WorldOne hopes to take Sermo global.

That’s part of the firm’s plans for a $35 million pledge from Deerfield Management Company—the financing will also help spruce up Sermo’s US presence. Mike Marett, head of global business development at WorldOne Interactive, said the company will be “enhancing the utility for the physician, making it more social and more relevant based on their needs.”

WorldOne, which acquired Sermo last July, boasts a global network of 1.8 million healthcare professionals across 80 countries, including 385,000 US physicians and a million US HCPs, and hopes to use the financing as a springboard for the evolution of its offering from physician panels to online community.

Said WorldOne chief Peter Kirk in a statement: “With the Sermo acquisition to complement our innovative engagement product portfolio and global reach to over one million physicians, we had the core ingredients to build a much needed interactive destination for physicians around the world. With this recent round of funding, we now have the necessary resources to execute against that grand vision.”

Deerfield partner James Flynn said his firm was “excited by the synergies between WorldOne’s physician community and research assets and Deerfield’s own market intelligence capabilities.”

Boston-based Sermo, which launched in 2005, has had its ups and downs—the company had to refocus its business model on pharma after a sideline catering to Wall Street firms cratered amid recessionary cutbacks. It’s the granddaddy of physician social networks, but increasingly, it’s got company.

In September, San Francisco startup Doximity announced that it had secured $17 million in funding from a consortium led by Morgenthaler Ventures, bringing the company’s total funding to $27 million. In February, Medikly, a newer New York software-as-a-service firm, said it had landed $1.2 million in financing from Easton Capital. And M3 Group is stitching together a global physician network, having acquired MDLinx in the US and Doctors.net.uk, and most recently, inked a content share deal with CME firm Medcenter, extending its reach to Spain, Portugal and Latin America.