Comment from Wenner Sharon

I'm writing because I care deeply about reducing animal suffering, and I believe this guidance is a real chance to do that without compromising drug safety. I’ve spent time learning about alternatives to animal testing — things like organ-on-a-chip models, organoids, and AI-based modeling — and what strikes me most is that we already have so much scientific evidence available in many cases. Human data, published research, past studies, validated non-animal methods. The question isn’t whether we have enough information — it’s whether we’re actually using all of it before deciding another animal study is necessary. So here’s what I ask the FDA to do: Please make it crystal clear what counts as a strong “Weight of Evidence” package — basically, the full folder of everything we already know that answers a safety question. Right now that standard is vague, and vagueness pushes people toward defaulting to another animal study just to be safe, even when it isn’t truly needed. Please make sure all existing evidence — not just animal data — gets weighed seriously and given real consideration, not treated as an afterthought. Please track whether this guidance is actually working. If the goal is fewer unnecessary animal studies, there should be a way to measure whether that’s happening, not just hope that it is. And please give researchers a chance to fill in gaps in their existing evidence before jumping straight to another animal study. A little more time to strengthen what they already have could save an animal’s life without costing anything in terms of safety. Rigorous science and compassion for animals aren’t opposites. This guidance can prove that. I hope the FDA takes this chance seriously. Thank you for reading this and for considering these changes.