Misajon, 29, was attacked last Thursday morning. He died at 1:30 a.m. yesterday due to the failure of his internal organs, particularly the liver and the pancreas.
"(The) GMA Network is saddened by the heinous act committed against Misajon," the broadcast station said in a statement.
It called on the authorities "to leave no stone unturned in bringing the perpetrators to justice."
Reports said Misajon, along with a female companion, was on his way to Jaro district in Iloilo City and took a shortcut dirt road behind SM City when he was attacked.
Probers said four people approached Misajon’s car. One of them smashed the glass window and poked a gun at his temple.
Misajon reportedly managed to parry the gun which, however, went off, hitting him in the left side of the abdomen.
Iloilo City Mayor Jerry Treñas has asked the police to speed up its probe of the incident. The National Union of Journalists of the Philippines has also condemned the incident.