Replies to post #180154 on Biotech Values

[DewDiligence]

PTLA—what are your specific concerns about the commercial viability of andexanet alfa? Are you skeptical about whether there is truly an unmet need for an antidote, or are you anticipating that PTLA's collaborators are developing their own antidotes?

There is an unmet need for a FXa antidote, but I don’t think it’s an especially large commercial opportunity. Moreover, my sense is that the Big Pharma companies with FXa inhibitors (PFE/BMY, Bayer/JNJ, Daiichi Sankyo) are reluctant to make the availability of an antidote a focal point of their marketing campaigns because doing do would suggest that the drugs are unsafe. Any of the above Big Pharma could easily afford to munch PTLA if they thought it was strategic to control of the first FXa antidote, so we’re left with the inference that they don’t think it is.

Your question about competing antidotes is also valid. We know that JNJ (#msg-89624322) and Daiichi Sanyo (http://www.perosphere.com/content/news/httpwww.perosphere.comcontentnewsreleases042513.htm ) have done some work in this area.

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Overall, the biggest concern I have with PTLA is not about Andexanet alfa, but rather is about Betrixaban, the company’s own FXa inhibitor that is a day late and a dollar short (#msg-89332292, #msg-89332563).

[DewDiligence]

PTLA—Phase-3 data before the open/$184M* financing after the close:

http://finance.yahoo.com/news/portola-pharmaceuticals-announces-phase-3-120000960.html

http://finance.yahoo.com/news/portola-pharmaceuticals-announces-proposed-offering-202532734.html

In the phase-3 trial in question, Andexanet alfa hit all endpoints in reversing the anticoagulant effect of Eliquis. PTLA hopes to convince the FDA that demonstrating an actual clinical benefit for FXa reversal can be done in a post-marketing study, but I’m not sure the FDA will concur. Moreover, I’m not sure the commercial market for an FXa antidote is as large as PTLA claims (#msg-104066689).

I also have questions about PTLA’s clinical program for its own FXa inhibitor, Betrixaban, as noted in #msg-105048954.

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*The financing announced today specifies $160M in gross proceeds for an unspecified number of shares. If there’s a typical underwriter’s option that is exercised, the amount raised will be $184M.