Bear in mind that the IMS scripts are for the US only, which is at most one-third of the global HBV market. Moreover, as goseek pointed out, IDIX’s sales reps probably knew for at least a month that they were soon going to be out of a job.
The issue now is how much detailing NVS plans to do with its own reps. I have no doubt that the drug will sell if it is aggressively detailed.