Evaluation of Dalteparin for Long-term (One Year) Treatment of Blood Clots in Subjects With Cancer

Inclusion Criteria:

1. Male and female subjects, age greater than or equal to 18 years of age.
2. Females should be either of non-childbearing potential as a result of surgery, radiation therapy, menopause (one year post onset), or of childbearing potential and willing to adhere to an acceptable method of pregnancy prevention.
3. Subjects must be newly diagnosed, symptomatic proximal deep-vein thrombosis of the lower extremity, pulmonary embolism, or both.
4. Subjects must have active malignancy defined as a diagnosis of cancer (excluding basal cell or squamous cell carcinoma of the skin) within six months before enrollment, having received any treatment for cancer within the previous six months, or having documented recurrent or metastatic cancer.
5. Prior to enrollment, subjects must not have received therapeutic doses of anticoagulant therapy (including low molecular weight heparin \[LMWH\]) for \>48 hours (or \>4 doses within 48 hours).
6. Eastern Cooperative Oncology Group (ECOG) performance status of 0, 1 or 2.
7. Subjects must have a life expectancy of \>6 months.
8. Subjects must have a platelet count of \>75,000 mm\^3.
9. The subject must not be on any oral anticoagulant therapy for concomitant diseases.
10. Subjects must have no active or serious bleeding episodes within two weeks prior to study entry.
11. Subjects must be able to comply with scheduled follow-ups.

Exclusion Criteria:

1. Subjects who have a high risk of serious bleeding (e.g., recent neurosurgery within 30 days, history of intracranial hemorrhage, acute gastroduodenal ulcer, etc.).
2. Subjects who are on hemodialysis.
3. Subjects who have a prior placement of a Greenfield filter or other device to prevent embolization of deep vein thromboses.
4. Subjects with a known contraindication to the use of heparin (e.g., heparin-induced thrombocytopenia).
5. Subjects with a known hypersensitivity to heparin, dalteparin sodium, other LMWHs or pork products.
6. Subjects who are currently participating in another clinical trial involving anticoagulation therapy (with the exception of acetylsalicylic acid (ASA) in the 30 days prior to study entry, or who are actively using any investigational drugs/treatments 30 days prior to study entry involving anticoagulation therapy (with the exception of ASA , t.i.d).
7. Subject is pregnant or breast feeding.
8. Subjects with uncontrolled hypertension characterized by a sustained systolic pressure \>170 mmHg and/or diastolic pressure \>100 mmHg.
9. Subjects with a serious concomitant systemic disorder (for example, active infection including HIV or cardiac disease) that in the opinion of the investigator, would compromise the subject's ability to complete the study.
10. Any condition that makes the subject unsuitable in the opinion of the investigator.
11. Subjects with leukemia or myeloproliferative syndrome.