High-Dose Chemotherapy and Autologuos Stem Cell Transplantation in Previously Untreated Peripheral T-Cell Lymphoma - Final Analysis of a Large Prospective Multicenter Study (NLG-T-01)

Systemic peripheral T-cell lymphomas (PTCL) are malignancies responding poorly to conventional therapy. To evaluate the efficacy of a dose-dense approach consolidated by upfront high-dose chemotherapy supported by autologous stem-cell transplantation (HDT/ASCT) in PTCL, the Nordic Lymphoma Group conducted the, so far, largest PTCL-restricted prospective phase II study in previously untreated systemic PTCL. This is the final report of the NLG-T-01 study with a 5-years median follow up.

Patients with previously untreated systemic PTCL aged 18–67 years were included. ALK-positive anaplastic large cell lymphoma (ALCL) cases were excluded. An induction regimen of six cycles of bi-weekly cyclophosphamide, doxorubicin, etoposide, vincristin and prednisone (CHOEP) was given. Age-based (>60 yrs) omission of etoposide was recommended. If in complete or partial remission, patients received high-dose chemotherapy with carmustine, etoposide, cytarabine and melphalan/cyclophosphamide (BEAM/BEAC) followed by HDT/ASCT.

A total of 166 patients with previously untreated PTCL were enrolled. Of these, 160 were histopathologically confirmed and included the following subtypes: PTCL-not otherwise specified (PTCL-NOS) (n=62; 39%), ALK-negative ALCL (n=31; 19%), angioimmunoblastic lymphoma (AIL) (n=30; 19%), enteropathy-associated T-cell lymphoma (n=21; 13%), panniculitis-like (n=6; 4%), T/NK nasal-type (n=5; 3%), and hepatosplenic (n=5; 3%). The M/F ratio was 2.0 and the median age 57 yrs (range 22–67 yrs). The majority of the cases presented with advanced-stage disease (81%), B-symptoms (59%) and elevated s-LDH (62%). Nevertheless, 71% of all patients had a good performance score (PS) (WHO 0–1) at inclusion. With regard to the International Prognostic Index (IPI), risk factor distribution was as follows: 1 factor n=45 (28%), 2 factors n=52 (32%), 3 factors n=30 (19%), 4–5 factors n=33 (21%). Of the 160 patients, a total of 114 (71%) underwent HDT/ASCT with 90 in complete remission at 3 months post-transplant. Early failures occurred in 26% of the patients. The treatment related mortality was low (4%). At a median follow-up of 60 months, 83 patients were alive. The median follow-up for deceased patients (N=77) was 9 months. The consolidated 5-yr overall (OS) and progression-free survival (PFS) values for the entire cohort were 51% and 44%, respectively. Best results were obtained in ALK-negative ALCL with 5-yr OS and PFS of 70% and 61%, respectively. IPI was a useful overall prognostic discriminator for the low/low-intermediate vs. intermediate-high/high groups with regard to 5-yr OS (p=0,047) and 5-yr PFS (p=0,029). If applied separately to each of the four major subtypes, IPI had a predictive value for OS in AIL (p=0,02) and for PFS in both AIL (p=0,02) and PTCL-NOS (p=0,03). The clinicopathological parameters that showed a significant impact on OS and PFS were: female gender (correlated with a better outcome), age (analyzed as continuous variable), PS≥2 (correlated with adverse outcome), and cytotoxic phenotype (correlated with adverse outcome in AIL). All these parameters retained their prognostic value at multivariate level, except for cytotoxic phenotype, where multivariate analysis could not be performed because of too small numbers.

Dose-dense induction followed by HDT/ASCT is well tolerated and leads to long-term PFS in 44% of patients with systemic PTCL. This represents an encouraging outcome, particularly considering the high median age and adverse risk profile of the present study population. Therefore, based on these results, dose-dense induction and HDT/ASCT should be considered in transplant-eligible PTCL patients.

Jantunen:Genzyme: Honoraria.