RE:RE:RE:Spider PlotHelpful and a fairly realistic portrayal of how these things probably work.
On a different note, I'm not even really sure they are fully recruiting at all places yet. I can't say I really understand how the process works between THTX, the Contract Research Org they hired to compile all the data and run the website for investigators, and the cancer centers. I think I know, but can't say for sure.
But what is also probably happening is that you need a cancer center advocate and I think you all are correct in saying positive data will drive doctors to the trial and there isn't much yet.
We know there have been patients at Detroit and PA. For the others, we really don't know. I can't find the drug in the trials at Cedars Sinai despite them being a site. The doctors (Alain Mita and Monica Mita) seem to have some trials up there, but no TH1902 that I could find. Overall, Cedars has around 5-6 Phase 1 trials for solid tumors. They have a few SeaGen ones, Bristol Myers and even a Bioatla (the Soleus backed guys). So there's definitely competition and this was just a Phase 1 screen. There's probably a few more for Phase 2 and 3 programs for solid tumors. It wouldn't surprise me that they have not had patients enroll in each center yet. I don't know who's responsibility that is --Marsolais pitching, CRO pushing, Lead Investigator (MDAnd) pushing, or maybe you just can't do much.
qwerty22 wrote: This is 23 patients taking pembro every 3 weeks and getting scanned every 9 weeks, there are 23 patients and 5 responders. The top graph is a Spider plot. Every line is a patient, every dot on the line is a scan. People with progressive disease progress quickly and come off trial quickly. Most SD and responders hang around for longer, I only see two SD patients dropping out early, some come off trial when their disease eventually progresses. Most patients who are eligible to stay on trial stick around for at least 5 scans (15 drug cycles).
You can see from this plot that one responder converts at their first scan, two more on 2nd scan, another on 3rd and last on 4th. You need a follow on scan as a responder to confirm these patients so add one scan for confirmed response.
These are patients with metastatic disease. They may well be less sick than THTX's patient (or not) but you can see patients mostly run the course, they mostly don't drop out. It's how their cancer develops that mostly decides when they come off study. I think in 1a they could well have been getting the sickest of the sick. The drug at that stage is completely unproven and as a minimum they just need to complete the first cycle for the company to get the info they need. There should be a move to less sick patients given they have now proved a very little about this drug. If the story continues to progress with positive news that situation should improve as well. We probably shouldn't overplay too much the sickness of these people. There is the general notion that the trial is designed to answer the questions it's meant to, dropout rates should be figured into that.
It's plots like this where I get the idea the first few scans are crucial, at least the first three cycles but as much as first 5. While THTX are keeping us in the dark it's probably useful to try to use the experience from other trials to try to understand the practicalities of our trial.