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Most patients cannot be included in randomized clinical trials. We report real-world outcomes of all Danish patients with multiple myeloma (MM) treated with daratumumab-based regimens until 1 January 2019. Methods Information of 635 patients treated with daratumumab was collected retrospectively and included lines of therapy (LOT), hematologic responses according to the International Myeloma Working Group recommendations, time to next treatment (TNT) and the cause of discontinuation of treatment. Baseline characteristics were acquired from the validated Danish Multiple Myeloma Registry (DMMR). Results Daratumumab was administrated as monotherapy (Da-mono) in 27.7%, in combination with immunomodulatory drugs (Da-IMiD) in 57.3%, in combination with proteasome inhibitors (Da-PI) in 11.2% and in other combinations (Da-other) in 3.8% of patients. The median number of lines of therapy given before daratumumab was 5 for Da-mono, 3 for Da-IMiD, 4 for Da-PI, and 2 for Da-other. In Da-mono, overall response rate (ORR) was 44.9% and median time to next treatment (mTNT) was 4.9 months. In Da-IMiD, ORR was 80.5%, and mTNT was 16.1 months. In Da-PI, OOR was 60.6% and mTNT was 5.3 months. In patients treated with Da-other, OOR was 54,2% and mTNT was 5.6 months. The use of daratumumab in early LOT was associated with longer TNT (p<0.0001). Patients with amplification 1q had outcome comparable to standard risk patients, while patients with t(4;14), t(14;16) or del17p had worse outcome (p = 0.0001). Multivariate analysis indicated that timing of treatment (timing of daratumumab in the sequence of all LOT that the patients received throughout the course of their disease) was the most important factor for outcome (p<0.0001). Conclusion The real-world outcomes of multiple myeloma patients treated with daratumumab are worse than the results of clinical trials. Outcomes achieved with daratumumab were best when daratumumab was used in combination with IMIDs and in early LOT. Patients with high-risk CA had worse outcomes, but patients with amp1q had similar outcomes to standard-risk patients.

In this retrospective study we reviewed the clinical course of every patient with multiple myeloma treated from 2006 to 2016 at Vejle Hospital: 303 patients with a median age of 69 years at diagnosis received a median of four (range 1-18) lines of therapy; 149 in a 2006-2010 cohort and 154 in a 2011-2016 cohort. After initiation of treatment, the median decrease in the number of patients per each subsequent line of therapy was 22%. Lenalidomide-dexamethasone (n = 156), bortezomib-dexamethasone (n = 107), and bortezomib-lenalidomide-dexamethasone (n = 84) were the most commonly used regimens. The partial response or better rate was 78%, 58%, 55%, and 44% in lines of therapy one to four, respectively. The median (95% confidence interval [CI]) progression-free survival was 18 (15-22), 10 (8-13), 8 (7-10), and 6 (4-8) months in lines of therapy one to four, respectively. The median (95% CI) overall survival (OS) was 4.1 (3.7-4.8) years. Compared with the 2006-2010 cohort, patients in the 2011-2016 cohort had longer OS; 5.3 (4.7 to not reached) versus 3.4 (2.7-4.0) years, p < 0.0001. This was especially true in patients not treated with high-dose therapy and autologous stem cell transplantation; 4.7 (3.2-5.9) versus 2.6 (2.0-3.3) years, p = 0.0052. Patients in the 2011-2016 cohort were on treatment during a greater part of their life and had higher exposure to high-dose melphalan with autologous stem cell transplantation, lenalidomide, pomalidomide, daratumumab, and carfilzomib.

Presentation with severe acute kidney injury due to cast nephropathy (CN) is a medical emergency in multiple myeloma (MM), with high risk of dialysis-dependent renal failure and death. Accrual of patients with CN into interventional studies is difficult, while phase III trials exclude patients with severe renal insufficiency. Real-world data are warranted. We assessed 2252 patients from the population-based Danish Multiple Myeloma Registry (DMMR) who were diagnosed between 2013 and 2017. We identified 204 patients with clinically-suspected CN, defined as serum creatinine concentration >177 μmol/L and serum free light chain (sFLC) concentration >1000 mg/L at the time of diagnosis. The median age was 72 years. Thirty-one percent of patients presented with dialysis-dependent renal failure. Kidney biopsies were performed in 19% of patients and showed CN in 74% of cases. Despite prompt initiation of bortezomib-based therapy in 94% of patients, 33% of patients died in the first year after diagnosis. Compared with the rest of the patients in the DMMR with symptomatic MM, patients with clinicallysuspected CN had worse overall survival (OS) irrespective of transplant eligibility. Achievement of renal recovery was associated with deep reductions of involved sFLC. Achievement of very good partial response or better in the first line of therapy and/or deep reduction of involved sFLC at 3 months after initiation of therapy were associated with superior OS. In conclusion, MM patients presenting with clinically-suspected CN have an alarmingly high one-year mortality when treated with current standards of care. Early and deep hematologic response is crucial for survival. 1 | INTRODUCTION Renal failure, defined by serum creatinine higher than 177 μmol/L, occurs in approximately 20%-30% of patients with multiple myeloma (MM) at the time of diagnosis. 1-4 Severe renal impairment requiring hemodialysis occurs in 3%-9% of all patients with newly-diagnosed MM, and unless renal function is recovered, it leads to considerable mortality during the first months after diagnosis. 1,2,5-10 Myeloma cast nephropathy (CN) is the most common form of monoclonal immunoglobulin-mediated kidney disease. 11,12 It results from the interaction of excessive amounts of monoclonal light chains with

Daratumumab (DARA) has improved the outcome of treatment of multiple myeloma (MM). DARA acts via complement-dependent and -independent mechanisms. Resistance to DARA may result from upregulation of the complement inhibitory proteins CD55 and CD59, downregulation of the DARA target CD38 on myeloma cells or altered expression of the checkpoint inhibitor ligand programmed death ligand-1 (PD-L1) or other mechanisms. In this study, EVs were isolated from peripheral blood (PB) and bone marrow (BM) from multiple myeloma (MM) patients treated with DARA and PB of healthy controls. EV size and number and the expression of CD38, CD55, CD59 and PD-L1 as well as the EV markers CD9, CD63, CD81, CD147 were determined by flow cytometry. Results reveal that all patient EV samples express CD38, PD-L1, CD55 and CD59. The level of CD55 and CD59 are elevated on MM PB EVs compared with healthy controls, and the level of PD-L1 on MM PB EVs is higher in patients responding to treatment with DARA. CD147, a marker of various aspects of malignant behaviour of cancer cells and a potential target for therapy, was significantly elevated on MM EVs compared with healthy controls. Furthermore, mass spectrometry data suggests that MM PB EVs bind DARA. This study reveals a MM PB and BM EV protein signatures that may have diagnostic and prognostic value.