This study is designed to determine the recommended dose, safety, pharmacokinetics, and early efficacy of the combination of pralatrexate plus oral bexarotene in patients with relapsed or refractory CTCL.

This is a multi-center, dose-finding, Phase 1 study of pralatrexate plus bexarotene in patients who have relapsed or refractory CTCL.

Primary Objective(s):

• Determine the maximum tolerated dose (MTD) and recommended dose of pralatrexate plus bexarotene with concurrent vitamin B12 and folic acid supplementation when administered to patients who have failed prior systemic treatment.

Secondary Objective(s):

• Determine the safety profile of pralatrexate plus bexarotene when administered to patients with relapsed/refractory cutaneous T-cell lymphoma (CTCL).
• Collect preliminary efficacy data.
• Determine the pharmacokinetic (PK) profile of pralatrexate plus bexarotene in patients who underwent plasma PK sampling

Inclusion Criteria:

• Cutaneous T-cell lymphoma patients with subtypes of mycosis fungoides (MF) Stage IB or higher, Sézary syndrome, or primary cutaneous anaplastic large cell lymphoma who have failed a previous systemic treatment.
• Patients must have received at least 1 previous systemic therapy, and either progressed or not tolerated their last prior treatment regimen.
• Eastern Cooperative Oncology Group Performance Status less than or equal to 2.
• Adequate blood, liver, and kidney function as defined by laboratory tests.
• Women of childbearing potential must practice medically acceptable contraception from study treatment start until at least 30 days after the last dose of study treatment. Negative serum pregnancy test within 14 days before the first day of study treatment (not required for patients who are postmenopausal for at least 1 year or surgically sterilized). Study treatment should not be given to women who are breastfeeding.
• Males who are sexually active must agree to practice medically acceptable barrier contraception while receiving study treatment and for 30 days after the last dose of study treatment.
• Give written informed consent & privacy authorization.

Exclusion Criteria:

• If there is a history of prior malignancies other than non-melanoma skin cancer, carcinoma in situ of the cervix, localized prostate cancer, or localized thyroid cancer, patient must be disease free for at least 5 years. Patients with other prior malignancies less than 5 years before study entry may be enrolled if they received treatment resulting in complete resolution of the cancer and have no current clinical, radiologic, or laboratory evidence of active or recurrent disease.
• Human immunodeficiency virus (HIV)-positive diagnosis with a CD4 count of less than 100 mm3 or detectable viral load within the past 3 months, and receiving combination anti-retroviral therapy.
• Diagnosis of Hepatitis B virus, or Hepatitis C virus with detectable viral load or immunological evidence of chronic active disease or receiving/requiring antiviral therapy.
• Active central nervous system disease requiring treatment.
• Active uncontrolled infection, underlying medical condition, or other serious illness impairing the patient's ability to receive protocol treatment.
• Discontinuation of prior oral bexarotene due to an allergic reaction or treatment-related toxicity.
• Major surgery within 2 weeks of planned start of treatment.
• Conventional or investigational chemotherapy or radiation therapy encompassing greater than 10% of bone marrow within 4 weeks prior to study treatment.
• ECP, phototherapy with PUVA, or ultraviolet (UV) therapy within 2 weeks prior to study treatment.
• Systemic corticosteroids within 3 weeks of study treatment, unless patient has been taking a continuous dose of no more than 10 mg per day of prednisone or equivalent for at least 4 weeks.
• Initiation of or change in dosage of topical corticosteroids within 3 weeks of study treatment (topical steroid use within 3 weeks is allowed provided the strength and use has been stable for at least 4 weeks).
• Investigational drugs, biologics, or devices use within 2 weeks prior to study treatment or planned use during the study.
• Monoclonal antibody within 3 months without evidence of PD.
• Use of oral retinoids, except bexarotene, within 4 weeks of study treatment or high-dose vitamin A (once daily multi-vitamin allowed).
• Previous exposure to pralatrexate.
• Uncontrolled hypercholesterolemia or hypertriglyceridemia.