A pair of Bay State regenerative medicine firms, Histogenics Corp. and ProChon Biotech Ltd., merged in an all-stock deal that brings ProChon CEO Patrick O’Donnell into the Histogenics corner office.

O’Donnell told MassDevice.com that a deal has been in the works since the early part of 2011.

"The idea was that you had an opportunity not only to bring together two synergistic technologies and develop a broader regenerative medicine pipeline, but you had an opportunity to take what will probably be the next two regenerative medicine products to hit the U.S. market and put them under one roof," O’Donnell told us. "We exist to be bought and it kind of takes the wait-and-see effect away, from the perspective of a major global orthopedic or pharmaceutical company interested in this space, of which technology wins in the marketplace."

No layoffs are planned in connection with the merger, he added, noting that the companies will consolidate their HQs in Histogenics Waltham, Mass., offices. That operation will go from about five people to roughly 21 by the end of the year, O’Donnell said.

Asked about being tapped to lead the new Histogenics as president and CEO, O’Connell said that decision came about fairly easily.

"We had a very good management team at ProChon in place already, and Histogenics only had a few folks on board, so it just made sense that our management team assumed control," he explained.

Histogenics’ backers include Altima Partners, Boston Millennia Partners, Foundation Medical Partners, and ProChon Holdings BV.

"Merging these two companies will have a significant positive impact on the adoption of regenerative medicine, beginning with cartilage regeneration and extending to other applications in the near term," O’Donnell said in prepared remarks. "We will leverage each company’s distinctive capabilities to develop a broad regenerative medicine pipeline that will address surgical applications in orthopedics, vascular, and neurosurgery. We are excited and very enthusiastic about the results we have seen to date and the opportunities that lie ahead."

Histogenics has one product, an autologous knee cartilage regeneration system called NeoCart, in a pivotal Phase III trial. ProChon’s BioCart product, which uses a proprietary growth factor with a biocompatible scaffold for knee cartilage repair, is in a Phase II trial. The company plans to pursue both tracks, O’Donnell said.