Proceeding pursuant to CPLR article 78 (transferred to this Court by order of the Supreme Court, entered in Albany County), to, among other things, review a determination which imposed a loss of good time credit due to petitioner’s failure to complete the residential substance abuse treatment program.
Petitioner was found guilty of violating the prison disciplinary rule that prohibits inmates from possessing alcohol, and the determination was subsequently affirmed on administrative appeal. Due to this disciplinary infraction, petitioner was directed to participate in the residential substance abuse treatment (hereinafter RSAT) program. He filed an unsuccessful grievance and refused to participate in the program, which resulted in negative evaluations, his eventual removal from the program and the loss of nine months of good time credit. Petitioner commenced this CPLR article 78 proceeding challenging the prison disciplinary determination and later sought to supplement his petition to challenge his placement in the RSAT program and subsequent loss of good time credit. Following joinder of issue, *1133Supreme Court, among other things, dismissed that part of the petition challenging the RSAT placement and loss of good time credit, and transferred the prison disciplinary portion of the petition to this Court.
Initially, we note that inasmuch as petitioner has not advanced any arguments in his brief regarding the prison disciplinary determination, he has abandoned any challenge to that determination (see Matter of Harris v Selsky, 28 AD3d 982, 982 n [2006]). Moreover, given that petitioner was released from prison on January 3, 2007 after serving his sentence, any challenge to the RSAT placement and loss of good time credit is now moot (see Matter of Roach v Goord, 19 AD3d 839 [2005]).
Cardona, P.J., Mercure, Peters, Carpinello and Lahtinen, JJ., concur. Adjudged that the determination is confirmed, without costs, and petition dismissed.