Prosensa and GSK expand RNAi collaboration in Duchenne Muscular Dystrophy

Collaboration

The Dutch RNAi specialist Prosensa has announced the start of two further programmes under its existing alliance with GlaxoSmithKline (GSK) in which the partners are developing treatments for Duchenne Muscular Dystrophy (DMD). GSK has made an upfront payment to access the two programmes and will make additional milestone payments.

Prosensa says starting these additional programmes is a validation of both the potential of Prosensa’s exon skipping technology platform and of the ongoing relationship.

With the addition of two new programmes, the alliance is now developing treatments that target four different subpopulations of patients suffering from DMD. The new programmes focus on the skipping of four exons, 45, 52, 53, and 55, in addition to the existing work on skipping exon 51 and 44.

Mutations at these exons in the dystrophin gene interrupt production of dystrophin, a protein that is essential for muscles to function. It has been shown that skipping over these faults allows a functional form of dystrophin to be produced. DMD patients vary in which exons are affected, creating the need for specific therapies for each sub group.

Under the terms of the collaboration, GSK has an option to select two of these additional four compounds for later-stage development and commercialisation. Prosensa will retain certain limited European commercialisation rights alongside GSK for the two compounds selected by GSK. For the two compounds not selected by GSK, Prosensa will retain full commercialisation rights.

“Prosensa and GSK’s commitment to progress further developments of additional products that can provide for a solution in DMD is encouraging and welcomed by all of us” said Elizabeth Vroom, Chair of the United Parent Project Muscular Dystrophy, which unites different groups set up by parents of children with DMD in many countries all over the world.

“The expansion of our DMD portfolio with four additional compounds is a great step forward in our efforts to develop safe and effective treatments for this severely debilitating disease and to help as many patients as possible,” said Hans Schikan, Chief Executive Officer of Prosensa.

The alliance with GSK, signed in 2009, could yield up to £437 million plus double-digit royalty payments for Prosensa. The company is backed by venture capital investors including Abingworth, AGF Private Equity, GIMV, LSP and MedSciences Capital.