RE:The trial's pathway I think they'll do the two groups unless there's serious safety issues, which seems doubful given all the previous administrations at around this level. For myself, I think the initial level of dosage is on the low side (around the 200-ish level if I recall using last dose type). It may be efficacious given all the other pre-screening optimizing going on and having seen previous success in serous ovarian. But I think it may be more safety, a hope to show stable or maybe someones partial. But the second level is really closer to the efficacions level they used before --the 300-ish level. The potency should show better efficacy and hopefully the safety issues are still within parameters (there's always going to be eye issues and some neuropathy issue and other SAEs with any targeted oncology drug, but not enough to kill someone).
So realistically I think you shoudl look for the first 6 to show complete safety, learn something around the new regime, maybe/maybe not some kid of efficacy, but likely not blow away efficacy. The second larger batch is where you'd hope to see efficacy. Any kind of show in the first cohort to me would be huge --massive --even SDs and the like, as it wasn't a very large dose and would show a bit of the Proof of Concept that it's getting in quickly, on target, it grabs hold of Sort1, internalized, kills come of the cells. Just need to then pump up the dose to boost efficacy.