I Have A Step Grandson, 10 Yrs. Old, Who I

I have a step grandson, 10 yrs. old, who I suspect is ODD. He defies his mother and step father constantly, annoys his younger brother, manipulates his mother and step father, lies/blames others/denies any wrongdoing. It has gotten to the point that my husband and I do not want him around. I am a retired educator having worked with difficult students for 26 yrs. I cannot get through to this child and his mother and step father do not heed my suggestions. What can be done to salvage this very intelligent child?