The APX films were made by Agfa. I agree they were excellent. When Agfa ceased its photographic business, their stock of film both cut and in the form of uncut rolls was sold. The amount of film in the uncut rolls was extensive but when it is sold then that's the end. I don't know if Agfa sold the rights to its emulsion technology. So perhaps another company might duplicate these films.
Agfa was a top tier manufacturer along with Kodak, Ilford, and Fuji. Even if some else has the emulsion formula I would seriously doubt that a new product would be as good.