Abstract Cancer/testis antigens (CTAs), comprising the MAGE, CTAG, SSX and GAGE families, are expressed in different tumor types and restricted in normal tissues to germ cells of the testis. Many CTAs contain epitopes recognized by cytotoxic T cells and are potential targets for active immunotherapy. In MM, different CTAs have been shown to be expressed in cell lines and patient cells, and are associated with more proliferative and advance stage tumors. However, correlation with survival has never been reported. We undertook a global survey of CTA expression using gene expression profiling of CD138-enriched plasma-cell (PC) RNA in 15 normal, 101 MM, 22 MGUS and 24 SMM samples using the Affymetrix U133A chip (Affymetrix, Santa Clara, CA). 22 CTA genes were differentially expressed across the samples and unsupervised clustering using these genes clearly identifies a group of patients with high CTA expression. Most CTAs have significantly higher expression in MM as compared to SMM and especially MGUS, which has similar expression as normal PCs. As these antigens are not expressed in normal PCs, an upper limit of normal expression (ULN) was derived based on mean+3SD of expression in normal PCs for each CTA. A strict cut-off of normalized expression value greater than 2xULN was used to assign positive expression for each CTA genes. Using this method, the most commonly expressed CTAs are MAGE-A3 (73% of MM), MAGE-C1 (45%), MAGE-A6 (35%), SSX-1 (21%), GAGE-5 (18%) and NY-ESO-1 (14%). We then assigned patients with expression of more than 2 of these genes as having a CTA signature and correlated with clinical parameters. 45 patents (41 MM and 4 SMM) have the CTA signature. These patients have a significantly higher PCLI (median 0.2 v 0.7, p=0.0003). In fact, there is a significant correlation between the number of positive CTAs and PCLI (r=0.59, p<0.0001). Interestingly, there is no association between patients with a CTA signature and any of the recurrent genetic abnormalities (IgH translocations, chromosome 13 deletion and TC classes), yet MM patients with this signature have a significantly shorter survival (median 459 days vs not reached, log-rank p=0.017). A prognostic hierarchy exists amongst these CTAs. Only MAGE-A6, MAGE-A12, SSX-1 and SSX-5 expression has significant prognostic implications with the SSX family conferring the worse prognosis. Using a restricted panel of 3 CTAs (SSX-1, -5 and MAGE-A12), about 28% of MM patients expressing one or more of these genes can be identified with poor survival (median less than 1 year) that is independent of genetic subtypes. The genes differentially expressed between patients with and without the CTA signature are mainly involved in cell cycle regulation. Since the expression of this large set of CTAs appears to be under epigenetic control, we speculate that the same epigenetic processes that lead to dysregulation of the cell cycle also cause ectopic expression of CTA genes. As CTA expression is rare in MGUS, epigenetic processes may therefore also mediate transformation from MGUS to MM. These poor prognosis patients represent good candidates for novel therapies targeting the epigenetic machinery.
Gene Expression Profiling Identifies 4 Sub-Classes with Distinct Clinical Associations in Hyperdiploid Myeloma.
Abstract Hyperdiploid myeloma (H-MM) affects about 50% of MM. These patients exhibit significant karyotypic and clinical heterogeneity. In this study, we addressed possible biological heterogeneity within H-MM by gene expression profiling of CD138-enriched plasma-cell RNA from 53 H-MM patients using the Affymetrix U133A chip (Affymetrix, Santa Clara, CA). Analysis was performed using GeneSpring 7 (Agilent Technologies, Palo Alto, CA). Unsupervised hierarchical clustering performed using the top 100 most variable genes (generated by ANOVA) identifies 4 putative patient clusters. These clusters were reproduced using principal component analysis. Cluster 1 was characterized by high expression of a large group of cancer testis antigens and mitosis/proliferation related genes (TOP2A, NEK, ASPM, CENPA). Cluster 2 was characterized by high expression of genes involved in IL-6 and HGF signaling (MET, IL6R, SOCS3, SPINT1). Cluster 3 was characterized by high expression of genes involved in TNF/NF-KB signaling and anti-apoptosis (NFKB2, CFLAR, BIRC3, TNFAIP3, RRAS2). Cluster 4 was characterized by high expression of genes involve in angiogenesis (protocadherin, EDNRB). Unsupervised hierarchical clustering using the same set of genes in an independent cohort of H-MM patients (n=60) yielded the same 4 patient clusters over-expressing similar genes. The gene expression profile of these clusters were not driven by differences in trisomies (only about 25% of genes that define the clusters were located on the commonly trisomic chromosomes). Association between the 4 clusters and clinical parameters such as survival, chromosome 13 deletion (Δ13), presence of IgH translocations, PCLI, RAS mutation and p16 methylation was analyzed. Cluster 1 tumors were more proliferative (median PCLI 3.8, p<0.05). Cluster 2 was associated with presence of Δ13 (56%, p<0.05) although none of the genes that defined this cluster falls on chromosome 13. p16 methylation was also less common in cluster 2 (13%, p=0.06). Cluster 3 was associated with low PCLI (median 0.2, P<0.05). Most of the patients with p16 methylation also belonged to this cluster (67%, p=0.06). There was a complete absence of Δ13 in Cluster 4. Patients in the 4 clusters also had significantly different survival (log-rank p=0.002.). The difference in survival was independent of Δ13 since Δ13 has no impact on survival in this patient cohort. The molecular profiles of these subclasses may explain some of these associations. CTA expression is associated with proliferative tumors with poor prognosis. IL-6 is an important survival factor and HGF signaling has been associated with poor survival in MM which may explain the relative poor prognosis of this group. Cluster 3 may have better survival as it is associated with an anti-apoptotic signature rather than proliferative signature. In summary, gene expression profiling identified 4 sub-classes within H-MM (validated on an independent dataset and using different clustering techniques) with distinct clinical and biological associations. The gene signature associated with each sub-classes provide a molecular basis for the different clinical behaviour and further insights into deregulated pathways in H-MM.
Didox Induced Apoptosis Occurs by Inhibiting DNA Synthesis and Repair Via Down-Regulation of Ribonucleotide Reductase M1 in Multiple Myeloma (MM).
Abstract Ribonucleotide reductase is the rate-limiting enzyme of deoxynucleoside triphosphate synthesis and is therefore an excellent target for cancer chemotherapy. Inhibition of ribonucleotide reductase results in inhibition of DNA synthesis and has anti-neoplastic effects. Several ribonucleotide reductase inhibitors (RRIs) are already in clinical practice, including Hydroxyurea and Gemcitabine. Here we examine the anti-MM activity of a novel RRI, Didox. Our data shows that Didox has potent cytotoxicity against MM cells in 48-hour cultures. Apoptosis induced in MM cell lines by Didox (200mmol/l), evidenced by increased sub-G1 cell fraction, is caspase dependent, confirmed by blocking experiments with Z-VAD-FMK. Unlike other RRIs which mainly target the pyrimidine metabolism pathway (hydroxyurea and gemcitabine), didox targets both the purine and pyrimidine metabolism pathways in MM, as demonstrated by transcriptional profiling using the Affymetrix U133A 2.0 gene chip. Specifically, our data shows a ≥ 2 fold downregulation of genes in these pathways as early as 12 hours after exposure to Didox. Importantly, ribonucleotide reductase (RR) M1 component transcript was downregulated, associated with downregulation of this enzyme by Western Blot analysis, and inhibition of DNA synthesis. Furthermore, genes involved in DNA repair mechanisms were also downregulated after exposure to Didox, demonstrated by heirachial clustering of gene chip data and further validation by western blotting. Specifically RAD 51 homologue, which is involved in nucleotide excision repair and recombination repair, was downregulated in MM cells both transcriptionally as well as at the protein level. This was accompanied by downregulation of the BCL family protein including Bcl-2, Bclxl, and XIAP both at the transcriptional and post transcriptional levels. Since Didox acts on MM cells by inhibiting DNA synthesis and repair, combination studies with melphalan, an alkylating agent commonly used in MM, were next performed. Our data shows a strong in vitro synergism, with combination indices of <0.7 by the Chou Talahay method. When combined with DNA damaging agents like doxorubicin, additive cytotoxicity was noted. These studies therefore provide the preclinical rationale for evaluation of Didox, alone and in combination with alkylating agents and anthracyclines, to improve patient outcome in MM.
Response to Rituximab in Type II Cryoglobulinemia.
Abstract Introduction: Type II Cryoglobulinemia (CG) is a heterogeneous disorder caused by a monoclonal antibody with activity against polyclonal antibodies. No standard therapy exists, but two small recent studies have suggested a role for rituximab. We describe our experience with 8 patients with Type II CG who were treated with Rituximab. Methods: The data was obtained from a prospectively held dysproteinemia database and by directly reviewing patient records. Follow up time ranged from 7 to 63 months. All patients had symptomatic disease with a monoclonal IgMκ Type II cryoglobulin and had undergone previous therapy for CG. Results: Six of the patients had an underlying lymphoproliferative disorder (LPD), with two of these also having hepatitis C, and two others having Sjogren syndrome. One patient had essential CG and one had Gaucher disease with hyperslpenism. A total of 14 courses of treatment were given, as some patients received rituximab on multiple occasions. Five patients received rituximab either alone or with low dose prednisone initially, with one of these later receiving rituximab with cyclophosphamide and prednisone. One patient was treated initially with R-CHOP and subsequently with rituximab alone, one received rituximab with chlorambucil and prednisone, and one received rituximab with plasma exchange and prednisone. The patients were treated for a variety of indications including cutaneous ulcers, progressive renal failure, the underlying LPD, and biochemical recurrence of disease. Six of 8 patients experienced an improvement in their clinical status. Of the two patients who did not improve, one had end stage liver disease at the time of rituximab and died 2 years later, and the other had a progressive chronic B cell lymphoproliferative disorder leading to sepsis and death. Though lab values were not available on one patient, 4 of the remaining 7 demonstrated improvement in cryocrit, total complement, C4, and/or rheumatoid factor. The lab values correlated well with the clinical response, as treatment failures showed no laboratory changes. Cutaneous manifestations including rash and ulceration were the most responsive to treatment. Renal disease generally failed to improve, and the response of LPDs were variable. No adverse events associated with rituximab were reported, including no flares of hepatitis. Conclusion: The high prevalence of LPD associated cryoglobulinemia distinguishes our results from the previous studies which had focused on patients with hepatitis C. Given the lack of any cryoglobulinemia specific therapy, and the potential toxicity of other immunosuppressive or anti viral therapies, rituximab remains a reasonable, safe, and effective therapeutic choice. Treatment Regimens and Responses Patient Comorbid Condition Symptom Regimen Response: Clinical/Lab LPD= lymphoproliferative disorder; HCV= Hepatitis C Virus; ESRD= End Stage Renal Disease; Y=Yes; N= No; U= Unknown 1 B Cell LPD Leg Ulcers Rituxan Prednisone Y/Y 1 Leg Ulcers Rituxan Prednisone Y/U 2 None Rash, Paresthesia Rituxan Prednisone Y/Y 2 Pupura Rituxan Prednisone Y/Y 2 Pupura Rituxan Prednisone Y/Y 2 Pupura Rituxan Prednisone Cytoxan Y/Y 3 HCV, low grade NHL Renal Failure Rituxan N/N 4 MALToma, Sjogren Disease MALToma R-CHOP Y/U 4 MALToma Rituxan N/U 5 Gaucher with hypersplenia Renal Failure Rituxan Y/Y 6 Lymphoplasmacytic Lymphoma, HCV, ESRD Lymphoma Rituxan Y/U 6 Lymphoma Rituxan N/N 7 B Cell LPD Renal Failure, ulcers, rash, LPD Rituxan chlorambucil prednisone N/N 8 MALToma Sjogren Disease Rash, Fatigue Rituxan Prednisone Y/Y
Lenalidomide Has Activity in a Phase II Trial in Patients with Primary Systemic Amyloidosis.
Abstract Background: Primary systemic amyloidosis (AL) is an incurable plasma cell disorder. For selected patients high dose chemotherapy with peripheral blood stem cell support is effective, but even in those patients, only 50% derive organ responses. Other patients are too sick to undergo that therapy. Thalidomide has limited utility in this disease, largely because of its toxicity profile in patients with AL. Lenalidomide, Celgene’s lead clinical compound in a new group of drugs called IMiDs®, is highly active in patients with multiple myeloma, especially in conjunction with dexamethasone. We sought to determine the toxicity and efficacy of lenalidomide in patients with AL. Methods: Patients with symptomatic AL who had a measurable plasma cell disorder (defined as serum M-spike ≥ g/dL urine M-spike >200 mg/24 hours; or involved immunoglobulin free light chain (FLC) ≥10 mg/dL and an abnormal FLC ratio) and adequate organ reserve defined as a creatinine ≤3 mg/dL, absolute neutrophil count ≥1000, platelet count ≥75000, and a hemoglobin ≥8 g/dL were eligible. Patients were started on lenalidomide 25 mg/day for 21 days followed by a 7 day rest (1 cycle). Dose modifications were made based on toxicity. If there was evidence of progression before 3 months or no evidence of hematologic response after 3 cycles, dexamethasone 40 mg p.o. days 1–4 and 15–18 was added. Results: Twenty-three patients were enrolled between 10/28/04 and 4/7/05; 14 were previously treated. Patient characteristics are shown in Table. Organ involvement was as follows: cardiac (61%); renal (70%), hepatic (22%); nerve (13%). Nine patients withdrew from study before completing 3 months of therapy. The reasons were: cancel (1); death (4); adverse events (2); and progression (2). At the time of our preliminary analysis in July 2005, an additional 3 patients have withdrawn from study: death (1) and patient refusal (2). Of the 5 patients who died, 4 had severe cardiac involvement and at least 3 organs involved by amyloid. The median follow-up for the eleven patients remaining on study is 6.2 months. Of the 12 patients who have crossed the 3 month treatment landmark, there are 7 hematologic partial responses (4 confirmed and 3 unconfirmed), two renal responses and one liver response. Of these same 12 patients, all but one has had dexamethasone added to their treatment program. The most common grade 3–4 adverse advents at least possibly attributable to lenalidomide were neutropenia (43%), thrombocytopenia (26%), rash (17%), dyspnea (9%), fatigue (9%), and edema (4%). Expansion of the trial is planned to accrue an additional 10 evaluable patients. Conclusions: Early results suggest that lenalidomide ± dexamethasone has activity in patients with primary systemic amyloidosis. Supported in part by the Caliguiri Fund for Amyloidosis Research, Robert A. Kyle Hematologic Malignancies Program, and Celgene. Patient Characteristics Median Range Age 64 44–88 Major Organs 2 0–3 Involved FLC, mg/dl 23 4.1–278 Serum alb, g/dl 2.8 1.2–3.7 Urine protein, g/24 hrs 3.7 0.02–14.3 Creatinine, mg/dl 1.3 0.7–2.6 Alkaline phos IU/l (nml <115) 99 57–1729 NY Heart Class 1 1–3 Troponin T, mcg/l 0.03 0.01–0.55 NT-proBNP, ng/l 1419 109–42844 LV Septum, mm 13 9–24 LV EF, % 63 22–72
Autologous Stem Cell Transplantation for Multiple Myeloma in Patients over 70 Years: A Matched Comparison with Patients under 65 Years.
Abstract Background: High dose therapy with autologous stem cell rescue has been shown to prolong survival in patients with multiple myeloma in randomized controlled trials. However, most of the prospective studies have included younger patients, usually 65 or less. It is important to have a better understanding of the outcome of transplantation in the older patients given the median age of onset of myeloma of 65 years. We retrospectively reviewed our institutions experience with high dose therapy for patients over 70 years. Methods: We identified 35 patients with multiple myeloma, from the transplant database, who were at or over the age of 70 at the time of their high dose therapy. We matched these patients to 70 patients (two matches for each patient), based on stage at transplant (primary refractory, plateau phase, relapse off therapy, or relapse on therapy), Durie Salmon stage, high or low labeling index, conventional cytogenetics (abnormal vs normal), presence or absence of circulating plasma cells at time of transplant, and whether cyclophosphamide was used as part of mobilization in that order of priority. Results: The median age of the two groups were 55.3 (Range 37.3–64.8) and 71.7 (Range 70–75.8) years at the time of transplant. The median time to transplant from diagnosis was similar (6.4 for the older patients compared to 6.9 months for the other, P = NS). Ten of the 35 older patients received reduced dose melphalan (140 mg/2)) compared to 3 patients in the control group; P < 0.01. The median follow up from transplant was 10.1 months for the older patients compared to 18 months for the control group. The overall response rate was similar for the two groups (97.1% for the older patients compared to 95.5 for the control group). Eleven (31%) of the older patients and 17 (24%) of the control patients achieved a CR (P = NS). The post transplant progression free survival estimate at 1 year post transplant was 65.3% for the older patients compared to 66% for the control group (P = 0.3)The two year estimated overall survival from transplant was similar in the two groups; 58% for the older patients compared to 67% for the control group. The overall survival from diagnosis was similar for the two groups (P = 0.6). The median number of days hospitalized was 9 days for the older population compared to 5 days for the control group (P = 0.37). Four patients died within the first one hundred days, one (3%) among the older patient group and 3 (4.3%) in the control group. Conclusions: High dose therapy and autologous stem cell transplantation is feasible in selected patients with multiple myeloma over 70 years. It is likely that these older patients were selected based on their overall performance status, a factor that is difficult to analyze in this retrospective review. Nearly 70% of the elderly patients received full dose melphalan for conditioning (200 mg/m2). The toxicity of transplant as well as the outcome appears to be very similar to the younger patients. Patients with multiple myeloma should not be excluded from high dose therapy solely on the basis of their chronological age.
Comparison of Newly Diagnosed and Relapsed Refractory Multiple Myeloma Using Transcriptional Profiling of Myeloma Cells.
Abstract Background: Multiple myeloma (MM) is a plasma cell malignancy that is incurable with current approaches. The median survival for patients with MM is around four years and a significant proportion of patients experience a course characterized by multiple relapses treated with different therapies. The median survival for patients relapsing after the initial therapy is nearly 18 months and successive treatment strategies result in decreasing response durations, likely reflecting acquired drug resistance. In order to better understand the biological changes associated with advanced, relapsed, refractory MM, we compared gene expression profiles (GEP) of malignant plasma cells isolated from patients with relapsed refractory MM and compared them to plasma cells from patients with newly diagnosed MM. Methods: In order to obtain two relatively homogenous group of patients, we compared samples from 44 patient with newly diagnosed MM enrolled in the ECOG E1A00 clinical trial (comparing thalidomide and dexamethasone to dexamethasone alone) to 44 patients with relapsed refractory MM enrolled in a phase II trial of Velcade (SUMMIT), where most patients had four or more previous relapses. 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: A total of 864 genes were identified which were at least two fold and significantly different between the newly diagnosed and relapsed patients. Using Ingenuity software, 437 of these genes were mapped to different biological networks. Examination of the canonical pathways demonstrated several important cellular pathways differentially regulated between the two groups. Several important mediators of the cytokines, receptors and respective signaling pathways appear to be down regulated in the relapsed group and included IGF-1, HGF, SDF-1 alpha, gp130 and importantly the MEK/ERK pathway. Additionally expression of adhesion molecules such as VCAM1 and PECAM was decreased in the relapsed group compared to newly diagnosed pts. There appear to increased tissue hypoxia in the relapsed marrow as indicated by up regulation of HIF-1 alpha as well increased levels of Placental growth factor. Myeloma cells from relapsed disease were characterized by decreased expression of mcl1, FLIP1, and bcl-xL and increased caspase 8 relative to newly diagnosed group. Also seen was decreased expression of the glucocorticoid and interferon receptors in the relapsed setting. Conclusion: Comparison of the GEP between MM cells from newly diagnosed and relapsed pts demonstrates important differences that have potential biological relevance. The plasma cell in the relapsed setting appears to be more independent of the tumor microenvironment. Additionally, differential expression of some of the genes provides clues to mechanisms of drug resistance commonly observed in the relapsed pts. We are in the process of validating some of the key findings from these analyses.
Combining Measurements of Plasma Cell Apoptosis and Proliferation in Multiple Myeloma Identifies Patients with Poor Survival.
Abstract Background: Multiple Myeloma (MM) is characterized by accumulation of malignant plasma cells with relatively low proliferative and apoptotic rates. The proliferative rate of plasma cells, measured in terms of % plasma cells labeled by bromodeoxyuridine (BrdU) using slide based fluorescence microscopy (plasma cell labeling index or PCLI) has been shown to be a powerful prognostic factor in MM. We have previously shown that the % bone marrow plasma cells in apoptosis (PCAP) determined by a flow cytometry method that uses Annexin V staining or 7-amino Actinomycin D (7-AAD) correlates with disease stage in MM. The goal of this study was to examine the prognostic value of the PCAP. Methods: We studied 145 patients with MM including 74 with newly diagnosed MM, 40 with relapsed MM, and 31 with MM on treatment in whom simultaneous measurements of % plasma cell apoptosis and PCLI were available. The PCLI is expressed as the percentage of cytoplasmic immunoglobulin positive plasma cells that have taken up BrdU. The PCLI was characterized as high when >= 1%. Mononuclear cells isolated from bone marrow aspirate, following red cell lysis with ACK solution, are incubated with CD38-PE and either CD138-FITC or CD45-FITC. This is followed by incubation with 7-AAD and the plasma cells are gated using the CD38/CD45 staining pattern. The Annexin method used a similar strategy, with Annexin V in place of 7-AAD. The percentage of plasma cells in apoptosis (PCAP) was categorized as high when >5%, the median value. Results: The median follow up for the entire group was 34 months (range, 0.1 mo to 9 years) and 112 (77%) had died at the time of analysis. Forty seven patients (32%) had a high PCLI (>=1%). The median overall survival for the patients with high PCLI was 14.6 months versus 42.3 months for those with a low PCLI; P = 0.0005 (log rank test). Seventy-five (51.7%) patients had a high PCAP. The median overall survival for those patients was 28.9 months versus 40.2 months for those with a low PCAP; P = 0.078. We next examined if there was any correlation between a high PCAP and high PCLI and found none; P = NS by (Fisher’s exact test). Additionally in a multivariate Cox model using both PCLI and PCAP, both were independently prognostic for overall survival. We then developed an index by adding PCLI to log transformed PCAP (PCLI + log PCAP). Using a cutoff of 1.5 for the new index we were able identify a group of patients with poor survival. The 59 patients with a high value for the new index had a median survival of 19.3 months vs 46.1 months for the rest (P < 0.0001, log rank test). Conclusion: The measurement of plasma cell apoptosis has prognostic value in patients with MM. More importantly, we have shown that by combining measures of two important biological characteristics of the plasma cell, namely proliferation and apoptosis, patients with a poor prognosis can be identified. Such a prognostication strategy can help stratify patients in clinical trials as well as shed light on the disease biology.
Stromal Cell IL-8 Production Is Increased in MM and May Impact Both Tumor Cells and the Microenvironment.
Abstract Background: Multiple myeloma (MM) is an incurable hematological malignancy characterized by the expansion of a plasma cell clone that localizes to the bone marrow. Stromal cells residing in the bone marrow respond to signals from MM cells and other cell types by producing cytokines and other proteins that stimulate tumor cell growth, survival, adhesion, migration, and drug resistance. We have examined the proteins produced by stromal cells in response to stimulation by bone marrow from patients diagnosed with monoclonal gammopathy of undetermined significance (MGUS), smoldering multiple myeloma (SMM), and MM. Furthermore, we have begun analyzing the properties of one of these proteins, the pro-angiogenic chemokine IL-8, in MM. Methods: Bone marrow aspirates from patients with MGUS (n=3), SMM (n=7), and MM (n=6) were cultured for 48 hours, and the culture supernatants were incubated with stromal cells for an additional 48 hours. Protein levels were analyzed using antibody array and ELISA. Microvessel density (MVD) was determined as a measure of angiogenesis in patient bone marrow samples using CD34 staining. Flow cytometry analysis of MM cell lines and patient bone marrow samples was performed using monoclonal antibodies against IL-8 receptors CXCR1 and CXCR2. Results and Conclusion: We observed a significant increase in stromal cell IL-8 production stimulated by bone marrow cells from patients with active myeloma and a subset of SMM patients (16.67 ± 9.82 ng/ml) in comparison to bone marrow of patients with MGUS and all other SMM patients (0.55 ± 0.17 ng/ml; P=0.0004). Use of an IL-1 inhibitor and recombinant IL-1β demonstrated that IL-8 production was dependent upon IL-1β signaling. Increased BM microvessel density correlated with stimulation of stromal cell IL-8 production (P=0.0005). Furthermore, the majority of MM cell lines (7/9) and MM patient plasma cells were found to express IL-8 receptors CXCR1 and CXCR2. In addition to its function as a pro-angiogenic factor, IL-8 may directly influence MM cells through its CXCR1 and CXCR2 receptors. We conclude that stromal cell IL-8 production parallels MM disease activity, is IL-1β induced, correlates with bone marrow angiogenesis, and may influence MM disease via impact upon both the microenvironment and tumor cells.
Cardiac Biomarkers Predict for Ability To Tolerate and Complete Therapy with Lenalidomide ± Dexamathosone in AL Amyloidosis.
Abstract Background: Primary systemic amyloidosis (AL) is an incurable plasma cell disorder. Lenalidomide, especially in conjunction with dexamethasone, has been shown to be highly active in patients with multiple myeloma. Methods: We studied the toxicity and efficacy of lenalidomide in patients with symptomatic AL. Patients received single agent lenalidomide. If progression by 3 months or no evidence of hematologic response after 3 cycles, dexamethasone was added. Originally, twenty-three patients (Cohort 1) were enrolled according to study design. Because of a significant early drop out rate and notable activity of the regimen, the trial was modified to include an additional 15 patients (Cohort 2). Baseline characteristics and adverse events are available for all enrolled patients, but at the time of this writing, response data are available for Cohort 1 patients due to short follow-up of Cohort 2, but will be updated by the time of the meeting. Results: Median age was 64 years, with 69% male. Twenty-three were previously treated. Organ involvement was cardiac (67%), renal (64%), hepatic (17%), nerve (17%). Thirty-three, twenty-two, and forty-four percent of patients were cardiac biomarker stage 1, 2, and, 3 respectively. Of the 37 patients, one was a cancel, and 6 have not yet made it through 3 months of protocol treatment and event monitoring. The respective median follow-ups for Cohorts 1 and 2 are 17 and 3.4 months. Of the remaining, 30 patients, within the first 3 cycles of therapy fifteen patients discontinued treatment: 7 early deaths and 8 adverse events or other causes. Three additional patients died 0.5 to 2 months after stopping treatment. The best predictor for early withdrawal and/or death was baseline NT-proBNP and cardiac biomarker staging system (cut-offs for serum troponin T <0.035 ng/ml and NT-proBNP <332 pg/ml--Stage I neither above cut-off; Stage III, both above cut-off; and Stage II, one above cut-off). Figure1 Figure1. Figure 2 Figure 2. Of the twenty 22 patients assessed for response ten patients responded to treatment for an overall response rate of 45%, including 23% organ responders. Among the patients with organ responses, there were four renal responses, two cardiac responses and two liver responses. All but one of the responders had dexamethasone added to their treatment program. The most common grade 3−4 adverse events at least possibly attributable to lenalidomide were neutropenia (38%), thrombocytopenia (21%), fatigue (15%), and rash (12%). Conclusions: Lenalidomide and dexamethasone has significant activity in patients with AL with an overall response rate of 45%. Baseline NT−proBNP may be an effective eligibility screening strategy for subsequent trials.