Elimination of CD20-Expressing Cells in Multiple Myeloma by Iodine I-131 Tositumomab (Bexxar®) Correlates with Response to Therapy

Abstract It has been proposed that treatment failures in multiple myeloma (MM) are related to the chemoresistance of a subset of malignant myeloma cells with clonogenic potential to the anti-myeloma drugs (Matsui et al., Cancer Research2008, 68:190). Studies suggest that these putative myeloma stem cells (MSC) are CD138neg and express CD20, which is usually absent in more differentiated malignant plasma cells (Matsui et al., Blood2004, 15:2332). These findings provided a rationale for a treatment strategy to eliminate chemoresistant clonogenic MSC using anti-CD20 antibodies. To evaluate the clinical effects of anti-CD20 treatment, we developed a phase II trial with Bexxar as a consolidation treatment for MM. We hypothesized that Bexxar would be more efficacious than unlabeled antibody in the eradication of highly radiosensitive myeloma cells by both direct and cross-fire effects. Preclinical studies showed that tositumomab, the antibody used in Bexxar, inhibited colony formation of clonogenic myeloma cells. To be eligible for Bexxar treatment, patients must have completed at least 4 cycles of therapy (1st to 3rd line) and have measurable disease in a plateau of at least partial response (PR). To date, 10 of 30 patients have been enrolled, of which 5 were treated with Bexxar after completion of initial therapy prior to proceeding to autologous stem cell transplant (ASCT). Patients proceeding to ASCT required hematopoietic stem cells collection prior to Bexxar and 3 months after Bexxar. Eight patients are evaluable for response and toxicities. At 3 months post Bexxar, 1 patient achieved a partial response (PR), 4 patients had stable disease (SD), and 1 patient progressed (PD). At 1 year post Bexxar, 1 patient with initial PR achieved CR and remains in CR, 1 patient is in unconfirmed CR, 2 are in partial response (PR), and 3 remain in SD. After a median 20 months of followup (range 4–24), all patient are alive, 4 in continued response, 3 with SD. Hematological toxicities were mild to moderate (1 patient grade 3 and 4 patients grade 2 thrombocytopenia, 4 patients grade 2 neutropenia). Non-hematological toxicity was limited to HAMA (6 patients). Out of patients who received Bexxar prior to transplant, 3 collected stem cells post-Bexxar without problems, one requires re-collection. Three patients who proceeded to ASCT to date using the post-Bexxar stem cell collection, engrafted at 11–12 days, and had no unexpected toxicities with ASCT. We also analyzed CD20+ cells in bone marrow aspirates (BM) and stem cell collections (SCC) using samples collected from 4 patients before and after Bexxar. Bexxar treatment eliminated a median 80% of CD20+ cells (range 23–97). For a given patient, elimination of CD20+ cells from SCC correlated with elimination of CD20+ cells from BM. The most complete elimination of CD20+ cells from BM was observed in 2 patients who at 1 year achieved CR (94% and 97%), compared to patients who achieved PR (23% and 68%). We conclude that anti-CD20 consolidation treatment of myeloma patients with Bexxar used as targeted therapy against clonogenic myeloma cells is feasible and well tolerated. Clinical outcomes to date are encouraging considering that clonogenic MSC represent <5% of malignant plasma cells and delayed responses observed in this study could be expected. While early, clinical outcomes appear to correlate with the efficacy of the CD20+ cell elimination by Bexxar treatment in myeloma.

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Targeted Therapy Against Clonogenic Myeloma Cells with Iodine I-131 Tositumomab (Bexxar™).

Blood ◽

10.1182/blood.v110.11.4796.4796 ◽

2007 ◽

Vol 110 (11) ◽

pp. 4796-4796 ◽

Cited By ~ 1

Author(s):

Andrzej Jakubowiak ◽

Malathi Hari ◽

Ammar Al-Zoubi ◽

Tara Kendall ◽

Yasser Khaled ◽

...

Keyword(s):

Stem Cells ◽

Stem Cell ◽

Plasma Cells ◽

First Line ◽

Myeloma Cells ◽

Consolidation Treatment ◽

First Line Therapy ◽

Line Therapy ◽

Anti Cd20 ◽

Stem Cell Collection

Abstract It has been proposed that treatment failures in multiple myeloma (MM) may be related to chemoresistance of malignant myeloma clonogenic cells (myeloma stem cells). Studies suggest that these cells are CD138− and express CD20, which is usually absent in more differentiated malignant plasma cells (Matsui et al, Blood 2004,15:2332). These findings provided a rationale for a treatment strategy to eliminate clonogenic myeloma cells using anti-CD20 antibodies. We conducted preclinical studies in vitro with tositumomab, the unlabeled anti-CD20 antibody in Bexxar. Bone marrow aspirates from MM patients were depleted of CD138 and CD34 to obtain CD138−CD34− cell populations by MACS separation using antibodies coupled to magnetic microbeads. These cells were treated with tositumomab for 24 hrs and plated in methylcellulose media. After 3 weeks of incubation, tositumomab inhibited colony formation of clonogenic myeloma cells. To evaluate the clinical effects of anti-CD20 treatment we developed a phase II trial with Bexxar as a consolidation treatment of MM. We hypothesized that Bexxar would be more efficacious than unlabeled antibody in eradication of highly radiosensitive myeloma cells by direct and cross-fire effects. To be eligible for Bexxar treatment, patients must have completed at least 4 cycles of therapy (1st to 3rd line) and have measurable disease in a plateau of at least partial response (PR) lasting at least 6 weeks. Patients undergoing first line therapy who are eligible for transplant are required to collect stem cells prior to Bexxar and have a second stem cell collection 3 months after Bexxar treatment. Samples for clonogenic studies are collected prior to Bexxar treatment, and at 3 months and 1 year post treatment. To date, 7 of 30 patients have been enrolled, 3 after completion of first line therapy with Velcade, Doxil, Dexamethasone (VDD) and prior to autologous stem cell transplant (ASCT), 4 in a plateau of PR after ASCT. Bexxar treatment was tolerated well in all patients with expected toxicities. Hematologic toxicities were mild. Two patients developed grade 3, and 4 grade 2 neutropenia, 4 patients grade 2 thrombocytopenia, and 1 grade 2 anemia. One patient (post ASCT) developed symptomatic HAMA requiring admission and 3 other patients (1 post ASCT, 2 prior to ASCT) developed HAMA titers without symptoms. Three patients who proceeded to ASCT collected stem cells prior to and after Bexxar treatment and all used post-Bexxar stem cell collections for ASCT. There were no difficulties encountered with stem cell collection. All engrafted at 11–12 days and had no unexpected toxicities with ASCT. Patients who proceeded to ASCT had stable disease (SD) at the end of 3-month period of Bexxar treatment. All remain in remission 6–9 months post Bexxar treatment (all in VGPR). Of patients who were treated with Bexxar post ASCT, 1 achieved a minor response (> 25%), 2 have SD with a followup of 1–12 months, and 1 had progressive disease at 3 months with subsequent 9 months of SD without intervention. The effects of Bexxar treatment on clonogenic myeloma cells are under evaluation and will be presented. We conclude that anti-CD20 consolidation treatment of myeloma patients with Bexxar used as targeted therapy against clonogenic myeloma cells is feasible and well tolerated. Clinical outcomes to date are encouraging, since clonogenic myeloma cells represent <5% of malignant plasma cells and the positive effects of treatment may require longer followup to be fully appreciated.

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Myeloidderived peripheral blood suppressor cells at haematopoietic stem cell mobilisation in multiple myeloma patients

Hematology and Transfusiology ◽

10.35754/0234-5730-2021-66-2-218-230 ◽

2021 ◽

Vol 66 (2) ◽

pp. 218-230

Author(s):

T. A. Aristova ◽

E. V. Batorov ◽

V. V. Sergeevicheva ◽

S. A. Sizikova ◽

G. Yu. Ushakova ◽

...

Keyword(s):

Multiple Myeloma ◽

Stem Cell ◽

Partial Response ◽

Peripheral Blood ◽

Plasma Cells ◽

Suppressor Cells ◽

Complete Response ◽

Haematopoietic Stem Cell ◽

Hla Dr ◽

Healthy Donors

Introduction. Multiple myeloma (MM) is a B-cell malignancy with clonal expansion of plasma cells in bone marrow. Highdose chemotherapy with autologous haematopoietic stem cell transplantation is among main consolidation therapies in MM. Myeloid-derived suppressor cells (MDSCs) are immature myeloid-accompanying cells able to suppress the immune response. The administration of granulocyte colony stimulating factor (G-CSF) to mobilise haematopoietic stem cells (HSCs) increases the MDSC count in peripheral blood (PB).Aim — to study MDSC subsets in PB of remission MM patients and their incidence dynamics at HSC mobilisation.Methods. The study surveyed 35 MM patients prior to and after HSC mobilisation. The counts of granulocytic (G-MDSCs; Lin–HLA-DR–CD33+ CD66b+), monocytic (М-MDSCs; CD14+ HLA-DRlow/–) and early MDSCs (E-MDSCs; Lin–HLA-DR– CD33+ CD66b–) were estimated in flow cytometry.Results. Remission MM patients differed from healthy donors in higher relative counts of G-MDSCs (Lin–HLA-DR– CD33+ CD66b+) and increased relative and absolute counts of М-MDSCs (CD14+ HLA-DRlow/–). М-MDSCs significantly outnumbered G-MDSCs. MDSC subset counts were elevated in complete response (CR) and very good partial response (VGPR), as well as in partial response (PR). Higher relative MDSC counts were associated with greater pretreatment (2–3 lines of chemotherapy). After HSC mobilisation with cyclophosphamide 2–4 g/m2 + G-CSF (filgrastim 5 μg/kg/day), the median relative E-MDSC and M-MDSC counts increased by 2.3 and 2.0 times, respectively, while the relative G-MDSC count raised 46-fold perturbing the MDSC subset balance.Conclusion. Remission MM patients had the increased relative G-MDSC and both relative and absolute M-MDSC counts compared to donors. A greater patient pretreatment was associated with higher relative G-MDSC counts. Treatment response (CR/VGPR vs. PR) was not coupled with MDSC count variation. The G-CSF-induced HSC mobilisation entailed a significant expansion of all three MDSC subsets in PB.

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Donor Cell Myeloma: A Unique Case

Blood ◽

10.1182/blood-2018-99-112526 ◽

2018 ◽

Vol 132 (Supplement 1) ◽

pp. 5743-5743

Author(s):

Guillermo J. Ruiz-Argüelles ◽

Alejandro Ruiz-Argüelles ◽

Javier Garces-Eisele ◽

Virginia Reyes-Nuñez ◽

Maria Fernanda Vallejo-Villalobos ◽

...

Keyword(s):

Multiple Myeloma ◽

Stem Cell ◽

Prospective Studies ◽

Acute Myelogenous Leukemia ◽

Plasma Cells ◽

Donor Cell ◽

Myelogenous Leukemia ◽

Myeloma Cells ◽

Allogeneic Hsct ◽

Acute Myelogenous

Abstract Leukemia relapse occurring in donor cells, so called donor cell leukemia (DCL) after allogeneic hematopoietic stem cell transplantation has been previously reported in the literature. Some authors have suggested that the development of DCL is perhaps a more common occurrence than traditionally thought. Donor cell myeloma (DCM) seems to be less frequent than DCL. This 46-year old male when first seen in 2000 was diagnosed with stage IIIa multiple myeloma. A monoclonal IgA kappa spike was recorded at diagnosis. Treatment with melphalan and prednisone was delivered every four to six weeks for a total of 22 courses. Fourty months after the initial diagnosis, an M2 acute myelogenous leukemia was identified. Treatment with chemotherapy resulted in complete remission. Matched UCB cells were localized at the London Cord Blood Bank. The UCB belonged to a male product of a white western European mother and a black Nigerian father who was a carrier of hemoglobin S. Hemoglobins A, F and S were detected in the UCB, consonant with sickle cell trait. The patient was allografted employing the "Mexican" NST conditioning regimen, granulocyte count recovered to more than 0.5 x 109/L on day 14, with the platelet count never dropping below 20 x 109/L. On day +40, the polymorphic microsatellite markers revealed mixed chimerism. The hemoglobin S gene was identified on day +20 and on day +60, full chimerism was shown. Cyclosporine A was stopped on day +350. The patient returned 170 months after the transplant with low back pain and the bone marrow aspiration disclosed 80% abnormal plasma cells, an IgA kappa monoclonal spike of 3.1 gr/dl, and complete chimerism. Malignant plasma cells were sorted by means of flow cytometry before genetic fingerprinting; cells were stained with an admixture of fluorescent monoclonal antibodies and cells co-expressing dim CD45, bright CD38 and CD56 were sorted out to ≥99% purity. Sorted cells were shown to have donor origin (Figure 1). The patient was treated with thalidomide, dexamethasone and bortezomib and the monoclonal spike disappeared; an autologous stem cell transplant is planned. Most people consider that the development of a malignancy in the cells of the donor is a rare event and very few prospective studies have analyzed the real prevalence of this phenomenon. Prospectively, we have found that 7% (95% CI 2.9 to 13.6%) of patients with leukemic activity after an allogeneic graft do have a donor cell-derived leukemia; this figure contrasts with those described elsewhere in non-prospective studies. A major problem in the analysis of donor cell derived malignancies is that demonstration of the donor cell origin of malignant activity. In this case, the demonstration of DNA of the donor in the fluorescence-activated sorted malignant plasma cells is indicative of the origin of the myeloma cells. Interestingly, the immunoglobulin type produced by the initial myeloma cells is the same as that of the donor-cell myeloma; Despite being two myelomas producing the same immunoglobulin subtype, both should be considered as de novomalignancies and as such, treated; we have previously shown that donor cell leukemias do have a response when treated as de novo, non-secondary leukemias. To our best knowledge, this is the second report of DCM following allogeneic HSCT. Prior to this case, Kim et al reported a DCM after an allogeneic transplant in a patient with refractory anemia with ringed sideroblasts. Previously, two cases have been reported of donor-origin MM, but they occurred in patients who underwent solid organ transplantation of the kidney and heart-lung. Kumar et alreported a case of DCM developing after unrelated allogeneic HSCT in the both donor and recipient but they did not conducted a comprehensive molecular cytogenetic study. In the case published by Maestas et al, an abnormal proliferation of plasma cells was identified in the donor, thus making possible that a malignant plasma cell clone was already present in the donor stem cells. In summary, we have clearly shown that this patient has had three different malignancies: 1) De novomultiple myeloma, 2) Secondary acute myelogenous leukemia and 3) De novodonor cell-derived multiple myeloma. The mechanisms involved in these episodes could be useful to better understand tumorigenesis. Disclosures No relevant conflicts of interest to declare.

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Phase II Randomized Trial of Bevacizumab Versus Bevacizumab and Thalidomide for Relapsed/Refractory Multiple Myeloma.

Blood ◽

10.1182/blood.v106.11.2571.2571 ◽

2005 ◽

Vol 106 (11) ◽

pp. 2571-2571 ◽

Cited By ~ 3

Author(s):

George Somlo ◽

William Bellamy ◽

Todd M. Zimmerman ◽

Paul Frankel ◽

Joe Tuscano ◽

...

Keyword(s):

Multiple Myeloma ◽

Stem Cell ◽

Stem Cell Transplant ◽

Plasma Cells ◽

Progression Free Survival ◽

Staining Intensity ◽

Cell Transplant ◽

Myeloma Cells ◽

Anti Vegf ◽

Grade 3

Abstract Vascular endothelial growth factor (VEGF) plays a seminal role in neo-angiogenesis. VEGF is present on myeloma cells, and its receptors, VEGFR1 (Flt-1) and VEGFR2 (KDR) are detectable on the surface of neighboring myeloid and monocytic elements. Hence, VEGF is implicated in the pathogenesis of multiple myeloma (MM). Thalidomide, an important agent in the treatment of MM, among its many postulated mechanisms of actions also inhibits VEGF-mediated neo-angiogenesis. We set out to test the feasibility and explore the efficacy of combining an anti-VEGF agent with thalidomide. With the availability of the anti-VEGF antibody rhuMAB bevacizumab, a trial of bevacizumab 10 mg/kg given intravenously every 2 weeks alone (in thalidomide-exposed patients) versus a randomized comparison of bevacizumab +/− thalidomide 50–400 mg/day (in thalidomide naive patients) was initiated by the California Cancer Consortium. Twelve patients (median age:58 years; range:50–75) with initial stages of I (n:2), II (n:2) and III (n: 8), all with refractory MM have been enrolled. Patients received a median of 1 prior regimen (range:0–5). Six patients had failed an autologous stem cell transplant prior to enrollment. In patients who have received bevacizumab alone, grade 3 toxicities included fatigue and neutropenia (1), hypertension (1), and hyponatremia (1). In the group receiving bevacizumab and thalidomide, grade 3 lymphopenia was observed in 1 patient during cycle 3, and one patient was taken off study due to exacerbation of pre-exisiting (diet pill induced) pulmonary hypertension and was considered inevaluable. Median time to progression for the 6 patients treated with bevacizumab alone was 2 (range 1–4) months. Progression-free survival for the 5 evaluable patients treated with bevacizumab and thalidomide is 6 +, 7, 8 +, 10, and 30 + months, with 2 patients still on study and in response. Two of these patients did not progress but were taken off study (one for patient’s choice, and one due to the physician’s choice to pursue a stem cell transplant at 7.5 months, this patient is listed above as in response at 30 + months). Immunohistochemical staining (IHC) revealed 2 + to 4 + expression of VEGF on myeloma cells in 7 cases of the available 8 pre-treatment bone marrow samples. Weak staining (1+) of VEGFR1 was observed on the surface of myeloma cells in 5 cases. VEGFR2 expression was also observed on plasma cells by IHC (1+ to 2+) in 5 cases. Myeloma cells from a patient treated with bevacizumab alone for a duration of 4 months, and from a patient receiving bevacizumab and thalidomide for 7.5 months before going on to transplant, demonstrated the strongest staining intensity for VEGF. Due to slow accrual the study had been closed to accrual, although 2 patients continue on the bevacizumab and thalidomide arm. However, in light of our findings further testing of bevacizumab, preferably in combination with other active agents is warranted. Supported by NO1 CM 17101.

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Flow Cytometric Detection of Circulating Myeloma Cells Pretransplant in Patients with Multiple Myeloma: A Simple Risk Stratification System.

Blood ◽

10.1182/blood.v106.11.1164.1164 ◽

2005 ◽

Vol 106 (11) ◽

pp. 1164-1164

Author(s):

David Dingli ◽

Grzegorz S. Nowakowski ◽

Angela Dispenzieri ◽

Martha Q. Lacy ◽

Suzanne R. Hayman ◽

...

Keyword(s):

Multiple Myeloma ◽

Flow Cytometry ◽

Stem Cell ◽

Prognostic Factor ◽

Response To Therapy ◽

Independent Prognostic Factor ◽

High Dose ◽

Rapid Progression ◽

Myeloma Cells ◽

The Impact

Abstract Background: The presence of circulating myeloma cells (CMC) detected by flow cytometry at the time of diagnosis of multiple myeloma is associated with a shortened response to therapy and reduced overall survival (OS). We hypothesized that the presence of CMC at the time of stem cell collection prior to high dose therapy (HDT) and autologous stem cell transplantation (ASCT) would identifies a cohort of patients with a high risk of rapid progression. Methods: The Mayo Clinic myeloma transplant database was queried for patients who were mobilized using cyclophosphamide and hematopoietic growth factors. CMC was determined using flow cytometry by gating on a population of CD38 bright and CD45 negative cells. The impact of CMC on OS and time to progression (TTP) and its role in the context of established prognostic parameters was evaluated. Results: Of 246 patients with MM undergoing ASCT, 95 had CMC. Patients with CMC had significantly higher plasma cell labeling index, adverse cytogenetics, B2-M and resistant disease. Complete response (CR) rates post transplant were 32% and 36% for patients with and without CMC (p=0.5034). OS was 33.2 and 58.6 months (p=0.0052) while TTP was 14.1 and 22 months respectively (p=0.0005). Figure Figure On multivariate analysis, CMC remained an independent prognostic factor in a model that included cytogenetics and disease status at time of transplant (p=0.0314). A prognostic system based on the presence or absence of CMC and karyotype abnormalities was developed. Patients with neither, one or both parameters had a median, OS of 55, 48 and 21.5 months respectively (p<0.0001) while TTP was 22, 15.4 and 6.5 months for the same groups (p<0.0001). Conclusion: The presence of CMC at the time of HDT and ASCT is an independent prognostic factor. The combination of CMC and cytogenetics provides a simple yet powerful scoring system that stratifies patients and guides their management.

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Multiple Myeloma Patients Who Are Chemosensitive and Present with Plasma Cells Lacking Phosphorylated Retinoblastoma and/or Cyclin A Expression Benefit From High Dose Therapy and Autologous Stem Cell Transplantation More.

Blood ◽

10.1182/blood.v116.21.1345.1345 ◽

2010 ◽

Vol 116 (21) ◽

pp. 1345-1345

Author(s):

Selami Kocak Toprak ◽

Gulsah Kaygusuz ◽

Nazmiye Kursun ◽

Duygu Ozu ◽

Merih Kizil Cakar ◽

...

Keyword(s):

Multiple Myeloma ◽

Stem Cell ◽

Initial Treatment ◽

Plasma Cells ◽

Cyclin A ◽

Response To Therapy ◽

Novel Agents ◽

High Dose ◽

Cell Transplant ◽

Group 1

Abstract Abstract 1345 Background and aim: Multiple Myeloma (MM) plasma cells are known to posses low replicative potential and plasma cell labelling index is generally accepted as a strong prognostic factor. TC classification of MM defines categories of myeloma cases expressing different cyclins (Fonseca et all, Leukemia 2009). Although cyclin dependent kinase inhibitors (CDKI) are important for cell cycle, they are not included in this molecular classification. Patients and Methods: With an aim to define high and low proliferative myeloma cases antibodies detecting cyclins (Cyc) A, D1, D2, D3, phosphorylated retinoblastoma (Rb), p16, p21, p27, Ki67 were applied to tissue sections obtained from either marrow plasmacytoma of 106 consequtive myeloma patients (median: 59, 32–79 years) diagnosed between 1998–2007. 100 patients <65 years (n:51) were evaluable for treatment outcome and received an induction of VAD (4-6 cycles), followed by a novel agent containing regimen (2-4 cycles) or autologous stem cell transplant (ASCT) depending on the response to induction. Postransplant consolidation or subsequent transplants were performed when < VGPR was obtained. Elderly patients (n:49) received induction for at least a year. Novel agents (Thalidomide: 66.7%, Bortezomib: 27.5%) were given in 94.2% of patients as ≥2 line treatment. Mann Whitney U, Kaplan-Meier or log rank analysis were performed using the SPSS version 15.0. Results: Loss of CDKI's were detected in 55.4–88.5 % of the cases. Cyclin D1D2D3 or Cyclin A expression was detected in 29.2, 21.7, 5.7 or 19.8 % of the cases. Rb was detected in 25%. Among the CDK's or CDKI's only Cyc D2 was correlated with Ki67 percentage (p=0.027). Loss of all CDKI's was observed in 31.1 %. The majority of p16 (-) cases were Cyc A (-) too (p=0.001). Loss of p16 and p 27 was observed more frequently than loss of p 21 (88 and 85% versus 54%). Patients were either both CycA and p21 (-) (50%) or both CycA and p21 (+) (31 %) (p=0.025). However there was no patient expressing Rb and p16. On the contrary, the majority patients were both Rb and p16 (-) (60%) (p=0.037). Groups of patients with high proliferative protential group 1 (Cyc D+ p16-), group 2 (CycA+ p21-), group 3 (CycA+ Rb+) and low proliferative protential group 4 (Rb- p16+), group 5 (CycA- Rb-) were analyzed. These were observed 42.5 %, 5.5%, 11.7%, 15.4% and 57.1%. No correlation could be found between the CDKI/Cyc defined risk groups and ISS, B2MG, LDH, CRP, OS. However among p16 (-) cases Rb (-) ones (n:39) had longer OS than Rb (+) patients (n:18) (49 vs 39 months). All p16 (+) patients were Rb (-) too and had a shorter OS (42 vs 84 months, p=0.006). Response to initial treatment was ≥ VGPR 16.8 %, ≥ PR 52%, refractory 21.4 %. High proliferative group 1 or patients with high LDH values had higher initial response rates (82.1 vs 53.8 %, p: 0.016 and 67.6 % vs 36 % p= 0.018). The deepest response was observed with initial treatment among 47.3 % and was improved following ASCT (18.3%). ASCT also improved OS among all (58 vs 34 months, p=0.0) but more strongly among Rb and/or CycA (-) patients (Table). The response to initial treatment did not influence OS. However if response is not upgraded following subsequent treatments OS deteriorated (5 year OS: 34 vs 44 months p=0.022) (Figure). These suboptimal responding patients could not be predicted by ISS, age, B2MG, high/low proliferating group definition. Although LDH was high in 72.7 vs 54.5 % of poor-responders this comparison was not significant. Conclusion: While depth of response to therapy did not, improvement of response with subsequent therapy ie novel agents or ASCT prolongged OS (34 vs 44 months, p=0.022) and was associated with lower LDH values. Compared to gene expression profilling, tissue array using monoclonal antibodies is a method which can be more widely applicable and in our study was able to define new prognostic parameters. Overall ASCT extended OS. This effect was stronger among patients lacking Rb and/or Cyc A, This finding echoes the need for better treatment modalities for patients with poorer prognosis ie Rb and/or Cyc A positivity. Multivariate analysis results will be presented during the congress. Disclosures: No relevant conflicts of interest to declare.

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Tandem Autologous Stem Cell Transplantation for Multiple Myeloma Patients Based on Response to Their First Transplant—A Prospective Phase II Study

Clinical Medicine Insights Oncology ◽

10.4137/cmo.s16835 ◽

2014 ◽

Vol 8 ◽

pp. CMO.S16835 ◽

Cited By ~ 5

Author(s):

Michael Byrne ◽

Donya Salmasinia ◽

Helen Leather ◽

Christopher R. Cogle ◽

Amy Davis ◽

...

Keyword(s):

Multiple Myeloma ◽

Stem Cell ◽

Partial Response ◽

Stem Cell Transplantation ◽

Cell Transplantation ◽

Autologous Stem Cell Transplantation ◽

Phase Ii ◽

Plasma Cells ◽

Progression Free Survival ◽

Prospective Phase

In this prospective phase II clinical trial, multiple myeloma (MM) patients were randomized to receive a second (tandem) autologous stem cell transplantation (ASCT) based on whether they achieved a partial response or worse (≤PR) following initial ASCT (ASCT1). Patients who achieved a very good partial response or better (≥VGPR) had salvage ASCT at relapse. Seventy-five patients received conditioning therapy and ASCT1. A total of 44 patients (59%) achieved ≥VGPR, whereas 31 patients entered ≤PR and were offered tandem ASCT. In all, 20 patients agreed to tandem ASCT. Demographic and clinical characteristics were similar between the two cohorts except for median lactate dehydrogenase (LDH) ( P = 0.0141) and percentage of marrow plasma cells before ASCT1 ( P = 0.0047), both lower in the ≥VGPR group. Intent to treat analysis showed that patients who achieved ≥VGPR to ASCT1 had a trend toward improved progression-free survival (PFS) (37 vs. 26 months, P = 0.078) and superior overall survival (OS) (not reached vs. 50 months, P = 0.0073). Patients with ≤PR who declined tandem transplantation had shortened PFS (20 vs. 28 months, P = 0.05) but similar OS (53 vs. 57.5 months, P = 0.29) compared to those who received it. Thus, a favorable clinical response to ASCT1 identifies a low-risk group with superior long-term prognosis despite similar PFS.

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CD200 Is Preferentially Expressed in CD138 dim Multiple Myeloma Cells: Implications for a Myeloma Stem Cell Subpopulation with Potential Immune-Resistance.

Blood ◽

10.1182/blood.v114.22.4877.4877 ◽

2009 ◽

Vol 114 (22) ◽

pp. 4877-4877

Author(s):

Xiaochuan Chen ◽

Rhona Stein ◽

David M. Goldenberg

Keyword(s):

Stem Cells ◽

Multiple Myeloma ◽

Stem Cell ◽

Cancer Stem Cells ◽

Cell Line ◽

Cell Lines ◽

Cell Population ◽

Cell Subpopulation ◽

Myeloma Cells ◽

Expression Levels

Abstract Abstract 4877 Introduction The CD138negCD20+ cell population has been suggested as the putative multiple myeloma (MM) cancer stem cells, both in MM cell lines and in patient specimens. CD200 is an immunosuppressive membrane glycoprotein reported to be co-expressed with other stem-cell markers in prostate, breast, brain, and colon cancers. Also, CD200 is a negative prognostic factor for MM. It remains unknown whether CD200 is expressed in the CD138negCD20+ MM cell population, the putative MM cancer stem cells. Here we addressed this question by assessing CD200 expression in different subpopulations of MM cells according to their CD138 expression levels. Methods Two MM cell lines (RPMI8226 and NCI-H929) were co-stained with FITC-labeled anti-CD200, PE-labeled anti-CD20, and APC-labeled anti-CD138 antibodies for multicolor flow cytometry analysis. The cells were gated into 4 subpopulations (h1>h2>h3>h4 corresponding to CD138 expression levels: high>dim>low>negative). In each gated cell population, CD200 expression was assessed, and the CD200+ and CD200neg cell subpopulations were further gated for analysis of their CD20 expression levels. Results In the RPMI 8226 cell line, the distribution of gated h1, h2, h3, and h4 populations was 87.51%, 5.86%, 5.26%, and 1.29%, respectively. In the h2 (CD138dim) population, 22.88% of the cells were CD200+. In contrast, CD200 was expressed at much lower levels in the other three populations, ranging from 7.28% (h1), 6.65% (h3), to 0.48% (h4). In CD200+ cells from the gated h1, h2, h3, and h4 population, CD20+ cells were 19.50%, 23.03%, 27.67%, and 18.75%, respectively, while in the CD200neg cells, CD20+ cells were 20.79%, 22.50%, 25.08%, and 28.02%, respectively. In the NCI-H929 cell line, 18.59% of the cells in the h2 population were CD200+, whereas only 1.61%, 1.69%, and 0.47% of the cells in the h1, h3, and h4 populations were CD200+. In each population, there were more CD20+ cells in CD200+ cells than in CD200neg cells, which were 24.52% vs 0.04% (h1), 41.94% vs 11.34% (h2), 11.11% vs 3.06% (h3), and 50.00% vs 2.25% (h4), respectively. Conclusions These results demonstrate that the immunosuppressive molecule CD200 is preferentially expressed in a CD138dim subpopulation of multiple myeloma cells. Depending on cell line, the putative myeloma stem cell marker CD20 is either preferentially, or not preferentially, expressed in the CD200+ cells, suggesting that an immune-resistant subpopulation of MM stem cells might exist, which may have important implications for designing immunotherapeutic approaches to treat this disease. Disclosures Goldenberg: Immunomedics, Inc.: Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties.

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Plasma Cell CD20 Expression After Autologous Stem Cell Transplantation in Multiple Myeloma: Primary Aberrant Expression or Receptor up-Regulation

Blood ◽

10.1182/blood.v120.21.4538.4538 ◽

2012 ◽

Vol 120 (21) ◽

pp. 4538-4538 ◽

Cited By ~ 1

Author(s):

Yasser Khaled ◽

Melhem M. Solh ◽

David Ward ◽

Chung-Che Chang

Keyword(s):

Stem Cells ◽

Multiple Myeloma ◽

Flow Cytometry ◽

Stem Cell ◽

Stem Cell Transplantation ◽

Autologous Stem Cell Transplantation ◽

Plasma Cells ◽

Histochemical Staining ◽

Aberrant Expression ◽

Cd20 Expression

Abstract Abstract 4538 CD20 is a trans-membrane protein expressed on mature B cells through all stages of their differentiation. However, its expression is down regulated at the point of differentiation into plasma cells and expressed only in 16–22% of mature plasma cells. CD20 expression on plasma cells has been described with both favorable prognosis in association with translocation t(11;14) and unfavorable prognosis in association with plasma cell leukemia. The incidence of CD20 expression on plasma cells from patients with relapsed/refractory multiple myeloma is not well addressed in literature and CD20 testing is not routinely done in this patient population. Additionally, it is not known if CD20 represents a primary aberrant expression in newly diagnosed cases of multiple myeloma or represents a secondary genetic change at the time of relapse related to hypothesized myeloma stem cells. In order to study the above questions, we retrospectively reviewed the medical records of 92 patients with symptomatic MM who underwent ASCT between January 2008 and December 2011. As of July 2012, 38 patients have relapsed. Bone marrow biopsy and flow cytometry results were available for 33 patients at time of diagnosis and relapse.CD20 expression was positive on plasma cells by flow cytometry in 11 out of 33 patients (33%) at time of relapse. Interestingly, CD20 expression at diagnosis was negative in 4 out of those 11 patients. This up-regulation of CD 20 expression at time of relapse was associated with clonal evolution in two patients (deletion-17 and complex hypodiploid cytogenetics, respectively). Confirmatory immune-histochemical staining for CD20 was positive only in 2 of those 4 patients. Rituximab Outcomes: Three of the 11 patients with relapsed disease after autologous transplant were treated with Rituximab/Bortezomib. Rituximab was given weekly for 4 weeks at dose of 375 mg/m2 and Bortezomib was given at dose of 1.3 mg/m2on day 1, 8 &15 for 2–4 cycles. Time to progression for these three patients was 12, 5 and 3 months. These patients were CD20 positive both at time of diagnosis and relapse. An additional patient with primary refractory myeloma and negative CD20 expression at diagnosis was found to be CD20 positive after 5 unsuccessful lines of therapy suggesting CD20 up regulation. This patient achieved complete remission after treatment with weekly Rituximab/Bortezomib × 4 weeks followed by an autologous stem cell transplantation. Conclusion: CD20 expression on plasma cells at time of relapse/progression can occur in one third of patients with multiple myeloma and may provide an additional therapeutic target. The cause of discrepancy between CD20 expression by flow cytometry and immune-histochemical staining is unclear and suggests that the two methods may be complementary for a comprehensive evaluation of CD20 expression in multiple myeloma.CD20 up-regulation in patients with relapsed/refractory myeloma who were previously CD20 negative at diagnosis may represent a secondary genetic event heralding a more aggressive disease. Future prospective studies evaluating CD20 expression on plasma cells at different stages of disease progression may optimize the timing for anti-CD20 therapy while harnessing the concept of myeloma stem cells. Disclosures: Khaled: Celgene and Takeda Pharmacutical: Honoraria, Speakers Bureau. Solh:Celgene: Speakers Bureau.

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Combination High-Dose Cyclophosphamide and Bortezomib Is Safe and Effective for Stem Cell Harvesting in Chemotherapy Refractory Multiple Myeloma.

Blood ◽

10.1182/blood.v108.11.5459.5459 ◽

2006 ◽

Vol 108 (11) ◽

pp. 5459-5459 ◽

Cited By ~ 1

Author(s):

Miriam Katzman ◽

Theresa George ◽

Heather Doell ◽

Patricia Danyluk ◽

Sheri Briggs ◽

...

Keyword(s):

Stem Cells ◽

Multiple Myeloma ◽

Stem Cell ◽

Combination Chemotherapy ◽

Plasma Cells ◽

Stem Cell Mobilization ◽

High Dose ◽

Cell Harvesting ◽

Cell Mobilization ◽

Cell Harvest

Abstract Introduction: High-dose melphalan and autologous stem cell transplantation is the accepted therapy for most patients with multiple myeloma (MM) following steroid-based induction therapy. In a significant proportion of patients, however, the disease is refractory to standard induction. The use of dose-intense combination chemotherapy, such as D-PACE (dexamethasone, doxorubicin, cyclophosphamide, and cisplatin), may affect the ability to harvest an adequate number of hematopoeitic stem cells prior to transplantation. In addition, in those patients not achieving adequate cytoreduction despite combination chemotherapy, there is a theoretical risk of stem cell product contamination by malignant plasma cells. Bortezomib is a therapeutic agent with a novel mechanism of action, which in preliminary studies appears to be synergistic to alkylating agents and does not appear to affect stem cell yield. We piloted the addition of bortezomib to high-dose cyclophosphamide during stem cell harvesting in a series of patients failing to achieve an adequate response to D-PACE salvage. Patients and Methods: Between 2002 and 2006, fifteen MM patients refractory to standard dexamethasone-based induction therapy received ≥ 2 cycles of D-PACE prior to proceeding to autologous stem cell harvest and transplantation. 7/15 patients achieved adequate cytoreduction and proceeded to high-dose cyclophosphamide (3 g/m2) and filgrastim plus ancestim stimulation for stem cell mobilization. However, 8 patients in this cohort did not achieve adequate disease cytoreduction following D-PACE. Therefore, bortezomib was added to the mobilization regimen on days 1, 4, 8, and 11, in addition to high-dose cyclophosphamide given on day 11. Identical growth factor stimulation was provided. Response assessment included days to stem cell harvest, number of CD34 cells harvested, plasma cells in the product, disease response, and hematologic parameters. Results: Pre-treatment toxicities from D-PACE were similar in both groups. The addition of bortezomib to cyclophosphamide during stem cell mobilization did not lead to increased symptomatic toxicity. Grade 3/4 thrombocytopenia occurred in 5/8 patients receiving combination bortezomib/cyclophosphamide. No episodes of significant bleeding, peripheral neuropathy, or skin rash were noted. The average CD34-positive stem cell harvest in both groups was >5.0 × 106/kg. Time to stem cell harvesting was not significantly different between the groups. Flow cytometric examination of the harvested product from the bortezomib/cyclophosphamide group consistently demonstrated <2% cells bearing plasma cell markers. One patient in each group failed to mobilize sufficient stem cells. Bone marrow plasmacyte counts following combination therapy and harvesting decreased in all assessed patients. Time to engraftment was similar in both groups. Post-transplant disease control and survival remains to be assessed, as some patients in the combination group have only recently undergone transplantation. Conclusion: The addition of bortezomib to high-dose cyclophosphamide during stem cell mobilization does not increase toxicity or decrease stem cell harvest yield or quality, and appears to achieve adequate disease reduction in patients otherwise refractory to combination chemotherapy. This may result in improved relapse-free survival in patients with refractory MM.

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