At 1:30 PT you'll have your explanation.
1. They looked at results of 24 patients (planned interim).
2. They decided to add 12 more patients for one of two reasons:
A. Results were excellent but placebo group too high so they want more patients to confirm.
B. The drug effect they saw was too wide spread and they want more patients to have a truer understanding of the effect.
That's how I understand the quote below from Stonehouse:
But the key – I think a key element is to go to the 36 you need to see a good treatment effect, right. That’s important. So if it’s a bust, obviously we wouldn’t continue. But if you see a good treatment effect, then the placebo rate is higher than we had planned, or the distribution of effect on attack rate is wider than we expected, then that would make sense to go to 36.