There is a multitude of different, incompatible but similar functioning ICs for that purpose so I wouldn't risk experimenting with other types to see which might work. The bold print on the IC is not normal so I would guess the PSU manufacturer is using 'house codes', their own part number even though it might really be a more generic IC inside. The cost of printing your own number on an IC when buying in bulk is negligible!
I would consider a new PSU unless you are prepared to do some extensive reverse-engineering to discover the schematic and working parameters of the existing part - even then you may not find a replacement unless you buy them in bulk.
Brian.