I wouldn't consider the change of sexual orientation a "cure", because it's not a disease, and homosexuality does not endanger anyone. But I wouldn't rule out that it's possible to change sexual orientation. All it means is that you change the priming, what features a person reacts to. Some react to male features, some to female, others to the features of children, others to the features of elderly, and again others to features of certain animals. It's the same mechanism, and once it's understood, it's probably possible to change it.
defines pedophilia as "sexual preference
for children, boys or girls or both, usually of prepubertal or early pubertal age". And that one is believed to be "cured" one day, meaning that it is believed it's possible to change the sexual preference of pedophiles to something other than children. So why should it technically
be impossible to change the sexual preference in general?