If I understood your query correctly,this is possible via distributed clustered setup of WSO2 API Manager.
This blogpost will be help you to get initial understanding on how WSO2 API Manager[AM] designed for scalability.
For the moment,we are in the process of updating WSO2 AM documentation with API Manager deployment details in a distributed setup and those will be available in near future. Additionally this slideset would help to you as it is containing some deployment patterns which can be used for API Manager.
Thanks;