Extracorporeal Photopheresis and Mogamulizumab for the Treatment of Erythrodermic Cutaneous T Cell Lymphoma

Inclusion Criteria:

Documented informed consent of the participant and/or legally authorized representative

Assent, when appropriate, will be obtained per institutional guideline

Agreement to allow the use of archival tissue from diagnostic tumor biopsies

If unavailable, exceptions may be granted with study principal investigator (PI) approval
Age: >= 18 years
Eastern Cooperative Oncology Group (ECOG) =< 2

Histologically confirmed mycosis fungoides (MF) or Sezary syndrome (SS). Safety lead-in: >= stage IIB OR >= stage IB-IIA folliculotropic/transformed MF. Phase 2: >= stage IB

Stage of disease according to Tumor-Node-Metastasis-Blood (TNMB) classification
Pathology report must be diagnostic or be consistent with MF/SS criteria
SS is defined as meeting T4 plus B2 criteria; where the biopsy of erythrodermic skin may only reveal suggestive but not diagnostic histopathologic features, the diagnosis may be based on either node biopsy or fulfillment of B2 criteria
For MF where the histological diagnosis by light microscopic examination is not confirmed, diagnostic criteria that been recommended by the International Society of Cutaneous Lymphomas (ISCL) should be used.
Measurable disease per Modified Severity Weighted Assessment Tool (mSWAT) and/or Sezary count
Baseline skin biopsy taken within 6 months available for central review submission

Without bone marrow involvement: Absolute neutrophil count (ANC) >= 1,500/mm^3 (performed within 7 days prior to day 1 of protocol therapy unless otherwise stated)

NOTE: Growth factor is not permitted within 14 days of ANC assessment unless cytopenia is secondary to disease involvement

With bone marrow involvement: ANC >= 1,000/mm^3 (performed within 7 days prior to day 1 of protocol therapy unless otherwise stated)

NOTE: Growth factor is not permitted within 14 days of ANC assessment unless cytopenia is secondary to disease involvement

Without bone marrow involvement: Platelets >= 100,000/mm^3 (performed within 7 days prior to day 1 of protocol therapy unless otherwise stated)

NOTE: Platelet transfusions are not permitted within 14 days of platelet assessment unless cytopenia is secondary to disease involvement

With bone marrow involvement: Platelets >= 75,000/mm3 (performed within 7 days prior to day 1 of protocol therapy unless otherwise stated)

NOTE: Platelet transfusions are not permitted within 14 days of platelet assessment unless cytopenia is secondary to disease involvement
Total bilirubin =< 1.5 x upper limit of normal (ULN) (unless has Gilbert's disease)(performed within 7 days prior to day 1 of protocol therapy unless otherwise stated)
Aspartate aminotransferase (AST) =< 2.5 x ULN (unless has Gilbert's disease)(performed within 7 days prior to day 1 of protocol therapy unless otherwise stated)
Alanine aminotransferase (ALT) =< 2.5 x ULN (unless has Gilbert's disease)(performed within 7 days prior to day 1 of protocol therapy unless otherwise stated)
Creatinine clearance of >= 60 mL/min per 24 hour urine test or the Cockcroft-Gault formula (unless has Gilbert's disease) (performed within 7 days prior to day 1 of protocol therapy unless otherwise stated)
If not receiving anticoagulants: International normalized ratio (INR) OR prothrombin (PT) =< 1.5 x ULN (performed within 7 days prior to day 1 of protocol therapy unless otherwise stated)
If on anticoagulant therapy: PT must be within therapeutic range of intended use of anticoagulants (performed within 7 days prior to day 1 of protocol therapy unless otherwise stated)
If not receiving anticoagulants: Activated partial thromboplastin time (aPTT) =< 1.5 x ULN (performed within 7 days prior to day 1 of protocol therapy unless otherwise stated)
If on anticoagulant therapy: aPTT must be within therapeutic range of intended use of anticoagulants (performed within 7 days prior to day 1 of protocol therapy unless otherwise stated)

Hepatitis C virus (HCV)*, active hepatitis B virus (HBV) (surface antigen negative), and syphilis (rapid plasma reagin [RPR])

If positive, hepatitis C ribonucleic acid (RNA) quantitation must be performed

Meets other institutional and federal requirements for infectious disease titer requirements

Note Infectious disease testing to be performed within 28 days prior to day 1 of protocol therapy
Subjects with MF and a history of staphylococcus colonization are eligible provided they continue to receive stable doses of prophylactic antibiotics
Women of childbearing potential (WOCBP): negative urine or serum pregnancy test If the urine test is positive or cannot be confirmed as negative, a serum pregnancy test will be required

Agreement by females and males of childbearing potential* to use an effective method of birth control or abstain from heterosexual activity for the course of the study through at least 3 months after the last dose of protocol therapy

Childbearing potential defined as not being surgically sterilized (men and women) or have not been free from menses for > 1 year (women only)

Exclusion Criteria:

Prior mogamulizumab
Any systemic therapy, including monoclonal antibody within 28 days or 5 half-lives (whichever is shorter) of initiating protocol therapy
Chemotherapy, radiation therapy, biological therapy, immunotherapy within 21 days prior to day 1 of protocol therapy
Any skin-directed therapy within 14 days prior to initiating protocol therapy
Any radiation therapy within 21 days prior to initiating protocol therapy

Immunosuppressive medication within 14 days prior to the first dose of study treatment. The following are exceptions to this criterion:

Intranasal, inhaled, topical or local steroid injections (e.g., intra-articular injection) and are on stable dose for at least 28 days
Systemic corticosteroids at physiologic doses of < 10 mg/day of prednisone or equivalent
Live, attenuated vaccine within 30 days prior to the first dose protocol therapy

Disease free of prior malignancies for >= 5 years with the exception of:

Currently treated squamous cell and basal cell carcinoma of the skin, or
Carcinoma in situ of the cervix, or
Surgically removed melanoma in situ of the skin (stage 0) with histological confirmed free margins of excision, or
Prostate cancer (T1a or T1b using the TNM [tumor, nodes, metastasis] clinical staging system) that has/have been surgically cured, or
Any other malignancy that has/have been curatively treated with surgery and/or localized radiation
Active infection requiring antibiotics
Known hepatitis B or hepatitis C infection
Other active malignancy
Females only: Pregnant or breastfeeding
Prior stem cell transplantation
Acute infection requiring systemic treatment
Conditions requiring chronic steroid or immunosuppressive treatment that likely need additional steroid or immunosuppressive treatments in addition to the protocol therapy
Renal failure requiring hemodialysis or peritoneal dialysis

Unstable cardiac disease as defined by one of the following:

Cardiac events such as myocardial infarction (MI) within the past 6 months
NYHA (New York Heart Association) heart failure class III-IV
Uncontrolled atrial fibrillation or hypertension
Major surgery (as defined by the investigator) within the 28 days prior to the first dose of study treatment

Active or prior documented autoimmune or inflammatory disorders requiring therapy within the past 3 years prior to the start of treatment. The following are exceptions to this criterion:

Vitiligo or alopecia
Hypothyroidism (e.g., following Hashimoto syndrome) stable on hormone replacement; or
Psoriasis not requiring systemic treatment
History of primary immunodeficiency
Any other condition that would, in the Investigator's judgment, contraindicate the patient's participation in the clinical study due to safety concerns with clinical study procedures.
Prospective participants who, in the opinion of the investigator, may not be able to comply with all study procedures (including compliance issues related to feasibility/logistics)