Telaprevir most commonly causes anemia, rash, or pruritus.
Boceprevir most commonly causes anemia, neutropenia, or dysgeusia.
http://hepatitiscnewdrugs.blogspot.com/2010/02/telaprevirboceprevir-new-drugs-alters.html
24 weeks of treatment vs 48 is huge that is new vs current tx, and with much higher success with SVR in new tx.
telparevir does not seem to cause anemia, mostly the rash.
Boceprevir's main side effect is anemia and their are gastro issues for some, I have not noticed a huge difference in sides when it was added in my trial. The average drop in hgb from boceprevir is 1 point below what it would normally be with SOC.
Telaprevir's main side effect is rash and it can also cause anemia.
There are many other drugs in development besides those two. I am not sure of their side effects.