Well, so this is why you cannot read too much into a Phase 1b study, but the results are certainly positive and encouraging - and better than I expected. It is well known that Immunotherapy takes time to have an effect and that patients continue to deteriorate at first, until the immune response is generated and the immune system has time to ramp up and start working. Some of these patients will have been on the low or middle dose arm of the study (10 or 30 micrograms) - receiving far less dosage than the 50 microgram maximum.
It is worth considering that the 5 patients with a "partial response" would initially have shown as "stable disease" - and then progressed to significant tumour shrinkage. We have no way of knowing, but it is very possible that the 4 with "stable disease" will progress from that to "partial response."
Equally, we have no way of knowing (yet) whether the "partial response" group will continue to improve and end up with a full response. My understanding is that they will continue to monitor patients so we may find out more as time goes by.
It would be nice to see what dose levels the various patients received (10, 30 or 50 micrograms). Some will have been on the very low dose level.
And yes - we need a comparison with the control group who received standard of care Chemotherapy alone.
As Leslie said - these are only "top line results." To know more, we will have to wait for Professor Wiedermann's presentation in San Francisco next month.
I think it's a very positive report, but it was a small cohort dose escalation study to determine toxicity and dose level. It was a total success in those two primary endpoints. Effect on tumour size was only the final "exploratory" outcome because the trial was not capable of testing for that conclusively.
However, 90% of the patients who attended the day 56 evaluation showed stable disease or a significant reduction in tumour size.
They were truly unwell people at the start of the study. They all have "Metastatic gastric or GEJ adenocarcinoma, or locally advanced disease not amenable to surgical resection." That is a very, very bad diagnosis to have.
So if you were one of the 90% who now have stable disease or a significant reduction in tumour size, you would be pretty darn happy about the outcome.
It cannot be conclusive, and Mer's questions are very good, but the Phase 1b just exceeded my expectations.
Roll on Phase 2!
Cheers
Dave
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