Saturday morning’s presentations were devoted to the latest news about clinical trials and drug development.

Among the highlights:

• Duchenne muscular dystrophy (DMD): Edward Kaye from Sarepta Therapeutics presented his company’s most recent data about its experimental drug eteplirsen, designed to treat about 13 percent of the Duchenne muscular dystrophy (DMD) population, and discussed plans for development of additional drugs. Like other “exon-skipping” drugs in development for DMD, eteplirsen is designed to coax muscle cells to leave out a section (“exon”) of the genetic instructions for the dystrophin protein and make a shorter-than-normal, but still functional, form of this protein. It is hoped that the short dystrophin protein will offer some protection to muscle fibers, slowing their degeneration and prolonging function in patients. Kaye presented data from a 12-participant, phase 2b trial of eteplirsen that suggest the drug is safe and is at least somewhat effective. Boys who received more than three years of continuous treatment with eteplirsen walked farther in six minutes than are boys who received a placebo for the first six months and then received the drug, although all participants showed a decline in their six-minute walking distance over the course of the trial. Sarepta plans to submit an accelerated approval application for eteplirsen to the U.S. Food and Drug Administration (FDA) based on the phase 2b trial. However, favorable results from a phase 3, confirmatory trial of the drug, now underway, will be needed before the drug receives full approval. Eteplirsen targets exon 51 of the dystrophin gene and is designed to treat boys with DMD who have mutations near that section. Kaye said Sarepta is also developing compounds targeting exons 45 and 53, designed for patients with dystrophin mutations near those parts of the gene.
• DMD: Joanne Donovan from Catabasis Pharmaceuticals discussed her company’s data about CAT-1004, an experimental anti-inflammatory drug in development to treat DMD regardless of the specific dystrophin gene mutation. Quelling inflammation in DMD-affected muscle fibers could help preserve fibers and prolong function. A two-week, phase 1 trial conducted in healthy adults was without serious adverse events and showed biochemical evidence that inflammation was reduced. The drug will soonn be tested in boys with DMD.
• DMD: Mike Boss from Summit Therapeutics presented the latest information about his company’s experimental DMD compound SMT C1100. SMT C1100 is designed to sustain production of a protein known as utrophin in muscle fibers, potentially improving the health and sturdiness of these fibers and therefore prolonging muscle function. Utrophin is a protein that is very similar to dystrophin, which is missing in DMD patients’ muscles. Normally, utrophin is only produced during fetal development and later on during muscle-fiber regeneration. But there is a body of evidence suggesting that keeping utrophin “turned on” in dystrophin-deficient fibers at all times can at least partially compensate for the missing dystrophin. A phase 1 trial of SMT C1100 was recently conducted in 12 DMD-affected boys, with promising results. The drug, which is given as an oral liquid, was well tolerated and appeared safe, and biochemical indicators of reduced muscle damage were seen. However, it was found that several participants did not absorb the drug very well because of dietary factors and the timing of their intake of food. Therefore, a new phase 1 trial is now underway, during which the families are receiving specific instructions about dietary components and timing.
• Becker muscular dystrophy (BMD): Craig McDonald from the University of California, Davis, presented results from an eight-week, pilot trial of a compound called epicatechin in seven adults with Becker muscular dystrophy (BMD). BMD is similar to DMD in that it results from a lack of the dystrophin protein in skeletal and cardiac muscle cells. However, in BMD, some dystrophin is made, generally reducing the severity of the disease course compared to that of DMD. However, serious cardiac prob lems are often seen in BMD. Epicatechin, a plant-derived compound being developed by Cardero Therapeutics, is said to mimic the effects of exercise in muscle fibers, which could help preserve BMD-affected fibers and prolong function. The trial was very small and short in duration, and it did not include a placebo group for comparison to the treated group. However, there were several favorable biochemical and physiologic and protein changes seen in the participants, and the distance walked in six minutes increased in some. Four people reported anecdotal evidence of functional improvement, such as walking without a cane, stooping to pick up items from the floor and standing for longer periods. There were no adverse events.