Fresh from a multimillion-dollar loss on his investment in pain drug developer QrXPharma , rich list property developer Lang Walker is trying to eject founder Gary Pace and chairman Peter Farrell of ResMed fame from the ­biotechnology company’s board.

The Sydney-based company has plunged in value after the US regulator advised against approval of its pain management drug Moxduo. Investors were shocked because QrXPharma had been considered likely to succeed where so many speculative biotech­nology companies had failed before it.