i guess you have to decide if you want the alternative of not having particpated,and holding off what potentially could stall your sons deterioration.If my son was suitable i would try it and i am sure they will monitor all adverse events.It is a very personal choice...as parents who want to do the best for our sons we do not have many great alternatives.Only my thoughts and i know it is not easy of putting your son into trials.All trials carry risk.
It is difficult to say since the AVI trial was dose ranging and only one boy in the 20 mg/kg dose group showed significant (55%) dystrophin positive fibers. In the GSK 24-week extension trial they reported 60-100% positive fibers. More importantly GSK noticed variable improvement in the 6-min walk test with some boys improving while others DID NOT. AVI did not see any improvement.To date, they do not have a clear understanding if there is a correlation b/w % dystrophin and functional improvement, which is actually what would get a drug approved (not the dystrophin, but the functional improvement)!
As for the timelines, AVI will start a very small 24-week trial at higher doses, boys are already selected/waiting for this one. Then next phase, larger pivotal trial will start end of 2012 the earliest. GSK will start a phase 2, 48-week trial this Fall, however I think they plan to to have 3 groups: 3 mg/kg (LOWER than what they use in Europe and other countries around the World) as well as 6 mg/kg and placebo.