Study of Pralatrexate to Treat Participants With Relapsed or Refractory B-cell Non-Hodgkin’s Lymphoma

Inclusion Criteria:

Histologically/cytologically confirmed, measurable (lesion or node =2 cm by CT [at least 1 cm if by spiral CT]) B-cell Non-Hodgkin's Lymphoma, using the Revised European American Lymphoma (REAL) World Health Organization (WHO) disease classification
Progressive or persistent disease after ≥ 1 prior treatment(s)
Recovered from toxic effects of prior treatment
At least 4 weeks since most recent cytotoxic therapy
Easter Cooperative Oncology Group (ECOG) performance status ≤ 2
Adequate blood, liver, and kidney functions as defined by laboratory levels
1.0 mg/day orally of folic acid for at least 7 days prior & 1 mg intramuscular of vitamin B12 within 10 weeks of the planned start of pralatrexate
Females of childbearing potential must agree to use medically acceptable birth control from start of pralatrexate 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
Males who are not surgically sterile must agree to use medically acceptable birth control from start of pralatrexate until at least 90 days after the last administration of pralatrexate
Available for repeat dosing and follow-up
Able to give written informed consent

Exclusion Criteria:

Relapsed participants with diffuse large B-cell lymphoma (DLBCL) who are candidates for high-dose therapy and autologous stem cell transplantation (SCT) and for whom high-dose therapy and autologous SCT is a standard curative option
Active concurrent malignancy (except non-melanoma skin cancer or carcinoma in situ of the cervix). If there is a history of prior malignancies other than those exceptions listed above, the participant must be disease-free for ≥ 5 years. Participants with other prior malignancies < 5 years before study entry may still be enrolled if they have received treatment resulting in complete resolution of the cancer and currently have no clinical, radiologic, or laboratory evidence of active or recurrent disease
Congestive heart failure Class III/IV according to the New York Heart Association Functional Classification
Uncontrolled hypertension
Known human immunodeficiency virus (HIV)-positive diagnosis
Symptomatic central nervous system (CNS) metastases or lesions for which treatment is required. Participants who received prophylactic CNS treatment are eligible.
Participants who have undergone an allogeneic SCT
Participants who have relapsed < 100 days from the time of an autologous SCT
Participants with disease refractory to peripheral blood SCT or who have relapsed < 100 days from the time of transplant
Active uncontrolled infection, underlying medical condition, or other serious illness that would impair the ability of the participant to receive protocol treatment.
Major surgery within 14 days of enrollment
Receipt of any conventional chemotherapy or radiation therapy (encompassing a substantial [> 10%] amount of bone marrow) within 4 weeks (6 weeks for nitrosoureas or mitomycin C) prior to study treatment or planned use during the course of the study
Receipt of systemic corticosteroids within 1 week of study treatment, unless participant has been taking a continuous dose of no more than 10 mg/day of prednisone or its equivalent for at least 1 month
Use of any investigational drugs, biologics, or devices within 4 weeks prior to study treatment or planned use during the course of the study
Previous exposure to pralatrexate
Females who are pregnant or breastfeeding