TRANSPLANTATION AND CELLULAR ENGINEERING Lenograstim 5 lg/kg is not superior to biosimilar filgrastim 10 lg/kg in lymphoma patients undergoing peripheral blood stem cell mobilization after chemotherapy: preliminary results from a prospective randomized study Francesco Marchesi , 1 Michele Vacca, 2 Diana Giannarelli, 3 Francesco Ipsevich, 2 Annino Pandolfi, 2 Svitlana Gumenyuk, 1 Daniela Renzi, 1 Francesca Palombi, 1 Francesco Pisani, 1 Atelda Romano, 1 Antonio Spadea, 1 Elena Papa, 1 Marco Canfora, 3 Luca Pierelli, 2 and Andrea Mengarelli 1 BACKGROUND: Randomized trials comparing chemomobilization efficiency between lenograstim and biosimilar filgrastim are lacking. Our previous retrospective study suggested that lenograstim could be more effective than biosimilar filgrastim when used at the same conventional dosage (5 mg/kg) only in lymphoma patients undergoing peripheral blood stem cell mobilization. We planned a prospective randomized study comparing lenograstim 5 mg/kg with biosimilar filgrastim 10 mg/kg to verify the hypothesis of lenograstim superiority even at half the dosage (stress test). Herein we report data after enrolling 60% of planned patients. STUDY DESIGN AND METHODS: From October 2014 to November 2017, a total of 42 of 70 planned patients with lymphoma were randomly assigned to receive lenograstim 5 mg/kg (21) or biosimilar filgrastim 10 mg/kg (21). Patients were stratified according to treatment line at the time of mobilization (1 or 2). Primary endpoint was the rate of achievement of the CD341 cell collection target dose ( 4 3 10 6 /kg). An improvement by 23% was expected to validate the hypothesis of lenograstim superiority. RESULTS: The two cohorts were balanced for all the baseline features. We observed an identical rate of patients able to reach the targeted CD341 cell dose and of mobilization failures (90.4 and 4.8% in both cohorts) and a perfect equivalence in any of the secondary collection outcomes. The hypothesis of lenograstim superiority was not corroborated at interim analysis. CONCLUSION: Lenograstim at conventional dosage has failed to demonstrate its superiority over biosimilar filgrastim at double the dosage at interim analysis in their first head-to-head trial. C urrent best approach for peripheral blood hematopoietic stem cell (PBSC) mobilization and collection in lymphoma patients is the combination of chemotherapy and granulocyte– colony-stimulating factors (G-CSF). The main published guidelines consider acceptable both lenograstim and fil- grastim at the dosage of at least 5 mg/kg after chemother- apy, 1-3 where the vast majority of the data on an in vivo equivalence between filgrastim and lenograstim arises from retrospective or randomized studies on populations includ- ing patients with inhomogeneous diagnosis. From this point of view, there are two major concerns. First, the level of evidence delivered by retrospective studies is low. Sec- ond, comparing the mobilization outcomes by holding together cohorts of myeloma, lymphoma, leukemia, and solid tumor patients, which are characterized by such a ABBREVIATIONS: ANC 5 absolute neutrophil count; PBSC(s) 5 peripheral blood stem cell(s). From the 1 Hematology and Stem Cell Transplant Unit and the 3 Biostatistics Unit, Scientific Direction, IRCCS Regina Elena National Cancer Institute, Regina Elena National Cancer Institute; and the 2 Immuno-Transfusional Medicine, Leukapheresis and Cellular Therapy Unit, S. Camillo-Forlanini Hospital, Rome, Italy. Address reprint requests to: Francesco Marchesi, MD, Hematology and Stem Cell Transplant Unit, IRCCS Regina Elena National Cancer Institute, Regina Elena National Cancer Institute, Via Elio Chianesi 53, 00144 Rome, Italy; e-mail: fran- cesco.marchesi@ifo.gov.it. Received for publication December 29, 2017; revision received January 12, 2018; and accepted January 14, 2018. doi:10.1111/trf.14533 V C 2018 AABB TRANSFUSION 2018;58;1143–1148 Volume 58, May 2018 TRANSFUSION 1143