GlaxoSmithKline (GSK)'s recent collaboration with Prosensa on therapeutics for Duchenne muscular dystrophy (DMD) is another sign that large pharma is willing to focus on niche markets. DMD is a childhood neuromuscular disease caused by a mutation in the dystrophin gene, the normal product of which is necessary for proper muscle formation. It affects 1 in 3,500 newborn boys, causing muscle weakness that often leads to respiratory or cardiac failure. Under the alliance, announced in October, GSK licenses Leiden, The Netherlands–based Prosensa's PRO051, an antisense RNA oligonucleotide that skips exon 51 of the gene dystrophin, allowing for production of a functional protein. The compound is scheduled to enter phase 3 trials early next year. The London-based pharma is paying $25 million upfront for the program, which also includes options on three other compounds targeting different exons (the mutation addressed by PRO051 is responsible for only 13% of DMD cases), and will fund clinical development. The deal “fits squarely in with our current strategy of diversifying into other broader disease areas, accepting that it won't have anywhere near the return of a blockbuster,” says Shelagh Wilson, vice president and head of GSK's European Center of Excellence for External Drug Discovery. “It RNA-targeting drugs appear to be uniquely suited to treat disorders caused by expression of mutant proteins, protein overproduction or misfolding” (Nat. Biotechnol. 27, 874, 2009).