(ShareCast News) - AIM-listed drug discovery and development company Summit Therapeutics has enrolled its first patients in phase II proof of concept trials in the US of ezutromid in patients with Duchenne muscular dystrophy.Summit said enrolment and dosing of patients into Phase Out DMD in the UK is ongoing.Summit believes utrophin modulation has the potential to slow down or even stop the progression of DMD, regardless of the underlying dystrophin gene mutation.Chief financial officer Ralf Rosskamp said: "Our PhaseOut DMD clinical trial is an important component of bringing ezutromid to patients and families who are in urgent need of a disease modifying therapy, and we are making progress with patient enrolment in this clinical trial, with enrolment ongoing in the UK and now in the US."DMD is a progressive muscle-wasting disease that affects around 50,000 boys and young men in the developed world. It is caused by different genetic faults in the gene that encodes dystrophin, a protein that is essential for the healthy function of all muscles.There is currently no cure for the disorder and life expectancy is into the late twenties.At 1310 GMT, the shares were up 0.7% to 186.22p.