This purpose of this study is to help to evaluate the pharmacokinetic (PK) profile of pralatrexate when administered to patients with various degrees of hepatic impairment and to evaluate the safety and establish the dosing recommendations for pralatrexate administered once weekly for 6 weeks of every 7-week treatment cycle in patients with hepatic impairment. Pharmacokinetics (or PK) is the study of how your body absorbs, breaks down, and removes a study drug.

This is an open-label, non-randomized, multi-center study to evaluate the PK and safety of pralatrexate in patients with advanced solid tumor or hematological malignancy with normal hepatic function or mild, moderate, or severe hepatic impairment.

Inclusion Criteria:

• Patient must be willing and capable of giving written Informed Consent and must be able to adhere to dosing and visit schedules as well as meet all study requirements
• Patient is diagnosed with advanced solid tumor or hematological malignancy.
• Patient is at least 18 years of age and has a life expectancy of at least 6 months.
• Patient has normal or abnormal hepatic function as defined by normal, mild (Child-Pugh A), moderate (Child-Pugh B ), or severe (Child-Pugh C) liver impairment
• Patient has adequate hematologic and renal function as defined by:

Absolute neutrophil count (ANC) ≥1000/μL Platelet count ≥100,000/μL Creatinine ≤ 1.5 mg/dL or calculated creatinine clearance ≥50 mL/min

• Patient has an Eastern Cooperative Oncology Group (ECOG) performance status ≤ 2.
• Patient is willing to practice 2 forms of contraception, one of which must be a barrier method, from study entry until at least 30 days after the last dose of pralatrexate
• Females of childbearing potential must have a negative pregnancy test within 30 days prior to enrollment. Females who are postmenopausal for at least 1 year (defined as more than 12 months since last menses) or who are surgically sterilized do not require this test.

Exclusion Criteria:

• Patient has had previous exposure to pralatrexate
• Patient has used any investigational drugs, biologics, or devices within 30 days prior to study treatment or plans to use any of these during the course of the study.
• Patient has an active, uncontrolled infection, underlying medical condition, or other serious illness that would impair the patient's ability to receive the protocol-defined treatment.
• Patient has known or suspected intolerance or hypersensitivity to the investigational product or any related compound.
• Patient has congestive heart failure at Class III/IV according to the New York Heart Association (NYHA) Functional Classification
• Patient has had major surgery within 30 days prior to enrollment.
• Patient with central nervous system (CNS) metastases
• Patient is pregnant or breast-feeding.