In March last year, Irrfan had announced his diagnosis and said he was going abroad for treatment. He returned to India in February this year.
Asked how is he on the sets, Dinesh told : "He is outstanding and mind-blowing. He is in top form. His character is going to be very memorable."
"Angrezi Medium" is the sequel to the 2017 entertainer "Hindi Medium".
Last month, Irrfan had tweeted an image of himself standing in front of a fictional sweet shop. He had captioned it: "GMB serving since 1900s. It's going to be fun to tell another story 'Angrezi Medium'. Coming soon, with Mr. Champakji."
Is special care being taken for him?
"He is such a special actor. He is a very strong human being. He takes care of the unit as much as the unit takes care of him," said the producer.
The movie also stars Kareena Kapoor Khan.
"They are not paired romantically. She is playing a cop. It's a very interesting character and pivotal to the plot," he said.
Among various other projects, Dinesh is also tied up with his horror-comedy universe.
"There was an intent right from the beginning to make (own universe). There were three separate teams working on 'Stree', 'Rooh-Afza', which goes on the floors next month, and 'Munjha'.
"I am supposed to monitor this universe and how these films collide... eventually all come together so that is a five-year horizon," said Dinesh.
What about the second part of "Stree"?
"'Rooh-Afza' comes next year in March and 'Munjha' will come next year end. 'Stree 2' should be expected in 2021," he shared.
Though they all come under the same genre, he promises them to be different.
"They are all different characters and have completely different tones. If you have similar characters, it won't be interesting. Also, with every script, you need to up the ante," he said.