750mg/m2 iv

CR: complete disappearance of all enhancing abnormalities on contrast-enhanced cranial magnetic resonance imaging (MRI); no evidence of active ocular lymphoma as defined by absence of cells in the vitreous and resolution of any previously documented retinal or optic nerve infiltrates; negative cerebrospinal fluid (CSF) cytology; at the time of CR determination, participant had discontinued use of all corticosteroids for at least 2 weeks. CRu requires fulfillment of CR criteria but with these limitations: Fulfills CR criteria but had continued requirement for corticosteroid therapy at any dose; small but persistent enhancing abnormality on MRI related to biopsy or focal hemorrhage; persistent minor abnormality on follow-up ophthalmologic exam (related to persistent non-malignant cells in vitreous, or alterations in retina/optic nerve not consistent with tumor infiltration) if the abnormality is unlikely to represent ocular lymphoma.

PR: greater than or equal to (≥) 50 percent (%) decrease in the contrast-enhancing lesion seen on MRI as compared with the baseline images; (2) Corticosteroid dose was irrelevant to the determination of PR; for participants with ocular disease, ophthalmologic exam must show a decrease in vitreous cell count or retina/optic nerve cellular infiltrate but may have continued to show persistent malignant or suspicious cells; for participants with CSF positive for neoplastic cells, CSF cytology may be negative or continue to show persistent malignant or suspicious cells in patients with ≥50% decrease in the primary brain lesions; no new sites of disease.

Time from entry into trial until death of any cause. Participants who were alive at the time of the analysis were censored at the date of the last follow-up assessment. Participants without follow-up assessment were censored at the day of last dose and participants with no post baseline information were censored at the baseline date.

Participants received single doses of rituximab 750 mg/m^2 IV at Weeks 1 through 5, and 7, 9, 11, 14, 16, 18, 20, and 22; cytarabine 2 g/m^2 IV every 24 hours for 2 doses at Weeks 11 and 22; and single doses of MTX 8 g/m^2 IV at Weeks 3, 5, 7, 9, 14, 16, 18, and 20.

CR: complete disappearance of all enhancing abnormalities on contrast-enhanced cranial magnetic resonance imaging (MRI); no evidence of active ocular lymphoma as defined by absence of cells in the vitreous and resolution of any previously documented retinal or optic nerve infiltrates; negative cerebrospinal fluid (CSF) cytology; at the time of CR determination, participant had discontinued use of all corticosteroids for at least 2 weeks. CRu requires fulfillment of CR criteria but with these limitations: Fulfills CR criteria but had continued requirement for corticosteroid therapy at any dose; small but persistent enhancing abnormality on MRI related to biopsy or focal hemorrhage; persistent minor abnormality on follow-up ophthalmologic exam (related to persistent non-malignant cells in vitreous, or alterations in retina/optic nerve not consistent with tumor infiltration) if the abnormality is unlikely to represent ocular lymphoma.

Due to early study termination, all efficacy data were documented by data listings only, no data analysis was performed.

Participants received single doses of rituximab 750 mg/m^2 IV at Weeks 1 through 5, and 7, 9, 11, 14, 16, 18, 20, and 22; cytarabine 2 g/m^2 IV every 24 hours for 2 doses at Weeks 11 and 22; and single doses of MTX 8 g/m^2 IV at Weeks 3, 5, 7, 9, 14, 16, 18, and 20.