Well, I don't think you really gave all the datas necessary to solve your question. So, I will make a choice.
1) If I had to save someone's life by using an untested drug, I would do it, no matter the consequencies are. If the drug hasn't been tested so far and if it is the last solution to a beloved person's survival, then yes, I wouls use it.
2) Are there alternatives to using animals in testing? Yes of course, there are humans! Some of them are so desparate that they accept to test on themselves untested drugs on animals so far. This process is not legal everywhere and this is the raeson why it is not unanemously recognised.