Sweden's Medivir has signed a collaboration with Johnson & Johnson unit Janssen Pharmaceutica to develop treatments for dengue virus infection.

The two firms will initiate an R&D programme to co-develop drugs based on the inhibition of the dengue NS3 protease activity. Both parties will contribute equal resources to the research project and Medivir has an option to continue to contribute 50:50 funding for future development. No financial details have been disclosed but if all goes well, Janssen will be responsible for commercialisation. Medivir will receive pre-agreed royalties on net sales of future products "that reflect its contribution to the development of products".

The partners noted that dengue fever, a mosquito-borne viral infection, is a major problem in subtropical regions where the incidence has increased 30-fold over the last 50 years. Up to 50 million infections are now estimated to occur annually in more than 100 endemic countries and "approximately one-third of the world’s population is at risk".

Ron Long, Medivir chief executive, said his firm has "strong experience in the discovery of protease inhibitors for the treatment of infectious diseases", adding that the collaboration represents "a significant step forward in our ambition to retain more value in products by taking them further into development". 

The Huddinge-based group's lead drug TMC435, for the treatment of hepatitis C, is partnered with Janssen affiliate Tibotec and has recently reported positive interim data in three Phase IIb studies.