GlaxoSmithKline (GSK) and Dutch biopharma company Prosensa have added two new research programs to their existing collaboration to develop RNA-based therapies for Duchenne muscular dystrophy (DMD). The projects will cover the development of four compounds targeting different subpopulations of patients suffering from DMD.
Under the terms of the deal GSK will make two up-front payments to its partner. GSK has an option to select two of the four new compounds for later-stage development and commercialization. Prosensa could also earn additional preoption milestone payments. The firm also retains certain limited European commercialization rights for the two compounds selected by GSK and will have full rights to the other two compounds.The new projects will focus on the skipping of four exons; 45, 52, 53, and 55.
Prosensa’s exon-skipping technology aims to interfere with exon inclusion signals within an exon during splicing of the pre-mRNA to prevent the incorporation of the targeted exon in the mature RNA. This selective removal of mutated exons increases the level of functional transcripts and reverses disease symptoms, the firm claims.
Prosensa and GSK signed their original DMD alliance back in October 2009 with $25 million up front. The deal gave GSK an exclusive, worldwide license to develop and commercialize Prosensa’s lead candidate, PRO051, which is designed to treat DMD by skipping exon 51 of the dystrophin gene. The candidate is close to entering Phase III trials, Prosensa says.
GSK also gained exclusive options to license three more RNA-based compounds targeting additional DMD exons. One of these is the second lead compound, PRO044, which targets the skipping of exon 44. Prosensa started a Phase I/II trial with PRO044 in March.