Aba has never been shown to improve autism let alone cure it. ABA is commonly heard of because it is the only thing that is recommended to parents with newly diagnosed children. That and medication, which also shows no benefit; beyond making your child into a zombie.
Therapies can be helpful in many ways though and sometimes taking the most successful parts of different therapies and creating your own therapy regime works best. Those with autism are not all the same, what works for one will not necessarily work for another.
Here is a listing of different therapies, which will be added to as new information becomes available