Ireland-based Mallinckrodt has signed a definitive agreement with The Gores Group to acquire immunotherapy firm Therakos for $1.3bn.

The acquired business is anticipated to expand Mallinckrodt’s speciality brands portfolio and diversify its hospital offerings through the addition of a high-margin drug-device system, which is used in hospitals and major medical centres in 25 countries.

Therakos provides treatment platforms for immune disorders, including Cellex Photopheresis system, and also delivers autologous immune cell therapy through extracorporeal photopheresis (ECP).

"This transaction demonstrates our ongoing commitment to building a strong, highly profitable hospital growth business."

The photopheresis system secured approval from US Food and Drug Administration to treat skin manifestations of cutaneous T-cell lymphoma (CTCL) in persons who failed to respond to other forms of treatment.

Outside the US, the system obtained approval for ECP, allowing physicians to use it in different conditions including CTCL, graft versus host disease, Crohn’s disease, solid organ transplants and other diseases.

Mallinckrodt president Mark Trudeau said: "This transaction demonstrates our ongoing commitment to building a strong, highly profitable hospital growth business as we build and diversify Mallinckrodt’s speciality brands portfolio.

"With this expansion into immunotherapy we add to our footprint of nuclear medicine, pain management and respiratory neonatal critical care, broadening our touch points in hospitals and further expanding our portfolio with innovative therapies."

Therakos photopheresis platforms, including the Cellex system, are expected to further expand Mallinckrodt’s presence from multimodal surgical pain management and critical care respiratory therapies in neonatal intensive care units.

It will include innovative therapies that harness the patient’s own immune systems to fight disease and improve health.

Following the acquisition, Therakos’s commercial team will be integrated into Mallinckrodt’s current critical care organisation within its hospital speciality brands business.

Subject to customary closing conditions, the transaction is expected to be completed during the third quarter of this year.