The Efficacy of Bortezomib-CHOP In Patients with Advanced Stage T or NK/T Cell Lymphomas: The Results of Multicenter Phase II Study.

Advanced stage T-cell or NK/T-cell lymphomas usually show aggressive clinical course and their treatment outcomes are worse than B-cell non-Hodgkin lymphoma. Furthermore, the optimal treatment regimen is not still established for these disease entities. At present, cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP) regimen is still used as a primary treatment for advanced stage T or NK/T cell lymphomas although its efficacy is not satisfactory. Thus, more effective treatment regimen is required to improve treatment outcome. The incorporation of new targeted agents into CHOP regimen has been a widely used strategy to develop new regimen for the treatment of lymphoma. Bortezomib, a proteasome inhibitor approved for the use of treatment of multiple myeloma has been tried in many B-cell non-Hodgkin lymphomas. A recent in vitro study results showed that proteasome inhibitor could inhibit the growth of NK/T lymphoma cells. Based on these results, we designed a regimen combining CHOP with. Our previous phase I study determined the maximum tolerated dose of bortezomib as 1.6mg/m² for combination with CHOP. Thus, we performed the phase II study to evaluate the efficacy of bortezomib plus CHOP chemotherapy.

We enrolled patients with newly diagnosed T or NK/T cell lymphoma. All patients were Ann Arbor stage III/IV and had adequate organ function. Patients received bortezomib on days 1 and 8 (weekly schedule, 1.6 mg/m² per dose) in addition to 750 mg/m² cyclophosphamide, 50 mg/m² doxorubicin, 1.4 mg/m² vincristine on day 1 and 100 mg/day prednisolone on days 1 to 5, every 3 weeks. Six cycles of therapy administered every 21 days were planned. All patients provided written informed consents and this trial was registered at www.ClinicalTrials.gov (NCT00374699).

46 patients were enrolled between April 2007 and August 2009. Peripheral T-cell lymphoma, unspecified (n=16) and extranodal NK/T cell lymphoma (n=10) were dominant subtypes while angioimmunoblastic T-cell lymphoma (n=8) and ALK-negative anaplastic large cell lymphoma (n=6) account for 30.4% of all patients. Five patients with cutaneous T-cell lymphoma and one hepatosplenic T-cell lymphoma were also recruited. The median age at diagnosis was 52 years (range 21 – 66 years). Serum LDH elevation (n = 28, 60.9%) and stage IV patients were dominant (n = 32, 69.6%). Thus, the International Prognostic Index risk was dominantly high or high-intermediate (n = 26, 56.5%). Complete response was achieved in 30 patients (65.2%) and partial response was 5 patients (10.9%). As a result, the overall response rate was 76.1%. The comparison of complete response rate based on the subtype demonstrated that the complete response rate of peripheral T-cell lymphoma, unspecified (12/19, 63.2%), angioimmunoblastic T-cell lymphoma (6/8, 75%), anaplastic large cell lymphoma (4/6, 66.7%) and cutaneous T-cell lymphoma (5/5, 100.0%) was better than extranodal NK/T cell lymphoma (3/10, 30.0%). Five patients with extranodal NK/T cell lymphoma progressed during the treatment with bortezomib and CHOP. The hematologic toxicity was the major toxicity of this regimen, thus, grade 3/4 leucopenia and febrile neutropenia were the most frequent toxicity. However, there was no treatment-related mortality. In addition, neurotoxicity was tolerable, so the majority of peripheral neurotoxicity was grade 1 or 2.

The combined treatment of bortezomib with CHOP is an effective regimen for advanced stage T-cell lymphomas with acceptable toxicity. However, it may not be efficient for advanced stage extranodal NK/T-cell lymphomas.

No relevant conflicts of interest to declare.