Davide Renne, the Italian fashion designer and former head of women’s wear at Gucci, died nine days after becoming the creative director of Moschino. He was 46.

His death in Milan on Nov. 10 was confirmed by Aeffe, the parent group of Moschino, on Friday. He died after an apparent heart attack, according to sources familiar with the matter.

“There are no words to describe the pain we are experiencing at this dramatic time,” the statement, from Massimo Ferretti, the Aeffe chairman, said. “Today, we are left with the responsibility of carrying on what his imagination and creativity only envisioned.”

Mr. Renne, who had been at Gucci for 20 years before the announcement last month of his new role at Moschino, had been working on a debut collection that would have been shown at Milan Fashion Week in February. A well-loved figure in Italian fashion and right-hand man to the former Gucci designer Alessandro Michele, he had spoken of his excitement at being hired for a “dream role” at the top of one of the best-known names in Italian fashion.

“My sweet friend, inseparable brother, so much love,” Mr. Michele wrote in an Instagram post on Friday. “What an amazing and unforgettable journey we had together. So many laughs and pure joy.”

He called Mr. Renne “one of the most talented creatives I’ve ever known,” adding, “I can’t help but cry for you desperately now.”

The brand was founded in 1983 by Franco Moschino, who was known for both his quirky and tongue-in-cheek sense of humor and his innovative approach to design. It’s a legacy that has been continued by his successors — and one that Mr. Renne had appeared keen to explore. He succeeded the American designer Jeremy Scott, who left the brand last March.

“Franco Moschino had a nickname for his design studio: la sala giochi — the playroom,” Mr. Renne said at the time of his appointment. “This resonates deeply with me: What fashion — Italian fashion especially, and the house of Moschino most of all — can achieve with its enormous power should be accomplished with a sense of play, of joy. Thank you for giving me the keys to the playroom. I can’t wait to begin.”