The announcement was made Tuesday before Indianapolis Motor Speedway opened for the first day of preparations leading into the May 27 race. Fittipaldi was supposed to race the No. 19 car for Coyne but suffered serious injuries in a crash in Belgium earlier this month and is sidelined at least eight weeks.
Claman De Melo will be among the Indy 500 rookie class and is one of 35 drivers trying to earn one of the 33 spots in the race this weekend.
"I'm very much looking forward to turning my first laps aboard the No. 19 Paysafe Indy car on the oval at the Indianapolis Motor Speedway," Claman De Melo said in a statement. "It's an iconic venue and I'm extremely fortunate to be able to have the opportunity to drive here. Again, it's unfortunate that it's under these circumstances with Pietro's injuries so I realize how lucky I am to have this chance."
Claman De Melo filled in for Fittipaldi last week on Indy's road course and finished a career-best 12th.
The Associated Press contributed to this report.