"Editing" can be broadly defined.
graphics/evince can enter text fields in a pdf and save the results. I've used it to generate and print the 1040 tax form that gets mailed to the IRS.
mutool(1) can remove/merge pages, extract images/font files, change fonts and page size and generate new pdf's from extracted contents.
The OpenBSD oman forum tool comes up empty - here is a web link
mutool