Koo asked, "...can BTI be tested for safety in a Phase 1 clinical trial by itself?"

I suspect, Koo, that you are asking whether the peptide, xB3, without a payload, can be tested in a phase 1 clinical trial.

I don't think it would even be tested by itself in an animal model. If I recall correctly, there were questions asked about that years ago. From a proof of concept standpoint it would serve no purpose because xB3 is not a therapeutic. xB3 really only makes sense as an attachment to a therapeutic payload, a drug. Testing xB3 alone in animals would be a wasted expense because no really valuable information could come from it.

Because xB3, alone, has no therapeutic value, testing it in humans (phase 1) would not likely be allowed for ethical reasons. Preclinical studies and clinical trials are intended to test the safety and efficacy of drugs that have an intended therapeutic effect. I doubt the FDA would allow xB3 to be tested in clinical ttrials because it has no intended therapeutic effect.

I think it's necessary on some level to think of xB3-001, not as xB3 + trastuzumab, but as a drug that is just another version of trastuzumab that, by virtue of having one or more xB3 peptides forming part of the molecule, has a big extra capability - it can cross the BBB.

jd