Most likely "could be the morons at regal pushing it down to...

Most likely "could be the morons at regal pushing it down to accumulate" as iminvestor was guessing. There is no real bad news, IMO. P2 starts a month or 2 later and the time of the study will last longer but IMO the original 6 months on ATH434 was too short a time. 12 months on the drug is safer to get the wanted effects if the drug works. There are some indicators that can turn positive much earlier as brain iron content, neurofilament light but improving motor function may come late as was the case with the animal models. It will also demonstrate the possible side-effects which are best to be found early ( all drugs have these).
In fact, there is more positive news.
- Expecting a billion deal with PBT2
- Oct 2021: "The Compound ATH434 Prevents Alpha-Synuclein Toxicity in a Murine Model of Multiple System Atrophy"
- Oct 2021: "ATH434 Reverses Colorectal Dysfunction in the A53T Mouse Model of Parkinson's Disease"
- Nov 2021: "ATH434 Reduces α-Synuclein-Related Neurodegeneration in a Murine Model of Multiple System Atrophy", not commented by the company
- Jul 2021: "The iron chelator, PBT434, modulates transcellular iron trafficking in brain microvascular endothelial cells", the Kosman paper, not commented by the company.

The main thing is PBT2 news which can come any day. This is why I think the evident short activity could happen within the same single day, but I am not an expert in evaluating short activity methods.