Create Lines/Comments on read only PDF files

We have documents stored (drawings) on a server and they are all set up as read only for security purposes.

I'm wondering if there is a way to add Lines/comments so they stay there after I close and reopen the file?

As of right now, Adobe lets me add everything I want and I can press Save, but it actually does not save anything. After i reopen the file, all edits are lost.

I'm using Adobe Acrobat X