Oxford Biomedica plc announced that it was informed on 31 January by Sio Gene Therapies (Sio) that Sio intends to return the global rights for AXO-Lenti-PD and that they intend to cease work on this gene therapy programme in Parkinson's Disease. This follows Sio's announcement about the resignation of their CEO where Sio also indicates a constraint on resource requirements that has caused Sio to deprioritise the programme. All rights shall be returned to Oxford Biomedica at no cost to the Company.

Sio is currently conducting a Phase 2 SUNRISE-PD trial with AXO-Lenti-PD. In October 2020, Sio announced positive six-month follow up data from the second cohort of the trial, showing a 21-point mean improvement in UPDRS Part III 'OFF' score, a 40% improvement from baseline based on the two evaluable patients in the study. AXO-Lenti-PD continued to be shown to be well-tolerated with no treatment-related serious adverse events at six months.

To date, six patients have been dosed in the Phase 2 study. Oxford Biomedica originally out-licensed AXO-Lenti-PD (previously named OXB-102) to Sio Gene Therapies (previously called Axovant Gene Therapies), in June 2018.