(Sharecast News) - AIM-listed biotechnology company SalvaRx has entered into a conditional sale agreement that would see the Cambridgeshire-based firm offload its immuno-oncology assets to Portage Biotech.SalvaRx shares soared after announcing the deal, in which Portage will issue 757.9m new shares as payment to the cancer-focused drug discoverer, equivalent to roughly $75.8m based on Portage's closing price on Monday and a premium of more than 250% to SalvaRx's market valuation.Every SalvaRx shareholder will receive 18 Portage shares for each share in the group.SalvaRx stated its performance on AIM had been "relatively disappointing" and had opted to go ahead with the sale in order to "unlock and maximise value for shareholders".Chief executive Ian Walters, said, "I am pleased to sign a deal to sell our assets to Portage and at the same time crystallise value for the company's shareholders.""Given Portage's recent success and strong balance sheet, I believe it will be well placed to fund the assets of SalvaRx Limited through the next set of milestones," added Walters, who is also a member of the board at Portage.Assuming the deal is approved, SalvaRx will become a cash shell.As of 1420 BST, SalvaRx shares had rocketed 53.59% to 72p.