Here's an ES6 way to remove the entry easily :
let myObject = {
"ircEvent": "PRIVMSG",
"method": "newURI",
"regex": "^http://.*"
};
const removeItem = 'regex';
const { [removeItem]: remove, ...rest } = myObject;
console.log(remove); // "^http://.*"
console.log(rest); // Object { ircEvent: "PRIVMSG", method: "newURI" }