>what $ magnitude of [HIV] partnership are we looking at, in your opinion?<
That depends on the quality of the IDX899 head-to-head data vs Sustiva.
If IDX899 beats Sustiva on efficacy and resistance profile with no deficit in tolerability, a partnership will be worth very big bucks, IMO. (Sustiva sold at a $950M annualized rate during 3Q07.) If IDX899 is merely non-inferior to Sustiva in efficacy and tolerability, it may still have a place in the HIV SoC based on its higher barrier to resistance; in this case, a partnership could still be lucrative for IDIX but not to the same degree as above.
I’ll throw old some wild guesses that the first case above would be worth a $500M deal and the second case above would be worth a $150M deal. Obviously, there are shades of gray between the two cases depending on the details of the clinical results. Moreover, Sustiva could fail altogether in the phase-2 trial, although that’s not likely, IMO.
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