High-dose chemotherapy with hematopoietic stem cell transplantation for the treatment of primary central nervous system lymphoma

High-dose chemotherapy with autologous haemopoietic stem cell transplantation for newly diagnosed primary CNS lymphoma: a prospective, single-arm, phase 2 trial

BACKGROUND

High-dose methotrexate-based chemotherapy is standard for primary CNS lymphoma, but most patients relapse. High-dose chemotherapy with autologous stem cell transplantation (HCT-ASCT) is supposed to overcome the blood-brain barrier and eliminate residual disease in the CNS. We aimed to investigate the safety and efficacy of HCT-ASCT in patients with newly diagnosed primary CNS lymphoma.

METHODS

In this prospective, single-arm, phase 2 trial, we recruited patients aged 18-65 years with newly diagnosed primary CNS lymphoma and immunocompetence, with no limitation on clinical performance status, from 15 hospitals in Germany. Patients received five courses of intravenous rituximab 375 mg/m(2) (7 days before first high-dose methotrexate course and then every 10 days) and four courses of intravenous high-dose methotrexate 8000 mg/m(2) (every 10 days) and then two courses of intravenous rituximab 375 mg/m(2) (day 1), cytarabine 3 g/m(2) (days 2 and 3), and thiotepa 40 mg/m(2) (day 3). 3 weeks after the last course, patients commenced intravenous HCT-ASCT (rituximab 375 mg/m(2) [day 1], carmustine 400 mg/m(2) [day 2], thiotepa 2 × 5 mg/kg [days 3 and 4], and infusion of stem cells [day 7]), irrespective of response status after induction. We restricted radiotherapy to patients without complete response after HCT-ASCT. The primary endpoint was complete response at day 30 after HCT-ASCT in all registered eligible patients who received at least 1 day of study treatment. This trial is registered at ClinicalTrials.gov, number NCT00647049.

FINDINGS

Between Jan 18, 2007, and May 23, 2011, we recruited 81 patients, of whom two (2%) were excluded, therefore we included 79 (98%) patients in the analysis. All patients started induction treatment; 73 (92%) commenced HCT-ASCT. 61 (77·2% [95% CI 66·1-86·6]) patients achieved a complete response. During induction treatment, the most common grade 3 toxicity was anaemia (37 [47%]) and the most common grade 4 toxicity was thrombocytopenia (50 [63%]). During HCT-ASCT, the most common grade 3 toxicity was fever (50 [68%] of 73) and the most common grade 4 toxicity was leucopenia (68 [93%] of 73). We recorded four (5%) treatment-related deaths (three [4%] during induction and one [1%] 4 weeks after HCT-ASCT).

INTERPRETATION

HCT-ASCT with thiotepa and carmustine is an effective treatment option in young patients with newly diagnosed primary CNS lymphoma, but further comparative studies are needed.

FUNDING

University Hospital Freiburg and Amgen.

Upfront thiotepa, busulfan, cyclophosphamide, and autologous stem cell transplantation for primary CNS lymphoma: a single centre experience

Treatment of primary central nervous system lymphoma (PCNSL) with high-dose methotrexate-based chemotherapy and whole-brain radiotherapy (WBRT) is associated with high rates of relapse and severe neurotoxicity. In an attempt to improve upon these poor results, we treated 21 patients with PCNSL aged 34-69 years (median 56) with high-dose thiotepa, busulfan, cyclophosphamide (TBC) and autologous stem cell transplant (ASCT) as part of front-line therapy, without WBRT. Patient characteristics included: Karnofsky performance status (KPS) <70% (n = 17), age >60 years (n = 8), deep brain involvement (n = 16). Treatment-induced neurotoxicity was not observed in any of these patients. Currently, 11 of 21 patients (52%) are alive and progression-free at a median follow-up of 60 (7-125) months post-ASCT. Causes of death included progressive PCNSL (n = 4), progressive systemic lymphoma (n = 1), early treatment-related mortality (TRM, n = 3) and two late deaths from pneumonia 3 years post-ASCT. All patients who died of TRM were over 60 years of age and had poor performance status. In conclusion, TBC/ASCT offers potential long-term progression-free survival without neurotoxicity when used as part of upfront therapy for PCNSL. However, efforts to reduce TRM through improved patient selection and possibly through decreased intensity of the TBC regimen for older or less fit patients are recommended.