Billionaire property developer Lang Walker’s quest to shake up the board of troubled pain drug developer QRxPharma has been more successful than first imagined, following the resignation of chairman Peter Farrell and three directors ahead of Wednesday’s shareholder meeting.

Only Mr Farrell, who is also the director of ResMed, and company founder Gary Pace had been targeted by the dissenting shareholders. But directors Mike Quinn and Peter Campbell have also tendered their resignations.