A Single Arm Study Evaluating the Efficacy and Safety of Pralatrexate in Subjects With Relapsed or Refractory PTCL

Inclusion Criteria:

1. Subject has histologically/cytologically confirmed PTCL, using the World Health Organization (WHO) disease classification:

   1. PTCL not otherwise specified (NOS)
   2. Angioimmunoblastic T-cell lymphoma
   3. Anaplastic large cell lymphoma, ALK+
   4. Anaplastic large cell lymphoma, ALK-
   5. Extranodal NK/T-cell lymphoma - nasal type
   6. Enteropathy-associated T cell lymphoma
   7. Hepatosplenic T-cell lymphoma
   8. Subcutaneous panniculitis-like T-cell lymphoma
   9. Adult T-cell lymphoma/leukemia (human T-cell leukemia virus \[HTLV\] 1+)
   10. Aggressive NK-cell leukemia
   11. Transformed mycosis fungoides
2. Subject has to have documented progressive disease (PD) after at least 1 prior systemic treatment.
3. Subject may not have received an experimental drug or biologic as their only prior therapy. Subject must have clear PD after the last treatment received. Subject should have at least 1 biopsy from initial diagnosis or in the relapsed setting to confirm the diagnosis of PTCL. Subject must have recovered from the toxic effects of prior therapy.
4. Subjects with an enlarged lymph node or extranodal mass lesion clearly measurable in two perpendicular directions and greater than 1.5 cm maximum diameter on computed tomography performed within 14 days prior to study enrollment.
5. Eastern Cooperative Oncology Group (ECOG) Performance Status ≤ 2.
6. At least 18 years of age.
7. Expected life expectancy ≥ 3 months.
8. Adequate hematological, hepatic, and renal function as defined by:

   * Absolute neutrophil count (ANC) ≥ 1000/uL (or 1\*109/L), platelet count ≥ 100,000/uL (or 100\*109/L) (at both screening and within 3 days prior to dosing on cycle 1, day 1)
   * Total bilirubin ≤ 1.5 mg/dL, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤ 2.5 X upper limit of normal (ULN) (AST/ALT \< 5 X ULN if documented hepatic involvement with lymphoma)
   * Creatinine ≤ 1.5 mg/dL (or 132.6 µmol/L) or a calculated creatinine clearance ≥ 50 mL/min
9. Women of childbearing potential must have agreed to practice a medically acceptable contraceptive regimen from study treatment initiation until at least 30 days after the last administration of pralatrexate and must have a negative serum pregnancy test within 14 days prior to the first day of study treatment. Subjects who are postmenopausal for at least 1 year (\> 12 months since last menses) or are surgically sterilized did not require this test.
10. Men who are not surgically sterile must agree to practice a medically acceptable contraceptive regimen from study treatment initiation until at least 90 days after the last administration of pralatrexate.
11. Subject gives written informed consent (IC).

Exclusion Criteria:

1. Subject has:

   1. Precursor T-cell lymphoma or leukemia
   2. T-cell prolymphocytic leukemia (T-PLL)
   3. T-cell large granular lymphocytic leukemia
   4. Mycosis fungoides, other than transformed mycosis fungoides
   5. Sézary syndrome
   6. Primary cutaneous CD30+ T-cell disorders: Lymphoid papulosis and primary cutaneous anaplastic large cell lymphoma
2. Active concurrent malignancy (except non-melanoma skin cancer or carcinoma in situ of the cervix). If there is a history of prior malignancy, the patient must be disease-free for ≥ 5 years.
3. Congestive heart failure Class III/IV according to the New York Heart Association's Heart Failure guidelines.
4. Human immunodeficiency virus (HIV)-positive diagnosis.
5. Has, or history of, brain metastases or central nervous system (CNS) disease.
6. Active uncontrolled infection, underlying medical condition including unstable cardiac disease, or other serious illness that would impair the ability of the subject to receive protocol treatment.
7. Has major surgery within 2 weeks of study entry.
8. Receipt of any conventional chemotherapy or radiation therapy (RT) within 4 weeks (6 weeks for nitrosoureas or mitomycin C) prior to study treatment or planned use during the course of the study.
9. Receipt of corticosteroids within 7 days of study treatment, unless subject has been taking a continuous systemic dose of no more than 10 mg/day or equivalent dose of prednisone, or a local or inhaled or intranasal administration at fixed doses for at least 1 month prior to study treatment and tumor shrinkage was not observed.
10. Use of any investigational drugs, biologics, or devices within 4 weeks prior to study treatment or planned use during the course of the study.
11. Receipt of anti-tumor antibody therapy within 100 days prior to study treatment.
12. History of allogeneic hematopoietic stem cell transplantation. Or subjects with a history of autologous hematopoietic stem cell transplantation within 100 days prior to study treatment.
13. Previous exposure to pralatrexate.
14. Subject is pregnant or breast-feeding