Silicon Investor (SI) -- The First Internet Community

STOCKTALK

We've detected that you're using an ad content blocking browser plug-in or feature. Ads provide a critical source of revenue to the continued operation of Silicon Investor. We ask that you disable ad blocking while on Silicon Investor in the best interests of our community. If you are not using an ad blocker but are still receiving this message, make sure your browser's tracking protection is set to the 'standard' level.

Biotech / Medical : momo-T/FIF -- Ignore unavailable to you. Want to Upgrade?

To: Biotech Jim who wrote (11631)	8/9/2018 11:47:00 AM
From: tuck	Read Replies (1) \| Respond to of 12215

I have a small position in PIRS, but am a cautious holder. I continue to worry about antibody formation for the anti-calins. Have you seen any data, preclinical or otherwise, about that? Talked to management? Do you worry about it for anticalins more than for standard mabs, and if so, why? Is there an exposure time (perhaps not yet reached in early trials) at which point you'd expect a signal if there was such a problem? The difference between anticalins and naturally occurring endogenous lipocalins, as I understand it, is chiefly in the binding pockets. This is a consequence of using human lipocalin scaffolds to reduce immunogenicity upon repeat dosing. I do see a report of of one patient who had 17 doses of PRS-050 developing ADAs, but the other 24 patients in the study did not. Unfortunately, the report does not characterize the dosing regimen this patient received or titers (the dose range was pretty wide, see Fig1): First-in-Human Phase I Study of PRS-050 (Angiocal), an Anticalin Targeting and Antagonizing VEGF-A, in Patients with Advanced Solid Tumors None showed up in the PRS-080 trial (similar n, similar but narrower dose range) but that appears to have been just one dose. Similar to the 050 study, the 343 trial now recruiting may be more of an acid test in this regard; check out the dosing schedule: PRS-343 in HER2-Positive Solid Tumors This is open label, so we should see reports well before the end. 3x more patients than prior trials. 060 and 080 are relatively short regimens. I'd at least venture we won't see any ADA reports during this years readouts of the shorter trials :>) Roche in particular has a very high bar for progressing programs in the clinic. Which gave you MDGL :>) TIA & Cheers, Tuck