Biotech Values

[bellweather1]

Re:TGTXs TGR-1202(PI3Kdelta) vs Ibrutinib Monotherapy(in CLL)

jaybe,

I know you're new to TGTX, but if you're going to compare these two montherapies, in fairness, I think you have to consider the following:

1)the 800mg dose escalation cohort for TGR-1202 couldn't have started before Sept 1,2013(see Sept 27th slide show, pg 18. It confirms they were on the 800mg cohort at the time): http://files.shareholder.com/downloads/MHA/2844438963x0x694000/fdce5f29-e29e-4e0e-9dbc-1c4feedbe843/TG_Therapeutics_Corporate_Presentaton_September_2013_-_Newsmakers.pdf)

Therefore, since the ASCO abstract only covered data till the end of Jan 2014, max tx was only 5 months and probably about 3 months avg. Plus, at least half of the pts were probably treated at a suboptimal dose, since this delta only starts to show significant nodal responses at about 800mg(with original dosing parameters).

2)Since we know no MTD has been identified, I think we can assume the optimal dose will be at least 1800mg(or the new regimen equivalent), and probably higher(due to the absence of significant toxicities). When you put that together with the fact that efficacy tends to increase with successive cycles of tx with this category of med., I can only assume that better(possibly much better)performance is likely with TGR-1202 with additional time and more ideal dosing, and that the 67% PR rate was extremely good efficacy in this context.

3)Therefore, comparing these results unfavorably with an Ibrutinib tx group that presumably got the optimal dose for at least a full 6 months in generating 100% nodal PRs in CLL doesn't seem appropriate, and it may be that TGR-1202 could, particularly with the new dosing regimen, get very close to that, or even match it in time.

4)At the least, however,(and particularly if the tox advantages hold up at higher levels of exposure), these results suggest to me that TGR-1202 may very well eclipse Idelalisib as the best in class PI3K in the tx of B-Cell malignancies.

Regards,

bw