Any trial conducted after approval would be Phase
Post# of 72440
Ziagen has 83% bioavailability. Since 300 mg of Ziagen is bioequivalent to 350 mg of Prurisol, Prurisol has 71% bioavailability. Ziagen is often prescribed for 600 mg per day, so there's:
600 mg of Ziagen * 0.83 = 498 mg of abacavir in circulation
400 mg of Prurisol * 0.71 = 284 mg of abacavir in circulation
We already know that 200 mg is working. I think 400 mg is the sweet spot for efficacy without the nasty side effects. Anything higher could have side effects similar to Ziagen.