The agency formerly known as LyonHeart is going back to its maiden name ahead of the rollout of a new Omnicom healthcare agency network.

“We found that a lot of [client] companies were still calling us LLNS, including our biggest client,” said Sharon Callahan, who will serve as CEO of the new network. “It seems like a lot of the equity is in LLNS, and we don’t want to confuse the marketplace with another new name,” she added.

Callahan was mum on the details of the new network but said it will be an integrated offering consisting of five agencies, with PR, CRM, managed care consulting and med ed.

LLNS rebranded under the LyonHeart name in 2007, shortly after it was folded into the TBWAWorldHealth network. LLNS was quietly demerged from TBWA earlier this year. The shop’s top clients include Pfizer, Eisai and Daiichi Sankyo.

The new network, said Callahan, will be based on the recent global integration of a big pharma client’s business across Omnicom, which she presided over. The process took two years. “We found out what worked,” said Callahan. “We’re trying to achieve true collaboration across disciplines.”

Callahan was EVP healthcare for Omnicom’s Diversified Agency Services group before taking the CEO post. Anne Devereux, who was chairman and CEO of TBWA/WorldHealth, is chairman of the new network.