Dose-Dense Chemoimmunotherapy and Early Central Nervous System Prophylaxis For High-Risk Diffuse Large B-Cell Lymphoma. –Preliminary Results From a Nordic Phase II Study

Despite the advent of rituximab (R)-based chemoimmunotherapy, outcome for patients with high-risk diffuse large B-cell lymphoma (DLBCL) continues to be suboptimal, and the risk of central nervous system (CNS) progression is high. In a previous Nordic phase II study with dose-dense chemoimmunotherapy followed by systemic CNS prophylaxis, the CNS progression rate was lower than expected (4.5%), but all events occurred within 6 months after initiation of therapy (Holte et al., Ann Oncol 2013). Hence, in the present study, systemic CNS prophylaxis was moved to the beginning of therapy and CNS targeted therapy was further intensified by adding intrathecally administered liposomal AraC.

Inclusion criteria are age 18-65 years, primary DLBCL or grade 3B follicular lymphoma without clinical or radiological signs of CNS disease and cytology negative cerebrospinal fluid (CSF), age adjusted IPI 2-3, WHO performance score ≤3, and/or site specific risk factors for CNS recurrence. Treatment consists of two courses of high dose (HD)-Mtx in combination with R-CHOP14, four courses of R-CHOEP14 and a course of HD-AraC with R. In addition, liposomal AraC is administered intrathecally in courses 1, 3 and 5. All courses are administered with support of pegfilgastrim. Indications for radiotherapy are bulky masses at diagnosis and localized PET positive residual disease not eligible for biopsy. Primary endpoints are failure-free survival at 3 years, and CNS progression rate at 18 months. A secondary aim is to elucidate if CSF cytology negative/flow cytometry (FC) positive cases carry an increased risk of CNS progression with the present regimen.

Of the accrued 84 patients by July 22, 2013, 70 had a complete set of baseline data. Median age was 55 years (range 20-64). The majority presented with DLBCL (96%), advanced-stage disease (94%), elevated LDH (94%), B-symptoms (67%), and 49% with >1 extranodal site. Seven CSF-samples were FC positive. Data on toxicity, response and relapse rates were registered for 45 patients. One toxic death due to pneumonia was reported. Grade 4 hematological toxicity and infections were observed in 78% and 11% of the patients, grade 3-4 mucositis and gastrointestinal toxicity in 27% and 42%, and grade 3 arachnoiditis in 2.2% of the patients. CR, CRu, PR and PD rates at the end of chemoimmunotherapy were 69.0%, 14.3%, 14.3% and 2.4 %, respectively. After a median follow up time of 19 months, four patients have relapsed, two of whom with fatal CNS manifestations.

Preliminary results indicate highly satisfactory response rates and reasonable toxicity despite intensive therapy. HD-Mtx in combination with R-CHOP in the beginning of therapy and further intensification of treatment with CNS targeted liposomal AraC seem feasible and safe.

ClinicalTrials.gov Identifier: NCT01325194

Leppa:Amgen: Research Funding; Mundipharma: Honoraria, Research Funding. Holte:Mundipharma: Honoraria, Research Funding; Amgen: Research Funding.