Inclusion Criteria:

- Patients with histologically or cytologically confirmed indolent lymphoma (including
mantle cell lymphoma)

- Patients with measurable lesions (major axis > 1.5 cm by CT)

- Patients who failed to have PR to previous chemotherapies or antibody therapies.
Patients with subsequent relapse after a previously attained CR or with subsequent
recurrence after a previously attained PR

- Patients who have not received chemotherapies, antibody therapies or radiotherapies
for more than 4 weeks (more than 3 months in the case of the antibody therapies)

- Patients who have PS Grade 0 to 2 in the criteria of ECOG

- Patients with adequately maintained organ functions

Exclusion Criteria:

- Patients with infectious disease, serious complications, serious gastrointestinal
symptoms, serious bleeding tendency (DIC), CNS metastases, fever more than 38 degrees
Celsius, interstitial pneumonia or pulmonary fibrosis, active other malignancies,
AIHA or the history of allergies to similar purine analogs

- Patients who are positive for HBs antigen, HCV antibody or HIV antibody

- Patients who received G-CSF or blood transfusion within 1 week before the screening
test

- Patients who had ever received previous therapy with fludarabine phosphate injection
(Fludara), pentostatin (Coforin), cladribine (Leustatin) or SH T 586

- Patients who are pregnant, of childbearing potential, lactating, or who do not agree
to practice contraception