Three people were not ruled by the Evil Inclination at all. They are: Avraham, Yitzchak, and Yaakov. This is evident as the verse states regarding them: With everything, From everything, and everything. Some say this even applies to David, regarding whom the verse states: And my heart is empty inside (referring to his lack of evil inclination). The other opinion (that does not include David) understands that in this verse he was expressing his pain (not lack of Evil Inclination).
Tosfos explains that this does not mean that their Evil Inclination was always powerless over them, for if so, they would not be entitled to receive any reward for their good deeds. Rather, it means similar to that which is stated in the Gemora Yoma (38b): When the majority of a man’s years have passed without sin, he will no more sin. So too here, since the Holy One, Blessed be he, sees that a person has fought fiercely against his Evil inclination and has distanced himself from sinning, He assists him in his older years by protecting him from its tricks.
The Brisker Maggid writes in Machazeh Einayim that there can be people who are immune from the wiles of the Evil Inclination even without Hashem’s assistance. This, says the Eitz Yosef, can only be accomplished after years of dominating over the Yetzer Hara.