interim data from can-003 clinical trial

I spent some time today deciding whether to buy on the price dip today given “positive” interim clinical trial results. I decided not to and here is my reasoning.

The 7 non-randomised CVAC patients are relevant for safety but not for efficacy. The efficacy end point requires randomised patients. This group of 7 patients also have been on the study longer and this would affect mean PFS numbers. So the total number of scientifically relevant patients was 56 and I limited my analysis to this group.

The difference in PFS between randomised CVAC and OSC groups was 44 days. This is not a great difference so I wanted to work out the likelihood of this increasing or not and the likelihood of it being statistically significant at the end of the study (these 2 are related since a smaller difference is more difficult to prove statistically). So I then focussed on patients who had progressed in each group.

The number of patients who progressed was:
Remission 1: (CVAC: 9/18 OSC 5/17)
Remission 2: (CVAC: 4/11 OSC: 8/10)

So, the trend is heavily against CVAC in Remission 1 and for CVAC in Remission 2.

Overall: (CVAC: 13/29 OSC: 13/27)

Overall, there is not much of a trend. What the numbers have running against them going forward is the larger number of patients in the OSC group in Remission 1 who have not progressed. As we speak, these patients are probably increasing the mean PFS of the OSC group. While the opposite is true for the Remission 2 group, this will have less impact on the mean due to the lower PFS in this group (as one would expect).

This is interim data so I can only make an educated guess. I suspect that the CAN-003 study final results will not show an improvement in progression free survival in the Remission 1 group. There is likely to be a favourable trend for CVAC in the Remission 2 group but since this group is very small, there may not be a statistical difference. I thus suspect the overall result will be no significant difference when the 2 groups are combined.

I have no inside information or specialist insight, this is purely a personal analysis and is why I did not buy today. I would be keen to hear other views, this is my personal view and analysis only. I know holders often don't like posts like this from non-holders but if it is wrong, let's hear about it and why. Judging on the SP today, I suspect others have done a similar analysis.