Fonseca, Rafaël

Abstract In multiple myeloma (MM), despite well-characterized precursor states such as monoclonal gammopathy of undetermined significance (MGUS) and smoldering multiple myeloma (SMM), there is a lack of sufficient biomarkers to predict disease progression. Most genomic analyses have studied the malignant plasma cells, however, cancers form a complex ecosystem with the immune and stromal microenvironment. To characterize the cellular composition and transcriptional programs of each component of the tumor and microenvironment at different stages of MM progression, we employed single-cell RNA sequencing on 48K plasma and 40.8K immune microenvironmental cells from a cohort of 22 patients with varying stages of disease progression and 9 healthy donors. Expression profiles of plasma cells revealed clear tumor-specific differences in known oncogenic drivers in MM (MMSET/FGFR3, CCND1 and MAFB) as well as other clonally expressed genes (LAMP5, HIST1H1C, and AREG), distinguishing them from healthy plasma cells. We identified a subset of cycling plasma cells in malignant samples, observing a range of proliferative capacity across disease stages. Furthermore, our approach allowed a unique head-to-head comparison of gene expression changes in normal and malignant plasma cells from the same individual, revealing early alterations in genes related to immune modulation (NKBIA) or controlling transcription and differentiation (EID1). Some alterations were patient-specific, while others, such as MHC I overexpression and CD27 loss, were recurrently observed across subsets of the cohort. Analysis of the BM microenvironment demonstrated significant infiltration of natural killer cells, non-classical monocytes/macrophages, and T cells, even in the earliest stages of the disease. Further investigation revealed upregulation of MHC II expression at the mRNA level in CD14+ monocytes/macrophages and yet, intriguingly, analysis by CyTOF and immunohistochemistry revealed a shift towards intracellular localization of MHC II in these cells. Co-culture with MM cell lines was sufficient to induce the decrease of extracellular MHC II, providing strong evidence for MM-induced compromised antigen presentation by macrophages, and hinting at a mechanism of immune evasion. Together, our results provide a comprehensive view at the complex interplay of the immune and malignant cells in different stages of the disease. We demonstrate the immune response beginning in premalignant conditions to be heterogeneous, including compromised antigen presentation as well as alterations in cellular composition and signaling. Consideration of the type of immunological response may prove valuable in determination of progression risk, as well as open up potential strategies for therapy. Citation Format: Nicholas J. Haradhvala, Oksana Zavidij, Tarek H. Mouhieddine, Romanos Sklavenitis-Pistofidis, Jihye Park, Mairead Reidy, Abdallah Flaifel, Benjamin Ferland, Salomon Manier, Mark Bustoros, Daisy Huynh, Marzia Capelletti, Brianna Berrios, Mahshid Rahmat, Chia-Jen Liu, Meng Xiao He, Esteban Braggio, Rafael Fonseca, Yosef Maruvka, Jennifer Guerriero, Melissa Goldman, Eliezer Van Allen, Steven McCarroll, Jamil Azzi, Gad Getz, Irene M. Ghobrial. Single-cell RNA sequencing reveals compromised immune microenvironment in precursor stages of multiple myeloma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 139.

Background:It has been well documented that each additional line of treatment is associated with lower rates of deeper responses, shorter duration of treatment, and increased rates of toxicities/comorbidities in patients with multiple myeloma (MM; Yong K, et al. Br J Haematol 2016. 175[2]:252–264). These factors contribute to treatment discontinuation and impact the proportion of patients reaching subsequent lines of therapy.Aims:To characterize the rate of therapy attrition at relapse for patients with newly diagnosed MM (NDMM) who are transplant eligible in the United States.Methods:Patients with NDMM were identified from 3 US patient‐level data sources: the OPTUM™ Commercial Claims database (period: January 2000–March 2017), the OPTUM™ Electronic Medical Records (EMR) database (period: January 2007–March 2016), and the Surveillance, Epidemiology, and End Results (SEER)‐Medicare Linked database (period: January 2007–December 2014). Patients had 1) an index MM diagnosis on or after 1 January 2007, 2) medical prescription coverage in place at diagnosis, 3) no prior malignancies in the one‐year period prior to index diagnosis, 4) a one‐year look‐back period prior to index diagnosis, and 5) received ≥1 lines of therapy. Patients were considered transplant eligible if they received stem cell transplantation anytime during the follow‐up period. Baseline characteristics including comorbidities, index age, frontline treatment regimens and attrition rates at each subsequent line of therapy were characterized. Attrition was defined as the percentage of patients who did not have any recorded subsequent MM treatments as a result of death or lost to follow‐up in the database for any reason, including end of the database.Results:A total of 1,599 patients were included in this analysis. Baseline patient characteristics and pre‐existing comorbidities are summarized in Table 1. The induction regimens used as frontline treatments included bortezomib/dexamethasone (22%), lenalidomide/dexamethasone (13%), bortezomib/lenalidomide/dexamethasone (25%), all other bortezomib combinations (20%), and other (20%). The proportions of patients observed to progress to each subsequent line of therapy are summarized in Table 2. In total, 77% of patients received a second line of therapy, and only 55% received a third line treatment. The proportion of patients not receiving a subsequent line of therapy due to death is also summarized by lines of therapy in Table 2.Summary/Conclusion:A substantial number of patients with NDMM who are transplant eligible did not receive subsequent lines of therapy, with attrition by lines of therapy ranging from 23–40%. The increase in attrition rates with each additional line of therapy underscores the need to utilize upfront therapy associated with optimal progression‐free survival. Further studies evaluating the etiologic basis for this unexpectedly high attrition rate are warranted.image

Abstract Citron Rho-interacting serine/threonine kinase (CIT) is a serine/threonine kinase that acts as a key component of the midbody and is essential for cytokinesis. CIT has been reported to be highly expressed in some tumor tissues and to play a role in cancer proliferation; however, the significance of CIT has not been investigated in multiple myeloma (MM). Here, we identified, by protein microarray and immunohistochemistry, that CIT is 1 of the upregulated proteins in the plasma cells of MM patients compared with healthy controls. Analysis of a gene expression profile data set showed that MM patients with high CIT gene expression had significantly worse overall survival compared with MM patients with low CIT gene expression. CIT silencing in MM cell lines induced cytokinesis failure and resulted in decreased MM cell proliferation in vitro and in vivo. TP53 expression was found to be an independent predictor of CIT dependency, with low-TP53 cell lines exhibiting a strong dependency on CIT. This study provides the rationale for CIT being a potential therapeutic target in MM in future trials.

Abstract Chronic kidney disease is common in patients with multiple myeloma. Historically, individuals with end-stage renal disease and multiple myeloma did poorly with renal transplantation due to higher mortality rates from the malignancy itself or associated comorbidities. However, over the past 2 decades, there have been significant advances in the treatment of multiple myeloma with the advent of new therapeutic agents resulting in an improvement of long-term survival. As a result, more individuals with multiple myeloma are being referred for kidney transplantation, especially those with good functional capacity and minimal comorbidities. Recent literature has suggested that certain patients with multiple myeloma can successfully undergo renal transplantation after stem transplantation with consideration for maintenance therapy, although caution should be used with immunomodulating drugs due to the anecdotally reported risk of acute rejection. Therefore, having a multidisciplinary approach with the transplant team and hematology both before and after transplant is crucial in maximizing the chance of success for these individuals. This review summarizes the literature on renal transplantation in patients with multiple myeloma as well as the therapeutic advancements that have occurred which may allow certain patients to undergo successful transplantation.