Removing spaces within parentheses in VIM

I have a file which has unwanted spaces within the parentheses as shown below:
SUM(page_visits) ,
SUM(previews) ,
SUM(comments) ,
SUM(shared_items) ,
SUM(upload_bandwidth     ) ,

How do I remove these spaces in VIM editor?

Give the following command,
:1,$s/ *)/)/

There is a space before * in the command.