Abstract Table 1. Samples to p53 deletions p 53 deletion FISH aCGH FISH and aCGH MGUS 142 - - SMM 108 - - Newly diagnosed MM - 182 - Relapsed/refractory MM 62 156 19 HMCLs - 48 - Total 312 386 19 Background: Inactivation of p53 by mutation or allelic loss is a rare event in multiple myeloma (MM) at the time of disease diagnosis and believed to be more common in the late stages of the disease. Here we defined the prevalence of p53 deletions in monoclonal gammopathy of undetermined significance (MGUS), smoldering multiple myeloma (SMM), newly diagnosed MM, relapsed MM and human myeloma cell lines (HMCLs). Indirect mechanisms of p53 inactivation such as amplification of MDM2, or deletion of CDKN2A (p14ARF) were also investigated. Patients and Methods: A total of 631 MM samples and 48 HMCLs were analyzed for p53 abnormalities (Table 1) and compared with a cohort of plasma cell leukemia (PCL) previously published by us. Interphase fluorescence in situ hybridization (FISH) and highresolution array-based comparative genomic hybridization (aCGH) were used to detect p53 deletions. MDM2 amplification and p14ARF loss were evaluated by aCGH. Overall survival (OS) was estimated through Kaplan Meier method. Results: The prevalence of p53 deletions was 1.4%, 3.7%, 8.9%, 20% and 87.5% in MGUS, SMM, newly diagnosed MM, relapsed MM and HMCLs respectively (Figure 1). Of interest patients in first relapse showed a p53 deletion prevalence of 18% in comparison with 33% for patients in second relapse or more. We obtained p53 deletion status in 8 patients noted to have deletion at the time of relapse and in whom we had previous samples stored. In 7 of 8 cases deletions had been acquired (absent in the previous samples). The median OS for relapsed MM patients with or without p53 deletion were 4.2 months and 37.8 months respectively (p <0.001). MDM 2 amplification and p14ARF loss was detected in 0.4% and 2% of new diagnosed MM, 0.6% and 5.1% of relapsed MM and 2% and 29% of HMCLs respectively. Discussion: Emergence of p53 deletion/mutations denotes progression genetic events in MM. Importantly we show for the first time the overriding importance of p53 deletions as prognostic markers in relapsed MM. A molecular staging system that is based on the presence of p53 inactivation may be more powerful than classifying patients based on the loss of p53. Other abnormalities involving p53 pathway regulators like MDM2 gain and p14ARF loss are infrequent events in MM, even in advanced disease. Figure 1. Prevalence of p53 deletions Figure 1. Prevalence of p53 deletions
Phase II Study of Melphalan, Prednisone and Lenalidomide Combination for Newly Diagnosed Multiple Myeloma Patients Who Are Not Candidates for Stem Cell Transplantation
Abstract Melphalan (M), Prednisone (P) and Lenalidomide (R) are active in the treatment of multiple myeloma (MM). We evaluated the toxicity and efficacy of MPR in a phase I/II trial. Results of phase I part were previously reported (Blood2006, 108(11) abst 3558). M 5 mg/m2 on days (d) 1–4, 60 mg/m2 d 1–4 and R 10 mg d 1–21 of a 28 day cycle was determined as MTD for the phase II study. Methods: Patients with previously untreated MM who were not candidates for stem cell transplantation, age ≥18 yr, ECOG PS 0–3, evaluable or measurable disease, ANC >1500, platelets > 100,000 and creatinine ≤ 3.0 mg/dL were eligible. All patients received aspirin 325 mg/d as DVT prophylaxis. Routine antibacterial prophylaxis was not used. G/GM-CSF was used at the discretion of the treating physician for neutropenia. Response rate (RR), confirmed on two consecutive determinations was the primary end-point. The study had 90% power to detect a RR of at least 45%. Results: Twenty-six patients were accrued between July ’06 and Feb ’08. The median age was 74 y (64 – 87y), 17 (65%) were men. Six, 13, 6, 1 (23%, 50%, 23%, and 4%) patients had ECOG PS 0, 1, 2, and 3, respectively. Three (12%), 11 (42%) and 10 (38%) patients were ISS stage 1, 2 and 3. A total of 106 cycles were administered; median 4.5 (1–13). Seventy-seven % patients experienced at least 1 grade 3 or 4 toxicity. Neutropenia (42%/8%) and thrombocytopenia (20%/8%) were the most common grade 3/4 adverse events followed by anemia (16%/0%), fatigue (8%/4%), rash (11%/0%), and hyperglycemia (4%/0%). There were 20 treatment delays in 9 patients, and 18 dose reductions (9 in R, 11 in M and 1 P) occurred in 7 patients, most commonly because of neutropenia or thrombocytopenia. Eleven patients (42%) required G-CSF treatment. Eleven patients are currently receiving treatment; 15 have gone off study (4 completed per protocol, 3 refused, 3 adverse effects, 3 unrelated illnesses, 2 other). Median follow up of survivors is 8 m (0 – 22m). Eighteen (69 %; 95%CI 48–86) patients had a PR or better according to International Myeloma Working Group Uniform Response criteria; 3 (12 %) CR, 5 (19 %) VGPR and 10 (38%) PR. Median number of cycles before achieving a response was 2 (1 – 11). Median Progression Free and Overall Survival is 16.7m (95% CI 11.2–23.0), and 23 m (95% CI: 22 – 23), respectively. Conclusions: MPR combination is feasible with a manageable toxicity profile and has significant activity in the treatment of patients with MM who are not candidates for stem cell transplant, with an overall response rate of 69%, and a CR plus VGPR rate of 31%. Grade 3 or 4 neutropenia and thrombocytopenia was the most common toxicity, seen in up to 50% of patients in this cohort of predominantly elderly patients. Dose reduction in R and/or M was required in 27% patients. No patient developed neuropathy or thromboembolic complications.
Long Term Follow-up of Patients with Immunoglobulin Light Chain Amyloidosis Treated with Lenalidomide and Dexamethasone.
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. We previously reported a hematologic response rate of 41% and an organ response rate of 23% among 22 AL patients treated with lenalidomide and on-demand dexamethasone (Dispenzieri et al, Blood 2007). Long term outcomes of AL patients treated with lenalidomide have not yet been described. Methods: Thirty-seven patients were treated on an IRB approved treatment trial with single agent lenalidomide, starting doses of 25 mg in 22 and reduced dose of 15 mg in the last 15. If progression within or no evidence of hematologic response after 3 cycles, dexamethasone was added. Patients were classified according to cardiac biomarker stage (cut-offs for serum troponin T <0.035 ng/ml and NT-proBNP <332 pg/ml--Stage I neither above cutoff; Stage III, both above cut-off; and Stage II, any one above cut-off). Survival estimates were done according to the methods of Kaplan and Meier. Results: Median age was 64 years (range 44–88), with 70% male. Sixty-five percent of patients were previously treated, and the median time from diagnosis to study entry was 8.9 months (range 0.4–237). The biomarker staging breakdown was: I, 16%; II, 43%; and III, 41%. As of 7/11/08, 5 patients remain on active therapy. The overall hematologic response rate was 43% (1 CR and 15 PR), with only one patient responding to single agent lenalidomide, and the overall organ response rate was 20%. If one excludes the 13 patients who did not complete 3 months of therapy and have the opportunity of having dexamethasone added to their program, the respective hematologic and organ response rates were 62% and 32%. With a median follow-up of 33.6 months (range 14.4–42), twenty-two patients (59%) have died, but only 2 had deaths possibly related to treatment. Median duration of response, progression free survival and overall survival were 31 months, 14.8 months (95%CI: 5.7–28.1), and 18.8 months (95%CI: 11.7-not reached), respectively. Overall survival from diagnosis was 48 months (95%CI: 21.6–153.6). As shown in Table below, outcomes were dependent on underlying risk stratification and ability to stay on therapy. High risk patients were more likely to drop out early and less likely to respond. High risk patients had shorter OS All Patients Outcome Stage I Stage II Stage III p N 6 16 15 Survival from enrollment, mo NR 18.8 (11.7–33.6) 5.7 (3.2–18.3) 0.01 Survival from Diagnosis, mo NR 48.4 (20.4–62) 21.1 (11.2–31.7) 0.005 Progression Free Survival, mo 34.7 (33.7–NR) 18.3 (6.2–28.1) 4.4 (3–8.6) NS Drop out by cycle 4, % 17 31 60 NS Median # of cycles administered 31 6 3 0.04 Time to response, mo 6.2 (3.6–9.3) 6.4 (5.2–NR) 4.7 (3.8–NR) NS Hematologic response rate, % 83 38 27 0.05 Organ response rate, % 40 20 13 NS Duration of Response, mo NR 27.2 (13.6–NR) NR NS Subgroup analysis of patients receiving >3 cycles of therapy (i.e getting Len and Dex) N 5 12 7 Time on therapy, mo 35.2 8 10.5 Hematologic Response Rate, % 100 50 56 Organ response rate, % 50 27 25 Conclusions: Based on these data, single agent lenalidomide is not recommended for patients with AL; however, lenalidomide in combination with dexamethasone can be associated with good progression free and overall survival rates, even among patients with relapsed or refractory disease.
Prognostic Impact of the Plasma Cell Labeling Index (LI) in Newly Diagnosed Myeloma Patients Treated with Thalidomide-Dexamethasone (Thal/Dex) or Lenalidomide-Dexamethasone (Len/Dex).
Abstract Background: The plasma cell labeling index (LI), a slide-based measure of the percentage of bone marrow plasma cells in the S-phase of cell cycle, is a powerful prognostic tool in multiple myeloma (MM). A high LI is a marker of poor outcome, and is a useful adjunct to cytogenetics and fluorescent in-situ hybridization to risk-stratify MM patients. It has been shown to provide additional prognostic information in International Staging System (ISS) stages 1 and 2 patients treated with conventional chemotherapy ± autologous stem cell transplantation. However, the impact of a high LI is not known in patients receiving novel agents that have been integrated into the current treatment paradigm of newly diagnosed MM. The objective of this study was to determine the value of LI in patients treated with thalidomide-dexamethasone (Thal/Dex) or lenalidomide-dexamethasone (Len/Dex). Patients and Methods : Data from 125 newly diagnosed MM patients enrolled in clinical trials with either thalidomide (200mg/d) plus dexamethasone (Thal-Dex; n=50), or lenalidomide (25 mg/d on days 1–21 of a 4-week cycle) plus dexamethasone (Len-Dex; n=75) as initial therapy, were utilized. Patients within both the studies were categorized into 2 LI groups based on baseline LI: high (≥1%) vs. low (<1%) LI. Overall survival (OS) and progression-free survival (PFS) were estimated using Kaplan Meier method, and compared between the two LI groups within the Thal Dex and Len-Dex studies using log rank tests. Results : The median follow-up for patients on Thal-Dex and Len-Dex was 7.5 and 3 years, respectively. 36% (18/50) of patients in the Thal-Dex study and 35% (26/75) in the Len-Dex study had high LI. The baseline patient-characteristics, including age, stage (ISS), lactate dehydrogenase, calcium, hemoglobin and creatinine were comparable between the 2 studies. The median OS for patients receiving Thal-Dex was 4.7 years (95% CI 3.1–8.1); 2.3 years (95% CI 1.3–4.6) for patients with LI ≥1 compared to 6.9 years (95% CI: 3.9–NA) for those with LI <1 (P=0.02). The median OS for patients on Len-Dex was not reached for either the high or low LI group (P=0.80). The median PFS for all Thal-Dex patients was 1.7 years (95% CI: 1.4–3.1); 1.3 years (95% CI: 0.2–2.0) for patients with high LI vs.2.3 years (95% CI: 1.3–3.3) for patients with low LI; P = 0.01. The median PFS for Len-Dex patients was 2.6 years (95% CI: 1.8–3.1) years, and no significant difference was observed between the 2 LI groups, with PFS of 2.3 years (95% CI: 1.4–3.1) for patients with high LI, and 3.1 years for patients in the low LI group. Due to a shorter median follow-up of Len-Dex patients, a separate analysis censoring all patients in both the studies at 3 years was performed with similar results. Conclusion : LI remains a significant determinant of PFS and OS in newly diagnosed MM patients treated with Thal-Dex, with high baseline LI predicting poorer outcome. In contrast, during first 3 years of follow-up, the unfavorable prognostic effect of LI is not apparent with Len-Dex therapy, and longer follow-up is needed to determine if Len-Dex therapy overcomes the poor prognostic effect of high LI. Figure Figure
Phase II Trial of Lenalidomide, Cyclophosphamide, and Dexamethasone (CRd) for Newly Diagnosed Myeloma.
Abstract Background: The combination of lenalidomide and dexamethasone (Rev/Dex) has been shown to be a highly effective therapy for multiple myeloma (MM). Over half of the patients with newly diagnosed MM achieve a complete response with prolonged therapy. More recently, a phase III trial demonstrated improved survival with use of lenalidomide and low dose dexamethasone with one year survival in excess of 90%. We report the initial results from a phase II trial combining lenalidomide and low dose dexamethasone with cyclophosphamide (CRd) as initial therapy of newly diagnosed MM. Methods: The trial was initiated in July 2006 and completed the target accrual of 33 patients by July 2007. The treatment protocol consisted of lenalidomide given orally at a dose of 25 mg daily on days 1–21 of a 28-day cycle. Dexamethasone (dex) was given orally at a dose of 40 mg on days 1, 8, 15, and 22 of each cycle. Cyclophosphamide at a dose of 300 mg/m2 was given on days 1, 8, and 15 of each cycle. Patients also received an aspirin once daily as thromboprophylaxis. Response was defined as a decrease in serum monoclonal (M) protein by 50% or higher and a decrease in urine M protein by at least 90% or to a level less than 200 mg/24 hours, confirmed at least 4 weeks apart. Results: The median age was 63 years (range, 44–79). Eight patients (24%) had ISS stage III disease. At this time, 19 of the 33 patients are evaluable for confirmed responses (i.e., off-study or completed at least 4 cycles of therapy). Of these, 2 achieved VGPR and 13 had a partial response giving an overall response rate of 79%. The response rate was affected by 5 of 19 patients who went off study within three cycles due to toxicities [interstitial nephritis (1 pt), multiple grade 3 toxicities including infection (1 pt) atrial fibrillation and infection (1 pt)] or alternative treatment [no response and possible renal toxicity (1 pt) and progression at 4 cycles (1 pt)]. Overall, hematological toxicity was the most common with grade 4 toxicity seen in 6 patients (20%). Non-hematological grade 3 or higher toxicities included fatigue (4 pts), thrombosis (3 pts) and renal failure (2 pts). One patient with thrombosis came off study for other toxicities, and the other two continued on study with anticoagulation. Thirteen patients (43%) had dose reductions of both cyclophosphamide and lenalidomide, most commonly due to hematological toxicity. So far, 12 patients have gone off study, 6 went to stem cell transplant, 3 due to adverse events, 1 due to disease progression and 2 patients went to alternate treatment. Conclusions: CRd has excellent activity in newly diagnosed myeloma with an estimated overall response rate of 79%. Response evaluation of the entire 33 patients will be presented at the meeting. We believe that the initial use of a 300 mg/m2 dose of cyclophosphamide resulted in 5 of the first 19 pts experiencing early toxicity and withdrawal. As a result, an expansion of the current trial is evaluating lower doses of cyclophosphamide (300 mg fixed dose). Full analysis of this study will be needed to determine if CRd can improve outcome compared to Rd.
Phase II Pilot Study of Rituximab + CHOP in Patients with Newly Diagnosed Waldenström’s Macroglobulinemia, an Eastren Cooperative Oncology Group Trial (Study E1A02).
Abstract Waldenström’s Macroglobulinemia (WM) is a low-grade lymphoplasmacytic disorder associated with an IgM monoclonal protein that may present with anemia, lymphadenopathy, and hepatosplenomegaly. Since combination chemotherapy and Rituximab are both active in this disease, it is possible the response rate can be enhanced by using a combined modality of Rituximab and CHOP. This approach has been used in indolent lymphoma with remarkable results and limited toxicity. Objective: To determine the response rate in previously untreated patients with Waldenström’s Macroglobulinemia receiving rituximab and CHOP. Methods: This was a phase II study of standard R-CHOP in symptomatic WM patients. The study was activated on June 15, 2004 and closed on April 26, 2007 due to poor accrual. The median age of the sixteen patients enrolled was 60 (44–79 years), β2M 3 ug/ml (2.1–7.6), median hemoglobulin was 9 g/dl (7.7–10.9), Viscosity 3.4(1.6–10), and IgM 6389 (3229–13300 mg/dl). The most common symptoms were Fatigue (13/16), visual disturbance (7/16) and parasthesias or painful/numb feet (6/16). Only one patient had bulky adenopathy (6.3%). Results: Of 16 patients treated, 5 patients have no response data available (it will be presented at the meeting). Objective response was 91% (90% CI: 63.5% ∼ 99.5%) and 1 patient had a minor response with an overall response rate of 100%. Median time to response was 1.6 months from registration and median time to maximum response was 2.1 months. Median duration of response has not been reached. The median follow up time of the 16 patients was 18.3 months with a range of 3.6–24.8 months. Among the 16 treated patients, there were 8 (50%, 90% exact binomial CI: 27.9%∼72.1%) grade 4 neutropenia. 8 patients experienced grade 3 lymphopenia (50%, 90% exact binomial CI: 27.9%∼72.1%). Only 2 grade 3 febrile neutropenia were noted. As of August 4, 2007, none of the 16 patients has died. R-CHOP is a promising regimen in the treatment of patients with Waldenström’s Macroglobulinemia. To succeed in completing clinical trials in this rare disease better international collaboration and involvement in advocacy groups are required.
Melphalan and Dexamethasone Is an Effective Therapy for Primary Systemic Amyloidosis.
Abstract Background: Primary systemic amyloidosis (AL) is an incurable plasma cell disorder with a poor survival, especially in patients (pts) with multiple organ involvement. For pts with limited organ involvement, high dose chemotherapy with autologous stem cell (SCT) support is an effective approach. However, the toxicity of SCT limits its widespread use. Melphalan and dexamethasone has been previously shown to be effective in pts ineligible for SCT. Methods: We reviewed our experience with melphalan and dexamethasone for treatment of AL. Eighty one pts were treated between 2001 and 2003; median age at start of therapy was 63 years (range, 38–80) and 56 pts (69%) were males. Among these, 46 pts (57%) had 2 or more major organs (cardiac, renal, hepatic) involved. Intravenous melphalan (IV) was used in 45 pts (56%), 32 (40%) received oral melphalan (PO) and the rest received cycles of both. The most common doses were 16 mg/m2 for IV administration (every 4–6 weeks) and 0.22 mg/kg for PO administration (every 4 weeks). Dexamethasone was usually given at a dose of 40 mg for the first 4 days of each cycle. Results: Patients received a median of 5 cycles (range; 1–17). At the time of analysis, 53 (65%) pts were alive with a median follow up of 10.8 months (range, 1.4–47.1).The estimated median overall survival (OS) was 25.6 months for the entire group, with the number or type of organs involved not impacting survival. Hematological response (HR) was defined by a 50% reduction in either serum M-spike, urine M-spike, or the absolute difference between the involved and uninvolved immunoglobulin free light chains. A HR was observed in 43 pts (67%) of the 64 pts measurable for HR by conventional criteria. Achievement of HR was associated with a superior OS with a median post-therapy OS that was not reached, while non-responders had a median OS of 11.1 months (p<0.0001) (Figure 1). Among these pts, an organ response as defined by conventional criteria, was seen in 14 pts (22%), which was significantly correlated with obtaining a hematological response (33% vs. 5%, p=0.01). A 25% reduction in the difference between the involved and uninvolved FLC strongly predicted prolonged OS, with a median post-therapy OS that was not reached for responders vs. 11.3 months for non-responders (p<0.0001) (Figure 2). A decrease in post-therapy brain natriuretic peptide (BNP) also predicted for a survival improvement, with the median OS not reached for responders vs. a median OS of 17 months for non-responders (p<0.016). Conclusion: Treatment with melphalan and dexamethasone is effective and a significant survival advantage is achieved in patients with a hematological response. FLC and BNP response can help identify patients that are likely to benefit from this therapy. Figure Figure Figure Figure
Myeloma International Staging System Retains Its Prognostic Value at Disease Relapse.
Abstract Background: The international staging system is a simple, but powerful staging system that is based on two simple and easily available laboratory measurements. The system was developed and validated on a large group pf patients from across the world and has become the standard for patients with newly diagnosed myeloma. While it’s prognostic value is clear in patients with newly diagnosed myeloma, its value at relapse has not been explored. Methods: We examined a uniform cohort of patients relapsing after an autologous stem cell transplant to assess the utility of ISS determined at the time of documented relapse. Relapse was defined using standard EBMTR response criteria. Beta-2 microglobulin and albumin values from within 30 days of the date of relapse were extracted from the medical records. ISS was determined based on the published cut offs. Results: Of the 389 patients evaluated, 132 had values available for B2M and 276 patients had the serum albumin available. Only 131 patients had both the data available and the ISS stage could be determined. Of these patients, 64 patients (49%) were ISS stage I, 50 (38%) were stage II and 17 (13%) were stage III. An albumin < 3.5 mg/dL was prognostic for overall survival post relapse with a median survival of 10.5 months for those with albumin < 3.5 mg/dL compared to 26.3 months for the rest of the group (P < 0.0001). Similarly the median OS from relapse was 15 months for those with B2M > 3.5 mg/dL compared to 23.3 months for those with lower B2M (P = 0.014). The ISS stage predicted overall survival for this group of patients with the OS from relapse estimated at 27.3 mos, 17.8 mos and 12.3 months for ISS stage I, II and III respectively. Conclusions: In a uniform group of patients relapsing after autologous stem cell transplantation, the B2M and albumin maintain their prognostic value and allows the use of the International Staging System for determining prognosis. This supports the use of ISS stage in relapsed trials and will allow comparisons across studies. Results should be validated in a larger dataset that will allow comparisons to other known prognostic factors. Figure Figure
Improving Survival in Multiple Myeloma: Impact of Novel Therapies.
Abstract Background: Recent advances in the therapy of multiple myeloma (MM) have greatly increased the treatment options for this uniformly fatal plasma cell malignancy. It is not clear if introduction of novel therapies and the increased use of high dose therapy (HDT) in the past decade have translated into better outcome for patients (pts) with MM. Methods: We examined the outcome of two cohorts of pts seen at our institution. The first cohort consisted of 387 pts who relapsed after HDT and was examined for potential improvement in survival following relapse after HDT. These pts were divided into two groups; those who relapsed before or after December 31, 2000. The second cohort consisted of 2981 patients with newly diagnosed MM seen between January 1971 and December 2006 and was used to examine the trends in overall survival (OS). Results: Among those relapsing after HDT, there were 245 males (63%); median (range) age at HDT was 57 years (32.8–75.4) and the median time to HDT was 8.1 months (1–90 months) from diagnosis. The median time to relapse was 13.2 months (1.1 months-10.3 years) from HDT. In this cohort, a clear improvement in OS from time of relapse was seen over the past decade, with those relapsing after 2000 having a median OS of 23.9 months (95% CI; 19.8, 27.6) compared to 11.8 months (95% CI; 8.7, 14.9) for the rest (P < 0.001) (Figure 1). In a multivariate analysis, the effect of the date of relapse on survival was independent of other prognostic factors such as relapse <12 months after HDT, abnormal cytogenetics, and B2M > 5.5 mg/dL. Pts who were treated with one or more of the newer drugs (thalidomide, lenalidomide, bortezomib) had longer survival from relapse (30.9 months (95% CI; 23.6, 38.2) compared to 14.8 months (95% CI; 11.3, 18.4); P < 0.001) for others. Among the newly diagnosed MM cohort, the median age at diagnosis was 66 years (20.2 – 97 years), and 1,770 (59.4%) were males. The median follow up for the entire group was 27.4 months (0–29.4 years); and at the time of analysis 558 patients (18.7%) were alive with a median follow up of 32.7 months (0–29.4 years). Pts diagnosed in the last decade had an improved OS (44.8 months) compared to those diagnosed before this period (29.9 months; P < 0.001) (Figure 2). The improvement in survival seen in the last decade among newly diagnosed patients was predominantly among those younger than 65 years (60.3 mos vs. 33.3 mos improvement in median survival); compared to those over 65 at diagnosis (26.5 mos vs. 32 mos). Conclusion: In this study, for the first time, we demonstrate definite proof for improved outcome in patients with myeloma, both in the relapsed setting as well as at diagnosis, a change that is likely to continue with increased use of these drugs. Figure Figure Figure Figure
Proteomic Analysis of Multiple Myeloma Identifies Potential Targets for Drug Therapy.
Abstract The objective of this study was to investigate the underlying molecular alteration in multiple myeloma at the protein level in order to identify regulators of pathogenesis, discover novel targets of therapy, and compare genetic and proteomic alterations. We employed antibody protein microarrays (BD Clonetech, CA) to measure changes in the patterns of protein expression between MM and normal plasma cells. The antibody array is a new technique enabling protein differences to be assayed directly by hybridizing fluorescently labeled protein mixtures from cell extracts onto glass slides spotted with 512 different monoclonal antibodies. CD138+purified plasma cells were obtained from cryopreserved bone marrow samples of 12 newly diagnosed patients with MM. The labeling index was high (1% cutoff) in 7 samples and low in the other 5. Control plasma cells were obtained from 9 pooled CD138+ purified normal donor bone marrow plasma cells. Interphase FISH analysis for 17p deletion, 13q deletion, and t(11:14) were performed. To assess differential expression, the mean of the ratios of Cy5/Cy3 for each sample were analyzed using the Clontech software to calculate an internally normalized ratio. The normalized data were analyzed by the Genespring software. Unsupervised clustering identified 4 groups of MM. Changes of protein expression ≥2 fold in 70% of the samples as compared to control were identified. There were 6 proteins differentially expressed between all MM samples and control cells including proteins in the ras signaling pathway (KSR-1), the ubiquitin pathway (Ubc-H6), cyclin-dependent kinases (CDK4), cytokines (IL-6), DNA toposisomerase II, and the rho-interacting serine-threonine kinase CRIK. Proteins differentially expressed in MM groups 1 and 2 compared to normal control included cell cycle regulators (cul-2, MCM6, PCNA, TGFb1), kinases (p70S6K, PKC), and chromatin regulators (Ran, AKAP450, Rad50). Protiens differentially expressed in MM group 3 included cell cycle regulators (CDK2, CLK1, MENA), apoptosis regulators (XIAP, caspase 4, perforin) kinases (IKKa and RAC1 in the Wnt signaling pathway) and P53 regulators, while proteins identified in MM group 4 included NFkB/ubiquitin proteins (IKKa and Ubch6), cell cycle regulators (c-myc, CDK4), p53 pathway proteins (53bp2), ras-signaling proteins (KSR1), and the kinase CRIK. There were no differences in protein expression between the high and low labeling index groups. 13q was identified in 5 (42%), 17 p in 1(8%) and t(11:14) in 1(8%) patients. 80% of the 13 q deletion cases clustered in MM group 1 and 2 patients. Cyclin D-1 was upregulated in 5 (42%) patients including the patient with (11:14) translocation. This is the first proteomic study of patients with MM. The results are consistent with previously identified genetic alterations in MM indicating that this novel technique could be used in identifying molecular changes in MM. It identifies novel proteins dysregulated in MM that differ between the 4 MM groups. These results may be used in the future to individualize therapy based on the proteins dysregulated in each group. For example, IKK inhibitors may be useful in group 3 MM patients, while mTOR inhibitors (upstream of p70S6K) could be used in groups 1 and 2 patients. Future correlations with gene expression arrays and prognosis in a larger cohort of patients is warranted.