From the view point of these schools of thought, virtue ethics, utilitarian ethics, deontological ethics; will any of them actually support carrying out an action with an unknown consequence.
Well firstly deontological ethics does not care about consequences, known or unknown; all that matters is if the act is itself is 'good'. Eg if you believe killing is wrong then killing one to save ten is wrong, because consequences don't matter.
For example testing a drug on a lady not knowing if this drug can kill the lady but you wanna do it coz this is a breakthrough for your company and this breakthrough is needed to save the company from bankruptcy. Lets say the lady really has no say in this situation.
Let us assume the lady is the environment, the environment cant speak for itself.
The consequence can be good or bad, and it will definitely generate greater happiness if the drug yields desired results.
As for how a utilitarian would approach your scenario, he would think about on one hand the benefits if the drug works x possibility of it working, and on the other hand the bad/painful effects on the lady if it fails x probability of it failing. If there is more for the plus side then you should test the drug; if there is more for the bad side you shouldn't.