Purpose To compare the agreement between whole-body (WB) magnetic resonance (MR) imaging, 18 F-FDG PET/CT, and skeletal survey (SS) in patients with multiple myeloma (MM) for diagnosis, initial staging, response evaluation, and early detection of complications. Methods This is a retrospective cohort study including MM patients who were diagnosed, treated, and followed in 2 institutions. These patients were studied with SS, WB-MR, and/or 18 F-FDG PET/CT. We studied bone lesions by anatomical locations and analyzed the concordance between SS and a tomographic technique (WB-MR or 18 F-FDG PET/CT) and between both tomographic techniques (WB-MR and PET/CT). Results Forty-four MM patients with a mean age of 62.6 years (range, 38–85 years) were included from January 2012 to February 2016. Whole-body MR and 18 F-FDG PET/CT found more lesions than SS in every location except in the skull. Concordance between WB-MR and 18 F-FDG PET/CT was either good or excellent in most of the locations and in plasmacytoma studies. However, WB-MR was better than 18 F-FDG PET/CT in the study of complications (medullar compression and vascular necrosis). Conclusions Our results suggest the study of MM patients should include WB-MR and/or 18 F-FDG PET/CT, whereas SS is only useful for the skull. Whole-body MR and 18 F-FDG PET/CT are complementary techniques, because both of them show good concordance in almost every location. It is still necessary to individualize the indication of each technique according to patient characteristics.

Introduction COBE SPECTRA [COBE] (Terumo, BCT Lakewood CO) apheresis system has been the most used device for hematopoietic progenitor cells (HPC) collection. Recently, it has been replaced by the SPECTRA OPTIA [OPTIA] (Terumo, BCT Lakewood CO) apheresis system. The aim of our study is to compare both methods for HPC collection. Material and methods We retrospectively compared 302 HPC collection apheresis procedures (115 allogeneic donors and 187 autologous). The study cohort was divided according to the apheresis system used to analyze the differences between COBE and OPTIA, specifically efficacy of apheresis procedure and product characteristics. Results OPTIA collections result in a higher CD34+ collection efficiency in both groups (autologous 45.3% vs 41%, P < .006; allogeneic 54.9% vs 45%, P < .0001). The total of CD34+ cells ×106 /kg recipient collected in the product were comparable in both groups (autologous 2.9 in OPTIA group vs 2.8 in COBE group, P = .344; allogeneic 6.2 in OPTIA group vs 5.8 in COBE group, P = .186). The percentage of platelet loss in autologous donors was significantly lower (35.7% vs 40.8%, P < .01). Regarding quality of the product, we observed a significantly lower hematocrit in products collected with OPTIA in both groups (1.8% vs 4%, P < .0001) as well as significantly lower amount of leukocytes (median 153.4 vs 237.2 × 109/L in autologous, P < .0001; 239.5 vs 340.2 × 109/L in allogeneic P < .0001). Conclusion Both apheresis systems are comparable in collection of hematopoietic progenitor cells, with significantly higher collection efficiency with the OPTIA system. Collection products obtained with OPTIA contain significantly lower hematocrit and leukocytes.

The outcomes of patients with acute lymphoblastic leukaemia (ALL) presenting relapse after allogeneic stem cell transplant (allo‐SCT) are poor, with few data available in this setting. Objective and Methods To evaluate the outcomes of patients with ALL presenting relapsed after allo‐SCT, we performed a retrospective study including 132 from 11 centres in Spain. Results Therapeutic strategies consisted of palliative treatment (n = 22), chemotherapy (n = 82), tyrosine kinase inhibitors (n = 26), immunotherapy with inotuzumab and/or blinatumumab (n = 19), donor lymphocyte infusions (n = 29 pts), second allo‐SCT (n = 37) and CAR T therapy (n = 14). The probability of overall survival (OS) at 1 and 5 years after relapse was 44% (95% confidence interval [CI]: 36%; 52%) and 19% (95% CI: 11%; 27%). In the 37 patients undergoing a second allo‐SCT, the 5‐year estimated OS probability was 40% [22%; 58%]. Younger age, recent allo‐SCT, late relapse, 1st complete remission at 1st allo‐SCT and chronic graft‐versus‐host disease confirmed their positive impact on survival in the multivariable analysis. Conclusion Despite the poor prognosis of patients with ALL presenting relapse after a first allo‐SCT, some can be satisfactorily rescued and a second allo‐SCT still remains a valid option for selected patients. Moreover, emerging therapies really might improve ALL patients outcome when relapsing after an allo‐SCT.

4035 Introduction: Bendamustine is a dual alkylating agent with demonstrated efficacy in de novo multiple myeloma (MM) and in relapsed/refractory (R/R MM). We present the preliminary results from the experience of Spanish compassionate use registry of this agent in different treatment schedules of R/R MM, promoted by the GEM/PETHEMA Group (Benda-MMRR-11). This study has been approved by local ethical committee, CEIC, HUP, Madrid, Spain. Patients and Methods: 72 patients, 42 males and 30 females, with advanced R/R MM after several lines of previous treatment received a schedule containing Bendamustine (Levact®, Mundipharma, UK). Median age was 66 (35–86), with a median of 4 previous salvage lines (1–11). Bendamustine dose used ranged between 60 and 120 mg/m2 iv on days 1 and 2 for each 28 days cycle. The median of cycles was 2 (1–9). The combinations used were: Bendamustine + Prednisone in 27 patients, Bendamustine + Thalidomide + Prednisone in 11 cases, Bendamustine + Dexamethasone in 14 patients, Bendamustine + Bortezomib + Dexamethasone in 7 patients, Bendamustine + Bortezomib + Prednisone in 3 patients, Bendamustine + Thalidomide + Dexamethasone in 2 cases, Bendamustine monotherapy in 5 patients, Bendamustine + Thalidomide in 1 case, Bendamustine with Caelyx in 1 case and Bendamustine with Rituximab in 1 case. Results: In the 69 evaluable patients, the response was: overall response rate (ORR) 30.24%%, with complete response (CR) 11.5%, partial response (PR) 13.04%. Minimal response (MR) was 5.7%, and stable disease (SD) was 17.39%. Progression was documented in 52.1% of patients. In general, treatment was well tolerated; the most common adverse effect was hematological toxicity with grade 3–4 neutropenia in 31.8%, grade 3–4 thrombocytopenia in 30.4% and grade 3–4 anemia in 17.3%. Other toxicities included grade 3–4 infections in 27% of patients and grade 3–4 asthenia in 11.5%. Clinical results will be updated with more details regarding TTP, OS and efficacy and toxicity with each schedule. Comments: Bendamustine is an effective salvage therapy in patients with advanced R/R MM. Our results are consistent with previous published data in larger series of patients. More experience is needed with this agent to define the best combination and to assess its grade of efficacy that will be probably superior in earlier stages of myeloma evolution. Disclosures: Off Label Use: compassionate use.

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