AM-101 is ketamine, an old drug -- the only thing that's new is that it's a gel formation which is injected directly in to the ear. So, it's relatively invasive.
AUT00063 is a selective potassium channel modulator, which is a mechanism of action which has never really been explored for hearing disorders, and there are only one or two other drugs which have a similar mechanism, which are much less narrowly targeted. This drug is expected to be available as a normal pill you swallow.
AM-101 is closer to mass market; they have done a bunch of phase-III trials (larger groups of people than phase II). AUT00063 is expected to enter phase III at the beginning of next year.
Optimistically, if AUT00063 works out at all in the trials, it might be on the market in 2017/2018.