Swiss major Roche has licensed an immunosuppressant drug in early-stage testing from US company BioCryst Pharmaceuticals in a $530 million dollar deal, including $25 million in upfront payments.

The potential value of the deal is remarkable, given that BCX-4208 is currently in Phase I trials and the project still carries a significant degree of risk. It reinforces suggestions that Big Pharma, facing reductions in R&D productivity, are having to pay increasingly large amounts to license in promising projects.

BCX-4208 is a purine nucleoside phosphorylase (PNP) inhibitor that can reduce T- cell activity. Roche has licensed rights to develop it for the prevention of acute rejection in transplantation and for the treatment of autoimmune diseases such as psoriasis.

"BioCryst's BCX-4208 is a promising addition to our pipeline," said Peter Hug, Roche's global head of pharma partnering. "As a new therapeutic agent with a novel mechanism of action, it has the potential to offer significant improvement in treatment for transplant recipients and patients suffering from autoimmune related diseases."

In addition to the $25 million up-front payment Roche will provide BioCryst with $5 million for supply of material during the first two years of the collaboration. The news caused a 37.5% hike in BioCryst’s Nasdaq-listed shares to $16.24.

Future event payments could reach $530 million in addition to royalties on product sales of BCX-4208, said Roche. For five years, Roche will have a right of first negotiation on existing back-up PNP inhibitors in transplant rejection or autoimmune diseases. BioCryst retains the right to co-promote BCX-4208 in the USA for several indications.

BioCryst also hangs on to Fodosine (BCX-1777), a PNP inhibitor already in Phase II for T cell malignancies such as leukaemias and lymphomas. An oral formulation of this drug is in Phase I testing.

This is the second major development at BioCryst in recent weeks. The company saw another hike in its shares in October when it announced it was restarting testing of peramivir, a neuraminidase inhibitor that could be effective in treating avian flu.

BioCryst has started testing injectable formulations of the drug, which should bypass the oral bioavailability issues that led the firm to shelve the project two years ago.