Dyne Therapeutics Emerges With $50M to Take On Rare Muscle Disease

Xconomy Boston — 

One problem with drugs for muscular disorders is that not enough medicine reaches the muscle, says Romesh Subramanian, CEO of Dyne Therapeutics. Subramanian’s startup has developed a way to deliver drugs to all muscle types, and it is emerging from stealth with $50 million in funding to advance its compounds toward human testing.

Dyne was founded last year by Atlas Venture, which seeded and incubated the Cambridge, MA-based biotech. Atlas also invested in Dyne’s Series A funding announced Wednesday, joined by Netherlands-based venture firm Forbion and fellow Cambridge investor MPM Capital.

Dyne’s drug delivery technology takes a page from a type of cancer therapy called antibody drug conjugates. These drugs consist of a therapeutic hitched to an antibody that homes in on cancer cells. The targeted approach is meant to spare healthy cells from the drug’s toxic effects.

For Dyne, antibodies target its drugs specifically to muscle tissue. Subramanian (pictured above) says the company’s antibody conjugates bind to receptors that are abundant on muscle cells. Dyne aims to deliver oligonucleotides, molecules that can degrade disease-causing RNA. The FDA has already approved oligonucleotide therapies, such as Biogen’s (NASDAQ: BIIB) nusinersen (Spinraza). The Biogen drug, which treats spinal muscular atrophy, was developed to increase the production of a protein important for muscle function.

While Subramanian acknowledged Dyne’s approach could be applied to oligonucleotides that are already approved by the FDA, he says the company is working with compounds that it has developed. Dyne’s lead disease target is myotonic dystrophy type 1, a rare genetic disorder that leads to the creation of toxic RNA that impairs normal muscle function. Patients who have the disorder experience muscle weakness and can develop other problems, such as breathing difficulty. There are currently no FDA-approved drugs to treat the disorder, which Dyne says affects an estimated 40,000 people in the US.

Subramanian has experience developing RNA-targeting drugs, having co-founded RaNA Therapeutics, which is now Translate Bio (NASDAQ: TBIO), and led research at Alexion Pharmaceuticals (NASDAQ: ALXN). He says that while oligonucleotides worked in lab tests, in humans these drugs go to many different tissues in the body. That distribution leads to problems, such as liver toxicity.

“We avoid a lot of the tolerability issues by delivery only to the muscles,” Subramanian says.

In preclinical studies, Subramanian says Dyne delivered its drugs to skeletal, smooth, and cardiac muscle. He adds that the drugs were able to degrade RNA within muscle tissues. Dyne isn’t the only company trying to develop a myontonic dystrophy drug. Last year, San Diego-based Expansion Therapeutics raised $55 million to fund its research on a small molecule drug to treat the disorder.

Subramanian says Dyne will use its new capital to advance its drug for myotonic dystrophy type 1 toward tests in humans, though he declined to offer a timeline for reaching the clinic. The company will also continue research on other programs addressing other muscular disorders.

Photo by Dyne Therapeutics