Forest Labs will acquire Clinical Data for $1.2 billion, and expand its primary care sales forces in preparation for the launch of Viibryd (vilazodone HCI), executives said in a call this morning.

Viibryd is expected to land in pharmacies during the second quarter of this year, and will be positioned “broadly for select newly diagnosed patients, as well as those who don’t respond to or tolerate other anti-depressants,” said Bill Meury, VP marketing, Forest Laboratories, on the call.

Forest will expand its sales forces by an estimated 300 primary care reps in support of the Viibryd launch; the company already has four primary care sales force groups, with roughly 500 reps in each group. Additional reps will be added to the existing primary care groups, said Frank Perier, CFO and SVP, finance and administration, on the call. Currently, Forest has a stable of 3,000 reps, which includes a specialty sales force, an institutional sales force, a managed care sales force, and the four primary care units, Perier said.

Forest Labs hopes Viibryd will help to supplant Lexapro sales when that drug reaches patent expiration next year. In 2010, Lexapro had US sales nearing $2.5 billion, a 4.6% increase over 2009 sales, despite a large scaling back of marketing spend, according to SDI data. “We’re not putting any really significant commercial effort behind Lexapro…it’s in maintenance mode at this stage,” said Perier on the call. Forest ended DTC promotion for Lexapro in 2010, and spent just over $9 million on journal ads, according to SDI.

Asked about Viibryd’s mechanism of action this morning, Meury called the mechanism “novel but familiar.” Elaine Hochberg, EVP and chief commercial officer at Forest, said the company is in “active conversations” about phase 4 clinical trials to “elucidate the virtues” of Viibryd, responding to a reporter’s question about promoting the drug’s relatively favorable sexual side effects profile, when compared with other products in the category. Hochberg said Viibryd’s pricing would be “in line with other SSRIs in the market.”

Forest launched Teflaro (ceftaroline fosamil), an injection for pneumonia and bacterial skin infections, earlier this year, and expects an FDA decision on Daxas (roflumilast) by the end of March. Approved in the EU, Daxas received a complete response letter from FDA last May. Forest licensed Daxas from Nycomed in 2009, and David Solomon, SVP, corporate development and strategic planning, Forest, said on the call that the company has a “strong appetite” for new deals going forward, and “a lot of cash on hand.”