Less reliable according to the people who are refusing the approval, but not according to the people arguing for it.
It doesn't mean that's the case here, but it's certainly possible. The suppression of discussion of it means it's hard to really know.
"Special emphasis must be placed on the harm of excluding trials data supporting ivermectin in the prevention of COVID-19. If the preventive efficacy of ivermectin were to be known or accepted, this would allow deployment in regions without vaccines."