This is very difficult to do. First, as others said use a downcut bit. Second, divide the work into two stages. The first stage is to lightly score the material using at least two passes to cut through the melamine material. Second, move to normal cutting procedures.
There are several threads here which talk about cutting Melamine. I seem to remember they said to use a bit for cutting plastic works best. Don’t remember if they listed feeds and speeds. Should be pretty straight forward. I also found this entitled “CNC feed rates for Melamine”;