Dynacure, a small start-up in Strasbourg, France, has raised $55 million to develop nucleic acid-based drugs for rare genetic muscle diseases. Its first program will test an antisense oligonucleotide licensed from Ionis Pharmaceuticals to treat centronuclear myopathy (CNM), a condition that causes muscle weakness and wasting.
Dynacure CEO Stéphane van Rooijen plans to move fast and begin testing the compound in people with CNM in Europe next year. “$55 million is a really big round, especially in Europe,” and a “tremendous endorsement” of the company, he says.
It is also a further validation of Ionis’s antisense drugs, which are chemically modified strands of nucleic acids that bind and block complementary strands of RNA. The firm’s biggest success story is a spinal muscular atrophy treatment that it licensed to Biogen in 2016. Biogen posted $364 million in sales of the drug, Spinraza, in the first quarter of this year.
A variety of genetic mutations can cause CNM, which is named for the atypical appearance of muscle cell nuclei in the center of cells, rather than in the periphery where they are normally found. One form of CNM is marked by an overabundance of a protein called dynamin 2.
In 2014, Jocelyn Laporte and Belinda Cowling, scientists at the Institute of Genetics & Molecular & Cellular Biology in France, showed that lowering the dynamin 2 protein by 50% in mice effectively prevented the disease. That led them to work with Ionis to develop an antisense drug to reduce dynamin 2 levels. Laporte and Cowling founded Dynacure in 2016.
In 2017 they demonstrated that weekly doses of the Ionis compound effectively halted the disease in CNM mouse models just weeks after first injection. Untreated CNM mice died before 12 weeks of age (Nat. Commun. 2017, DOI: 10.1038/ncomms15661).
Dynacure licensed the Ionis compound in November 2017. Ionis’s 2017 annual report states that the agreement could bring it up to $210 million in license fees and milestone payments. Dynacure’s van Rooijen says there are 4,000 potential CNM patients in Australia, Europe, Japan, and the U.S.