While clinical trials results seem encouraging
Let us focus on Phase III Iomab-B Sierra trial and answer simple questions.
Will latest analysis performed on 75% of the population result in early termination for efficacy ?
The answer is NO, otherwise the company would have said so. Let us be clear on this.
So here comes the next question. What will be the outcome of the ad'hoc interim going forward for this 75% population ?
There can be two :
- Either the trial will continue till completion
- Either the IDMC will recommend the trial to stop
Can the IDMC recommend the trial to stop and for which reason ?
The answer is YES it can, for lack of power in the control arm
Let's look at the control arm
There were 5 patients evaluable (for primary endpoint) in the control arm at 50% interim VS 29 in the TEST arm (N=37+38)
There were 7 patients evaluable in the control arm VS 44 in the TEST arm at the 75% interim (N=53+53) => This is clearly not enough to terminate this trial at this point
How many evaluable patients will there when all 150 patients achieve treatment ? That is the outcome of the incoming ad'hoc meeting, it might be something like this :
N=75 TEST N=75 CONTROL
around 60- 62 patients evaluable in TEST and around 10 in Control
Clearly the IDMC might conclude through a conditional power analysis that there will never be enough evaluable patients in the control arm and recommend the study to be terminated for futility as designed as such. It might also recommend to continue till completion, but still the trial could complete without achieving enough power because of the control arm.
Thus Actinium management will need to talk to FDA to amend this trial and change the SAP (for instance to use historical survival instead of a control arm) or redo another better designed trial. I see this as very likely despite the encouraging results showed so far, whose gibberish language for the average investor is not showing clearly this reality. Talk to the FDA will take a lot of time and will delay things. The market will not accept this phase III news as good news
Sorry, but this is my understanding of the facts regarding Sierra Phase III Trial, but I guess we will know soon enough what is the outcome before the end of the year.
Fosco
