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jammyjames

01/07/21 3:44 PM

#345675 RE: flipper44 #345328

"This is what you were trying to limit the damage to in the Optune trial:

Quote:
....where i personally think novocure are being immoral however is quoting a totally unreliable 5-year survival % -Jimmy James



But then you turn around and state you agree with Dr. Liau and her colleagues (whom I agree with) were essentially correct when it was brought to your attention they said Optune does not work, and it was a poorly designed trial, but you think it just doesn’t work that well. "


What are you on about? the unreliable 5-year KM stat and whether optune actually works or not are totally different issues. There's no contradiction between having an unreliable 5-year stat and a therapy being statistically proven to work. You really show your lack of understanding of the stats when you come out with this rubbish. Same goes for the forecasting/extrapolation.

"And here on January 5 you defend the Optune censoring as essentially the same between arms and always fine as long as defined ahead of time.

Quote:
Then there's no issue so long as the censoring reasons are the same for both arms and the numbers are similar which they more or less seem to be. Also it doesn't matter so much that it's unblinded so long as those reasons for censoring are defined a priori.

"


You should put this back in its original context. Here i'll do it for you (post: 345029):

"Flipper: "The excessive censoring occurred to a higher percentage in the Optune arm, but Stupp’s SOC arm was pumped with excessive censoring as well."

Me: Then there's no issue so long as the censoring reasons are the same for both arms and the numbers are similar which they more or less seem to be. Also it doesn't matter so much that it's unblinded so long as those reasons for censoring are defined a priori. "


I was replying to your assertion that the SOC arm was also heavily censored. Maybe would have better if i had stated "if that were the case then there's no issue...". I had always thought that the optune arm was more heavily censored than the SOC arm. But actually looking at that data from page 18, table 4 of the SSED (https://www.accessdata.fda.gov/cdrh_docs/pdf10/P100034S013b.pdf) it doesn't look as bad as i originally thought. There's still clearly some bias in the trial:

1) there's slightly more disease progression and withdrawal with optune compared to SOC - that's the classic bias where heathier patients stay in the trial.
2) there are a lot of active follow up censors. The good thing is that it's a similar % on both arms. However there's no information on the breakdown of those numbers and for sure some bias can creep in there. Overall if the criteria for censoring is defined a priori this should be kept to a minimum.

But overall i think there would have to be a lot of bias to get those two arms overlapping. Hence, i think optune works but difficult to say exactly how much (for sure less than they claim) and at the same time i think that 5-year KM survival stat is meaningless. That's been my opinion the whole time only now i have slightly more faith that it works seeing a better break down of the censors.