Greipp, Philip R.

Abstract Background: Cytotoxic T-cell infiltrates are a nearly universal finding in the bone marrow of patients with multiple myeloma. It has been postulated that presence of T-cells in the bone marrow of multiple myeloma (MM) patients represents an immune response against the tumor and therefore, might be associated with an improved prognosis. However, the impact of bone marrow T-cells on the prognosis of multiple myeloma patients has not been studied systematically. Methods: Bone marrow biopsies of patients with newly diagnosed multiple myeloma were stained by immnohistochemistry for the CD8 antigen and reviewed by a blinded hematopathologist. Three high power fields are reviewed for each biopsy and the total number of CD8 positive cells counted and reported. For patients with more than 300 cells per 3 fields, results were reported as >300. The number of bone marrow CD8 positive cells was then correlated with patients’ clinical data, including other prognostic factors and overall survival. Results: Bone marrow biopsy specimens from 100 patients, performed within the week of a diagnosis of multiple myeloma and collected between May 1998 and January 2001 were evaluated. The median number of CD8 positive cells was 270 (33 – >300). Patients’ characteristics are shown in Table 1. Median follow up was 30 months (0–80). The number of cytotoxic T-cells as a continuous variable was a risk factor for shortened overall survival, HR 1.86 (95% CI 1.11–3.35). Using minimal p value approach, the cutoff of 270 cells (the median) risk stratified patients into two groups: the median survival of patients with > 270 CD8 positive cells was 16 months vs. 48 months in patients with ≤270 cells, p=0.005 (Figure). In multivariate analysis including age, B2M, albumin, CRP, bone marrow plasma cell percentage and plasma cell labeling index, the number of cytotoxic T-cells was an independent predictor of overall survival was HR 3.1, p=0.0017. Conclusion: We show that the number of cytotoxic T-cells in the bone marrow is a strong and independent prognostic factor in patients with newly diagnosed multiple myeloma. Our observation does not contradict the hypothesis that cytotoxic T-cells participate in an immune response against the tumor since our findings may represent a higher level of immune response associated with baseline aggressive disease biology. However, our study suggests for the first time that increased marrow cytotoxic T-cells have an adverse effect on outcome in myeloma, and suggest that these cells may have a direct facilitating effect on tumor growth and on the marrow microenvironment. Further studies of the biology of behind this observation are warranted. Characteristic N Median (range) Gender male 61 CRP 81 0.4mg/L (0.01–11.2) Albumin 99 3.6 g/dL (2.6–5.4) B2microglobulin 94 4.0 (0.9–28) μg/mL Marrow PC% 90 45% (11–99) PC labeling index 90 high (>1%) 36 BM CD8 cells 100 270 (33 – >300) ISS 94 1 19 2 41 3 34 Figure Figure

Abstract Background: Syndecan-1 (CD138) is a heparan sulfate bearing proteoglycan found on various epithelial cells as well as on B lineage cells depending on its stage of development. Syndecan-1 (CD138) is abundantly expressed by plasma cells, especially myeloma cells. The extra cellular domain along with the heparan sulfate side chains can be cleaved off the cell surface and can be detected in the serum as soluble syndecan. Syndecan possibly plays a multifunctional role in the biology of myeloma. It has been shown to be an independent prognostic factor in patients with multiple myeloma. It has also been shown to promote myeloma cell growth through different mechanisms. Its expression has also been suggested to correlate with bone disease in MM. Methods: In this study we studied serum levels of soluble syndecan in newly diagnosed MM patients enrolled in the Eastern Cooperative Oncology Group (ECOG) E9486 and its associated correlative laboratory clinical trial E9487. We evaluated the prognostic value of syndecan in MM and its relationship to other known prognostic factors for this disease. In addition, syndecan levels were correlated with clinical and laboratory markers of bone disease. Results: A total of 501 patients were studied and the median serum syndecan-1 was 158 ng/mL. Syndecan levels correlated positively with other prognostic factors and markers of tumor burden such as β2-microglobulin (correlation coefficient 0.3; P <0.00001), labeling index (0.25; <0.0001), creatinine (0.23; <0.0001), soluble IL6 receptor (0.3; <0.0001), BM plasma cell percentage (0.16; <0.0006), and disease stage (P=0.0007). Significant differences in the overall and progression free survival was found between two groups of patient separated using the median value as cut-off. The High syndecan group had a median overall survival of 36.3 months compared to 49.3 months for the low syndecan group (P < 0.0001). Similarly, the high syndecan group had progression free survival of 25.4 months compared to 33.5 months for the low syndecan group (P < 0.0001). In a proportional hazards model including syndecan-1 as well as labeling index, β2M, Platelet count, IL-6R, syndecan-1 retained its prognostic value for overall survival (HR 1.3, P = 0.021). Syndecan levels were correlated with various bone markers including C-terminal telopeptide of type I collagen (ICTP), osteocalcin (OC), C-terminal type I procollagen (PICP), bone-specific alkaline phosphatase (BAP), and tartrate resistant alkaline phosphatase (TRAP) and were found to correlate only with ICTP (0.25, P < 0.0001). No correlation was found between clinical markers of bone disease including presence of lytic lesions, osteoporosis and pathologic fractures on X-rays or bone pain. Conclusion: In this large study, we once again confirm the prognostic value of serum syndecan-1 levels in large group of patients with newly diagnosed myeloma. Syndecan-1 level correlates with other disease markers. Syndecan levels also correlated with ICTP, a marker of bone turnover, though no strong correlation was found between syndecan levels and clinical markers of myeloma bone disease. The biological basis of these finding needs further evaluation.

Abstract INTRODUCTION The bone marrow plasma cell labeling index (PCLI) and the beta 2 microglobulin (β2M) when combined provide a powerful staging system highly predictive of outcomes in myeloma patients (Greipp et. al., Blood, 81:3382–87, 1993). This staging system lacks information on cytogenetics and it has been demonstrated that deletion 13 (Δ13) by conventional cytogenetics is associated with poor outcomes. In conventionally treated patients Δ13 by FISH is an independent prognostic variable. We analyzed the importance of Δ13 by FISH in a cohort of patients receiving high dose therapy and assessed its value relative to known prognostic parameters, PCLI and β2M. PATIENTS AND METHODS 238 patients undergoing high dose therapy between January 1990 and September 2001 were studied. The minimum follow-up of patients was 34 months. The median age of the cohort 56 years. Interphase fluorescence in situ hybridization with Probes LSI13/D13S319 was performed with simultaneous immunofluorescent detection of bone marrow plasma cells by the presence of cytoplasmic immunoglobulin. PCLI was done by a slide-based immunofluorescence method with antibodies to bromodeoxyuridine. RESULTS Of the 238 patients studied 215 had a successful FISH analysis and 212 of these had a bone marrow labeling index. Deletion 13 was absent in 104 patients (48%) and present in 111 patients. The overall survival and time to progression for patients lacking and having deletion 13 was 47.8 vs 26.4 (OS) and 19.0 vs 11.7 (TTP)months respectively. A Cox model was constructed with the PCLI, the presence or absence of deletion 13 and serum β2M. Although all three variables were independently predictive of survival and time to progression, the β2M was the weakest of these three variables. The hazard function for survival for PCLI, deletion 13 and β2M was 1.4, 1.6 and 1.1 respectively. A staging system was constructed assigning 1 point for the presence of deletion 13 or a PCLI ≥ 1%. Patients fell into 3 categories of 0 points (N=69), 1 point (N=104) and 2 points (N=39). The overall survival for the three groups respectively were 56.5, 36.6 and 13.7 months (figure). The time to progression for the three groups were 22.3, 15.4 and 8 months (P<0.001). When analysis was limited to those patients transplanted within 12 months of diagnosis the results remained significant (P<0.003) with median survivals of stage 0, 1 and 2 of 72.5, 59.1 and 15.4 months respectively. TTP for stage 0, 1 & 2 in this same cohort of patients transplanted < 12 mos after diagnosis is 30.6, 21.5 & 8.2 months respectively. CONCLUSION Deletion 13 by FISH is an independent predictor of survival and time to progression providing information independent of the β2M and the PCLI. Combining the PCLI with FISH del 13 identifies patients who following transplant have a median time to progression of 8 months and a median OS of 13.7 months. This group may not benefit from autologous transplant and are candidates for novel therapeutic approaches. Figure Figure

Abstract Events mediating transformation from the pre-malignant MGUS to MM is largely unknown. Previous studies have highlighted RAS mutation as a progression event. However, this abnormality is present in only a small subset of patients. Global gene expression differences between MGUS and MM have been reported but provided little coherent biological insights. To define progression events, we examined the differences in gene expression profiles (GEP, Affymetrix U133A genechip) between 101 MM and 22 MGUS using a powerful functional genomic tool, Gene Set Enrichment Analysis (Subramanium et al PNAS 2005), that allow extraction of biological information based on enrichment of genes associated with a phenotype within gene-sets derived experimentally or extracted from database. We found that a predominant theme relating to MM progression is the over-expression of proliferation related genes in MM highlighted by the enrichment of cell cycle related gene-sets. Another common theme is the enrichment of gene-sets relating to MYC activation. Seven of eight gene-sets related to MYC activation in the database are significantly enriched (p-value <0.05 and false detection rate <0.05). Leading edge (enriched genes) analysis of enriched MYC-related and proliferation-related gene-sets revealed a core, overlapping signature of 8 genes specific to MYC and not proliferation. These genes are further verified as MYC transcriptional targets using Metacore, a network analysis tool. In addition, 7 of the 8 genes had been validated as MYC target genes by chromatin immunoprecipitation previously (www.myccancergene.org). We validated this signature in independent publicly available cell lines and mouse gene expression experiments where this signature is present in mammary epithelial cell lines engineered to over-express MYC but not E2F3, SRC and BCAT, and mouse embryonic fibroblast over-expressing MYC but not HER2 or with RB knocked-out. In addition, analysis of proliferation index in these datasets showed that there is dissociation of proliferation from this signature. This showed conclusively that our signature is MYC specific and not related to proliferation. Of interest, the signature is also present in cell lines with activating RAS mutation, which also have high expression of MYC, suggesting that MYC activation is a downstream effect of activated RAS signaling. Indeed, in our patient cohort, most patients with RAS mutation express this signature. When applied to 2 large GEP MM patient cohorts, this signature was not present in normal plasma cells, rarely present in MGUS, and present in a significant proportion of MM and almost all the human myeloma cell lines. When analyzed in the context of other B-cell malignancies, the signature is very strong in Burkitt’s lymphoma, present in most myeloma but absent in chronic lymphocytic leukemia, Waldenstrom Macroglobulinemia, and normal B-cells. Our analysis therefore suggests that MYC activation may be a unifying pathological event in MGUS to MM progression. As MYC translocations occur in only about 13% of newly diagnosed MM patients, activating RAS mutations and other trans-mechanisms may mediate MYC activation. Our recent demonstration that sporadic MYC activation in a mouse strain prone to monoclonal gammopathy led to MM development provides important functional proof.

Abstract Background: Primary systemic amyloidosis (AL) is an incurable plasma cell dyscrasia with limited therapeutic options. Based on the observed 25 to 50% partial response rates in myeloma patients, thalidomide has been tried in patients with AL. Two reports (Dispenzieri et al, Amyloid10:247; 2003; Seldin et al, Clinical Lymphoma3:241; 2003) have demonstrated that standard dose, single agent thalidomide (≥ 200 mg per day) has a higher than expected rate of adverse events in AL patients without hematologic or organ response, potentially due to rapid patient attrition. We therefore performed a prospective clinical trial using low dose, single agent thalidomide in patients with AL. Methods: In August 2001, we began accrual to a phase II trial of low dose thalidomide for patients with AL. Eligibility included: age ≥ 18 years, creatinine <3mg/dL, total bilirubin < 3 mg/dL, ANC ≥ 1 x 10(9)/L, left ventricular ejection fraction of >45%, histochemical proof of amyloid and a monoclonal plasma cell dyscrasia, symptomatic organ involvement, and ability to supply informed consent. Patients were started with thalidomide 50 mg per day, with a dose escalation to a maximum dose of 400 mg per day over a 19 week period as tolerated. Patients were evaluated monthly by their physician. These office visits were staggered with telephone toxicity checks monthly by the primary investigator. The endpoint of the study was hematologic and organ response by 12 months. Results: Eighteen patients were treated. The median age was 66 years (range 43–83). Eight were male. Twenty-eight percent had an ECOG performance status of 2 or 3. Five patients (28%) had received no prior therapy. Five had received one prior regimen; 6, two prior; and 2, ≥ three. Three had received prior PBSCT. Sixteen patients had a monoclonal lambda plasma cell disorder; two, monoclonal kappa. Immunoglobulin heavy chains were IgG (n=9), IgM (n=5), IgA (n=1), and none (n=3). Twelve patients (67%) had cardiac involvement; twelve (67%) renal; two liver; two symptomatic gastrointestinal; one pulmonary; and two nerve involvement. Study participants had significant symptomatology at baseline with dyspnea (n=12), light-headedness (n=6), and edema (n=13). Median number of organs involved was 1, range (1 to 4). Median time on study drug was 5.6 months, range 0.7–24 months. Reasons for discontinuation included: progression, 7 (39%); 3 each (17%) for adverse events, death, and patient refusal; and other causes in 2. The median tolerated dose was 100 mg. There were no hematologic responses observed. The overall organ response rate was 11%. There was one renal response at 1 year and a gastrointestinal response at 3 months with 24 hour fecal fat changing from 21 to 8.7 grams. The most common adverse effects attributable to thalidomide were: constipation (78%), edema (44%), sinus bradycardia (17%), dyspnea (11%), and paresthesias (11%). Light-headedness, rising creatinine, thrombosis, infection, syncope, and rash was attributed to the thalidomide in 5.6% of patients. Conclusions: Low dose thalidomide is tolerable in this fragile group of patients, but as a single agent efficacy is limited. Further study of combination therapy of thalidomide and low dose dexamethasone may be warranted. A study using the next generation immune modulatory drug Revlimid is scheduled to open to accrual. Funded by NIH grant CA 91561 and Celgene.

Abstract Sublethal doses of ionizing radiation induce a complex cellular survival response, one component of which is activation of the nuclear factor kappa B (NF-kB) pathway. PS-341 is a selective inhibitor of the 26S proteasome which prevents the proteasomal degradation of I-kB and thereby inhibits the activation of NF-kB. We therefore hypothesized that PS-341 should synergistically enhance the anti-myeloma effect of ionizing radiation (IR). The individual and combined effects of PS-341 and IR were analyzed using human MM cell lines (MM1, RPMI 8226, JJN-3 and ARH-77) and bone marrow samples from myeloma patients. Treatment of myeloma cell lines with 10nM PS-341 produced a modest anti-proliferative effect with G2/M-phase arrest and p21cip/waf-1 induction but minimal procaspase-3 cleavage and minimal apoptotic cell death: Similar sublethal damage was observed after single exposure to IR at a dose of 6 Gy. In contrast, sequential exposure to PS-341 (10 nM) and IR (6 Gy) resulted in potent (synergistic) induction of apoptosis, assayed by both fluorescein isothiocyanate conjugated annexin V-propidium iodide assay and cell cycle analysis. Overall cell viability was greatly reduced by the combination of PS3451 and IR, but not by either modality alone, as determined by 3-(4,5 dimethylthiazol-2yl) 2–5 diphenyltetrazolium bromide (MTT) assay and analysis of polyadenosine-5′-diphosphate-ribose polymerase (PARP) cleavage -product after 72 hours. As predicted, exposure to 6 Gy IR led to potent induction of nuclear NF-kB activity and this response was almost completely inhibited by simultaneous treatment with PS-341. The combination of PS341 and IR was next evaluated on CD138+ve and CD138-ve cell fractions from bone marrow aspirates of myeloma patients. Synergistic killing of primary myeloma (CD138+) cells was observed with relative sparing of normal marrow elements (CD138−). We conclude that PS-341 is a potent radiosensitizer for myeloma cell lines and primary myeloma cells. This provides a strong rationale to combine PS-341 with conventional external beam or with targeted radionuclide therapy for effective treatment of MM patients.

Abstract Multiple myeloma remains incurable and novel therapeutics are urgently needed. We have shown that live attenuated Edmonston strain measles virus (MV-Edm) is potently oncolytic in multiple myeloma xenograft models and can efficiently infect CD138 sorted primary myeloma cells inducing extensive intercellular fusion which leads to cell death (Blood, 2001, v98, p2002). In contrast, the virus causes minimal damage to normal PHA-stimulated peripheral blood lymphocytes, fibroblasts and smooth muscle cells. To facilitate non-invasive imaging of sites of viral gene expression, we introduced the human thyroidal sodium iodide symporter (NIS) gene into the viral genome (MV-NIS). MV-NIS infected myeloma cells efficiently concentrate radioiodine which provides a basis for noninvasive imaging and destruction of infected tumors using beta emitters such as 131I (Blood, 2004, v103, p1641). Clinical translation of MV-NIS in patients with refractory myeloma is planned. However, the mechanism underlying the tumor selectivity of MV-Edm has not previously been defined. MV-Edm uses either of two cellular receptors for cell entry and cell fusion; CD46, a regulator of complement activation, is expressed on all nucleated cells, wheras SLAM (signaling lymphocyte activation molecule) is expressed only on activated B lymphocytes, T lymphocytes, and monocytes, and is not present on myeloma plasma cells. Using a panel of CHO cell transfectants, we demonstrated that MV-Edm -mediated cell killing increases exponentially above a threshold CD46 receptor density (Can Res, 2004, v64, p4919). We subsequently obtained bone marrow aspirates from 18 myeloma patients and performed multi-parameter flow cytometry to determine the relative expression levels of CD46 on the myeloma plasma cells versus the rest of the hematopoietic cells in the bone marrow. The myeloma cells expressed significantly higher levels (5-fold) of CD46 receptors (MFI=294.9 + 204.4, means ± SD) on their cell surfaces compared to hematopoietic cells of the erythroid, myeloid and lymphoid lineages (MFI=58.6 ± 9.0). Analysis of the myeloma array data generated by the Shaughnessy lab indicated that, in comparison to plasma cells from healthy volunteers (2997 ± 1053, n=30, means ± SD), primary myeloma cells express 2-fold elevated levels of CD46 mRNA (6592 ± 4029, n=72, p=0.001, Wilcoxon signed rank test). Taken together, these findings provide strong support for the hypothesis that selective destruction of myeloma cells by oncolytic measles viruses is a direct consequence of their overexpression of the cellular receptor CD46.

Abstract Background: It has been hypothesized that multiple myeloma (MM) remains incurable due to a stemcell/proliferative component that responds only partially to standard treatment regimens. We have shown that abnormal production of IL-1beta in the myeloma microenvironment stimulates the generation of paracrine IL-6, the central myeloma growth factor, and that IL-1Ra will inhibit paracrine IL-6 production in vitro. Based on these preclinical studies, we have developed a Phase II trial using IL-1Ra. Purpose: To determine the biologic and clinical activity of IL-1Ra (Anakinra) in a subgroup of smoldering MM (SMM) patients that present with an elevated plasma cell labeling index (PCLI; a measure of myeloma cell proliferation). Methods: Patients that had ≥ 10% bone marrow plasma cells and/or an IgG or IgA M-spike ≥ 3 g/dL and did not require immediate chemotherapy were eligible. Patients received 100 mg of Anakinra (IL-1Ra) SQ qd for a total duration of 6 months. Results: Eleven of 29 patients enrolled on the protocol had an on-study PCLI > 0 and have completed six months of therapy with IL-1Ra. Seven of the 11 patients had a decrease in the PCLI of 75–100% (see Table), three had only modest changes (≤ 50%), and one had an increase. The decrease in the PCLI paralleled a decrease in the high sensitivity C-reactive protein (CRP) in all cases (43–90% decrease). The above results suggested that IL-1Ra inhibited IL-6 production in the myeloma microenvironment, as evidenced by a reduction in the CRP, resulting in suppression of myeloma cell growth. However, there was little effect on the M-protein. To investigate these clinical observations, we co-cultured IL-1beta transduced +/− myeloma cells with stromal cells +/− dexamethasone (DEX), IL-1Ra, or both for 48 hours and quantitated the percent apoptotic cells by flow cytometry and IL-6 production by ELISA. The results showed: 1) IL-1Ra was superior at inhibition of IL-6 but caused no increase in apoptosis; 2) the DEX apoptotic effect was eliminated by IL-6 3) DEX and IL-1Ra combined induced maximal IL-6 inhibition and apoptosis of myeloma cells. Based on these in vitro results, 5 of the 11 patients have been advanced to IL-1Ra + low dose DEX (20 mg/week) resulting in 4/5 minor responses (25–50% decrease M-spike) and 1/5 with stable disease. Conclusion: The use of IL-1Ra is a novel targeted therapeutic strategy that interferes with myeloma cell growth. By inhibiting IL-1beta induced IL-6 production, IL-1Ra specifically targets the proliferative myeloma fraction and also complements DEX induced apoptosis. Preliminary studies on the use of IL-1 inhibitors in SMM patients to delay/prevent progression to active MM and to minimize toxicity appear encouraging, however, more patients need to be studied. Patient # On Study 6 months % Change 1 PCLI 0.8% 0% −100% CRP (mg/L) 2.01 0.58 − 71% M-spike (g/dL) 2.5 2.4 − 4% 2 PCLI 0.2% 0% − 100% CRP 0.89 0.51 − 43% M-spike 2.8 2.7 − 3% 3 PCLI 0.2% 0% − 100% CRP 5.7 1.02 − 82% M-spike 2.9 2.9 0% 4 PCLI 4.1% 1% − 75% CRP 3.39 1.51 − 55% M-spike 3.8 3.6 − 5% 5 PCLI 0.4% 0% − 100% CRP 3.46 0.34 − 90% M-spike 2.7 3.1 15% 6 PCLI 0.3% 0% − 100% CRP 17 5.35 − 68% M-spike 4.4 3.9 − 11% 7 PCLI 1.2% 0% − 100% CRP 1.06 0.32 − 70% M-spike 3.1 2.9 − 6%

e19517 Background: Investigators cite complicated test (T) schedules as barriers to the conduct of clinical trials, especially T that do not contribute to outcome or pt safety. In MM protocols, some T are prone to being done inaccurately (e.g. UPEP, 24 hour urine collections), or are not useful (e.g. uric acid, AST/ALT) in determination of response (R) or safety. These T lead to increased cost, protocol violations, and do not enhance outcome. Methods: We analyzed data submitted for pts on E4A03 to examine frequency of missing data for R T: serum and urine (U) PEP, immunofixation (IFE) bone surveys (BS), and safety labs for C1-4. Results: Table outlines % pts with completed T. Most had T for serum M protein, as well as heme T but serum and U PEP, and IFE dropped off by C4. Other T e.g. uric acid were completed in 77%. Only 79% of pts had a BS repeated at C4. Incorrect or missing U data led to categorization of 16/445 (3.6%) pts as ineligible and was most frequent reason for ineligibility (69%). Missing U data led to 13/26 pts not evaluable. Analysis of SAE during the C1-4 revealed no SAE for hyperuricemia and < 5 SAE for AST/ALT. Only 5% of pts had lab-based SAE filed in 4 C. Conclusions: Required U T and BS to assess R in E4A03 were missing or completed inadequately and caused pts to be ineligible and or not evaluable. Such T need to be eliminated or replaced. Strategies to monitor data submission in real time may reduce subject loss due to T error. The requirement for routine T should be reassessed to create simpler trial design. Clinical trial information: NCT00098475. [Table: see text]

7621 Background: Thalidomide (Thal) in combination with dexamethasone (Dex) is an effective therapy for myeloma (MM). Though initially evaluated in MM because of its anti-angiogenic properties, it is not clear how much this contribute to its anti-MM effects. We examined whether the degree of angiogenesis influences response to Thal + Dex, as well as effect of therapy on marrow angiogenesis. We also examined whether expression of angiogenic cytokines by MM cells affect response to therapy. Methods: A total of 207 pts with newly diagnosed MM were randomized on the ECOG phase III trial (E1A00) to either Thal-Dex or Dex alone. Bone marrow microvessel density (MVD) was determined on 88 pts at diagnosis and at 4 mos after therapy in 25 pts. Expression of fibroblast growth factor (FGF) and vascular endothelial growth factor (VEGF) by MM cells was determined by RTPCR on 60 pts at diagnosis and on 22 pts at 4 mos. In addition, the percentage of marrow PCs in apoptosis was determined at diagnosis and 4 mos in 43 pts. A decrease in the serum M protein by 50% or in its absence, a decrease in urine M protein by 50% was considered a response. Results: The median BM MVD at diagnosis was 33 (3–118), and was similar in the pts responding to therapy (36.4) and in the non responders (45.4). We also separately looked at those receiving the combination vs. Dex alone, and did not find any correlation. The expression of FGF and VEGF in the PCs did not predict response to therapy with either the combination or Dex. Among the 17 responding pts, MVD decreased by a mean of 12 compared to an increase in the mean MVD of 3 among the non responders (P = NS). There was no significant correlation between the level of FGF or VEGF expression and the marrow MVD. There was no correlation between the percentage of myeloma cells in apoptosis at baseline and response to therapy. Conclusion: While the anti-angiogenic activity of Thal may play a role in its anti-myeloma effect, baseline MVD or tumor cell expression of angiogenic cytokines do not predict resistance or response to Thal-Dex or Dex alone. The findings here confirm previous observations that marrow angiogenesis is not related to the degree of secretion of angiogenic cytokines by individual cells, but rather the cumulative effect of the tumor mass. No significant financial relationships to disclose.