So sometimes, the population of a trial does not show efficacy but some subgroup does. Like folks with a different gene, a different stage in the disease, etc.

So sometimes, the population of a trial does not show efficacy but some subgroup does. Like folks with a different gene, a different stage in the disease, etc. Frequently those sub-populations lack statistical power. So then a new trial will be made targeting that sub-population if it looks promising enough (i.e.: cost vs. potential benefit/market size). Is that a bad thing? It's variable whether the study that failed to get statistical results will get published and if so, how. The legally required filings with the FDA are done in any case.