Impact of Previous Allogeneic Hematopoietic Stem Cell Transplantation on Chimeric Antigen Receptor (CAR) T Cell Treatment for Relapsed/Refractory Multiple Myeloma.

BACKGROUND: Anti-BCMA-directed chimeric antigen receptor (CAR) T cells are effective treatment for patients with refractory/relapsed multiple myeloma (RRMM). However, little is known about the impact of previous allogeneic hematopoietic stem cell transplantation (allo-HSCT) on lymphocyte collection for production of CAR T cells and subsequent treatment with CAR T cells. PATIENTS AND METHODS: We performed a retrospective analysis of cellular composition of lymphocyte collections, CAR T cell expansion and treatment outcomes of RRMM patients undergoing therapy with idecabtagene vicleucel (ide-cel) with and without history of allo-HSCT. 27 patients (11/27 female) with median age 63 (range 39-75) years were analyzed. Five patients (19%) had the history of allo-HSCT median of 5.5 years before ide-cel. RESULTS: Prior to apheresis, the white blood cell, absolute lymphocyte counts, CD3+ cells and monocytes did not differ in patients with and without prior allo-HSCT. We also noticed no differences in the collected CD3+ yields or cellular compositions of lymphocyte collections. One year after ide-cel infusion, the progression-free survival and overall survival of patients with and without previous allo-HSCT did not differ with 60% and 45% respectively (P = .58) and 66.7% and 74% respectively (P = .84). The highest expansion of CAR T was detected between day 7 after infusion and showed no difference regarding previous allo-HSCT (P = .71). No graft-versus-host disease during the follow-up was detected. CONCLUSION: Our data confirm that the treatment with ide-cel is feasible for patients with prior allo-HSCT. Furthermore, allo-HSCT did not influence cellular composition of lymphocyte collections, clinical outcome or in vivo expansion of ide-cel.

Single-cell multiomic dissection of response and resistance to chimeric antigen receptor T cells against BCMA in relapsed multiple myeloma.

Markers that predict response and resistance to chimeric antigen receptor (CAR) T cells in relapsed/refractory multiple myeloma are currently missing. We subjected mononuclear cells isolated from peripheral blood and bone marrow before and after the application of approved B cell maturation antigen-directed CAR T cells to single-cell multiomic analyses to identify markers associated with resistance and early relapse. Differences between responders and nonresponders were identified at the time of leukapheresis. Nonresponders showed an immunosuppressive microenvironment characterized by increased numbers of monocytes expressing the immune checkpoint molecule CD39 and suppressed CD8+ T cell and natural killer cell function. Analysis of CAR T cells showed cytotoxic and exhausted phenotypes in hyperexpanded clones compared to low/intermediate expanded clones. We identified potential immunotherapy targets on CAR T cells, like PD1, to improve their functionality and durability. Our work provides evidence that an immunosuppressive microenvironment causes resistance to CAR T cell therapies in multiple myeloma.

Cellular dynamics following CAR T cell therapy are associated with response and toxicity in relapsed/refractory myeloma.

B-cell maturation antigen (BCMA)-targeting chimeric antigen receptor (CAR) T cells revolutionized the treatment of relapsed/refractory multiple myeloma (RRMM). However, data on cellular (CAR) T cell dynamics and the association with response, resistance or the occurrence of cytokine release syndrome (CRS) are limited. Therefore, we performed a comprehensive flow cytometry analysis of 27 RRMM patients treated with Idecabtagene vicleucel (Ide-cel) to assess the expansion capacity, persistence and effects on bystander cells of BCMA-targeting CAR T cells. Additionally, we addressed side effects, like cytokine release syndrome (CRS) and cytopenia. Our results show that in vivo expansion of CD8+ CAR T cells is correlated to response, however persistence is not essential for durable remission in RRMM patients. In addition, our data provide evidence, that an increased fraction of CD8+ T cells at day of leukapheresis in combination with successful lymphodepletion positively influence the outcome. We show that patients at risk for higher-grade CRS can be identified already prior to lymphodepletion. Our extensive characterization contributes to a better understanding of the dynamics and effects of BCMA-targeting CAR T cells, in order to predict the response of individual patients as well as side effects, which can be counteracted at an early stage or even prevented.

Steady-state versus chemotherapy-based hematopoietic cell mobilization after anti-CD38-based induction therapy in newly diagnosed multiple myeloma.

BACKGROUND: The incorporation of anti-CD38 monoclonal antibodies (mAb) in induction regimens of newly diagnosed transplant-eligible multiple myeloma (MM) patients has been established as a new standard. However, the optimal strategy of stem cell mobilization in this context is not yet clear. STUDY DESIGN AND METHODS: From May 2020 till September 2022, we retrospectively reviewed patients receiving anti-CD38 mAb-based induction therapy followed by stem cell mobilization either in a steady-state protocol (SSM) using 10 µg/kg granulocyte colony-stimulating factor (G-CSF) for 5 days or in a chemotherapy-based protocol (CM) using 1-4 g/m2 cyclophosphamide and G-CSF. RESULTS: Overall, 85 patients (median age 61 years) were included in the analysis. In total, 90 mobilization attempts were performed, 42 with SSM and 48 with CM. There was no significant difference in the median concentration of CD34+ cells in peripheral blood (PB) prior to apheresis between SSM and CM (61/µL vs. 55.4/µL; p = .60). Cumulative CD34+ yields did not differ between the groups with median of 6.68 and 6.75 × 106 /kg body weight, respectively (p = .35). The target yield (≥4 × 106 CD34+ cells/kg body weight) was reached in 88% (CM) and 86% (SSM), with a high proportion even after a single apheresis session (76% vs. 75%). Plerixafor was found to be more frequently used in SSM (52%) than in CM (23%; p < .01). A total of 83 patients underwent autologous transplantation and all were engrafted. CONCLUSIONS: Stem cell collection in patients undergoing anti-CD38-based induction therapy is feasible with either CM or SSM, although SSM more frequently requires plerixafor.

Different treatment strategies versus a common standard arm (CSA) in patients with newly diagnosed AML over the age of 60 years: a randomized German inter-group study.

A randomized inter-group trial comparing more intensive treatment strategies to a common standard arm 3 + 7 (CSA) was conducted in patients with non-M3 AML. Untreated patients ≥ 60 years were allocated to the CSA (n = 132) or to the study group arms (n = 1154) of the AMLCG (TAD/HAM versus HAM/HAM ± G-CSF followed by TAD and maintenance) and the OSHO (intermediate-dose ara-C/mitoxantrone followed by ara-C/mitoxantrone). Median age of the 1147 eligible patients was 69 (range 60-87) years. CR/CRi status at 90 days was not significantly different between the CSA (54% (95%CI: 45-64)) and the study group arms (53% (95%CI: 47-60) and 59% (95%CI: 58-63)). The five-year event-free survival (EFS) probability (primary endpoint) was 6.2% (95%CI: 2.7-14.0) in the CSA, 7.6% (95%CI: 4.5-12.8) in study group A and 11.1% (95%CI: 9.0-13.7) in B. The 5-year OS was 17.2% (95%CI: 11.0-26.9), 17.0% (95%CI: 2.0-23.9), and 19.5% (95%CI: 16.7-22.8) in CSA, study group A and B, respectively. Neither study group differed significantly from the CSA regarding EFS, OS, or relapse-free survival. In multivariate analyses, allocation to the treatment strategy was not significantly associated with the time-to-event endpoints. The evaluation of more intensive treatment strategies did not show clinically relevant outcome differences when compared to CSA.

Impact of the changing landscape of induction therapy prior to autologous stem cell transplantation in 540 newly diagnosed myeloma patients: a retrospective real-world study.

INTRODUCTION: Autologous stem cell transplantation (ASCT) is the standard treatment for younger patients with newly diagnosed multiple myeloma (MM). However, due to restrictive exclusion criteria, more than half of eligible patients are usually excluded from transplant studies. METHODS: This retrospective monocentric analysis included 540 patients with MM who received an ASCT between 1996 and 2019. RESULTS: Up to 2005, induction therapy consisted mainly of conventional chemotherapies, e.g. vincristine/doxorubicin/dexamethasone (VAD). In the following years, the triple-combinations based on bortezomib coupled with doxorubicin/dexamethasone (PAD), melphalan/prednisolone (VMP), cyclophposphamide/dexamethasone (VCD) or bendamustine/prednisolone (BPV) became the most popular treatment options. A progressive improvement in PFS was observed in patients treated with the two current induction therapies BPV (47 months) or VCD (54 months) compared to VAD (35 months, p < 0.03), PAD (39 months, p < 0.01 and VMP (36 months, p < 0.01). However, there was no significant difference in median OS (VAD 78, PAD 74, VMP 72, BPV 80 months and VCD not reached). In our analysis, we also included 139 patients who do fulfill at least one of the exclusion criteria for most phase 3 transplant studies (POEMS/amyloidosis/plasma cell leukemia, eGFR < 40 mL/min, severe cardiac dysfunction or poor general condition). Outcome for these patients was not significantly inferior compared to patients who met the inclusion criteria for most of the transplant studies with PFS of 36 vs 41 months (p = 0.78) and OS of 78 vs 79 months (p = 0.34). CONCLUSIONS: Our real-world data in unselected pts also stress the substantial value of ASCT during the first-line treatment of younger MM pts.

Analysis of stem cell collections in adult patients with Ewing sarcoma.

BACKGROUND: Ewing sarcoma is one of the most frequent soft-tissue tumors in pediatric patients. The current treatment protocols recommend stem cell apheresis (SCA) after completion of the second course of induction therapy with vincristine, ifosfamide, doxorubicine, and etoposide (VIDE). The feasibility of SCA and graft compositions in adult patients with Ewing sarcoma have not been previously analyzed. METHODS AND MATERIALS: The authors analyzed 29 stem cell collections of 19 adult patients (9 male, 10 female) at a median age of 27 (range 19-53) years mobilized after VIDE (n = 17), cyclophosphamide/topotecan (n = 1) or vincristine, dactinomycin and ifosfamide (n = 1) chemotherapy. All patients were mobilized with filgrastim 5 µg/kg twice daily from day +7 of chemotherapy. The collections were performed if CD34+ cell count in peripheral blood was >10/µL. The target yields were ≥4×106 CD34+ cells/kg body weight. RESULTS: Median CD34+ cells/µL in peripheral blood before SCA were 45.8 (range 6.7-614.4)/µL. The median cumulative yields were 10.6 (range 1.5-38.8) CD34+ cells/kg body weight and ≥2×106 in all but two patients (89%). CD34, CD3, and CD56 yields in collections after the third VIDE and after later courses did not differ. Four patients underwent high-dose therapy with autologous transplantation, and all were engrafted. DISCUSSION: Stem cell mobilization is feasible in most Ewing sarcoma patients. Additionally, the present study's data suggest that it is safe to postpone stem cell collection to a later VIDE chemotherapy cycle if medically indicated.

Vital Hepatic Lymphoma Residuum or Excessive Immune Response? Challenging Treatment Decisions in a Patient With Systemic Lupus Erythematosus and Liver-Dominant Diffuse Large B-Cell Lymphoma: Case Report.

A 28-year-old female patient with active and difficult-to-treat systemic lupus erythematosus (SLE) was diagnosed with liver-dominant diffused large B-cell lymphoma. Repeated response 18F-FDG-PET studies showed persistently high, and, despite intensified immunochemotherapy, further increasing metabolic activity of one of the hepatic lymphoma residuals, whereas all other initial lymphoma manifestations had achieved complete metabolic remission. As biopsy of the 18F-FDG-PET-positive liver residual turned out to be inconclusive, complete resection was performed. Subsequent histopathological examination, however, revealed only necrotic tissue. Thus, no further lymphoma treatment was scheduled. The patient undergoes regular surveillance and is disease-free 13 months after resection. Similarly, treatment of SLE is no longer required due to lack of activity already after the first two cycles of lymphoma treatment. The case shows how closely SLE and diffused large B-cell lymphoma can be connected and stresses the importance of interdisciplinary treatment approaches. In the future, artificial intelligence may help to further classify 18F-FDG-PET-positive lymphoma residuals. This could lead to an increase of the positive predictive value of interim- and end-of-treatment 18F-FDG-PET. The patient's point of view enables another instructive perspective on the course of treatment, which often remains hidden to treating physicians due to lack of time in clinical routine.

Lenalidomide in combination with bendamustine and prednisolone in relapsed/refractory multiple myeloma: results of a phase 2 clinical trial (OSHO-#077).

INTRODUCTION: While lenalidomide monotherapy is established for relapsed and/or refractory multiple myeloma (MM) treatment, combination therapies including lenalidomide are still under investigation in a number of phase 2/3 studies. In the current study, a treatment regime of lenalidomide (Revlimid®), bendamustine and prednisolone (RBP) was tested in patients with relapsed/refractory MM. METHODS: In the previously completed phase 1 study RBP with a dose of 75 mg/m2 bendamustine days 1-2, prednisolone 100 mg days 1-4 and 25 mg lenalidomide days 1-21 was well tolerated. RESULTS: Between July 2011 and September 2013, 25 patients were included in this analysis. The median number of previous treatments was 1 (range 1-2). Twenty-two patients (88%) responded after at least two cycles of RBP (one sCR, five nCR, eight VGPR and eight PR). The median time to first haematological response was 28 days, and median time to best response was 56 days. Due to increased haematological toxicity a dose reduction in most patients required in subsequent cycles of therapy. The median progression-free and overall survival was 22 and 38 months, respectively. In conclusion RBP is a highly effective therapy for patients with relapsed/refractory MM. In contrast to our phase 1 study, dose reduction was necessary in many patients because of haematological toxicity.

Successful treatment of patients with newly diagnosed/untreated light chain multiple myeloma with a combination of bendamustine, prednisone and bortezomib (BPV).

INTRODUCTION: Patients with light chain myeloma frequently have a light chain tubular cast nephropathy, which can lead to severe renal impairment. In the present retrospective study, bortezomib was combined with other active substances like bendamustine and prednisone (BPV), in order to assess the efficacy and toxicity of the combination therapy in patients with light chain multiple myeloma. METHODS: Between September 2008 and May 2015, 25 patients with newly diagnosed light chain multiple myeloma were treated with bendamustine 60 mg/m2 on days 1 and 2, bortezomib 1.3 mg/m2 on days 1, 4, 8 and 11, and prednisone 100 mg on days 1, 2, 4, 8 and 11 once every 21 days (BPV). Prior to treatment, 4 patients (16%) had moderate renal dysfunction and 14 patients (56%) severe renal dysfunction or renal failure/dialysis. RESULTS: The median number of the BPV cycles was 2 (1-5). 24 patients (96%) responded with 4 stringent complete responses, 6 near-complete responses, 5 very good partial responses and 9 partial responses. The myeloma light chains decreased rapidly, reaching the best response after the first cycle in 9 and after the second cycle in additional 12 patients. 17 patients discontinued therapy after median 2 cycles of BPV treatment to receive autologous or allogeneic SCT. All together 12 of 18 patients with at least moderate renal failure improved their renal function. 3 of the 6 dialysis-dependent patients became dialysis-independent. With a median follow-up of 27 months, median progression-free survival and overall survival for patients at 30 months were 68 and 96%, respectively. The most common severe side effect was grade 3/4 leukocytopenia in 20% of the patients. Grade 3/4 thrombocytopenia was observed in 12% of the patients. Moderate to severe infection were seen in six patients. We conclude that BPV is effective and well tolerated in patients with newly diagnosed/untreated light chain multiple myeloma.

Stem cell mobilization and autologous stem cell transplantation after pretreatment with bendamustine, prednisone and bortezomib (BPV) in newly diagnosed multiple myeloma.

INTRODUCTION: Reliable information on stem cell toxicity and mobilization of stem cells for autologous stem cell transplantation (SCT) after induction treatment with a combination of bendamustine, prednisone and bortezomib (BPV) is missing. MATERIALS AND METHODS: A retrospective analysis of peripheral blood stem cell mobilization and autologous SCT was performed in 35 patients with MM who had received at least one cycle of a BPV-induction therapy consisting of bendamustine 60 mg/m(2) on days 1 and 2, bortezomib 1.3 mg/m(2) on days 1, 4, 8 and 11 and prednisone 100 mg on days 1, 2, 4, 8 and 11 between October 2008 and May 2014. The mobilization regimen consisted of cyclophosphamide 4 g/m(2) and G-CSF (2 × 5 µg/kg). Apheresis was started as soon as peripheral CD34(+) counts exceeded 20 × 10(6)/L with a harvest target of 8 × 10(6) CD34(+)/kg. The minimal accepted target was 2 × 10(6) CD34(+)/kg. The transplantation conditioning therapy consisted of melphalan 200 mg/m(2). RESULTS: A median number of two (range 1-5) BPV cycles were given. The majority of patients (n = 31, 89 %) responded with two sCR, five nCR, 11 VGPR and 13 PR after BPV induction. Three patients had MR, and one SD. Stem cell mobilization and harvest were successful in all patients. In 19 of 35 patients (54 %), a single apheresis was sufficient to reach the target. The median number of aphereses was one (range 1-4), and the median CD34(+) cell-count/kg was 13.5 (range 3.2-33.1)  × 106. All patients received an autologous SCT. Engraftment was successful in 34 of 35 patients. The median time to a leukocyte count >l × 10(9)/L was 11 days, and the time to untransfused platelet count of >50 × 10(9)/L was 13 days. Thirty-four patients (97 %) responded after the autologous SCT with 11 sCR, two CR, seven nCR, seven VGPR and seven PR. The progression-free survival at 18 months was 87 %, and overall survival was 92 %. CONCLUSION: Stem cell mobilization and autologous SCT are feasible in MM patients who have received BPV-induction therapy .

Bendamustine and prednisone in combination with bortezomib (BPV) in the treatment of patients with newly diagnosed/untreated multiple myeloma.

INTRODUCTION: Bortezomib is a proteasome inhibitor that has shown important clinical efficacy either as a single agent or in combination in patients with multiple myeloma (MM). In the present protocol, bortezomib was combined with bendamustine and prednisone, in order to assess the efficacy and safety of this combination therapy in patients with newly diagnosed/untreated MM. METHODS: Between June 2006 and October 2013, 49 patients with newly diagnosed/untreated MM were treated with bendamustine 60 mg/m(2) on days 1 and 2, bortezomib 1.3 mg/m(2) on days 1, 4, 8 and 11, and prednisone 100 mg on days 1, 2, 4, 8 and 11 bendamustine, prednisone and bortezomib (BPV) once every 21 days. Patients were divided into three groups: group A (n = 19) consisted of patients with normal renal function or mild dysfunction (eGFR ≥ 60 ml/min), group B (n = 15) patients with moderate or severe renal dysfunction (eGFR 15-59 ml/min) and group C (n = 15) patients with renal failure/dialysis (eGFR <15 ml/min). RESULTS: A median number of two (range 1-5) BPV treatment cycles were given to the patients. The majority of the patients (n = 40, 82 %) responded after at least one cycle of BPV therapy with five stringent complete responses (CRs), nine near complete responses, 12 very good partial responses and 14 partial responses. Five patients had MR, three stable and one progressive disease. After a median observation time of 13 months, progression-free survival (PFS) and overall survival (OS) at 12 months were 92 and 94 %, respectively, for patients with normal renal function or mild renal dysfunction (group A) and 83 and 93 %, respectively, for patients with moderate or severe renal dysfunction (group B). Outcome for these patients was slightly better but not statistically significantly better than that for patients with renal failure/dialysis (group C), who had a PFS, and OS of 66 % (p = 0.08) and 73 % (p = 0.05), respectively. These results indicate that this BPV combination is feasible, effective and well tolerated in patients with newly diagnosed MM and normal or impaired renal function.

Low tumor burden is associated with early B-cell reconstitution and is a predictor of favorable outcome after non-myeloablative stem cell transplant for chronic lymphocytic leukemia.

Abstract Reconstitution, engraftment kinetics and tumor cell clearance were analyzed after reduced intensity conditioning hematopoietic cell transplant (RIC-HCT) in patients with chronic lymphocytic leukemia (CLL). Patients were transplanted from unrelated (n = 40) or related (n = 10) donors after fludarabine and 2 Gy total body irradiation followed by cyclosporine and mycophenolate mofetil. The vast majority of patients (96%) engrafted with absolute neutrophil count (ANC) > 0.5 × 10(9)/L at day + 22. CLL cells decreased (median 2%, range 0-69%) within 28 days, but disappeared by day + 180 after HCT. Donor T-cell chimerism increased to > 95% at day 56 and donor B-cell chimerism to 94% at day + 360. Overall survival was 51 ± 8%, incidence of progression 37 ± 7% and non-relapse related mortality (NRM) 30 ± 7% at 4 years. The most common causes of NRM were graft-versus-host disease (GvHD) (14%) and sepsis (6%). Disease status at HCT was significantly associated with early B-cell reconstitution (p = 0.04) and with increased risk of relapse/progression in univariate and multivariate analysis (p = 0.022). Tumor cells were undetectable by day + 180, although B-cell reconstitution did not occur until 1.5 years after RIC-HCT. The best predictors for progression-free survival (PFS) and overall survival (OS) were complete response (CR) or first partial response (PR1) and the absence of bulky disease at transplant, respectively.

Bendamustine and prednisone in combination with bortezomib (BPV) in the treatment of patients with relapsed or refractory multiple myeloma and light chain-induced renal failure.

INTRODUCTION: Serious renal failure represents a severe complication of multiple myeloma (MM), with an estimated 25-50 % of patients being affected. Both bortezomib and bendamustine have been identified as quickly acting, effective and well-tolerated drugs and might therefore constitute an adequate combination regimen for patients presenting with light chain-induced renal failure. METHODS: Between March 2005 and March 2013, 36 patients with relapsed/refractory MM and light chain-induced renal failure (creatinine clearance <60 ml/min) were treated with bendamustine 60 mg/m(2) on days 1 and 2, bortezomib 1.3 mg/m(2) on days 1, 4, 8 and 11 and prednisone 100 mg on days 1, 2, 4, 8 and 11 (BPV). Patients were divided according to severity of renal impairment into group A (n = 20) with moderate or severe renal dysfunction (eGFR 15-59 ml/min) and group B (n = 16) with renal failure/dialysis (eGFR <15 ml/min). RESULTS: Twenty-four patients (67 %) responded with three CR, three nCR, six VGPR and 12 PR. Six patients had minor response, two stable and four progressive disease. With a median follow-up period of 22 months, median progression-free survival (PFS) and overall survival (OS) for patients of group A were 10 and 25 months, respectively. This outcome was significantly better compared to patients of group B with a median PFS and OS of 3 and 7 months, respectively. Eleven patients showed a CRrenal, five a PRrenal and 15 a MRrenal. These results indicate that this BPV combination is feasible, effective and well tolerated in patients with relapsed/refractory MM and light chain-induced renal failure.

Lenalidomide, bendamustine and prednisolone exhibits a favourable safety and efficacy profile in relapsed or refractory multiple myeloma: final results of a phase 1 clinical trial OSHO - #077.

This phase 1 dose finding study tested a combination of lenalidomide, bendamustine and prednisolone (RBP) in 21 patients in five cohorts with advanced multiple relasped/refractory myeloma (MM) to determine the maximum tolerable dose (MTD) of the combination. The first cohort received a starting dose of lenalidomide 10 mg/d, days 1-21, bendamustine 60 mg/m(2) /d, days 1-2, and prednisolone 100 mg/d, days 1-4. Dose escalation was done in cohorts of three to six patients with lenalidomide dose increasing to 15, 20 and 25 mg, and after reaching 25 mg/d, bendamustine was increased to 75 mg/m(2) . A total of 21 patients were enrolled and all completed at least two cycles. Two patients developed dose-limiting haemotoxicity: one patient on lenalidomide 25 mg/d and bendamustine 60 mg/m(2) and another patient at the highest dose level (lenalidomide 25 mg/d and bendamustine 75 mg/m(2) ). The MTD was not reached. Sixteen patients (76%) responded after at least two cycles of RBP with one stringent complete response (CR), one near CR, five very good partial response and nine partial response. After a median observation time of 16 months, progression-free survival at 18 months was 48% and overall survival was 64%. In conclusion, RBP with lenalidomide 25 mg/d, days 1-21 and bendamustine 75 mg/m(2) days 1-2 is well tolerated in patients with relapsed/refractory MM.

Combined bendamustine, prednisone and bortezomib (BPV) in patients with relapsed or refractory multiple myeloma.

INTRODUCTION: Bortezomib (Velcade) is a proteasome inhibitor that has shown important clinical efficacy either as a single agent or in combination with other cytostatic agents in multiple myeloma (MM). In the present protocol, bortezomib was combined with other active substances like bendamustine and prednisone (BPV), in order to assess the efficacy and toxicity of the combination therapy in patients with relapsed or refractory MM. METHODS: Between January 2005 and December 2011, 78 patients with relapsed or refractory MM were treated with bendamustine 60 (-120) mg/m(2) on days 1 and 2, bortezomib 1.3 mg/m(2) on days 1, 4, 8 and 11, and prednisone 100 mg on days 1, 2, 4, 8 and 11. The median number of prior therapies was 2 with a wide range of 1-9. Thirty-three patients had pre-existing severe thrombocytopenia and/or neutropenia (WHO grade 3 or 4). RESULTS: A median number of two (range 1-7) BPV treatment cycles were given to the patients. The majority of the patients (n = 54; 69 %) responded after at least one cycle of chemotherapy with 3 CR, 10 nCR, 10 VGPR and 31 PR. Median PFS and OS for patients without severe hematological toxicities due to previous treatments (n = 45) were 11 and 50 months, respectively. Outcome for these patients was significantly better than that for patients with severe hematological toxicities (grade 3 or 4, n = 33) with a PFS, and OS of 3 months (p < 0.05) and 5 months (p < 0.001), respectively. The regimen was well tolerated with few significant side effects in patients without severe hematological toxicities due to previous treatments. These results indicate that the combination of bortezomib, bendamustine and prednisone is well tolerated in patients with relapsed or refractory MM.

Spontaneous remission of acute myeloid leukemia relapse after hematopoietic cell transplantation in a high-risk patient with 11q23/MLL abnormality.

A 35-year-old female patient was diagnosed with acute myeloid leukemia with multiple genetic aberrations [48 XX, del(3)(q21), +6, t(11;15)(q23;q15), +21] including an 11q23/MLL abnormality. The patient achieved a complete remission after one induction chemotherapy cycle. After three courses of consolidation, a matched unrelated hematopoietic cell transplantation (HCT) was performed. Following an upper respiratory tract infection 7 years after transplant, her blood counts declined to leukocytes of 1 x 10(9)/l, platelets of 51 x 10(9)/l and hemoglobin of 7.5 g/dl. A bone marrow aspirate revealed 55% leukemic blasts carrying the unfavorable genetic aberrations seen at initial diagnosis (11q23/MLL). In the absence of any disease-specific treatment, the leukemic blasts cleared from the bone marrow within 6 days after diagnosis of relapse and peripheral blood counts returned to normal. Molecular analysis of the 11q23/MLL rearrangement was used to evaluate minimal residual disease, which became undetectable in repetitive FISH analyses. This is the first report of spontaneous remission in a patient with initially a multiaberrant leukemic cell clone and a proven 11q23/MLL abnormality at relapse after HCT.