This could either refer to Alex, his guide and friend, or more likely The old man, whose name was also Alex. I say "more likely" due to the fact that the birth year is 1903.
Or this could be from the director and have nothing to do with the book or characters within.
> The movie is fictional so that fact that the dedication is to an Alex is coincidental.
Most likely, it's dedicated to Liev Schrieber's grandfather, Alex, since Schrieber wrote the screenplay and directed and produced the film.
> Alexander Milgram, also known as Alex, was born January 15, 1906 in Ukraine and died August 14, 1993 at the age of 87 in Manhattan, New York. He was Liev's maternal grandfather.
