pretty much all of the cART drugs are toxic. Levels of dosing delivery are very important.