Goodbye and good luck18 Nov 2024 17:58
Quick one as after what happened (including watching the latest interview) I really don't want to waste any more time with this company any longer. Selection of patients? WTF?
Note that in the first 13 it was 85%(11/13) while with the next 12 (to get to 25) it was 58% (7/12). Within statistical probabilities but I'll let LD explain to you by email what she meant by patient selection.
Here goes in bullets.
- SCIB included epitopes that were identified in patients that spontaneously recovered, so pre validated in a way. Not the case with iSCIB1+.
- As I mentioned more than a year ago, because iscib1+ has these new epitopes, we don't know how they work. Iscib1+ is
now fully recruited with non hla a2 patients, so surely we have data on some of those. No mention though on how they are doing. You get the drift.
- iscib1+ on the hla a2 population should perform similary to scib1 but here is the thing, in my view iscib1+ is not eligible for orphan designation because it addresses a larger population.
- Therefore if in non hla a2 patients efficacy of iscib1+ is not great and is no longer eligible for orphan drug status it makes no sense to move forward with it. That's because scib1 original patent is as good as expired so they either use orphan status with scib1 for 6 years exclusivity or they riak someone else copying scib1 and undercutting iscib1+ in hla a2 patients.
- They cannot use iscib1+ that has the patent extension to only target hla a2 patients and keep the orphan drug status because the FDA would view that as salami slicing which they don't allow since 5 years ago at least.
- Avidimab mechanism of action is that it increases residence time of a regular antibody on the antigen, making it "slow off". It's a neat trick (that can be copied by the wat by using a different dimerisation method). SCIB is not a regular antibody though, the regular variable reguon that normally binds to the antigen has been replaced with the melanoma epitopes.
- So why are scancell saying it has higher avidity in T cells. Well, they are the only ones saying that and the data is published in the patent I talked about in my first report (check my very first comment on this thread). There, in a mouse study they showed that iscib is a lot better than scib. In fact in that study scib had almost no activity at all. However, in the original mouse experiment (also shown in the same patent) where they tested scib (different mouse model), it was obviously active. So this high avidity t cell argument due to avidimab is based on a specific mouse model and smells rotten to me.
The good news is at least if scib1 continues to show >70% response to the end, that gives you a much quicker pathway to starting the phase 2/3. iSCIB1+ is dead in the water in my humblest of opinions but if they decide to wait for that, it now has to recruit the hla a2 patients (same as scib1). About 20 of them. Do the math with the several recruitment data points we have already fr