Replies to post #115822 on Biotech Values

[DewDiligence]

I've seen that chart but it does not directly speak to my point - first, Avonex is not broken out…

Who cares? It makes perfect sense to consider Avonex, Rebif, Betaseron, and Extavia as a single group for this kind of analysis.

…and second, it profiles Gilenya's source of business in a conventional sense, i.e. which drugs patients were taking before they switched to Gilenya. Which is not the same as which drugs is Gilenya stealing share from - these are the drugs that patients would be prescribed in Gilenya's absence but instead are prescribed Gilenya.

Actually, the graphic in #msg-59293907 does speak to this question indirectly—it shows that half of Gilenya’s US scripts are coming from patients who were not on another drug. To a first-order approximation that is good enough for our purposes, these patient starts are being taken from other drugs in proportion to what those drugs’ share of the first-line setting was prior to Gilenya’s launch.