Spot on Ou….
While I think they can pull it off during the first interim review, the chances for success definitely increase at the second interim analysis.
I know you're reasoning is more sound and likely than mine.
The only things I would add are:
1. The 9 months PFS for the control group I used was a conservative high placeholder. Recently, Roche tested a drug and they still got 6.9 months in the control group using the latest/best surgery techniques along with the Stupps chemo/radiation protocol.
If the control group in the DCVAX-L trial is more like seven months, that means DCVAX-l only has to demonstrate 13 months pfs. That places the patients considered for this interim analysis out to November 2012.
2. Do not forget about the 33 treatment patients that were included in the trial from several years back.
312 - 33 = 279 patients. Only 279 patients to enroll as of Jan/Feb 2011.
Scientist don't think in quarters but NWBO does -- my low end was 15 per quarter. 7 quarters
x 15 = 105 + 33 = 138 by September 2012???
Would 138 (or less) be enough to power this trial? This is an orphan drug powering scenario. The 33 tail will ethically tilt PFS and OS in DCVAX-L's favor. NWBO previously received a P value of something like .0001 for PFS with a 20 person trial. The cross-over arm, as I explained in another post, will not harm the PFS. Finally, the 80% response rate may be the final push to get us over the hump.
The DMC has their work cut out for them, hopefully the stats will make it a no brainer for them, because their decision could mean lives or strengthening statistical relevance depending on their recommendation. That's a very tough job.
