Gupta, Vinay Kumar

8600 Background: The combination of bortezomib, dexamethasone, thalidomide, cisplatin, doxorubicin, cyclophosphamide and etoposide (VDTPACE) was developed as an intense regimen for disease control prior to tandem transplantation for multiple myeloma (MM) in total therapy protocols. The regimen is very effective in this setting, and since has also been used in the relapsed setting. We examined the outcomes of a set of patients undergoing VDTPACE therapy for relapsed MM at our institution. Methods: We identified 71 patients who received VDTPACE for relapsed MM, at Mayo Clinic from 7/2006 to 7/2012. Plasma cell leukemia was excluded. All data was extracted from clinical records. Results: The median age of patients was 59 years (range, 39-80); 48 (67.6%) were male. The median time from diagnosis to initiation of VDTPACE was 38.2 months (range, 2-125). The median number of cycles given was 1 (range, 1-9). The overall response rate after one cycle was 57.1% (14.3% VGPR, 22.2% PR and 20.6% MR) in the 63 patients in whom the response was evaluable. The median overall survival (OS) post-VDTPACE was 8.2 months (95% CI, 5.7-10.9). Eighteen (25.4%) patients went on to autologous stem cell transplantation (SCT), and 7 (9.9%) received matched allogeneic SCT following VDTPACE, and the median OS post-VDTPACE was significantly longer for these groups compared to those who were not transplanted (15.3 and 20.5 months, respectively vs 5 months, p-value <0.001). Thirty eight of 66 (57.6%) patients were rehospitalized after initial admission for infusion therapy for a median duration of 6 days (range, 1-26). The median platelet and red cell transfusions were 4 (range, 0-21) and 5 (range, 0-22) units, respectively. Renal toxicity was seen in 13/62 (21%) patients and 27/65 (41.5%) patients developed neutropenic fever. The median duration to absolute neutrophil and platelet count recovery was 18 (range 12-42) and 27 (range, 12-42) days, respectively. Three (4.2%) patients died within 30 days and 11 (15.5%) within 8 weeks of initiating VDTPACE. Conclusions: VDTPACE is an effective therapy in relapsed MM but is associated with significant morbidity and short-term mortality. It appears to be more effective when followed by an autologous or allogeneic SCT.

8587 Background: Patients (pts) undergoing an auto-transplant (ASCT) for multiple myeloma (MM) have disease assessment approximately 100 days later. This result may direct decisions of further therapy versus observation. However, some pts continue to experience a decline in their serum or urine monoclonal (M) - protein after day 100 without more therapy. Little is known about the prevalence and significance of this phenomenon. Methods: We identified 903 MM pts who underwent ASCT within 12 months (mos) of diagnosis (Dx) at our institution. Their day 100 post-ASCT M-protein from serum and urine electrophoresis with immunofixation as well as serum free light chains were compared to subsequent values during follow-up. The IMWG criteria were used to evaluate response. Results: Of the pts included, 510 (56%) were male and median age at ASCT was 59 (range 28-76). Median follow up from Dx and ASCT was 82 mos (95% CI; 75 - 86) and 74 mos (95% CI; 70 - 79) respectively. There were 453 (50%) pts seen in follow-up who had not achieved a CR at Day 100 nor initiated on maintenance therapy. Of these pts, 167 (37%) had a further decrease in their M-protein after day 100 at a median of 9.4 mos (95% CI; 8 – 10) post-ASCT. Given the time taken for maximal response, we assessed patients’ clinical response at one year post-ASCT. Compared to patients who did not have further clinical response between day 100 and 1 year, pts experiencing further response had a longer time to next therapy (TTNT) (43 mos vs. 17 mos, P < 0.001) as well as overall survival (OS) (96 mos vs. 62 mos, P < 0.001). Positive predictors for continued response included having an IgG isotype, evolution from a pre-existing MGUS, smoldering myeloma or solitary plasmacytoma and a Day 100 bone marrow plasma cell < 3%. In a multivariate analysis, elevated creatinine at Dx and lack of continued response predicted for shorter TTNT and OS post-ASCT. Older age and high-risk MM by FISH also predicted a shorter OS. Conclusions: In MM pts undergoing ASCT, continued M - protein response was seen in a third of the pts lacking a CR at day 100. This phenomenon appears prognostic and must be considered when interpreting studies evaluating post-ASCT response and the need for further therapy.

2058 Background: We present a tertiary center experience with high-dose methotrexate, rituximab and temozolomide (MRT) chemotherapy in both primary and secondary CNS lymphoma. Methods: A retrospective analysis was performed for a total of 27 patients (20 male, 7 female) who underwent treatment at Mayo Clinic, Rochester between November 2010 and October 2012. The median age was 63 years (range 23-73). Of these, 12 patients were diagnosed with primary CNS lymphoma, while 15 patients had secondary CNS lymphoma. All patients received at least 1 cycle of MRT. The most common histological subtype was diffuse large cell lymphoma (23 of 27 patients). Other histological subtypes were high grade lymphoma (2 patients), Burkitt’s lymphoma (1 patient) and Mantle cell lymphoma (1 patient). Results: Of 26 patients, who underwent imaging studies for response assessment after MRT, 14 patients achieved complete response (CR), 4 patients achieved partial response (PR), 2 patients had stable disease, while 6 patients had evidence of disease progression. Overall, the median number of chemotherapy cycles with MRT was 3 (range 1-6). For patients, who achieved CR, the median number of MRT cycles was 4 (range 2-6). MRT was well tolerated. Of 27 patients, who underwent their entire treatment at Mayo Clinic, grade 3 or higher treatment related toxicity were noted to be as follows – neutropenia (9/27), thrombocytopenia (4/27), anemia (7/29), and transaminitis (10/27). 16 of 27 patients proceeded to high dose chemotherapy and autologous stem cell transplant. Out of 16 patients, 14 received BCNU/Thiotepa as conditioning regimen, while 2 patients underwent BEAM conditioning. All 16 patients who underwent transplantation remain in CR at this time. Of the remaining 11 patients, 4 are being planned for autologous transplantation, 2 received and responded to salvage chemotherapy, while 5 patients died of progressive disease. Conclusions: Overall, the MRT regimen was well tolerated. Overall response rate was noted to be 67% (18 of 27 patients) and achieved CR in 54% patients (14 of 26 patients). Patients who underwent autologous stem cell transplantation as consolidation therapy continue to do well at a median followup of 12.5 months (range 2-20 months).

Abstract Background The management of extramedullary relapse (EM) of acute myeloid leukemia (AML) after allogeneic stem cell transplant (allo-SCT) is not standardized. We present a single institution experience, describing the risk factors, outcomes and management of EM leukemia relapse in AML patients who underwent allo-SCT. Methods After due IRB approval, 351 patients with AML who underwent allo-SCT at Mayo Clinic, Rochester, from 1985 through 2012, were evaluated for EM relapse. All patients had BM biopsies and cytogenetic studies at diagnosis and at relapse. Extramedullary relapse was identified by clinical exams and radiological methods and confirmed where possible by biopsies and cerebrospinal analysis (CSF). Clinical, pathological and transplant related data was retrospectively abstracted. Results Of 351 patients, 26 (7%) had EM involvement at initial diagnosis (17 CNS, 9 non-CNS, 3 both). Forty-four (13%) patients had CNS disease detected prior to allo-SCT. Of these, 17 (39%) were detected at AML diagnosis due to clinical signs/symptoms, 11 (25%) were detected to have CNS involvement at the time of AML relapse and 16 (36%) were asymptomatic; diagnosed on routine pre transplant CSF studies. All patients with pretransplant EM disease received appropriate therapy prior to undergoing transplantation. After allo-SCT, 21 (6%; 12 male) of 351 patients sustained an EM relapse (11 CNS alone, 9 non-CNS, 1 both). The non-CNS EM relapse sites were cutaneous, skeletal, renal, breast, testicular, gastrointestinal tract and soft tissue. In 12 patients with CNS relapse, 8 (68%) presented with localizing signs and symptoms and 4 were asymptomatic. The median age at EM relapse was 42 years (range; 2 - 61 years) and the median time to EM relapse was 443 days (range; 90- 6069 days). Salvage therapy offered in 18 patients included, intrathecal chemotherapy (IT) alone in 2, IT + systemic chemotherapy (CTX) in 2, allo-SCT in 1, CTX alone in 6, IT + radiation therapy (XRT) in 1, CTX, IT and XRT in 1, and CTX + XRT in 5 patients, respectively. Three patients were ineligible for further therapy. Median survival after EM relapse was 136 days (18 – 819, days), with 4 patients alive at last followup. At the time of AML diagnosis; 6 (29%) of 21 patients had EM involvement (2 breast, 1 lymph node, 1 CNS and lymph node, 1 cutaneous), 8 (38%) patients had a monocytic differentiation (AML-M4/M5) and 6 of 9 tested, had CD56 expression. Three (14%), 8 (38%) and 10 (48%) patients were risk stratified based on cytogenetic and molecular status (FLT3/NPM1) into favorable, intermediate and high risk, respectively. Subsequently, all 21 patients underwent allo-SCT with 14 patients undergoing matched related donor (MRD) transplants. The transplant conditioning was myeloablative in 16 (76%) patients, of which 11 (69%) received total body irradiation (TBI). Grade II-IV acute graft versus host disease (GVHD) was noted in 11 (52%) patients, while chronic GVHD was noted in 8 (38). On univariate analysis, factors associated with shortened survival after EM relapse included; high risk karyotype at diagnosis (p=0.009), concurrent bone marrow involvement with EM relapse (p=0.01) and reduced intensity conditioning (RIC) (p=0.04). Importantly, CD56 expression (p=0.27), CNS involvement at diagnosis (p=0.76), and chronic GVHD (p=0.383) were not prognostic. On a multivariate analysis, high risk karyotype (p=0.04) and concurrent bone marrow involvement (p=0.04) retained their negative prognostic value. Conclusions Although uncommon, EM relapse after allo-SCT for AML is associated with poor outcomes. Pretransplant CSF screening identifies a significant number of asymptomatic patients with CNS disease. High risk karyotype at diagnosis and concurrent BM involvement with EM relapse are poor prognosticators. Disclosures: No relevant conflicts of interest to declare.

Abstract Background The presence of circulating plasma cells (PCs) in multiple myeloma (MM) is a known poor prognostic marker. Prior studies have utilized a technically challenging slide-based immunofluorescence technique to detect and quantify the presence of circulating PCs which was not widely adapted in clinical practice. More recently, the routine use of flow cytometry has provided the opportunity to quantitatively assess circulating PCs in MM patients with relative ease. We report the prognostic value of quantifying circulating clonal PCs using multiparametric flow cytometry in MM patients with relapsed disease. Methods We evaluated all MM patients seen at the Mayo Clinic, Rochester from 2009 to 2011 with previous or ongoing relapsed disease and who had their peripheral blood samples evaluated by flow cytometry. Each blood sample had its peripheral blood mononuclear cells isolated by ficoll gradient and stained with antibodies to CD45, CD19, CD38, CD138 and cytoplasmic Kappa and Lambda Ig light chains. A six-color multi-parameter flow cytometer (Becton Dickinson FacsCantos II) was used to examine each sample with a target of detecting 150,000 events (cells) that was then analyzed using the Facs Diva Software. Plasma cells were selectively analyzed through combinatorial gating using light scatter properties and CD38, CD138, CD19, and CD45. Normal PC's were then separated from clonal plasma cells based on the differential expression of CD45, CD19 and polytypic Ig light chains. The clonal plasma cells detected were reported out as the number of clonal events/150,000 collected total events. For those samples where less than 150,000 events were gated or examined, the number of final clonal events was adjusted to 150,000 events. Survival analysis was performed by the Kaplan-Meier method and differences in survival assessed using the log rank test. Results There were 647 consecutive patients with a history of treated MM who had a peripheral blood flow cytometry as part of their routine clinical evaluation. The median patient age was 62 years (29-88) and 55% were male. The median time since diagnosis was 12 months (range: 1-363) and the median number of lines of treatment received was 2 (1-11). There were 81 (13%) patients with clonal circulating PCs with a median of 368 cells (4 – 133,464). The 2-year overall survival (OS) for the 81 (13%) patients with any circulating PCs was 17% compared with 65% for those with none (P<0.001). The presence of circulating clonal PCs was associated with high-risk disease by FISH (P <0.001) as well as higher PCLI (P <0.001). We then correlated the presence of circulating clonal PCs with the disease status at flow cytometry assessment. Among the study patients, only 145 (22%) had actively relapsing disease with the remaining 502 (78%) in a plateau including patients in CR. Circulating clonal PCs were more likely to be detected in patients with actively relapsing disease compared with plateau phase (43% vs. 4%, P < 0.001); none of the CR patients and <5% of the remaining plateau phase patients had any detectable circulating clonal PCs. We then restricted the analysis to the actively relapsing patients; the best cutoff predicting 1-year mortality by ROC analysis was 100 events. Based on this, we defined >=100 events as a cutoff for defining the prognostic role of circulating clonal PCs in actively relapsing patients. The median OS for those with >=100 clonal PC events was 12 months compared with not reached for those with <100 events (p<0.001; Figure 1 ). Among patients with actively relapsing disease, >= 100 circulating PCs was associated with a higher ISS stage, plasma cell labeling index and bone marrow PC% compared with those with <100 circulating PCs. In a multivariable model, only LDH > 222 (HR: 2.08, P = 0.045) and >= 100 circulating PCs (HR: 2.48, P = 0.048) were found to adversely affect OS in actively relapsing patients. Conclusion The utilization of flow cytometry to quantify circulating clonal PCs in patients with relapsed MM appears to have significant prognostic relevance. In patients with actively relapsing disease, >= 100 circulating PCs predicted for worse OS with a median of 12 months. Future studies are needed to determine if this would allow an opportunity to develop a more risk adapted approach for patients with relapsed disease. Disclosures: Kumar: Celgene: Consultancy, Research Funding; Millennium: Consultancy, Research Funding; Onyx: Consultancy, Research Funding.

Abstract Background Prior studies have shown that presence of increased circulating plasma cell (PCs) identified using a slide-based immunofluorescence method is an adverse prognostic marker for overall survival in multiple myeloma (MM), and increases the risk of progression in patients with MGUS and smoldering MM. However, utility in clinical settings has been limited by the cumbersome nature of the test and lack of widespread availability. We studied the prognostic value of circulating PCs using sensitive multiparametric flow cytometry that enable us to quantitatively assess circulating PCs in patients with MM. Methods We evaluated all newly diagnosed MM patients seen at the Mayo Clinic, Rochester from 2009 to 2011 who had their peripheral blood samples evaluated by flow cytometry prior to therapy. Patients with plasma cell leukemia were excluded. Each blood sample had its peripheral blood mononuclear cells isolated by ficoll gradient and stained with antibodies to CD45, CD19, CD38, CD138 and cytoplasmic Kappa and Lambda Ig light chains. A six-color multi-parameter flow cytometer (Becton Dickinson FacsCantos II) was used to examine each sample with a target of detecting 150,000 events (cells) that was then analyzed using the Facs Diva Software. PCs were selectively analyzed through combinatorial gating using light scatter properties and CD38, CD138, CD19, and CD45. Normal PC's were then separated from clonal PCs based on the differential expression of CD45, CD19 and polytypic Ig light chains. The clonal PCs detected were reported out as the number of clonal events/150,000 collected total events. For those samples where less than 150,000 events were gated or examined, the number of final clonal events was adjusted to 150,000 events. Survival analysis was performed by the Kaplan-Meier method and differences assessed using the log rank test. Results There were 158 consecutive patients with newly diagnosed MM who had their peripheral blood evaluated via flow cytometry as part of their routine clinical evaluation. The median age of this group was 66 years (39-95) and 59% were male. At the time of this analysis, 25 patients had died and the 2-year OS rate for the cohort was 83%. The 2-year OS for the 89 (55%) patients with any circulating PCs was 76% compared with 91% for those with none (P=0.02). The median number of circulating clonal PCs was 33 (range, 0-46,413)/ 150,000 gated events. Using a ROC analysis the best cutoff predicting 1 and 2-year mortality were 435 and 376 events, respectively. Based on this, we defined >=400 events as a cutoff for defining patients with high-risk disease. The median time-to-next-treatment (TTNT) for patients with circulating clonal PCs >=400 (n=37, 23%) was 14 months compared with 26 months for those with <400 events (n=121, 77%) (p<0.001; Fig 1a). The median OS for those with >=400 clonal PC events was 32 months compared with not reached for those with <400 events (p<0.001; Fig 1b). Patients with >= 400 circulating PCs had higher ISS stage, creatinine, LDH, PC labeling index and bone marrow PC% compared with the rest. In a univariate analysis examining the presence of circulating PC >=400, LDH, labeling index, marrow PC% and FISH risk status, only circulating PCs were prognostic for overall survival (P = 0.0011). Among the 89 patients with any circulating PCs, 26 (30%) had CD45+ clonal PCs. The TTNT in patients with a clonal CD45+ population was inferior to those with no CD45+ clonal PCs in circulation (median 11 vs. 19 months, P = 0.034) as was the OS (P = 0.039). Conclusion Quantitative estimation of circulating clonal PCs in patients with newly diagnosed MM is a powerful predictor of early relapse from therapy and mortality. A cutoff of >=400 clonal events/150,000 gated mononuclear events predicts for a median TTNT of 14 months and OS of 32 months. This parameter is more powerful than the current high-risk parameters such as FISH risk status as well as traditional high-risk markers such as ISS stage and LDH levels, and is able to identify a group of patients with particularly poor outcome. Disclosures: Kumar: Celgene: Consultancy, Research Funding; Millennium: Consultancy, Research Funding; Onyx: Consultancy, Research Funding.

Summary The presence of clonal circulating plasma cells (c PC s) remains a marker of high‐risk disease in newly diagnosed multiple myeloma (MM) patients. However, its prognostic utility in MM patients with previously treated disease is unknown. We studied 647 consecutive patients with previously treated MM seen at the Mayo Clinic, Rochester who had their peripheral blood evaluated for c PC s by multi‐parameter flow cytometry. Of these patients, 145 had actively relapsing disease while the remaining 502 had disease that was in a plateau and included 68 patients in complete remission (CR) and 434 patients with stable disease. Patients with actively relapsing disease were more likely to have clonal c PC s than those in a plateau ( P < 0·001). None of the patients in CR had any clonal c PC s detected. Among patients whose disease was in a plateau, the presence of clonal c PC s predicted for a worse median survival (22 months vs. not reached; P = 0·004). Among actively relapsing patients, the presence of ≥100 c PC s predicted for a worse survival after flow cytometry analysis (12 months vs. 33 months; P < 0·001). Future studies are needed to determine the role of these findings in developing a risk‐adapted treatment approach in MM patients with actively relapsing disease.

Key Points Survival of patients with primary plasma cell leukemia has improved in recent years, but is still inferior to those patients with multiple myeloma. This survival benefit appears to be mainly in patients older than 65 years of age.