H-1B transfer or new H-1B after using AP?

[Mendota]

My I-485 is pending over 180 days.

I used AP once after I travelled outside US once in 2005. As I understand my current H-1B is still valid.

My question is if I change employer now, do I need to file a new H-1B petition (against annual cap) or a H-1B transfer is enough?

Thank you