Abstract Primary plasma cell leukemia (pPCL) is an aggressive plasma cell disorder with poor outcome. We and others have previously demonstrated in a limited number of pPCL patients that novel agents and mainly bortezomib-based regimens (BBR) improve response rates and survival; in addition, two recent prospective studies have confirmed the efficacy of lenalidomide-dexamethasone and BBR respectively, followed by autologous transplantation (ASCT) in pPCL; however, the prognostic impact of the induction therapy was not evaluated in both studies. Herein, we explored the clinical characteristics and the impact of current treatments and biological markers on the outcome of an extended cohort of primary PCL (pPCL) patients treated upfront with novel agents, outside clinical trials. We analyzed the medical records of 50 patients with pPCL (M/F: 25:25; median age 65.5 years, range: 32-86 years; IgG: 19, IgA: 9, light-chain only: 14, IgD: 2, non-secretory: 6; ISS1: 5, ISS2: 16, ISS3: 29) out of 2711 myeloma patients (1.8%), registered in the Greek Myeloma study group database, between 2000-2015. Eastern Cooperative Group (ECOG) performance status was ≥2 in 52% of patients; 77% of patients presented with lytic bone disease and 11% with bone or soft tissue palsmacytomas. Bence-Jones protein was present in 68% of patients; 53% of patients had abnormal lactate dehydrogenase (LDH); 28% had hypercalcemia and 68% had hemoglobin After a median follow up of 61 months (95% CI: 34.5-87.4), 38 (76%) patients have died (disease progression: 18, infection: 16, other causes: 4) and 12 patients remain alive. Early mortality (≤1 month) occurred in 3/38 (6%) deceased patients; 31/38 patients who responded in induction treatment progressed; 27/31 patients who progressed received 2nd line treatment (lenalidomide-based: 7, BBR: 16, C/T: 4). Progression-free survival was 12 months (95% CI: 8.5-15.4) and it was marginally longer in patients treated with BBR+ASCT vs. others (18 months vs. 10 months, p=0.07). Median OS was 17 months (95% CI: 13-21 months) and it was double in patients treated with BBR+ASCT compared to others (33 months vs. 16 months); median survival after PCL progression was only 7 months (95% CI: 3-11 months). In the univariate analysis, performance status, LDH, induction treatment with BBR, or treatment with BBR+ASCT and quality of response (≥vgPR vs. These real-world data, based on the largest reported national multicenter series of pPCL patients to-date, support that treatment with BBR plus ASCT is the best currently available option that offers deep and durable responses and reduces early mortality in this setting. Quality of response and high LDH were the strongest independent prognostic factors for OS. We conclude that pPCL requires an aggressive upfront therapeutic approach with a bortezomib-based regimen followed by ASCT that would lead to maximum response and eventually to prolonged OS. Disclosures Katodritou: Amgen: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Genesis: Honoraria, Research Funding; Takeda: Consultancy, Honoraria. Terpos: Celgene: Honoraria; BMS: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Other: Travel expenses, Research Funding; Takeda: Consultancy, Honoraria; Amgen: Consultancy, Honoraria, Other: Travel expenses, Research Funding; Genesis: Consultancy, Honoraria, Other: Travel expenses, Research Funding; Novartis: Honoraria. Delimpasi: Janssen: Honoraria; Genesis: Honoraria; Amgen: Honoraria. Kotsopoulou: Genesis: Honoraria. Kyrtsonis: Genesis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding. Symeonidis: Roche: Honoraria; Amgen: Honoraria; Takeda: Consultancy, Honoraria; Genesis: Honoraria. Kastritis: Amgen: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Genesis: Consultancy, Honoraria. Dimopoulos: Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Genesis: Consultancy, Honoraria; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees.