Autologous Stem Cell Transplantation as First Line Therapy in Peripheral T Cell Lymphomas. Update of a Prospective Multicenter Study.

Peripheral T-cell lymphomas (PTCL) represent a heterogeneous group of non-Hodgkin’s lymphomas, which in general show a poor outcome following conventional chemotherapy. Long-term remissions are achieved in only 15 to 35 %. However, the impact of more aggressive therapeutic approaches such as myeloablative therapy with autologous stem cell transplantation (ASCT) as first line therapy is poorly defined mainly due to the lack of prospective PTCL-restricted studies. In 6/00 we initiated the first prospective PTCL-restricted multicenter study of myeloablative radiochemotherapy in primary diagnosed PTCL. The results of the first 30 patients (pts) are in press. We update our data on all pts entering the study.

Study design: Pts < 65 years with PTCL of all subtypes without primary cutaneous lymphoma and ALK1 expressing anaplastic large cell lymphoma were included. Treatment consisted of 4–6 courses of CHOP protocol followed by DexaBEAM or ESHAP regimen and collection of stem cells. Subsequently pts underwent total body irradiation (TBI) and high dose cyclophosphamide chemotherapy (60 mg/kg body weight) with ASCT.

Patient characteristics: From 6/00 to 8/04 65 pts (42 male) with a median age of 50 years were enrolled. Main subtypes were Peripheral T-cell lymphoma not otherwise specified (NOS, n= 26) and Angioimmunioblastic T-cell lymphoma (AILT, n= 19). According to the Ann Arbor classification, 81% of the pts had stage III/IV disease. The International Prognostic Index (IPI) was low/low intermediate in 54% and intermediate high/high in 46% of the pts, respectively.

Results: So far 54 of 65 pts are eligible for evaluation, while the remaining 11 pts are still under therapy. Thirty-three pts could be transplanted (61%). After a median follow up of 10 months after transplantation 22 pts (67%) are in sustained remission and 8 pts (27%) had relapsed. Post transplantation two pts died treatment-related (one secondary AML, one multiorgan failure). Twenty-one pts (39%) did not proceed to ASCT mainly due to progressive disease (n= 16). Treatment-related toxicity was comparable to other high-dose studies in malignant lymphomas.

Conclusion: Our data show feasibility and efficacy of first-line ASCT following myeloablative radiochemotherapy in PTCL. Sustaining remission seems achievable for a majority of pts. However, additional treatment strategies are required to prevent early progression prior myeloablative therapy. Longer follow-up is necessary to confirm long-term remission rate.