The highly anticipated results come as the company makes significant changes to its C-suite. Despite the turnover, Dyne said it is looking toward expedited approval pathways for its DMD treatment.
Dyne Therapeutics on Tuesday unveiled new data from its Phase I/II DELIVER trial, demonstrating that its investigational oligomer therapy DYNE-251 can induce record levels of dystrophin expression in patients with Duchenne muscular dystrophy.
The announcement comes amid several changes among the company’s executive staff. Dyne on Tuesday appointed Biogen alum Doug Kerr as its new chief medical officer, Johanna Friedl-Naderer as its new chief commercial officer and Lucia Celona as chief human resources officer.
These changes in the masthead come just months after president and CEO Joshua Brumm left Dyne, announcing in March 2024 that he will be pursuing a path in healthcare investing. Brumm was succeeded by John Cox.
DYNE-251 is an investigational treatment that consists of a phosphorodiamidate morpholino oligomer bound to a fragment antibody, which itself targets the transferrin receptor 1. This structure allows DYNE-251 to promote exon skipping specifically in muscle tissues, allowing them to produce a shorter but functional dystrophin protein, thereby slowing or reversing DMD progression. DYNE-251 is specifically designed for Duchenne muscular dystrophy (DMD) patients who are amenable to exon 51 skipping.
The new DYNE-251 results were among BioSpace’s top DMD readouts to watch this year.
At a 20-mg/kg dose level, given every four weeks, DYNE-251 resulted in a mean absolute dystrophin expression that was 3.71% of normal, without adjusting for muscle content. According to Dyne’s announcement, this expression level is more than 10 times higher than in a reference clinical trial that assessed the weekly standard of care treatment eteplirsen, in which dystrophin expression was at 0.3% of normal.
After controlling for patients’ muscle content, the mean absolute dystrophin expression jumped to 8.72%, which exceeds levels typically recorded in studies evaluating other investigational oligomers for DMD, according to Dyne. These results are in line with six-month data Dyne released in May for patients treated with the 10-mg/kg dose of DYNE-251.
DELIVER also assessed whether these biomarker findings would translate into mobility improvements. Results from the study showed that DYNE-251 also led to meaningful functional benefits across several domains, including the North Star Ambulatory Assessment, stride velocity, time to rise from floor and 10-meter walk/run time.
According to Dyne’s news release, Tuesday’s data represent “unprecedented dystrophin expression and functional improvement,” with chief medical officer Wildon Farwell noting in a statement that DYNE-251 “achieved the highest level of dystrophin expression reported for an exon-51 skipping therapy.”
“We believe these data reinforce the opportunity to transform the treatment paradigm for individuals living with Duchenne,” Farwell added. With these latest data, Dyne will proceed “quickly” to initiate registrational cohorts in DELIVER, with an eye toward “expedited approval pathways” for DYNE-251 in DMD. The biotech expects to provide registrational updates “by the end of this year,” Farwell noted.
DMD is a rare and severe genetic disease that occurs primarily in boys and affects around 12,000 to 15,000 people in the U.S. The condition is caused by a mutation in the dystrophin gene, which under healthy circumstances is crucial for the proper function of muscle cells. These genetic alterations lead to a dysfunctional protein—or its complete absence—which in turn gives rise to the hallmark symptoms of DMD, such as mobility and gait problems.
In its more progressed forms, DMD causes progressive weakness and can affect crucial organs, including the lungs and heart. There are currently no cures for DMD and approved therapies offer only management options and have limited benefit, according to Dyne.
