That's no useful static bias circuit at all. It must be driven by current sources, but the npn and pnp cascode stages are unable to provide constant current.
In the backend there there is the input stage (look in the image, "from IPS"). The amplifier is composed by two CFP differential with constant current generator and Wilson mirroring. I've to implement the error correction by Cordell or Hawksford in this configuration. What you see is the VAS plus output stage.