Transferring H1 to another employer will not save your I-485 petition filed with your current employer. You will have to start all over again from a new Labor Certification. all you can do is wait until it becomes 180 days that you have filed I-485 then find a similar job that your GC is petitiioned for and file for AC21 to switch to another company. Just pray that your company doesnt close down for another 6 months or so. The other option is to transfer H1b and start fresh with GC application.