Phase I Study of Recombinant Human IL-15 (rhIL-15) and Mogamulizumab for People With Refractory or Relapsed Adult T-Cell Leukemia and Mycosis Fungoides/Sezary Syndrome

-INCLUSION CRITERIA:

• Patients must have one of the following histologically or cytologically proven relapsed and/or refractory to at least one line of systemic treatment, T-cell malignancies confirmed by the Laboratory of Pathology, National Cancer Institute (NCI): mycosis fungoides/Sezary syndrome, or adult T-cell leukemia (chronic, acute, or lymphoma subtype by Shimoyama criteria)
• Patients with luster of differentiation 30 (CD30)+ Mycosis Fungoides/Sezary Syndrome (MF/SS) must have relapsed after or become intolerant to treatment with brentuximab vedotin
• A formalin fixed tissue block or 15 slides of tumor sample (archival or fresh) must be available for performance of correlative studies. NOTE: Patients must be willing to have a tumor biopsy if prior tissue or adequate archival tissue is not available (i.e., post- enrollment and prior to treatment).
• Disease must be measurable with at least one measurable lesion by Response Evaluation Criteria in Lymphoma (RECIL 2017) or modified severity-weighted assessment tool (mSWAT) criteria, or have an abnormal clonal T-cell population detectable by peripheral blood flow cytometry
• Age >18 years

NOTE: Because no dosing or adverse event data are currently available on the use of rhIL-15 in combination with mogamulizumab in patients 100,000/mcL

• Total bilirubin: less than or equal to 1.5 X institutional upper limit of normal (ULN)
• Aspartate aminotransferase (AST)Serum glutamic oxaloacetic transaminase (SGOT)/Alanine aminotransferase (ALT)Serum glutamic pyruvic transaminase (SGPT): less than or equal to 2.5 X institutional ULN
• Serum creatinine: less than or equal to 1.5 X institutional ULN, OR Creatinine clearance: greater than or equal to 50 mL/min/1.73 m2 for patients with creatinine levels >1.5 institutional ULN
• Negative serum or urine pregnancy test at screening for women of childbearing potential (WOCBP)

NOTE: WOCBP is defined as any female who has experienced menarche and who has not undergone successful surgical sterilization or who is not postmenopausal.

• Women of child-bearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry, for the duration of study participation, and 6 months after completion of rhIL-15 and mogamulizumab administration. Should a woman become pregnant or suspect she is pregnant while she or her partner is participating in this study, she should inform her treating physician immediately.
• Ability of subject to understand and the willingness to sign a written informed consent document

EXCLUSION CRITERIA

• Patients with other T-cell leukemias/lymphomas not specified in the inclusion criteria
• Anti-cancer treatment within 2 weeks of the first dose of rhIL-15 and mogamulizumab (4 weeks for anti-cancer monoclonal antibody or investigational agents, 6 weeks for donor lymphocyte infusion,100 days for allogeneic stem cell transplant)
• Systemic treatment for acute or chronic graft versus host disease (GVHD) within 12 weeks of the first dose of rhIL-15 and mogamulizumab
• Cohort 1 (Dose Escalation) only: history of grade 3/4 GVHD, or active grade 1/2 GVHD regardless of treatment
• Persisting toxicity related to prior therapy of grade > 1, with the exception of the following: alopecia, sensory neuropathy grade less than or equal to 2, or other grade less than or equal to 2 not constituting a safety risk based on investigator's judgment
• Patients who are receiving any other investigational agents
• Current use of immunosuppressive medication, EXCEPT for the following:
• Intranasal, inhaled, topical steroids, or local steroid injection (e.g., intra-articular injection)
• Systemic corticosteroids at physiologic doses less than or equal to 10 mg/day of prednisone or equivalent; or,
• Steroids as premedication for hypersensitivity reactions (e.g., computed tomography (CT) scan premedication)
• Patients with previous malignant disease other than th