Nuplazid is a decent earner for the US biotech in psychosis caused by Parkinson’s disease but following previous failures in Alzheimer's and dementia, the drug has now proved a dud for treating the negative symptoms of schizophrenia.

Not content with a stunning launch in the US, Acadia has splashed out $100m to bag the worldwide rights from partner Neuren for Rett syndrome therapy Daybue.

Daybue is the first drug approved to treat the rare neurodevelopmental disorder Rett syndrome, despite high clinical trial incidence of diarrhea. Product labeling includes clinician guidance for the side effect.

Ultragenyx is buying its Angelman syndrome partner GeneTx for $75m on the heels of an interim Phase I/II readout that shows signs of clinical activity and appears to resolve earlier safety worries.