Removing Last field from CSV string

Hi,

I have a string that I want to cut to 60 char and then remove the last
field and comma.

substring('Class V,Class VI,Class VII,Competitive Exam,Class VIII,Class
X,Class XI,Class IX,Class XII',1,60);

substring | Class V,Class VI,Class VII,Competitive Exam,Class VIII*,Class*

Now I try to remove the last field and comma ",Class"

To get Class V,Class VI,Class VII,Competitive Exam,Class VIII

Is there a function or easy way to do this?
Any help would be appreciated.

Thank you
Alex