linux - sed to replace comma and new line -

i'm trying replace this

colb, cola, ) 

with this

colb, cola ) 

in sed, can't seem work. i've tried both of these nothing seems happen

sed -e  's/, \n)/\n)/g'  sed -e  's/,\n)/\n)/g' 

i can new line replace can't comma followed newline followed ) replace newline followed )

extending on solution near-duplicate, work:

sed ':a;n;$!ba;s/,\n)/\ )/g'