Inclusion Criteria:

- Histologically confirmed OAML

- Non-conjunctival or bilateral conjunctival (TNM-based, above T1N0M0 or bT1N0M0), Ann
Arbor stage I and II OAML

- Previously untreated

- Age ≥18 years

- Performance status: ECOG 0-2

- Adequate hematological function: hemoglobin ≥9 g/dL,, absolute neutrophil count (ANC)
≥1,500/μL, and platelet count ≥100,000/μL, unless abnormalities are due to bone
marrow involvement by the lymphoma

- Adequate liver function tests:

i. Transaminase (AST/ALT) <3 times the upper normal value ii. Bilirubin <2 times the
upper normal value

- Adequate renal function:serum creatinine level <2 mg/dL (177 μmol/L)

- Life expectancy ≥ 6 months

- A negative serum or urine pregnancy test before treatment must be available for both
premenopausal women and for women who have <2 years after the onset of menopause.

- Informed consent

Exclusion Criteria:

- NHL subtypes other than OAML

- Primary conjunctival OAML, unilateral involved (T1N0M0)

- Ann Arbor stage III or IV

- CNS involvement by the lymphoma or any evidence of spinal cord compression. Brain
CT/MRI is only mandatory (within 4 weeks) with clinical suspicion of CNS involvement
by the lymphoma

- Pregnant or lactating women, women of child-bearing potential not using adequate
contraception

- Inadequate liver function tests:

i. Transaminase (AST/ALT) ≥3 times the upper normal value or ii. Bilirubin ≥2 times
the upper normal value

- Inadequate renal function:

i. serum creatinine level <2 mg/dL (177 μmol/L)

- Other serious illness or medical conditions i. Unstable cardiac disease despite
treatment; myocardial infarction within 6 months prior to study entry ii. History of
significant neurological or psychiatric disorders including dementia or seizures

- Active uncontrolled infection (HIV, hepatitis B, Hepatitis C, active Tuberculosis,
active bacterial, or active fungal infection)

- Any other malignancies within the past 5 years except for curatively treated
non-melanoma skin cancer or in situ carcinoma of the cervix uteri

- Known hypersensitivity to any of the study drugs or its ingredients (i.e.,
hypersensitivity to Polysorbate 20, CHO cell products, or recombinant human
antibodies)

- Concomitant administration of any other experimental drug under investigation or
concomitant chemotherapy, hormonal therapy, or immunotherapy