US regulators have rejected Digital Medicine - a drug/device system in which Otsuka's antipyschotic Abilify is embedded with Proteus’ ingestible sensor - for the treatment of psychiatric disorders, asking for more information.

Digital Medicine has been developed to enable digital recording of the pill’s ingestion, so that, with patient consent, this information can be shared with healthcare professionals and caregivers, with a view to improving adherence, a key treatment goal.

The companies are seeking approval for the product for the treatment of schizophrenia, as an acute treatment of manic and mixed episodes associated with Bipolar I Disorder (BP1) and as an adjunctive treatment for Major Depressive Disorder (MDD).

But in a response letter the US Food and Drug Administration said it required additional data, including regarding the performance of the product under the conditions in which it is likely to be used, and further human factors investigations, before it would re-consider approval.

"While we are disappointed in the FDA's decision not to approve this Digital Medicine at this time, both Otsuka and Proteus are committed to working with the FDA to address its questions and provide the additional data that has been requested," said Robert McQuade, chief strategy officer at Otsuka Pharmaceutical Development & Commercialisation. 

"We believe in the potential of this product to help people with serious mental illness manage their daily medication, which remains a serious unmet need."