What you need to know is that all reported interim data to date is blinded. So you cannot as yet measure treatment efficacy against control. You can only make projections based on how effective you think the treatment might be. The crossover provision allows control patients to switch to guaranteed DCVax treatment after disease progression. That is why to date 90% of all patients have received DCVax instead of only 66%. That is also why the OS endpoint is somewhat confounded. How can you measure treatment efficacy versus placebo, when most of placebo also got DCVax but later on after progression?
The treatment/control placebo ratio was always supposed to be 2:1.
So the ratio should be 220 treatment patients and 110 control (placebo) patients.
But it isn't 2:1. It is actually 232 and 99.
The prevailing view is that the hold on recruitment (Aug 2015) for some unknown reason led to a situation whereby no further patients were allowed to be recruited to placebo.
So another 34 patients were recruited but all went to treatment.
Hence we have a ratio more like 70:30.
I'll stop there, otherwise I could go on forever.
But, if you want to get an overview of the trial so far, read the interim report published in JTM and presented at ASCO in June '18.
It will answer maybe 60% of your questions, and probably raise a load more.
But it will give you the essential facts thus far.
Here's the link:- https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-018-1507-6
Then read the updated data presented at SNO this last Autumn and you can see how the data is developing.
All the signs of unprecedented long tail survival for 25-30% of trial population.
Only key data points available on the update, but they are here:- https://nwbio.com/updated-interim-data-from-phase-3-trial-of-dcvax-l-for-glioblastoma/