Frontzek F, Ziepert M, Nickelsen M, Altmann B, Glass B, Haenel M, Truemper L, Held G, Bentz M, Borchmann P, Dreyling M, Viardot A, Kroschinsky FP, Metzner B, Staiger AM, Horn H, Ott G, Rosenwald A, Loeffler M, Lenz G, and Schmitz N
Background: R-MegaCHOEP was the first phase 3 study comparing high-dose chemotherapy plus rituximab followed by autologous haematopoietic stem-cell transplantation (HSCT) with conventional chemotherapy plus rituximab in first-line therapy for patients aged 60 years or younger with high-risk aggressive B-cell lymphoma. Little is known about the long-term outcomes of these patients. We aimed to evaluate the long-term efficacy and safety of conventional chemotherapy versus high-dose chemotherapy after 10 years of follow-up in the R-MegaCHOEP trial., Methods: In this open-label, randomised, phase 3 trial done across 61 centres in Germany, patients aged 18-60 years with newly diagnosed, high-risk (age-adjusted International Prognostic Index [IPI] 2 or 3) aggressive B-cell lymphoma were randomly assigned (1:1, using Pocock minimisation) to eight cycles of conventional chemotherapy (cyclosphosphamide, doxorubicin, vincristine, etoposide, and prednisolone) plus rituximab (R-CHOEP-14) or four cycles of high-dose chemotherapy plus rituximab followed by autologous HSCT (R-MegaCHOEP). The trial was unmasked. Patients were stratified by age-adjusted IPI factors, presence of bulky disease (tumour mass ≥7·5 cm diameter), and treatment centre. The primary endpoint was event-free survival, analysed here 10 years after randomisation. 10-year overall survival, progression-free survival, conditional survival, relapse patterns, secondary malignancies, and molecular characteristics were also analysed. All analyses were done on the intention-to-treat population. This trial is registered with ClinicalTrials.gov, NCT00129090., Findings: Between March 3, 2003, and April 7, 2009, 275 patients were randomly assigned to R-CHOEP-14 (n=136) or R-MegaCHOEP (n=139). 130 patients in the R-CHOEP-14 group and 132 patients in the R-MegaCHOEP group were included in the intention-to-treat population. After a median follow-up of 9·3 years (IQR 5·1-11·1), 10-year event-free survival was 51% (95% CI 42-61) in the R-MegaCHOEP group and 57% (47-67) in the R-CHOEP-14 group (adjusted hazard ratio [HR] 1·3 [95% CI 0·9-1·8], p=0·23). 10-year progression-free survival was 59% (50-68) in the R-MegaCHOEP group and 60% (51-70) in the R-CHOEP-14 group (adjusted HR 1·1 [0·7-1·7], p=0·64). 10-year overall survival was 66% (57-76) in the R-MegaCHOEP group and 72% (63-81) in the R-CHOEP-14 group (adjusted HR 1·3 [0·8-2·1], p=0·26). Relapse occurred in 30 (16% [95% CI 11-22]) of 190 patients who had complete remission or unconfirmed complete remission; 17 (17%) of 100 patients in the R-CHOEP-14 group and 13 (14%) of 90 patients in the R-MegaCHOEP group. Seven (23%) of 30 patients had low-grade histology at relapse and had better outcomes compared with patients who relapsed with aggressive histologies. Lymphoma affected the CNS in 18 (28%) of 64 patients with treatment failure. 22 secondary malignancies were reported in the intention-to-treat population; in 12 (9%) of 127 patients in the R-CHOEP-14 group and ten (8%) of 126 patients in the R-MegaCHOEP group., Interpretation: Event-free survival and overall survival were similar between groups after 10 years of follow-up; outcomes were not improved in the R-MegaCHOEP group by high-dose chemotherapy and autologous HSCT. Patients who relapsed with aggressive histology showed a high incidence of CNS involvement and poor prognosis. For these patients, novel therapies are greatly warranted., Funding: Deutsche Krebshilfe (German Cancer Aid)., (Copyright © 2021 Elsevier Ltd. All rights reserved.)