Idenix Pharmaceuticals (IDIX)

[DewDiligence]

Hepsera has finally plateaued: worldwide 4Q07 sales were $77M. This was up 31% vs 4Q06 but down 3% vs 3Q07 (#msg-26219426).

Although Hepsera still has a 45% Rx share of the US HBV market (according to today’s GILD CC), US dollar sales in 4Q07 fell 11% relative to 3Q07. (Some of this drop could have been caused by inventory adjustments.)

Why the reversal? Hepsera is clearly not the most efficacious option for treating HBV (#msg-24374381) and this is slowly but surely manifesting itself in lower sales in the first-line setting.

As has been noted on this board many times, patients who are stable on a given HBV therapy will not switch to a newer and better agent unless resistance develops, so sales of Hepsera will not fall precipitously.