Voyager hold adds to gene therapy woes

2020 has been a big year for gene therapy – for all the wrong reasons. The latest blow to the field was yesterday’s clinical hold on the phase II trial of Voyager and Neurocrine’s Parkinson’s disease candidate, NBIb-1817, following reports of MRI abnormalities in some participants. Restore-1 has not been recruiting subjects since April because of the Covid-19 pandemic, but warning signs have since emerged, with the companies saying in November that the data monitoring board had asked for a pause in dosing to evaluate brain imaging data. A similar issue hit Lysogene in June, with abnormalities seen on brain MRI scans in patients receiving its Sarepta-partnered gene therapy SAF302. NBIb-1817 and SAF302 are being developed for different indications, but both are delivered directly into the brain and both use an adeno-associated viral vector. Meanwhile, Sio Gene Therapies – formerly known as Axovant – has a Parkinson's gene therapy that is delivered to the brain, Axo-Lenti-PD. That project, which employs a lentiviral vector, has shown a clean safety profile so far. Voyager's stock sank 10% this morning. The latest news comes the same week as a safety scare with Uniqure’s etranacogene dezaparvovec.