Yes.
In the Olympics, there is a 42.125-km foot race called a "marathon." It is named after a Greek city named "Marathon." It is named for a Greek legend about a runner who ran 42 km. to deliver the news that the Greeks had won the Battle of Marathon.
In English, the word "marathon" has come to mean some extremely long, almost endless effort. You can just use the word "marathon." "We are going to get together and have a study marathon to prepare for the test."
The pattern "X-a-thon" has come to mean "an X marathon." As a result, if we are planning some event or activity that is going to continue for a long time, we can coin an informal word by adding "-a-thon" to the activity: phone-a-thon, walk-a-thon, bike-a-thon, bake-a-thon, whatever. "A group of us are going to get together and edit Wikipedia all day--it's an edit-a-thon!"
Most of these are informal coinages, not "real words." Some have made it into the dictionary. A "telethon", without hyphens, is "A lengthy television program to raise funds for a charity."