Patients with primary central nervous system lymphoma (PCNSL) are treated with high-dose-methotrexate-based chemotherapy, which requires hospitalization and extensive expertise to manage related toxicity. Treatment with R-CHOP, the most commonly used combination against aggressive lymphomas, could overcome these difficulties, but CNS bioavailability of related drugs is poor due to their limited capability to cross the blood-brain barrier (BBB). Tumor necrosis factor (TNF) induces selective BBB permeabilization and enhances CNS access of anticancer drugs in animal models. The addition of NGR peptide improves biological properties of TNF, resulting in increased drug availability and antitumor synergistic effect, without increased toxicity. Thus, the addition of NGR-hTNF to R-CHOP may result in improved CNS drug availability and activity in patients with relapsed/refractory PCNSL; this hypothesis is being tested in this ongoing phase II trial called "INGRID". This trial will consider HIV-negative patients (age 18-80 ys; ECOG PS ≤3) with relapsed/refractory PCNSL previously treated with high-dose-methotrexate-based chemotherapy± radiotherapy, and with measurable disease.

There are three planned analyses:

1. An exploratory analysis (proof of principle) on the first 10 enrolled patients. In the case the experimental treatment will be safe and some tumor responses will be recorded, the chairman, after due multidisciplinary discussion, could propose to proceed with an open, non-comparative phase II trial, with overall response rate (complete and partial responses) as primary endpoint. The maximum overall response rate considered of low interest will be 30%, and the minimum response rate considered of interest will be 50%; to demonstrate that difference, a total of 28 patients will be needed (one-sided test; trype I error .10; power .9). Importantly, BBB permeabilization will be investigated using different methods. Variations in tumor microvasculature and vessel permeability will be assessed by DCE- and DSC-MRI. Permeability will be assessed in contrast-enhanced lesions, perilesional areas and normal appearing brain; results will expressed as KTRANS values normalized using contralateral normal appearing white matter, and compared by Wilcoxon Signed Rank Test. Concentrations of R-CHOP drugs were assessed on matched CSF and serum/plasma samples.Moreover, BBB permeability will be also assessed by 99mTc-diethylene-triamine-pentacetic acid (99mTc-DTPA) brain scintigraphy.
2. First of the two stages of Simon Minimax design, where 12 patients will be entered (including the 10 patients of the exploratory phase) and, if at least 4 responses will be observed, the study will be continued until a total of 28 patients will be entered.
3. Second stage of Simon Minimax design: final analysis of activity on the whole series (n=28); the experimental treatment will be declared active if at least 12 responses will be observed.

Inclusion criteria

• Histological or cytological diagnosis of (D)LBCL
• Disease exclusively localized into the CNS (brain, meninges, cranial nerves, eyes and/or spinal cord) both at first diagnosis and failure
• Progressive or recurrent disease
• Previous treatment with high-dose-methotrexate-based chemotherapy ± WBRT
• Presence of at least one target lesion, bidimensionally measurable
• Age 18 - 80 years
• ECOG performance status 0-3
• Adequate bone marrow (platelets >75.000/mm3, hemoglobin >8 g/dl, ANC >1.000/mm3), renal (serum creatinine <2 times UNL and creatinine clearance ≥40 mL/min), cardiac (VEF ≥50%), and hepatic (SGOT/SGPT <3 times UNL, bilirubin and alkaline phosphatase <2 times UNL) function.
• Given written informed consent prior to any study specific procedures, with the understanding that the patient has the right to withdraw from the study at any time, without any prejudice. Informed consent signed by a patient's guardian is acceptable if the patient is not able to decide inclusion in the study due to cognitive impairment

5.3 Exclusion criteria

• Known HIV disease or other chronic immunodeficiency
• Patients with positive flow cytometry examination of the CSF, but negative results in CSF conventional cytology, and without any other evidence of CNS disease
• Patients with concomitant extra-CNS disease at presentation or relapse
• Symptomatic coronary artery disease, cardiac arrhythmias not well controlled with medication or myocardial infarction within the last 6 months (New York Heart Association Class III or IV heart disease)
• Any other serious medical condition which could impair the ability of the patient to participate in the trial
• Concurrent treatment with other antineoplastic drugs
• Therapy with PPI (Proton Pump Inhibitors, that may interfere with chromogranine levels, see above). For gastroprotective therapy H2-blockers (i.e. ranitidine) are allowed.
• Pregnant and lactating female patients. Sexually active patients of child bearing potential must implement adequate contraceptive measures during study participation.
• Previous or concurrent malignancies at other sites diagnosed or relapsed within the last 3 years of follow-up. Patients with surgically cured in situ carcinomas and basal cell carcinoma of the skin are allowed.
• Presence of any psycological, familial, sociological or geographical condition potentially hampering compliance with the study protocol and follow-up schedule.