Gemcitabine, dexamethasone and cisplatin with or without rituximab is highly effective as a mobilization regimen in relapsed or refractory lymphoma

• Peripheral stem cell mobilization can be performed at day 15 following GDP±R with G-CSF given at day 9. • GDP±R achieves high stem cell collection success in relapsed lymphoma patients (96% at first attempt). • GDP±R seems to reduce consultation to emergency and hospitalization compared to intermediate dose cyclophosphamide. A combination of Gemcitabine, Dexamethasone and Cisplatin (GDP) with or without rituximab (±R) is an outpatient treatment widely used for relapsed or refractory (R/R) lymphoma. Limited data are available on stem cell mobilization following GDP treatment. A retrospective multicenter study was conducted from January 1 st , 2014, to December 31 st , 2020. Patients received GDP±R before autologous stem cell transplantation (ASCT) and were mobilized with either GDP±R or intermediate-dose cyclophosphamide (ID-CY). The primary objective was to determine the percentage of patients achieving ≥2 × 10 6 CD34 + /kg, median CD34 + yield, and number of apheresis days. The secondary objective compared these results with ID-CY. Ninety-two patients (median age 54) were treated for diffuse large B-cell (40%), Hodgkin (36%), or follicular lymphoma (16%). Of these, 83 were mobilized with GDP±R and 9 with ID-CY. G-CSF was administered at 5 mcg/kg (61%) or 10 mcg/kg (37%) daily, typically starting on day 9, after two GDP cycles. A successful stem cell collection at the first attempt occurred in 96% of GDP±R patients, and 94% of patients proceeded to ASCT. No significant difference was found between GDP±R and ID-CY in terms of successful collection (96% vs. 100%, p=NS), but fewer hospitalizations occurred within 21 days of mobilization (1% vs. 22%, p=0.02). This study demonstrated the feasibility of performing a peripheral blood stem cell mobilization at day 15 following GDP±R. It is highly effective and represents a better option due to its simplicity of administration, low rate of hospitalization and low cost.