Dutch biopharmaceutical company Prosensa received a £7.5 million (about $12 million) milestone payment from GlaxoSmithKline (GSK) on the achievement of successful data from a Phase IIa trial with the Duchenne Muscular Dystrophy (DMD) candidate GSK2402968 (PRO051). The drug is an antisense oligonucleotide that induces exon skipping of exon 51 in the DMD gene.
Six-month data from the open-label Phase IIa extension study in 12 DMD patients identified no serious safety issues. More complete data will be presented at the ongoing "International Congress of the World Muscle Society" in Japan. Prosensa says it projects starting a large, international multicenter pivotal study with PRO051 during 2010.
GSK and Prosensa have an ongoing DMD antisense therapeutics collaboration that now spans four candidates. The firms first teamed up in October 2009 for a collaboration centered on the development and commercialization of Prosensa’s lead compound PRO051. GSK also has an option to license Prosensa’s second lead compound, PRO044, which targets the skipping of exon 44. Prosensa started a Phase I/II study evaluating PRO044 in DMD patients during March and says GSK will use the results from this study to direct a decision on whether to exercise its option to the candidate.
In June the firms expanded their DMD collaboration even further with the initiation of two additional RNA-based drug programs. The two new programs center on the potential development of four candidates that skip different DMD exons: 45, 52, 53, and 55. Under the terms of the collaboration, GSK has an option to select two of these additional four compounds for later-stage development and commercialization. Prosensa retains certain limited European commercialization rights alongside GSK for the two compounds selected by GSK. For the two compounds not selected by GSK Prosensa will retain full commercialization rights.
Prosensa is focused on the discovery, development, and commercialization of RNA modulating therapeutics, primarily for neuromuscular disorders. In addition to its clinical- and preclinical-stage DMD candidates partnered with GSK, the firm has preclinical products in development for myotonic dystrophy, Huntington disease, and spinal muscular atrophy.