Redmond O'Neal is doing well with his "aggressive drug and alcohol rehabilitation program," Commissioner Jane Godfrey told the Los Angeles Superior Court during a progress report hearing on Thursday.
"He is responding very, very well," she said.
The 24-year-old son of Farrah Fawcett -- who is currently battling cancer -- did not appear at the hearing, but he will continue his in-custody treatment program.
O'Neal is still in the "trial" phase, Godfrey said.
The drug program -- run by Impact, an organization based in Pasadena -- could remove him from probation and wipe his record clean of previous drug convictions if he completes their mandates successfully.
His next hearing -- which he is not required to attend -- is scheduled for June 25.