To date, there is, to my knowledge, no biography published of R. Yitzhak Hutner. I assume that this is because of his well-known opposition to hagiography, combined with a reluctance in the Orthodox community to write an honest history that includes such "unsavory" episodes as attending college and studying under the Rav Kook. However, oddly enough, Encyclopedia Judaica has an entry on him written over 30years ago, almost a decade before his passing:
HUTNER, ISAAC (1907-), rabbinic scholar and yeshivah head. Born in Warsaw, he studied at Slobodka, where he was known as the "Warsaw Illui" ("prodigy"). When a branch of the Slobodka Yeshivah was established in Hebron, he went there and came under the influence of Rabbi A. I. Kook. After the pogrom in Hebron in 1929, in which many of the students were killed, he returned to Warsaw, from there going to study at the University of Berlin. During this period he wrote Torat ha-Nazir (1932 on Maim. Yad Nazir). In 1932 he returned to Jerusalem, there devoting himself to talmudic research. He visited Europe in 1934 to collate manuscripts of the commentary of Hillel b. Eliakim to the Sifra, and publishing anonymously Kovez He'arot le-Rabbenu Hillel (Jerusalem, 1961). In 1935, he emigrated to New York where he joined the faculty of the Rabbi Jacob Joseph School and in 1939 became the rosh yeshivah of the Yeshivah Rabbi Chaim Berlin. Under his leadership the yeshivah grew from relative obscurity to prominence, and with it grew his reputation in the world of religious scholarship. His discourses, which from 1945 appeared in pamphlet form, represent a synthesis of talmudic incisiveness, hasidic mysticism, musar, and often show the influence of the ideas of Judah Loew b. Bezalel (the Maharal). Many of these appeared in the two volumes of his Pahad Yizhak (1964, 1970). Even in his personal deportment he developed a synthesis between the Lithuanian rosh yeshivah and the hasidic rabbi. In 1950 he founded the Kolel Gur Aryeh for outstanding senior students, where his system of study is pursued.