Citations

Compared with traditional bulk sequencing technologies, single-cell technologies have advantages to evaluate cellular heterogeneity and investigate the evolution of cellular subpopulations from the tumor and microenvironment. Application of single-cell sequencing in Multiple Myeloma (MM) is especially beneficial given MM is a highly heterogeneous disease with uncontrolled clonal expansion of plasma cells. Single-cell RNA sequencing (scRNA-seq) has been previously utilized to understand this hematopoietic malignancy in both tumor and immune populations in MM (Ledergor G. et al., 2018, Zavidij, O. et al., 2020). Mass cytometry (CyTOF) has also been used to identify the expansion of novel memory B cells in MM. (Hansmann, L. et al., 2015). Among the various single cell techniques, cellular indexing of transcriptomes and epitopes by sequencing (CITE-seq) is a multimodal approach with simultaneous quantification of single-cell transcriptomes and surface proteins. Since these three single-cell approaches enable the identification of cell types, cell states and characterization of cellular heterogeneity at transcriptomic and/or protein levels, understanding the concordance of the measurements among these three modalities is of great interest. We applied scRNA-seq, CyTOF and CITE-seq on four baseline samples of CD138-negative 'immune cell' fractions from patients enrolled in the MMRF CoMMpass study (NCT01454297). Two subjects were fast progressors (PFS < 18 months) and two subjects were non-progressors (PFS not reached). With multi-center collaboration coordinated by Multiple Myeloma Research Foundation (MMRF), each sample was subject to scRNA-seq and CyTOF by 3 independent centers. All sites received aliquots of the same sample. On average, 1,060 immune cells were detected in each sample using scRNA-seq and >64K CD45+ cells were detected using CyTOF. CITE-seq was performed in one center and 4,805 CD138-negative immune cells were identified on average. To compare cell type abundance between scRNA-seq, CyTOF and CITE-seq, we calculated the cell subset frequency of each immune population relative to the CD45+ populations. Overall, all three approaches were concordant while there is a stronger concordance between scRNA-seq and CyTOF. Cell type abundance is especially consistent for B cells, monocytes/macrophages, and plasmacytoid dendritic cells (pDC) among the 3 methods. For the same patient of interest, natural killer (NK) cell frequency was detected at the lowest level in CyTOF relative to scRNA and CITE-seq. The T cell population showed the highest discrepancy among techniques, with highest abundance in scRNA-seq followed by CyTOF and lowest abundance in CITE-seq. Interestingly, CITE-seq detected far less CD4 T cells compared to the other two techniques while CD8 T cell frequency did not show drastic differences. In addition to cell type abundance, we further examined the concordance of expression of cell type signature genes between scRNA-seq and CyTOF. Overall, expression between RNA-level and protein-level is positively correlated with typical cell type markers highly expressed in both techniques, especially in the following cell populations: CD8+ T cells (CD3, CD8), NK cells (CD56, GranzymeB/GZMB, NKG2A/KLRC1), B cells (CD19, CD38), Monocytes (CD14, CD11c/ITGAX, CD33). To note, although the concordance in CD4+ T cells is generally good, we found the expression of CD4 is higher in CyTOF compared to scRNA-seq whereas CD127/IL7R tends to be overexpressed in scRNA-seq. This could explain why IL7R is often identified as a differentially expressed gene (DEG) in CD4+ T cell population while CD4 is barely seen in DEG list in scRNA-seq analysis. It is also interesting to notice that the expression of most NK cell markers has strong concordance between scRNA-seq and CyTOF except NKG2D/KLRK1, which has much higher expression in CyTOF relative to scRNA-seq. Our preliminary results suggested good concordance of immune cell type abundance identified in CyTOF, scRNA-seq and CITE-seq as well as concordant expression of some canonical cell type markers between RNA level and protein level. This work provides the field with reference data sets and shows more detailed examination of NK and T cell subsets is needed when handling single cell sequencing with different modalities. Disclosures Dhodapkar: Roche/Genentech: Membership on an entity's Board of Directors or advisory committees, Other; Lava Therapeutics: Membership on an entity's Board of Directors or advisory committees, Other; Kite: Membership on an entity's Board of Directors or advisory committees, Other; Janssen: Membership on an entity's Board of Directors or advisory committees, Other; Celgene/BMS: Membership on an entity's Board of Directors or advisory committees, Other; Amgen: Membership on an entity's Board of Directors or advisory committees, Other. Kumar:MedImmune: Research Funding; Amgen: Consultancy, Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments, Research Funding; AbbVie: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Janssen Oncology: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Carsgen: Other, Research Funding; Merck: Consultancy, Research Funding; Adaptive Biotechnologies: Consultancy; Celgene/BMS: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Genentech/Roche: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Oncopeptides: Consultancy, Other: Independent Review Committee; IRC member; Kite Pharma: Consultancy, Research Funding; Novartis: Research Funding; Sanofi: Research Funding; Takeda: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Tenebio: Other, Research Funding; Karyopharm: Consultancy; BMS: Consultancy, Research Funding; Genecentrix: Consultancy; Cellectar: Other; Dr. Reddy's Laboratories: Honoraria. Gnjatic:Neon Therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees; OncoMed: Consultancy, Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Research Funding; Genentech: Research Funding; Immune Design: Research Funding; Agenus: Research Funding; Janssen R&D: Research Funding; Pfizer: Research Funding; Takeda: Research Funding; Regeneron: Research Funding; Merck: Consultancy, Membership on an entity's Board of Directors or advisory committees. Bhasin:Canomiiks Inc: Current equity holder in private company, Other: Co-Founder.

Abstract Background: The free light chain (FLC) assay allows a nephelometric measurement of this free kappa and lambda light chains that circulate as monomers or dimers, not bound to the immunoglobulin heavy chain. Estimation of the free light chain levels and their ratio has utility in screening, prognostication and treatment response assessment in multiple myeloma, and is particularly useful in light chain myeloma. Previous studies have suggested that absence of a functional rearrangement on at least one of the IgH allele is the basis of light chain myeloma. Translocations involving the immunoglobulin heavy chain (IgH) locus on chromosome 14 can be detected using FISH in over half of the patients with myeloma. We hypothesized that presence of an IgH translocation may be associated with compromised production of heavy chains and leads to unbalanced, excess production of clonal light chain. Methods: From February 1988 to May 1992, 653 patients with previously untreated multiple myeloma were enrolled on the phase III clinical trial E9486. Serum free light chains were run on stored sera obtained at baseline in 495 patients as part of a previous study. Among these patients, 314 patients were previously studied using FISH for presence or absence of IgH translocations, p53 abnormalities and deletion 13 and were included in the current analysis. Results: The median difference between the involved and uninvolved FLC (FLCdiff) was higher among the group of patients with any IgH translocation abnormality compared to those with none (Figure 1). This was particularly evident among the patients with a t(14;16) who had the highest FLCdiff. In a multivariate analysis, we examined if the prognostic value seen with FLCdiff was independent of the presence of IgH translocations t(4:14) and t(14;16), which are associated with a worse outcome. The presence of t(4;14) or t(14;16) was associated with FLCdiff groups using a cutoff point of 185, with 13% of those with FLCd ≤185 and 27% of those with FLCd > 185 having the translocations (P= 0.008). At the cutoff value of 185, the prognostic value of the FLC-diff on progression free and overall survival appears to be independent of these high risk IgH translocations (P-value=0.03 and 0.003, respectively for PFS and OS) We then examined the prognostic value of the FLC-diff in the group of patients without these two high risk abnormalities and were able to confirm that they remained prognostic for PFS (P=0.009) and OS (p=0.005). However, among the group of patients with either of the two high risk IgH abnormalities, FLCdiff estimate added little to assessment of their outcome (P=0.97 and 0.20, respectively for PFS and OS). Conclusion: Elevated free light chain levels are associated with presence of IgH translocations and these patients are more likely to harbor the high risk genetic abnormalities. Routine FISH testing for patients with newly diagnosed myeloma will allow us to confirm these and allow better risk stratification of the patients. Additional work needs to be done to help us better understand the molecular basis for unbalanced light chain excretion by myeloma cells and the current finding of the association with IgH translocation abnormalities should form the basis for this work. Figure 1. Distribution of FLC ratio (inv vs. uninv) and FLC difference (inv − uninv) among patients. Solid squares represent patients with t(4;14) or t(14;16) or t(11;14) or other 14q32 translocation; open circles represent patients without t(4;14), t(14;16), t(11;14) and any other 14q32 translocations. The horizontal dashed lines refer to FLC ratio original values of 100 and 1000, and vertical dashed lines refer to FLC difference original values of 10 and 100. Solid line indicates significant association (P<=0.05) between the dichotomized FLC groups and translocation status. Figure 1. Distribution of FLC ratio (inv vs. uninv) and FLC difference (inv − uninv) among patients. Solid squares represent patients with t(4;14) or t(14;16) or t(11;14) or other 14q32 translocation; open circles represent patients without t(4;14), t(14;16), t(11;14) and any other 14q32 translocations. The horizontal dashed lines refer to FLC ratio original values of 100 and 1000, and vertical dashed lines refer to FLC difference original values of 10 and 100. Solid line indicates significant association (P<=0.05) between the dichotomized FLC groups and translocation status.

Abstract Background: Outcome of patients with Multiple Myeloma (MM) is influenced by a variety of baseline prognostic factors, most importantly presence of chromosomal abnormalities. Nevertheless, these biologically determined risk-factors do not account for a significant subset of patients whose outcome varies greatly from what one expects based on the underlying prognostic characteristics. We have previously demonstrated that outcome in myeloma is dictated not only by baseline risk-factors but also response to therapy (R2, risk and response dependent outcome). We studied response duration following initial therapy as a prognostic factor for long-term overall survival in myeloma in three ECOG clinical trials that enrolled patients with newly diagnosed myeloma. Methods: Data from three studies with long-term, mature follow up were analyzed: E9486, E5A93, and E1A00. The regimens used in these studies included Thalidomide/Dex, Dex, VBMCP, VBMCP + alpha-IFN, and VBMCP + Cyclophosphamide. Among progressed/relapsed patients, the association between time to progression and overall survival since relapse was explored using Cox proportional hazards model, in which time to progression was analyzed as a continuous variable. In addition, the association between response duration and overall survival since relapse was explored similarly among relapsed responders. Treatment effect and calendar time of diagnosis have been adjusted in the model. Also, to determine the best cut off point associated with the best differentiation of patients with short OS after relapse, an outcome-oriented method using log likelihood value was applied. Results: Among the 1136 patients enrolled in the three studies, 625 patients who have documented disease relapse have been included in the current study. Of these, 471 patients had responded to the treatment before relapse. Only 33 patients are alive as of Dec., 2007. For all 625 patients, the time to progression (continuous variable) was significantly associated with overall survival from the time of relapse/progression (P<0.0001), with hazard ratio of 0.77 (95%CI: 0.72~0.81) at time to progression increasing by 1 year (i.e., the later the progression/relapse, the lower the risk). The best cutoff point of the time to progression is 3 yrs (the 75th percentile). The hazard ratio of patients progressing within 3 yrs since randomization vs. after 3 yrs is 2.4 (95% CI: 1.9 ~ 2.9) and P-value<0.0001. The median OS from relapse was 0.96 years for the former vs. 2.43 years in the latter group (Figure). Among the 471 relapsed responders, the response duration (continuous variable) was also significantly associated with overall survival since relapse (P<0.0001), with hazard ratio of 0.76 (95%CI: 0.70~0.81) at response duration increasing by 1 year (i.e., the longer the response duration, the lower the risk). The effects seen with each regimen are detailed in the table. The best cutoff point of the response duration is 2 yrs (median). The hazard ratio of patients with response duration less than or equal to 2 yrs vs. more than 2 yrs is 2.1 (95% CI: 1.7 ~ 2.6) and P-value<0.0001. Conclusions: Among patients treated with alkylator based therapy, the duration of response from the initial therapy is an important predictor of the subsequent outcome among patients with myeloma. Given the heterogeneity of the disease and imprecise predictive ability of the known baseline prognostic factors, the duration of response to initial therapy should be taken into account, to deliver risk and response-adapted therapy. The prognostic value of this feature across different clinical trials, points towards the role of underlying disease biology, both disease aggressiveness and ability to rapidly develop resistance to therapies as two important determinants of outcome. Table 1: Hazard ratio of overall survival since relapse for patients progressed within 3 yrs since randomization vs. after 3 yrs in each treatment arm Treatment arm Treatment arm HR (95% CI) P-value TTP<=3yrs vs. >3 yrs Thal/Dex N/A N/A Dex 0.4 (0.05, 3.9) 0.46 VBMCP(E5A93+ E9486) 1.9 (1.4, 2.7) 0.0001 VBMCP+alpha2IFN (E5A93+ E9486) 3.0 (2.2, 4.1) <0.0001 VBMCP+CYCLOPHOSPHAMIDE 2.3 (1.5, 3.6) 0.0001 Response duration <=2 yrs vs. >2 yrs Thal/Dex 0.2 (0.003, 18.5) 0.51 Dex 0.15 (0.02, 0.98) 0.048 VBMCP(E5A93+ E9486) 1.7 (1.2, 2.3) 0.0009 VBMCP+alpha2IFN (E5A93+ E9486) 3.0(2.1, 4.3) <0.0001 VBMCP+CYCLOPHOSPHAMIDE 2.1 (1.4, 3.3) 0.006 Figure 1: Overall survival since relapse between patients progressed within 3 yrs since randomization vs. after 3 yrs. Figure 1:. Overall survival since relapse between patients progressed within 3 yrs since randomization vs. after 3 yrs.

Abstract Glucocorticoid (GC) is an effective anti-myeloma agent by directly inducing apoptosis and growth inhibition in myeloma cells. The anti-myeloma action of GC is mediated by its intracellular receptor, the glucocorticoid receptor (GR). The response to GC is variable among myeloma patients and resistance to glucocorticoid treatment develops almost invariably. The mechanism regulating glucocorticoid-sensitivity in not well understood, although it has been hypothesized that the regulation might occur at both the receptor (GR) and post-receptor level. In MM.1 myeloma cell lines, we observed significant down-regulation of GR expression as the cells develop GC-resistance, suggesting that GR expression level is an important determinant of GC-response. Here we present evidence that GR expression level directly correlates with the clinical outcome in myeloma patients who were treated with GC-containing regimens. First, using a quantitative real-time PCR analysis, we performed a retrospective analysis of GR gene expression on bone marrow plasma cell samples from 35 patients with newly diagnosed myeloma who were then treated on the ECOG study E1A00. This is a phase 3 trial which randomized patients to dexamethasone (dex) alone vs. dex in combination with thalidomide. Pre-treatment expression levels of GR-alpha, GR-beta and GR-P splicing isoforms were measured for 35 patients, of whom, 10 had post-treatment samples available. Interestingly, a large variation of the GR expression levels was observed across the patient samples, with the GR-alpha being the predominant isoform. However, a clear correlation between GR expression and treatment response was not seen, likely due to the small sample size. To access a larger patient pool, we retrospectively analyzed the GR expression levels using the cDNA microarray data from the Arkansas group on 351 newly diagnosed myeloma patients treated with Total Therapy 2, of which dexamethasone was an essential component throughout the treatment course. Of the 351 patients, both event-free (EFS) and overall survivals (OS) were compared between 49 patients (14%) with low levels of GR expression and the rest (86%) with high levels of GR expression. Strikingly, the cases with low levels of GR expression were associated with statistically significantly worse EFS and OS compared to those with high levels of GR expression, with the 5-year EFS of 20% vs. 52% and OS of 34% vs. 68%, P < 0.01. In summary, we have shown for the first time that the baseline level of glucocorticoid receptor expression in newly diagnosed myeloma patients predicts their clinical response to GC-containing regimen and the overall clinical outcome.

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.

Abstract BACKGROUND Stereotactic radiosurgery (SRS) for benign intracranial meningiomas is an established treatment. OBJECTIVE To summarize the literature and provide evidence-based practice guidelines on behalf of the International Stereotactic Radiosurgery Society (ISRS). METHODS Articles in English specific to SRS for benign intracranial meningioma, published from January 1964 to April 2018, were systematically reviewed. Three electronic databases, PubMed, EMBASE, and the Cochrane Central Register, were searched. RESULTS Out of the 2844 studies identified, 305 had a full text evaluation and 27 studies met the criteria to be included in this analysis. All but one were retrospective studies. The 10-yr local control (LC) rate ranged from 71% to 100%. The 10-yr progression-free-survival rate ranged from 55% to 97%. The prescription dose ranged typically between 12 and 15 Gy, delivered in a single fraction. Toxicity rate was generally low. CONCLUSION The current literature supporting SRS for benign intracranial meningioma lacks level I and II evidence. However, when summarizing the large number of level III studies, it is clear that SRS can be recommended as an effective evidence-based treatment option (recommendation level II) for grade 1 meningioma.

Abstract BACKGROUND No guidelines have been published regarding stereotactic radiosurgery (SRS) in the management of Spetzler-Martin grade I and II arteriovenous malformations (AVMs). OBJECTIVE To establish SRS practice guidelines for grade I-II AVMs on the basis of a systematic literature review. METHODS Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)-compliant search of Medline, Embase, and Scopus, 1986-2018, for publications reporting post-SRS outcomes in ≥10 grade I-II AVMs with a follow-up of ≥24 mo. Primary endpoints were obliteration and hemorrhage; secondary outcomes included Spetzler-Martin parameters, dosimetric variables, and “excellent” outcomes (defined as total obliteration without new post-SRS deficit). RESULTS Of 447 abstracts screened, 8 were included (n = 1, level 2 evidence; n = 7, level 4 evidence), representing 1102 AVMs, of which 836 (76%) were grade II. Obliteration was achieved in 884 (80%) at a median of 37 mo; 66 hemorrhages (6%) occurred during a median follow-up of 68 mo. Total obliteration without hemorrhage was achieved in 78%. Of 836 grade II AVMs, Spetzler-Martin parameters were reported in 680: 377 were eloquent brain and 178 had deep venous drainage, totaling 555/680 (82%) high-risk SRS-treated grade II AVMs. CONCLUSION The literature regarding SRS for grade I-II AVM is low quality, limiting interpretation. Cautiously, we observed that SRS appears to be a safe, effective treatment for grade I-II AVM and may be considered a front-line treatment, particularly for lesions in deep or eloquent locations. Preceding publications may be influenced by selection bias, with favorable AVMs undergoing resection, whereas those at increased risk of complications and nonobliteration are disproportionately referred for SRS.

Abstract Background This systematic review reports on outcomes and toxicities following stereotactic radiosurgery (SRS) for non-functioning pituitary adenomas (NFAs) and presents consensus opinions regarding appropriate patient management. Methods Using the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses, a systematic review was performed from articles of ≥10 patients with NFAs published prior to May 2018 from the Medline database using the key words “radiosurgery” and “pituitary” and/or “adenoma.” Weighted random effects models were used to calculate pooled outcome estimates. Results Of the 678 abstracts reviewed, 35 full-text articles were included describing the outcomes of 2671 patients treated between 1971 and 2017 with either single fraction SRS or hypofractionated stereotactic radiotherapy (HSRT). All studies were retrospective (level IV evidence). SRS was used in 27 studies (median dose: 15 Gy, range: 5–35 Gy) and HSRT in 8 studies (median total dose: 21 Gy, range: 12–25 Gy, delivered in 3–5 fractions). The 5-year random effects local control estimate after SRS was 94% (95% CI: 93.0–96.0%) and 97.0% (95% CI: 93.0–98.0%) after HSRT. The 10-year local control random effects estimate after SRS was 83.0% (95% CI: 77.0–88.0%). Post-SRS hypopituitarism was the most common treatment-related toxicity observed, with a random effects estimate of 21.0% (95% CI: 15.0–27.0%), whereas visual dysfunction or other cranial nerve injuries were uncommon (range: 0–7%). Conclusions SRS is an effective and safe treatment for patients with NFAs. Encouraging short-term data support HSRT for select patients, and mature outcomes are needed before definitive recommendations can be made. Clinical practice opinions were developed on behalf of the International Stereotactic Radiosurgery Society (ISRS).

Abstract Background: Conventional AlloTx for MM is associated with TRM exceeding 20%. Non-myeloablative AlloTx (NST) utilizes the known graft-vs-myeloma (GVM) effect in an attempt to eradicate minimal residual disease. Preliminary studies of NST in MM demonstrated significant CR and low 100 day post-NST TRM (Badros et al Blood97:2574, 2001). However, even though response rates were high, the vast majority of pts with significant MM disease at the time of transplant, relapsed within the first year. To provide maximal tumor cytoreduction to allow for a subsequent GVM effect, the ECOG designed a Phase II trial of AHSCT for maximal tumor cytoreduction followed by a matched sibling NST to allow for a GVM effect. Methods: The study was designed as a two-stage process based upon early transplant mortality in the first 100 days. Eligibility included pts treated as part of induction therapy or salvage therapy. Chemotherapy responsive disease was not required. Only matched sibling donors were allowed. Pts must have had adequate PS and physiologic organ function. After stem cell mobilization, pts received melphalan 200 mg/m2 with AHSCT. Pts underwent NST 100–182 d post-AHSCT following fludarabine 30 mg/m2 daily × 5 and cyclophosphamide 1 g/m2 for 2 days. GVHD prophylaxis included cyclosporine and corticosteroids. For pts with acute GVHD, Zenapax 1 mg/kg for 5 doses q 3 d was recommended. GM-CSF was incorporated post-AHSCT and NST. The primary endpoints were day 100 TRM, early graft failure, extent of acute GVHD, toxicities, DFS and OS. The study was suspended for 6 mo after the first 19 pts to evaluate early TRM-no early TRM was observed and the study was re-opened. Results: From 5/3/01 to 1/14/05, 32 pts from 10 institutions were enrolled on the study. 23 patients, median age 51 (range 32–64) completed both transplants (28% drop-out rate): 7 (30%) CR (2 in CCR), 11 (48%) PR and 2 (9%) NR and 3 (13%) NE as the best overall response. Of the 32 pts who completed AHSCT, there were 12 grade 4 toxicities pre-NST; 11/23 pts had grade 4 toxicities post-NST. Acute grade III/IV GVHD was observed in 4 (17%); chronic GVHD was observed in 9 pts (39%): 5 limited; 4 extensive resulting in 3 CR (33%), 1 CCR, and 3 PR (33%). 1 pt (4%) had graft-failure. Two pts (8.7%; 95% CI 1.6%, 24.9%) had TRM prior to day + 100 post-NST. With a median follow up of 3.5 years from registration, the median PFS was 4.4 years and the 2-year survival rate was 78% (95% CI: 61% ∼ 95%) for the 23 pts who completed both transplants. Conclusions: AHSCT followed by NST is feasible in a Cooperative Group setting with a low early TRM. The PFS and OS were superior to historical reports for single and tandem AHSCT. AHSCT-NST tandem transplants resulted in a 78% overall response, including 30% CR (2/7 CCR) - similar to other reports for AHSCT-NST. 3/9 pts with chronic GVHD achieved CR demonstrating the GVM effect. However, a plateau in PFS or OS was not observed indicating that the GVM effect is not sufficient to produce long- term disease control and is unlikely curative using this treatment schema. Future studies should include novel therapies to induce better responses pre-transplant and consideration for post-NST maintenance to further eradicate MRD while allowing for GVM.

Abstract Background: Patients with newly diagnosed multiple myeloma is at increased risk of thrombotic events, primarily venous thrombosis. The risk is significantly increased in patients receiving certain therapeutic regimens such as the combination of thalidomide and dexamethasone. Deep vein thrombosis, especially if complicated by pulmonary embolism, can result in death. It is not clear if venous thrombotic events can result in compromised survival in this group of patients. Methods: We studied patients enrolled in the Eastern Co-operative Group trial (E1A00) that randomized patients with newly diagnosed myeloma to single agent dexamethasone or thalidomide and dexamethasone. Patients with grade 3 or greater thrombotic events (DVT, or myocardial ischemia, or stroke) were identified. Wilcoxon rank sum test (for continuous variables) or Fisher’s exact test (for categorical variables) was used to compare age, baseline M-protein, hemoglobin, WBC, platelets count, creatinine, beta2-microglobulin, or ECOG PS between patients with and without thrombotic events. Results: Among the 207 patients enrolled, 36 patients (17.4%) had grade 3 or greater thrombotic events with any treatment attribution, of whom, 27 patients had DVT, 3 patients had an MI and 6 pts had a stroke. However, in only 31 of these patients were the event considered treatment-related (possible, probable, or definite) and among these 24 had a DVT. The baseline characteristics did not differ between the patients with thrombosis and those without, irrespective of its relationship to treatment. Similarly, the baseline characteristics did not diff for those with venous or arterial thrombosis. The overall survival was similar among the patients developing a DVT compared to those without a thrombotic event, when all DVT events were considered irrespective of the treatment attribution (Figure). However, majority of the patients with an arterial event (3 patients with MI and 6 with stroke) had a short overall survival. Conclusion: Venous thrombosis remains a common complication in patients with myeloma, especially when treated with thalidomide and dexamethasone. While occurrence of thrombosis clearly contributes to morbidity and often leads to dose reductions and missed doses, it does not appear to have an adverse impact on the overall survival of these patients. Figure Figure