He was admitted into the University of São Paulo as a student in the faculty of Philosophy and Social Sciences and took classes with Fernando Novais, Gioconda Mussolini, and Otávio Ianni, among other teachers.
As an actor, he worked in the plays Arena Conta Zumbi by Augusto Boal and Gianfrancesco Guarnieri, The Inspector General by Gogol, directed by Augusto Boal, and Candide by Voltaire, with theater adaptation by Carlos Alberto Sofreie for the Studio São Pedro, directed by Myriam Muniz.
He also adapted part of the work of the Portuguese poet Fernando Pessoa into a theater piece, together with Jandira Martini and Luiz Raul Machado.
In 1974, he directed a theater piece about Fernando Pessoa for Teatro Opinião, with Cláudio Cavalcante and Maria Cláudia in the main roles.
Izaías also received the following awards: As a script writer of feature films and TV Series: As a dramatic advisor: He was invited by the Municipal Secretary of Culture, Celso Frateschi, to be part of the Judging Committee of the program of theatre incentive to the city of São Paulo.
His project Boal: Embaixador do Teatro Brasileiro – research in scenic arts - is approved by ProAc da Sec.