Therakos Receives MDR Approval in Europe for Treating Immune-Related Adverse Events in Patients with Inadequate Response to Corticosteroids

DUBLIN, Oct. 21, 2026 /PRNewswire/ -- Therakos Development Limited, a global pioneer in immunomodulatory therapy delivered at the bedside through extracorporeal photopheresis (ECP), announced today that its THERAKOS™ CELLEX™ Photopheresis System has received certification under the EU MDR for an expanded indication. The system is now indicated in Europe for the treatment of immune-related adverse events (irAEs) associated with immune checkpoint inhibitor (ICI) therapy in adults who have had an inadequate response to corticosteroids. It is the first and only therapy approved for this use anywhere in the world.

ICI therapy has transformed cancer care by harnessing the immune system to deliver durable antitumor responses. However, this same immune activation can trigger potentially severe irAEs, compromising treatment continuity and patient outcomes. Corticosteroids remain the standard initial treatment for clinically significant irAEs, often requiring interruption or discontinuation of ICI therapy. For patients who do not respond adequately, additional immunosuppressive treatments may be necessary, potentially further compromising antitumor immunity. These challenges underscore a critical unmet need for therapeutic approaches that effectively manage immune-related toxicities while preserving the benefits of cancer immunotherapy.

"The management of steroid-refractory irAEs remains a challenge since data on effectiveness of different drugs is scarce and immunosuppression can hinder antitumor response. The THERAKOS™ CELLEX™ Photopheresis System, which is now approved for this indication in Europe, represents a significant advancement in treatment of steroid-refractory irAEs," said Prof. Dr. Lucie Heinzerling, MPH, Professor of Dermatology and Venereology, LMU University Hospital, Ludwig Maximilian University.

"At Therakos, we are committed to addressing the needs of patients who are impacted by immune-related complications of ICI therapy," said Sandra Thompson, Co-Chief Executive Officer, Therakos. "As the first and only therapy approved to treat these complications, the THERAKOS™ CELLEX™ Photopheresis System gives European medical oncology teams an important new option for treating their patients."

ECP takes a different approach than traditional options. Rather than broadly suppressing the immune system, it is designed to help re-establish immune balance using the patient's own cells. The goal is to address the toxicity without broad immunosuppression. It is well established that immunosuppression can compromise the cancer therapy itself.

"Immune-related toxicity has long been treated as a systemic problem, but it's better understood as a tissue-specific one. ECP resolves inflammation at the site where it occurs, through the body's own anti-inflammatory signaling, rather than suppressing the immune system broadly. As immunotherapy reaches more patients and more combinations, managing its toxicity without compromising its benefit will define how far the field can go. This expanded indication in Europe puts a therapy that does exactly that in clinicians' hands," said Prof. Dr. Robert Zeiser, Professor of Medicine and Director of the Division of Tumor Immunology at the Department of Hematology, Oncology, and Stem-Cell Transplantation at the Medical Center University of Freiburg.

Clinicians can access the THERAKOS™ CELLEX™ Photopheresis System for irAEs associated with ICI therapy in adults who have had an inadequate response to corticosteroids through an existing network of over 190 centres in Europe as a result of this MDR approval.

About Therakos

Therakos is a global pioneer in autologous immunomodulatory therapy delivered at the bedside through Extracorporeal Photopheresis (ECP). Supported by more than four decades of clinical experience and evidence-based medicine, the Therakos ECP system was among the first FDA-approved cell-based immunomodulatory therapies. Our mission is to restore and protect human immunity. Rather than broadly suppressing the immune system, our approach is designed to help re-establish immune balance by harnessing the power of a patient's own cells. Through ongoing investment in research, evidence generation, and innovation, we are advancing the science of immunomodulation to expand understanding and improve outcomes for patients living with complex immune-mediated diseases. Learn more at https://therakos.eu/ 

About Extracorporeal Photopheresis (ECP)

ECP is an immunomodulatory therapy delivered at the bedside. A small volume of the patient's white blood cells is collected, treated with a photoactive agent and ultraviolet A light, and returned to the patient. Rather than broadly suppressing the immune system, ECP is designed to help re-establish immune balance using the patient's own cells.

IMPORTANT SAFETY INFORMATION FOR THE THERAKOS™ CELLEX™ PHOTOPHERESIS SYSTEM

Indications

As certified in the EU, the THERAKOS™ CELLEX™ Photopheresis System is indicated for patients older than 18 years of age for the administration of photopheresis in the following:

• Cutaneous T Cell Lymphoma (CTCL)
  
  
• Solid Organ Transplant Rejection (SOT) (heart, lung)
  
  
• Treatment of immune-related adverse events (irAEs) associated with immune checkpoint inhibitor (ICI) therapy in patients with inadequate response to corticosteroids

The THERAKOS™ CELLEX™ Photopheresis System is also indicated for use in EU MDR jurisdictions in patients older than 3 years of age for the management of:

• Acute and Chronic Graft versus Host Disease (aGvHD, cGvHD)

Contraindications

The THERAKOS™ CELLEX™ Photopheresis System is contraindicated in:

• Patients possessing a specific history of a light sensitive disease.
  
  
• Patients who cannot tolerate extracorporeal volume loss or who have white blood cell counts greater than 25,000 / mm³.
  
  
• Patients who have coagulation disorders or who have previously had a splenectomy.

Warnings and Precautions

THERAKOS™ CELLEX™ Photopheresis System treatments should always be performed in locations where standard medical emergency equipment is available. Volume replacement fluids and/or volume expanders should be readily available throughout the procedure.

• Do not expose the device to a magnetic resonance (MR) environment. The device may present a risk of projectile injury, and thermal injury and burns may occur. The device may generate artifacts in the MR image, or may not function properly.
  
  
• Thromboembolic events, including pulmonary embolism and deep vein thrombosis, have been reported in the treatment of Graft versus Host Disease (GvHD). Special attention to adequate anticoagulation is advised when treating patients with GvHD.
  
  
• When prescribing and administering THERAKOS™ CELLEX™ Photopheresis System for patients receiving concomitant therapy, exercise caution when changing treatment schedules to avoid increased disease activity that may be caused by abrupt withdrawal of previous therapy.

Adverse Events

• Hypotension may occur during any treatment involving extracorporeal circulation. Closely monitor the patient during the entire treatment for hypotension.
  
  
• Transient pyretic reactions, 37.7–38.9°C (100–102°F), have been observed in some patients within six to eight hours of reinfusion of the photoactivated leukocyte-enriched blood. A temporary increase in erythroderma may accompany the pyretic reaction.
  
  
• Treatment frequency exceeding labelling recommendations may result in anaemia.
  
  
• Venous access carries a small risk of infection and pain.

Please refer to the THERAKOS™ CELLEX™ Photopheresis System Operator's Manual for a complete list of warnings and precautions.

IMPORTANT SAFETY INFORMATION FOR METHOXSALEN USED IN CONJUNCTION WITH THERAKOS™ CELLEX™ PHOTOPHERESIS SYSTEM

Consult the 8-methoxypsoralen (Methoxsalen (20 micrograms / mL)) professional leaflet or the oral 8-methoxypsoralen formulation package insert before prescribing or dispensing any medication.

Warnings and Precautions

• Patients exhibiting multiple basal cell carcinomas or having a history of basal cell carcinoma should be diligently observed and treated.
  
  
• Methoxsalen may cause fetal harm when given to a pregnant woman. Women undergoing photopheresis should be advised to avoid becoming pregnant.
  
  
• Special care should be exercised in treating patients who are receiving concomitant therapy (either topically or systemically) with known photosensitizing agents.
  
  
• Oral administration of methoxsalen followed by cutaneous UVA exposure (PUVA therapy) is carcinogenic.
  
  
• Patients should be told emphatically to wear UVA absorbing, wrap-around sunglasses for twenty-four (24) hours after methoxsalen treatment. They should wear these glasses any time they are exposed to direct or indirect sunlight, whether they are outdoors or exposed through a window.

Refer to the package insert for methoxsalen sterile solution (20 micrograms / mL) or the oral 8-methoxypsoralen dosage formulation for a list of all warnings and precautions.

The THERAKOS^® CELLEX^® Photopheresis System is not approved by the U.S. Food and Drug Administration (FDA) for the treatment of immune-related adverse events (irAEs) associated with immune checkpoint inhibitor (ICI) therapy in adults who have had an inadequate response to corticosteroids.

Contact

Media enquiries
Debbie Miller, Therakos
Debbie.Miller@therakos.com

©2026 Therakos Development Limited.

TKS-26-00481 Oct 2026