Chesterfield, UK-based Mallinckrodt plc will acquire Therakos Inc. for about $1.325 billion from Los Angeles-based The Gores Group, an investment firm.

The Gores Group bought Therakos from Ortho Clinical Diagnostics, formerly a unit of Johnson & Johnson (JNJ), in December 2012. Mallinckrodt reported net sales of $2.54 billion in 2014, and focuses on drugs for autoimmune and rare diseases and medical imaging technology.

Therakos, headquartered in West Chester,PA, focuses on autologous immune cell therapy using its extracorporeal photopheresis (ECP) technology. The technology has been approved by the U.S. Food and Drug Administration (FDA) for the treatment of skin manifestations of cutaneous T-cell lymphoma (CTCL) in patients who haven’t responded to other treatment. It is widely approved worldwide for ECP in a number of conditions, including CTCL, Graft Versus Host Disease, Crohn’s disease, and solid organ transplants.

“This transaction demonstrates our ongoing commitment to building a strong, highly profitable hospital growth business as we build and diversify Mallinckrodt’s specialty brands portfolio,” said Mark Trudeau, president and chief executive officer, Mallinckrodt. “In expanding our hospital portfolio we continue to move decisively in line with our strategic roadmap. And we believe we will be able to unlock untapped value in Therakos—making ECP treatment accessible to more patients in more hospitals by applying some of the innovative contract, service and customer intimacy principles that have been so successful with our Inomax (nitric oxide) for inhalation.”