Kumar, Shaji

Abstract BAFF is a member of the tumor necrosis factor (TNF) family and is critical for the maintenance and homeostasis of normal B-cell development. Importantly, BAFF promotes the generation of rapidly dividing immunoglobulin secreting plasmablasts from activated memory B cells by enhancing their survival. Given that MM is a cancer of plasma cells and that the signaling cascades implicated in receptor ligand interactions of BAFF are crucial in MM cell biology, we hypothesized that this cytokine may play a critical role in MM cell development, survival, and proliferation. We performed gene expression profiling (GEP) on CD 138+ plasma cells isolated from 90 MM patients (45 newly diagnosed and 45 relapsed) and 11 healthy controls using the Affymetrix U133A arrays. Our data demonstrates increased expression of transmembrane activator and calcium modulator and cyclophilin ligand interactor (TACI) and B-cell maturation antigen (BCMA), 2 receptors used by BAFF to exert its effects. Our data also shows an increased expression of a proliferation-inducing ligand (APRIL), another member of the TNF family with homology to BAFF. Expression levels of BAFF and BAFF-R could not be determined because of lack of these probe sets on the Affymetrix U133A arrays. GEP analysis shows increased BCMA expression (p<0.0001, student T test) on newly diagnosed and relapsed MM versus normal plasma cells. Flow cytometry on MM cell lines demonstrated a differential expression of the three receptors of BAFF, with BCMA present on most cell lines but BAFF-R expressed at low levels only on LR5 cells and DOX40 MM cells. In contrast, flow cytometry performed on MM patient cells demonstrated the presence of all 3 receptors on CD 138+ cells. ELISA assays performed on 30 MM sera demonstrated a mean BAFF level of 618 pg/ml (range: 128–2126pg/ml) versus 235pg/ml (range: 158–326pg/ml) in 7 normal donor sera. Fifty six% (17/30) of MM patients had BAFF levels in excess of the highest value noted in normals. To understand the role BAFF might play in the biology of MM, we studied the effects of recombinant BAFF (rh-BAFF) on MM cells directly and in the context of its bone marrow microenvironment. (abstract # 554746) rh-BAFF conferred a survival advantage to MM cells and protected them against dexamethasone-induced cytotoxicity. Importantly, anti-apoptotic proteins Bcl2 and Mcl-1 were upregulated, as were growth and survival signals belonging to the JAK/STAT and MAPKinase pathways. Conversely, neutralizing antibody to BAFF blocked, at least in part, blocked the upregulation of anti-apoptotic proteins with associated growth and survival, confirming that these effects were due to BAFF. Importantly, all of these signals were downregulated even in the presence of bone marrow stromal cells (BMSCs). These data therefore show a role for BAFF mediating MM cell survival and provide the framework for inhibiting BAFF, either alone or in combination with dexamethasone, to improve patient outcome in MM.

Abstract Background: Thalidomide is an active anti-myeloma agent with single agent activity in all stages of the disease. When combined with dexamethasone disease response is seen in nearly two-thirds of patients with newly diagnosed MM. Though initially evaluated for treatment because of its anti-angiogenic properties and the finding of increased bone marrow angiogenesis in MM, it has become clear that thalidomide exerts its anti-myeloma activity through several different mechanisms. While the mechanism of action of dexamethasone has been studied to a great extent in the setting of myeloma, the molecular basis for the activity of this combination is largely unknown. Methods: Myeloma cells from patients with newly diagnosed MM who were enrolled in a phase III trial (ECOG E1A00) comparing thalidomide and dexamethasone combination (T+D) with dexamethasone alone (D) were studied by gene expression profiling. Samples from diagnosis were compared to those at four months following therapy to study the effect of treatment. Four patients who achieved a partial response with T+D were studied and in addition compared to four patients achieving a partial response with D alone. Plasma cells from bone marrow aspirates were separated by magnetic bead selection of CD138 positive cells and studied using Affymetrix HG-U133A chips using standard methodology. The arrays were analyzed using Genespring 7.2 software following GCRMA normalization and genes with differential expression between the two datasets were examined. Differentially expressed genes were further analyzed using Ingenuity Pathways Analysis program Results: 549 genes were two fold or more differentially expressed between the pretreatment and post treatment samples in the T+D group, of which 275 genes were mapped to different networks using the Ingenuity program. Examination of the canonical pathways demonstrated several pathways that were altered as a result of the therapy. The most significant pathways included those related to immune function including antigen presentation (multiple HLA class II antigens), and PRG2 (NK cell activator). Several mediators of B cell signaling including CD45, PKC (α ,β), SHP2, and Erk1/2 were up regulated following treatment. Increase in the expression of several adhesion molecules including β integrins, fibronectin, VCAM1, L selectin, and LFA3 were noted. Up regulation of IL-6 signaling pathway including gp130, JAK2 and IL8 were noted following therapy. Striking increase in the gene expression for CXCR4 and its ligand SDF-1α was noted as well. 129 genes were differentially regulated by dexamethasone alone, of which 67 were mapped to different networks. The pathways influenced by the dexamethasone alone differed significantly from that of the combination. Conclusion: This exploratory analysis offers an interesting insight into the potential mechanisms of action of the T+D combination in MM. The up regulation of immune response related genes are in accordance with some of the mechanisms described for thalidomide. Also, the differences observed between the patients receiving T+D vs. D allows for assessment of the effects of thalidomide. These findings need confirmation in a larger study.

Abstract Background: The measurement of monoclonal (M) protein in the serum and urine is critical for response assessment and disease evaluation in patients with multiple myeloma (MM). The serum free light chain (FLC) assay offers a new and sensitive method of assessing response to therapy. An important question that has not been adequately addressed is the correlation between 24 hour urine M protein levels and serum FLC measurements, and the extent to which response to therapy estimated using the FLC assay correlates with that assessed using the 24 hour urine M protein level. Methods: A total of 2194 sets of data, with simultaneous UPEP and serum FLC measurement, were studied. These included 752 unique patients, with individual patients having 1–23 paired assessments over time. FLC estimation was carried out using the serum FLC assay (Freelite; The Binding Site Limited, UK) performed on a Dade-Behring Nephelometer. Based on the established reference range, kappa/lambda FLC ratio <0.26 or >1.65 were defined as abnormal indicating the presence of monoclonal lambda and kappa FLC, respectively. The monoclonal light chain isotype was considered the involved FLC isotype, and the opposite light chain type as the uninvolved FLC type. The Urine M protein by UPEP was compared to the serum levels of the involved light chain using Spearman Rank Correlation. For comparisons in individual patients over time, those with at least 10 measurements each were studied. Results: The median involved FLC level in patients with an undetectable urine M protein was 2.3 mg/dl compared to 32.2 mg/dL among those with a detectable urine M protein (P<0.001). Among the 1676 points with an abnormal FLC ratio, only 75% had an M protein detected in the urine, P < 0.001. Conversely, among patients with a positive urine M-protein, 91% had an abnormal FLC ratio. When all the 2194 data points were considered together, there was a significant correlation between the urine M protein level and the FLC levels (FLC level calculated as the difference between involved and uninvolved levels), rho=0.763, P < 0.001. The correlation did not change when patients with a serum creatinine of over 2.5 were excluded. The correlation between FLC levels and urinary M protein can be affected by several factors such as renal function that will differ across patients. Therefore, we examined whether the correlation between the two variables is stronger when the variations introduced by inter-patient differences in the relationship between the two variables are eliminated. In order to do this, we studied individual patients on whom multiple data points over time were available. One patient who had the maximum number of paired assessments (23 pairs) of serum FLC level and urinary M protein; the correlation between the two variables over time was highly significant, rho 0.981, p<0.001. Similarly 26 other patients who had measurable urine M protein levels in whom 10 nor more paired observations over time were available, also showed significant correlations, rho, range 0.726–0.981, p<0.01. Conclusion: There is a significant correlation between urine M-protein and serum free light chain across patients and the correlation is stronger in individual patients in whom the effect of inter-patient variation in other confounding factors can be eliminated. These data if confirmed in a clinical trial setting would support the use of serum FLC levels instead of urinary M protein measurements to assess response to therapy.

Abstract INTRODUCTION Stem cell transplant has been increasingly used in the initial therapy of newly diagnosed systemic AL. Introduction of the free light chain assay has made it easier to quantify responses in patients with AL. It is unclear whether the goal of therapy should be a hematologic response or, as in multiple myeloma, a complete response. This paper addresses the impact of the degree of response on outcome. PATIENTS AND METHODS 282 consecutively transplanted patients are included in this analysis. None of the patients were excluded. There were 169 men (59%). 28% of the cohort have died. 69% had renal involvement, 51% cardiac involvement, 11% peripheral nerve involvement, 16% hepatic involvement. The median percentage of plasma cells at the time of transplant was 7. Echocardiographic analysis revealed a median septal thickness of 12 and a median ejection fraction of 65%. Patients ranged in age from 31 to 71 with a median of 57 years and were transplanted at a median of 4.2 months following histologic diagnosis of amyloidosis. 27% of patients received reduced intensity conditioning usually due to moderate cardiomyopathy or renal insufficiency. 201 patients achieved a hematologic response and 93 of these achieved a complete response. The criteria for response were reported in accord with the consensus definition for response established at The Xth International Symposium on Amyloid and Amyloidosis. A complete response required immunofixation negativity of serum and urine with a normal free light chain ratio. A hematologic objective response required a 50% reduction of serum and urine monoclonal protein with a 50% reduction in the free light chain value. Figure 1 shows the Kaplan Meier curves demonstrating the survival of all patients based on whether they achieved a complete response, partial response, or failed to achieve response. There were 93 CR, 108 PR, and 81 nonresponders. The differences in all three curves are significant at P<.001. Figure 2 demonstrates the same cohort of patients using a six month landmark analysis to exclude the effect of treatment related mortality on outcome. There were 86 CR, 91 PR, and 36 NR for a total of 213 patients. There was a difference in response rate based on conditioning intensity (p<0.01) and age (p=0.046). The median survival was only reached in the NR at 40.1 months and, in the landmark analysis the differences between all three survival curves were statistically significant. CONCLUSION Patients who achieve a hematologic complete response following sct for AL do better than other patients. Patients who achieve an objective response have a superior outcome than patients who fail to achieve a hematologic response, in a landmark analysis at six months. It is unclear if consolidation chemotherapy should be offered to partial responders in an attempt to convert them into CR’s. Figure Figure Figure Figure

Abstract Background: Although microvessel density increases significantly from monoclonal gammopathy of undetermined significance (MGUS) to multiple myeloma (MM), we have been unable to demonstrate an increase in expression of VEGF by isolated plasma cells between MGUS and MM (add your Blood ref). When MM cell lines are grown in co-culture with marrow derived stromal cells there is upregulation of VEGF and IL6. This effect is thought to be mediated primarily by the stromal cells, although plasma cells can also secrete these cytokines to form an autocrine pathway. We examined if there is differential expression of VEGF when plasma cells derived from various stages of plasma cell disorders (MGUS, smoldering multiple myeloma (SMM), and MM) are studied in co-culture with stromal cells. Methods: Plasma cells were obtained from fresh marrow aspirates from patients with MGUS, SMM or MM. Normal control plasma cells were obtained at the time of orthopedic surgeries. Plasma cells were isolated from whole marrow using a magnetic bead separation technique with antibodies against CD138. The marrow stromal cells were obtained from an established stromal cell line from a patient with MGUS. Plasma cells were then grown in co-culture with stromal cells, with control wells having either only stromal cells or only plasma cells, with RPMI medium containing 10% fetal bovine serum. The supernatant was removed after 48 hour cultures, spun down to remove cells and frozen at −70C. VEGF and IL6 levels were determined using ELISA kits (R&D, Minneapolis, MN). Results: A total of 71 samples were studied including normals (10), MGUS (8), SMM (15) and MM (38). The median VEGF levels with plasma cells alone were 30.2 pg/mL (range; 16–132), with stromal cells alone was 737 pg/ml (316–1826) and with the co-culture was 1057 pg/mL (306–4267), representing a median increase of 41% (−48% to 331%) with co-culture. There was no significant difference between the disease groups in terms of the baseline VEGF secretion by plasma cells or the increase in VEGF with coculture (Figure). The median IL-6 levels with plasma cells alone were 22.3 pg/mL (range; 4–276), with stromal cells alone was 2457 pg/ml (906–5359) and with the co-culture was 5982 pg/mL (301–129,000), representing a median increase of 99% (−67% to 3362%) with co-culture. There was no significant difference between the disease groups in terms of the baseline VEGF secretion by plasma cells or the increase in VEGF with coculture (Figure). Conclusions: In this study we clearly demonstrate the upregulation of VEGF and IL-6 when primary cells are grown in contact with marrow derived stromal cells validating previous observations with cell lines, and once again highlighting the importance of these cytokines and the marrow microenvironment. However, since there is no significant difference between the various groups studied, higher absolute levels of VEGF and IL-6 in MM may be solely related to the effect of an increased tumor burden on marrow stromal cells. However, this does not exclude differences between disease stages in terms of the marrow stromal cells, which we are currently studying. Figure Figure

Abstract AMD3100, a CXCR4 receptor antagonist, has been studied as a stem cell mobilization agent for the purpose of autologous stem cell transplantation (ASCT) in hematologic malignancies. Lymphocyte subset analysis of peripheral blood in patients treated with AMD3100 has been studied in healthy volunteers. To date, no reports exist describing the lymphocyte subsets of the autograft in patients undergoing AMD3100 stem cell mobilization for the purposes of ASCT in non-Hodgkin lymphoma (NHL). Considering our prior work demonstrating the significant impact of autograft lymphocyte content on clinical outcomes of patients undergoing ASCT for NHL we set out to profile autograft lymphocyte subsets of patients undergoing mobilization with AMD3100. Using flow cytometry, we analyzed aliquots of apheresis products in 7 patients with NHL undergoing AHSCT who received AMD3100 in addition to G-CSF as a part of their mobilization regimen. These results were compared to 29 patients with NHL who had undergone stem cell mobilization with G-CSF alone. There were no significant differences between these two groups of patients in terms of sex, age, performance status, histology, LDH, and number of pretransplant chemotherapeutic regimens. CD34+ cells collected at apheresis did not differ significantly between the groups. However, compared with G-CSF alone, patients that received AMD3100 had an approximate 5-fold increase in CD4+ cells (0.62 x 109 cells/kg vs. 0.12 x 109 cells/kg, p = 0.0004), a 3.5-fold increase in the absolute number of autograft CD3+ cells (1.21 x 109 cells/kg vs. 0.33 x 109 cells/kg, p = 0.0017), and a 2.5-fold increase in CD8+ cells (0.48 x 109 cells/kg vs 0.19 x 109 cells/kg, p = 0.215). A significant increase was also noted in CD4+25+ cell compartment (0.17 x 109 cells/kg vs. 0.006 x 109 cells/kg, p = 0.0001). No significant difference was noted in the absolute number of autograft CD16+56+ NK cells. Finally, an increase in the autograft total absolute lymphocyte count (41.6 x 109 cells/kg vs. 2.88 x 109 cells/kg, p < 0.001) as well as peripheral blood absolute lymphocyte count at day 15 after AHSCT was observed in those patients who had received AMD3100 (0.79 x 109 cells/kg vs. 0.58 x 109 cells/kg, p = 0.04). The increased lymphocyte content of the autograft (total and subset) would suggest the potential of positive impact on clinical outcomes in patients mobilized with AMD3100. Indeed, none of the patients who received AMD3100 had relapsed disease at one year post-transplant (although two of these patients are currently 9 months and 11 months post-transplant respectively), whereas 10 of the 29 control patients had relapsed disease at one year. Further studies are necessary to confirm these observations and ascertain their clinical significance.

Abstract Background: While the therapeutic armamentarium for plasma cell disorders have expanded recently with introduction of thalidomide, lenalidomide and bortezomib, these diseases are still incurable and more agents are needed. We have previously demonstrated expression of CD 52 on plasma cells in MM, MGUS and AL amyloidosis. Based on this data we conducted a Phase II Study of Campath (Alemtuzumab; Monoclonal Anti-CD52 Antibody) in Primary Systemic Amyloidosis and Relapsed or Refractory Multiple Myeloma. Methods: The study was an IRB approved, Phase II protocol, with a two stage design and interim analysis at 14 patients, to assess the efficacy and toxicity of Alemtuzumab. The regimen involved a dose escalation during week one (Day I 3 mg SQ; Day II 10 mg SQ; Day III 30 mg SQ; then 30 mg SQ three times a week for a planned total of 17 additional weeks). All patients received concurrent Co-Trimoxazole, Fluconazole and Valacyclovir prophylaxis. The planned accrual was 32 patients. Results: A total of 14 patients were accrued, 8 patients with MM and 6 patients with AL. There were 8 females and 6 males in the study. The median age was 62 years (range: 50–78) years. The patients were heavily pretreated with the median number of treatments being 4. There were 5 grade 3–4 toxicities (CMV viremia (2 pts), skin rash (2 pts), and febrile neutropenia (1 pt)). Seven patients had evidence of disease progression and were removed from study. One patient completed the treatments with a mixed response. One patient had a sudden death while on study. The median duration of therapy was 6 weeks (range 3 weeks to 17 weeks). The accrual was stopped after 14 patients when the interim analysis showed a lack of anti-tumor efficacy and significant toxicity. Conclusion: This phase II study in patients with relapsed / refractory myeloma or amyloidosis demonstrated no evidence of clinical activity with use of Campath. In addition it was also associated with significant toxicity in this population. We do not recommend use of campath as a primary treatment modality in these patients. The lack of efficacy despite demonstrated expression of CD52 on clonal plasma cells once again highlights the need for combining treatments with multiple mechanisms in order to improve the response and outcome in these patients. Whether it can synergize with other therapies at lower doses without significant toxicity remains unknown.

Abstract Background: The p53 tumor suppressor gene has a common sequence polymorphism that results in either proline or arginine at amino-acid position 72. The Pro72 and Arg72 variants have been reported to differ in its functional activity. The Arg72 variant induces apoptosis more efficiently than Pro72 variant by its greater ability to localize to the mitochondria and increase the release of cytochrome c into the cytoplasm. In addition, recent studies have demonstrated that Arg72 variant was a better suppressor of cellular transformation, an activity believed to rely on the pro-apoptotic function of p53. Moreover, the Pro72 variant has been associated with a higher incidence of tumors. Aim: To evaluate the effect of the polymorphic variants of codon 72 and clinical outcome in patients with plasma cell malignancies. Patients and Methods: We analyzed 79 patients with plasma cell malignancies seen at Mayo Clinic between 2000 and 2003. Genomic DNA was extracted from CD138+ sorted plasma cell from bone marrow aspirates. PCR amplification of codon 72 and posterior sequencing was used for the analysis. Results: A total of 79 patients were analyzed. Thirty-four patients (34%) were heterozygous for p53, 57 (59%) homozygous for Arginine and 6 (6%) homozygous for Proline. The distribution among disorders was as follow, 52 patients had MM, 14 patients with SMM and 13 with MGUS. Among patient with MM 25% were Pro/Arg heterozygous, 71 % were Arg/Arg homozygous and 3.8% Pro/Pro homozygous. Survival data among MM patients and genotype were analyzed to Kaplan- Meier method. No significant differences were found among patients who carried homozygous (72R) or heterozygous genotype and overall survival. We exclude the analysis in MGUS and SMM for a low number of patients available. Conclusions: These findings indicate that codon 72 arginine p53 may not be associated with a prolonged survival in patients with Multiple Myeloma, but further study is needed to assess whether this polymorphism is associated with progression of MGUS to MM, age of onset, clinical manifestations, response to treatment etc.

Abstract Background: We reported a high response rate with the combination of lenalidomide plus dexamethasone (Rev/Dex) as initial therapy for newly diagnosed multiple myeloma (Blood2005;106:4050–3). We now present new data on time to progression (TTP), progression free survival (PFS), and overall survival (OS) from this phase II trial, and also include updated response data. Patients and Methods: 34 patients (23 male and 11 female) were enrolled. Lenalidomide was given orally 25 mg daily on days 1–21 of a 28-day cycle. Dexamethasone was given orally at a dose of 40 mg daily on days 1–4, 9–12, 17–20 of each cycle. Patients were allowed to go off treatment after 4 cycles of therapy to pursue autologous stem cell transplantation (SCT), but treatment beyond four cycles was permitted at the physician’s discretion. For patients continuing therapy beyond 4 months, the dose of dexamethasone was reduced to 40 mg on days 1–4 of each cycle. Response was assessed by modified EBMT/International Myeloma Working Group Uniform Response criteria. All patients received aspirin (81 mg or 325 mg daily) as prophylaxis against DVT. Results: The median age was 64 years (range, 32–78). All patients were evaluable for response and toxicity. Median follow up is 21 months. Thirteen patients proceeded to SCT following initial therapy with Rev/Dex and were censored at that time point for purposes of calculation of response, TTP and PFS. Patients who discontinued therapy to proceed to SCT received a median of 4 cycles of therapy (range, 4–13), while those staying on Rev/Dex (n=21) received a median of 19 cycles of therapy (range, 2–30). Thirty-one of 34 patients (91%) achieved an objective response to therapy; including 6 patients (18%) achieving a complete response (CR) and 13 patients (38%) achieving very good partial response for a CR+VGPR rate of 56%. The CR+VGPR rate among the 21 patients staying on Rev/Dex as primary therapy without SCT was 67% (CR 24%, VGPR 43%). Median TTP, PFS, and OS have not been reached (Figure). By Kaplan-Meier method, the estimated 2 year progression rate was 18%. The 2-year PFS rate and OS rate were 74% and 91%, respectively. Fifty-five percent of patients experienced grade 3 or higher non-hematologic toxicity at any point during therapy, most commonly fatigue (21%), neutropenia (21%), anxiety (6%), pneumonitis (6%), muscle weakness (6%), and rash (6%). Two patients died on study: one attributed to infection unrelated to therapy, the patient had stopped all therapy for over a month before the fatal infection occurred; the other death was due to infection felt possibly related to therapy. One patient developed a pulmonary embolism (grade 4 toxicity), but recovered with therapy; no other patient developed deep vein thrombosis or pulmonary embolism. Conclusion: Rev/Dex is highly active and well tolerated in the treatment of newly diagnosed multiple myeloma with a high CR+VGPR rate of 56% for the trial, and 67% among the subset of patients receiving this regimen as primary therapy. Responses are durable with a low progression rate at 2 years.

Abstract Introduction: Stem cell transplant is an increasingly widely applied technique for managing amyloidosis. As in multiple myeloma, the treatment would not be expected to be curative and patients would be expected to relapse in most instances. In addition, approximately one-third of patients fail to respond to initial therapy. The role of second transplantation in treatment failures or patients who relapse is reviewed. Patients: Of 242 patients undergoing high dose conditioning and stem cell transplantation for amyloidosis (AL) at the Mayo Clinic, 6 subsequently underwent a second transplant. Results: Patient 1, who had single organ renal amyloid nephrotic syndrome responded and relapsed at 73 months, received a second stem cell transplant achieving a hematologic complete response with normalization of a markedly elevated pre transplant free light chain (59 to 1.9 mg/dL) and is alive at 12 months. Patient 2 relapsed 42 months after transplant for single organ renal amyloidosis; the second stem cell transplant, has normalized his free light chain ratio reduced his urinary protein loss from 5450 to 1482 mg/day and he is alive 21 months following his second transplant (63 months overall). Patient 3 relapsed 34 months after a response of renal and cardiac amyloidosis. After transplant two, he failed to achieve a 50% reduction in his free light chain, began hemodialysis 7 months post transplant and died one year post transplant. Patient 4 with single organ cardiac involvement relapsed 30 months following his first transplant and died on day +5 of his second transplant of an acute pulmonary embolus. Patient 5 was a response failure after his first transplant, had a second transplant 35 months later, having failed Dexamethasone followed by Melphalan/Dexamethasone therapy, and died 3 months later of progressive disease. Patient 6 had single organ vascular involvement manifest by calf and thigh claudication and failed to respond with his first transplant with a persistently elevated free light chain. The second transplant was performed six months after the first without further free light chain reduction and persistent claudication at 11 months. Conclusion: Patients who failed to achieve a hematologic response after a first transplant appear not to benefit from a second course of high dose therapy. Among 4 patients who were previously responsive and relapsed, one achieved a hematologic complete response, one achieved a hematologic partial response, and two died. The two patients achieving a second hematologic response had the longest response duration (73 and 42 months) following their first transplant, and the second response presumably reflects favorable (indolent; non proliferative) biology of the underlying plasma cell dyscrasia. High dose therapy and stem cell transplant may be an effective salvage regimen for patients who responded to a first transplant and whose response lasted greater than 36 months.