Catabasis Pharmaceuticals' Edasalonexent Slowed Duchenne Muscular Dystrophy Disease Progression Through One Year of Treatment

Catabasis Pharmaceuticals, Inc. (NASDAQ:CATB), a clinical-stage biopharmaceutical company, reported on 4/25/18 new positive magnetic resonance efficacy results showing slowed disease progression in boys with Duchenne muscular dystrophy (DMD) in the MoveDMD trial through 48 weeks of edasalonexent treatment. Both magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) were performed in the Phase 2 MoveDMD trial and open-label extension. Statistically significant improvement in the rate of change in lower leg composite MRI T2 at 12, 24, 36 and 48 weeks on oral 100 mg/kg of edasalonexent treatment were observed compared to the off-treatment control period (p<0.05 for all time points). Improvements in changes in both soleus and vastus lateralis (VL) MRS fat fraction through 48 weeks of edasalonexent treatment compared to the off-treatment control period were also demonstrated.

“The results reported to date from the MoveDMD trial have been consistent and support edasalonexent as a disease-modifying therapy. Overall, in the MoveDMD trial edasalonexent has slowed progression of this disease based on improvements in multiple assessments of physical function and biomarkers of muscle health and inflammation,” said Jill C. Milne, Ph.D., Chief Executive Officer of Catabasis. “We believe that these effects ultimately will translate to boys with Duchenne maintaining functional abilities longer.”

On April 17 of this year Catabasis announced that they were reducing their workforce by 42% to devote resources to  edasalonexent development. CEO, Jill C. Milne, Ph.D, said at the time, “... These important corporate changes will allow us to focus our resources on continuing to advance edasalonexent and improving the lives of boys affected by this devastating disease.”

MRI is a non-invasive approach to assess disease progression in DMD. MRI T2 as well as MRS fat fraction and T2 were performed in the Phase 2 MoveDMD trial and open-label extension. MRI T2 measures combined inflammation and fat in one measurement. MRS T2 measures the inflammatory component independently and MRS fat fraction measures the amount of fat in the muscle. As boys with DMD get older, the amount of fat in their muscles increases with consequent loss of functional abilities. Changes in MRI T2 and MRS fat fraction are known to correlate with changes in function in boys with DMD. Increases in both measures strongly correlate with worse performance on timed function tests and predict future loss of functional abilities. FDA considers MRI to be an important supportive early endpoint demonstrating therapeutic effect as mentioned in the recently released FDA guidance on development in DMD.

Statistically significant improvement in the rate of change in lower leg composite MRI T2 at 12, 24, 36 and 48 weeks of oral 100 mg/kg of edasalonexent treatment were observed compared to the off-treatment control period (p<0.05 at all time points). After 48 weeks of 100 mg/kg of edasalonexent treatment, MRS fat fraction of the soleus muscle increased by an average of 0.85%, while in the same boys during the off-treatment control period the average annualized increase was 2.6% per year. Boys from the ImagingDMD natural history study who were largely on steroids had an increase in soleus fat fraction of approximately 3% per year. After 48 weeks of edasalonexent treatment, MRS fat fraction of the VL (one of the quadriceps) increased by 5.9%, while in the same boys during the off-treatment control period the average annualized increase was 10.4% per year. Boys from the ImagingDMD natural history comparison study who were largely on chronic steroids had an increase in VL fat fraction of approximately 7% per year. MRS T2 of soleus and VL decreased from baseline. The changes in the rate of increase in fat fraction in the soleus and VL muscles demonstrate greater stability with edasalonexent treatment in the MoveDMD trial with less of an increase in fat in their muscles compared to the same boys prior to treatment. The increase in fat fraction observed on edasalonexent treatment was also less than that observed in natural history in a different population of boys with DMD.