What Is THERAKOS® Photopheresis?

The THERAKOS Photopheresis System is an immunomodulatory therapy that uses extracorporeal photopheresis (ECP) to help enhance immunologic response.* THERAKOS Photopheresis was first approved by the FDA in 1987 for the palliative treatment of CTCL skin symptoms in patients who were not responsive to other types of treatment.1,2

Since launch over 35 years ago, there have been over 1 million THERAKOS Photopheresis treatments given. THERAKOS Photopheresis is now available in approximately 170 treatment centers across the United States.3 Treatment centers are independent, third-party facilities not owned, operated, or controlled by Mallinckrodt Pharmaceuticals.

*The exact mechanism of action of UVADEX is not known.

The THERAKOS Photopheresis system includes:

CELLEX instrument
The CELLEX instrument performs the extraction, treatment, and reinfusion of white blood cells for an integrated, closed photopheresis procedure.1
To learn more about CELLEX and software upgrades, visit the CELLEX Instrument Overview or Interactive Photo Gallery.
UVADEX (methoxsalen) Sterile Solution
UVADEX is the photosensitizing agent used to treat the white blood cells in the CELLEX photoactivation chamber.1
Procedural kit
The procedural kit includes all single-use supplies needed to perform one treatment, including the photoactivation module, centrifuge bowl, treatment bag, return bag, and pump tubing.4 Customers can access updates to the Operator’s Manual and technical bulletin(s) through the MyTHERAKOS portal.

FDA, US Food and Drug Administration.

A Systemic Treatment Option

Skin symptoms of mycosis fungoides, the most common subtype of CTCL, typically have a long, indolent course5,6 Patients may experience a long series of different treatments.

Treatment decisions can incorporate the disease stage, overall prognosis, patient quality of life, and most bothersome symptoms, as well as treatment history and patient preference.7

Some systemic treatment options for CTCL skin manifestations:


When it’s time for systemic therapy, consider one that makes sense for patients in the middle of a long series of possible treatments.5,8

CELLEX Instrument Overview 

The CELLEX instrument is a sophisticated touchscreen medical device that is part of an integrated, closed photopheresis system. Only healthcare professionals who have special training and experience in the THERAKOS CELLEX Photopheresis System should operate the CELLEX instrument.4 Healthcare professionals with a background in apheresis are the most common CELLEX operators. Please read the appropriate Operator’s Manual before using this product. To enroll in photopheresis-specific training, visit the MyTHERAKOS portal.

CELLEX automatically calculates the appropriate methoxsalen dose and returns all treated leukocytes to the patient.4

Software upgrades

With these latest upgrades, operators and patients both may benefit from a more automated procedure, as well as a quieter treatment experience with potentially fewer alarms and interruptions.4,9

v5.1 Upgrades

v5.4 Upgrades

Expanded software automation with potentially
fewer interruptions during treatment10

Reduced centrifuge speed for a quieter treatment
environment for a majority of the treatment9

Enhanced prime sequence may result in fewer
alarms and interruptions during treatment9,10

Simplified troubleshooting of some prime
alarms during prime sequence4

Prioritized alarm audio/visual notifications to
reduce noise4

New operator’s manual includes improved
troubleshooting steps and updates4

Interactive Photo Gallery for CELLEX

Get more information about CELLEX components

Use icons to learn more
Tap on monitor Tap on centrifuge Tap on peristaltic pumps Tap on methoxsalen bag Tap on UV plate



Please read the full Operator’s Manual, including the Warnings and Cautions, prior to using this product.


  1. UVADEX (methoxsalen) Sterile Solution (prescribing information). Therakos Inc; March 2023.

  2. Ward DM. Extracorporeal photopheresis: how, when, and why. J Clin Aphersis. 2011;26(5):276-285.

  3. Data on File – Ref-VV-00822. Mallinckrodt Pharmaceuticals.

  4. THERAKOS® CELLEX® Photopheresis Operator's Manual for Use With Software 5.4. 1470493_Rev06_EN-US. Mallinckrodt; 2020.

  5. Prince HM, Whittaker S, Hoppe RT. How I treat mycosis fungoides and Sézary syndrome. Blood. 2009;114(20):4337-4353.

  6. Kim EJ, Hess S, Richardson SK, et al. Immunopathogenesis and therapy of cutaneous T-cell lymphoma. J Clin Invest. 2005;115(4):798-812.

  7. Lansigan F, Foss FM. Current and emerging treatment strategies for cutaneous T-cell lymphoma. Drugs. 2010;70(3):273-286.

  8. Scarisbrick JJ, Bagot M, Ortiz-Romero PI. The changing therapeutic landscape, burden of disease, and unmet needs in patients with cutaneous T-cell lymphoma. Br J Haematol. 2021;192:683-696.

  9. Data on File – Ref-VV-01111. Mallinckrodt Pharmaceuticals.

  10. THERAKOS® CELLEX® Photopheresis Operator's Manual for Use with Software 5.1. 1470464_RevA-US-UK-CA. Mallinckrodt; 2018.


UVADEX® (methoxsalen) Sterile Solution is indicated for extracorporeal administration with the THERAKOS® CELLEX® Photopheresis System in the palliative treatment of the skin manifestations of Cutaneous T-Cell Lymphoma (CTCL) that is unresponsive to other forms of treatment.


UVADEX (methoxsalen) Sterile Solution should be used only by physicians who have special competence in the diagnosis and treatment of cutaneous T-cell lymphoma and who have special training and experience in the THERAKOS CELLEX Photopheresis System. Please consult the CELLEX Operator's Manual before using this product.


UVADEX is contraindicated in:

  • Patients exhibiting idiosyncratic or hypersensitivity reactions to methoxsalen, other psoralen compounds, or any of the excipients

  • Patients possessing a specific history of a light-sensitive disease state, including lupus erythematosus, porphyria cutanea tarda, erythropoietic protoporphyria, variegate porphyria, xeroderma pigmentosum, and albinism

  • Patients with aphakia because of significantly increased risk of retinal damage

  • Patients that have contraindications to the photopheresis procedure


  • Patients who are receiving concomitant therapy (either topically or systemically) with known photosensitizing agents such as anthralin, coal tar or coal tar derivatives, griseofulvin, phenothiazines, nalidixic acid, halogenated salicylanilides (bacteriostatic soaps), sulfonamides, tetracyclines, thiazides, and certain organic staining dyes such as methylene blue, toluidine blue, rose bengal, and methyl orange may be at greater risk for photosensitivity reactions with UVADEX

  • Oral administration of methoxsalen followed by cutaneous UVA exposure (PUVA therapy) is carcinogenic. Methoxsalen also causes DNA damage, interstrand cross-links and errors in DNA repair

  • Methoxsalen may cause fetal harm when given to a pregnant woman. Women of childbearing potential should be advised to avoid becoming pregnant.  If UVADEX is used during pregnancy, or if the patient becomes pregnant while receiving UVADEX, the patient should be apprised of the potential hazard to the fetus 

  • Severe photosensitivity can occur in patients treated with UVADEX. Advise patients to wear UVA absorbing, wrap-around sunglasses and cover exposed skin or use a sunblock (SPF 15 or higher), and avoid all exposure to sunlight for twenty-four (24) hours following photopheresis treatment

  • After methoxsalen administration, exposure to sunlight and/or ultraviolet radiation may result in "premature aging" of the skin

  • Since oral psoralens may increase the risk of skin cancers, monitor closely those patients who exhibit multiple basal cell carcinomas or who have a history of basal cell carcinomas

  • Serious burns from either UVA or sunlight (even through window glass) can result if the recommended dosage of methoxsalen is exceeded or precautions are not followed

  • Exposure to large doses of UVA light causes cataracts in animals. Oral methoxsalen exacerbates this toxicity

  • Safety in children has not been established

  • Thromboembolic events, such as pulmonary embolism and deep vein thrombosis, have been reported with UVADEX administration through photopheresis systems for treatment of patients with graft-versus-host disease, a disease for which UVADEX is not approved


  • Side effects of photopheresis (UVADEX used with the THERAKOS Photopheresis Systems) were primarily related to hypotension secondary to changes in extracorporeal volume (>1%)

For the THERAKOS® CELLEX® Photopheresis Procedure:


The THERAKOS CELLEX Photopheresis System is indicated for use in the ultraviolet-A (UVA) irradiation, in the presence of the photoactive drug 8-methoxypsoralen (8-MOP®), of extracorporeally circulating leukocyte-enriched blood, in the palliative treatment of the skin manifestations of cutaneous T-cell lymphoma (CTCL), in persons who have not been responsive to other forms of treatment.



The THERAKOS CELLEX Photopheresis System is not designated, sold, or intended for use except as indicated.

Certain underlying medical conditions contraindicate THERAKOS Photopheresis, including patients:

  • who cannot tolerate extracorporeal volume loss during the leukocyte-enrichment phase

  • exhibiting idiosyncratic or hypersensitivity reactions to 8-methoxypsoralen/psoralen compounds

  • with coagulation disorders

  • who have had previous splenectomy


  • THERAKOS Photopheresis 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

  • Patients who may not be able to tolerate the fluid changes associated with extracorporeal photopheresis should be monitored carefully

  • Procedures, such as renal dialysis, which might cause significant fluid changes (and expose the patient to additional anticoagulation) should not be performed on the same day as extracorporeal photopheresis

  • Individual patients may require a heparin dosage that varies from the recommended dose to prevent post-treatment bleeding or clotting during a treatment


  • 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 labeling recommendations may result in anemia

  • Venous access carries a small risk of infection and pain

Please see accompanying Full Prescribing Information, including the BOXED WARNING for UVADEX, and see the THERAKOS Photopheresis System Operator’s Manual.