if the info from the Gilead earnings call is correct, then there are _two_ factors
a) "at the doctor" ~ constraints are not physicians but back office and bureaucracy (I think the limit they mentioned was 250.000 patients)
b) "by the payer" ~ warehousing by _some_ payers (~ it was sth like some are very open on fibrosis restrictions, some only treat sicker patients/do warehousing
they also noted slide 22 again in the Q&A session (prescriptions written (not filled!)). there it says:
Genotype Fibrosis Score F3-F4, 44% F0-F2, 56%
they hinted that some of the lower fibrosis score patients do not get there prescriptions filled so might be a pool for the future
2.) vpak
good question. I only read about having problems to sell vpak even with free vouchers:
BS! The voucher program is working!! I left 20 vouchers at my top Hepatologist's office with the receptionist! She said she would place them in the waiting room by the People mags!! V Power!!!
I think the rejection rates over time are highly interesting. If Vpak comes down from about 80% rejection rate to a 40-50% rejection rate as other treatments, this should have an effect even without better marketing/broader acceptance.
(I hope this link has not already been posted, I haven't seen this info yet - it is from 11.03.2015)