A sponsor may withdraw an initiative or referendum by submitting a written request to the secretary of state. The sponsor may withdraw an initiative or referendum until the time when the measure's ballot title and summary are finally established. The ballot title and summary are considered finally established five days after the attorney general submits the ballot title and summary to the secretary of state or, in the case of an appeal, when the court has rendered a final order. The sponsor cannot withdraw an initiative or referendum after it is finally established.