resistance (merck has a high resistance barrier PI but i think it may have some tox issues)
Resistance within single classes of DAA's seems to be a minor issue. Sofosbuvir-based combo(s) reduce the viral load to undetectable levels within a week or two after the start of treatment. The virus doesn't have time to build resistant variants due to the high potency, and fast acting nature, of these nuke based combos. Even the ABBV combo has shown 90%+ SVR rates with little resistance issues so far. There will be differentiated class combinations for patients that show class resistance. The most important metric is DAA development are