Patient, family caregiver, and economic outcomes of an integrated screening and novel stepped collaborative care intervention in the oncology setting in the USA (CARES): a randomised, parallel, phase 3 trial.

BACKGROUND: The current standard of care of screening and referring patients for treatment for symptoms, such as depression, pain, and fatigue, is not effective. This trial aimed to test the efficacy of an integrated screening and novel stepped collaborative care intervention versus standard of care for patients with cancer and at least one of the following symptoms: depression, pain, or fatigue. METHODS: This randomised, parallel, phase 3 trial was conducted in 29 oncology outpatient clinics associated with the UPMC Hillman Cancer Center in the USA. Patients (aged ≥21 years) with any cancer type and clinical levels of depression, pain, or fatigue (or all of these) were eligible. Eligible family caregivers were aged 21 years or older and providing care to a patient diagnosed with cancer who consented for this study. Patients were randomly assigned (1:1) to stepped collaborative care or standard of care using a central, permuted block design (sizes of 2, 4, and 6) stratified by sex and prognostic status. The biostatistician, oncologists, and outcome assessors were masked to treatment assignment. Stepped collaborative care was once-weekly cognitive behavioural therapy for 50-60 min from a care coordinator via telemedicine (eg, telephone or videoconferencing). Pharmacotherapy for symptoms might be initiated or changed if recommended by the treatment team or preferred by the patient. Standard of care was screening and referral to a health-care provider for treatment of symptoms. The primary outcome was health-related quality of life in patients at 6 months. Maintenance of the treatment benefits was assessed at 12 months. Participants included in the primary analysis were per intention to treat, which included patients missing one or both follow-up assessments. This trial was registered with ClinicalTrials.gov (NCT02939755). FINDINGS: Between Dec 5, 2016, and April 8, 2021, 459 patients and 190 family caregivers were enrolled. 222 patients were assigned to standard of care and 237 to stepped collaborative care. Of 459 patients, 201 (44%) were male and 258 (56%) were female. Patients in the stepped collaborative care group had a greater 0-6-month improvement in health-related quality of life than patients in the standard-of-care group (p=0·013, effect size 0·09). Health-related quality of life was maintained for the stepped collaborative care group (p=0·74, effect size 0·01). Patients in the stepped collaborative care group had greater 0-6-month improvements than the standard-of-care group in emotional (p=0·012), functional (p=0·042), and physical (p=0·033) wellbeing. No adverse events were reported by patients in either group and deaths were considered unrelated to the study. INTERPRETATION: An integrated screening and novel stepped collaborative care intervention, compared with the current standard of care, is recommended to improve health-related quality of life. The findings of this study will advance the implementation of guideline concordant care (screening and treatment) and has the potential to shift the practice of screening and treatment paradigm nationwide, improving outcomes for patients diagnosed with cancer. FUNDING: US National Cancer Institute.

Carfilzomib, Lenalidomide, and Dexamethasone Followed by Lenalidomide Maintenance for Prevention of Symptomatic Multiple Myeloma in Patients With High-risk Smoldering Myeloma: A Phase 2 Nonrandomized Controlled Trial.

IMPORTANCE: High-risk smoldering myeloma has a 5-year risk of progression to symptomatic multiple myeloma of approximately 75%. Treatment with lenalidomide decreases the risk of progression; however, novel triplet regimens are superior, and earlier disease may be more treatment sensitive. OBJECTIVE: To evaluate the use of carfilzomib, lenalidomide, and dexamethasone (KRd) with lenalidomide maintenance therapy as early intervention in high-risk smoldering myeloma and to determine the rates of minimal residual disease (MRD)-negative complete response (CR). DESIGN, SETTING, AND PARTICIPANTS: In this single-arm, single-center, phase 2 nonrandomized controlled trial, responses were evaluated at every cycle during KRd treatment and every 3 cycles subsequently. Bone marrow biopsies and imaging were performed by cycle 8 and then annually. The study enrolled patients from May 29, 2012, to July 23, 2020, at the National Institutes of Health Clinical Center, a highly specialized tertiary cancer center. Patient key eligibility criteria included a diagnosis of high-risk smoldering myeloma based on the Mayo Clinic, Spanish, and/or Rajkumar, Mateos, and Landgren criteria. INTERVENTIONS: Patients received eight 4-week cycles of intravenous carfilzomib 36 mg/m2 (first 2 doses, 20 mg/m2), dexamethasone (20 mg, cycles 1-4; 10 mg, cycles 5-8 twice weekly), and lenalidomide 25 mg (days 1-21) followed by twenty-four 28-day cycles of maintenance lenalidomide 10 mg (days 1-21). Stem cell harvest and storage were optional. MAIN OUTCOMES AND MEASURES: The primary outcome was the MRD-negative CR rate. Key secondary outcomes included duration of MRD-negative CR and progression to multiple myeloma. RESULTS: A total of 54 patients (median age, 59 years [range, 40-79 years]; 30 men [55.6%]; and 2 Asian [3.7%], 15 Black [27.8%], 1 Hispanic [1.9%], and 36 White [66.7%] patients) were enrolled, with a median potential follow-up time of 31.9 months (range, 6.7-102.9 months). The MRD-negative CR rate was 70.4% (95% CI, 56.4%-82.0%), with a median sustained duration of 5.5 years (95% CI, 3.7 years to not estimable). The 8-year probability of being free from progression to multiple myeloma was 91.2% (95% CI, 67.4%-97.9%), and no deaths occurred. Nonhematologic grade 3 adverse events occurred in 21 patients (38.9%) and included thromboembolism, rash, and lung infection, with no grade 4 events. CONCLUSIONS AND RELEVANCE: Results of this phase 2 nonrandomized controlled trial suggest that treatment of high-risk smoldering myeloma with novel triplet regimens, such as KRd and lenalidomide maintenance therapy, may alter the natural history of smoldering myeloma by significantly delaying development of end-organ disease. Randomized clinical trials are needed to confirm this favorable benefit-to-risk profile. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01572480.

Combination therapy with carfilzomib, lenalidomide and dexamethasone (KRd) results in an unprecedented purity of the stem cell graft in newly diagnosed patients with myeloma.

Still, many physicians give 4 cycles of combination therapy to multiple myeloma patients prior to collection of stem cells for autologous bone marrow transplant. This tradition originates from older doxorubicin-containing regiments which limited the number of cycles due to cumulative cardiotoxicity. Using older regiments, most patients had residual myeloma cells in their autologous stem-cell grafts during collection. Emerging data show that newly diagnosed multiple myeloma patients treated with modern carfilzomib/lenalidomide/dexamethasone (KRd) therapy, on average, take 6 cycles until reaching minimal residual disease (MRD) negativity. We assessed newly diagnosed patients treated with KRd focusing MRD status both in the individual patient's bone marrow, and the corresponding autologous hematopoietic progenitor cell grafts during collection. Per protocol, stem-cell collection was allowed after 4 to 8 cycles of KRd. We found similar stem-cell yield independent of the number of cycles of KRd. At stem-cell collection, 11/30 patients (36.6%) were MRD negative in their bone marrow; all 11 patients had MRD negative hematopoietic progenitor cell grafts. Furthermore, 18/19 patients who were MRD positive in their bone marrows also had MRD negative hematopoietic progenitor cell grafts. These observations support 6 cycles of KRd as an efficacious and safe induction strategy prior to stem-cell collection.

Hepatotoxicity Associated With Vismodegib.

An 82-year-old Caucasian woman with a history of basal cell carcinoma on vismodegib presented with nausea, vomiting and intermittent abdominal pain. Laboratory results were remarkable for the elevation of liver enzymes. Endoscopic retrograde cholangiopancreatography and percutaneous transhepatic cholangiogram (PTC) did not show evidence of intrahepatic or extrahepatic obstruction of the biliary tract. During PTC external biliary catheter was placed; however, bilirubin continued to rise. Further, laboratory work-up and imaging studies ruled out other possible aetiologies for hepatotoxicity such as infections, autoimmune hepatitis and other drugs known to be hepatotoxic thus leaving vismodegib the most likely cause of hepatotoxicity.

Host-related immunodeficiency in the development of multiple myeloma.

Host-related immunodeficiency is known to play a role in the development of multiple myeloma (MM) from its precursor conditions (monoclonal gammopathy of undetermined significance, MGUS, smoldering multiple myeloma, SMM). In order to understand the underlying immune changes in this process, we characterized immune patterns from MGUS to SMM to MM. We further sought to identify potential novel immune biomarkers that may predict progression of SMM to MM. We characterized patterns of circulating lymphocytes in 181 patients using multiparametric flow cytometry. We found decreased B- (p = .0003), increased T- (p = .037) and unaltered NK cell proportions from MGUS to SMM to MM. To gain insights into functional variability, we further characterized immunophenotypic lymphocyte subsets, which uncovered differences in CD57 subsets. Specifically, we found that SMM patients who eventually progressed to MM showed decreased proportions of CD57-CD56 + (p = .0061) and CD57-CD16 + (p = .035) lymphocyte subsets. We thus report novel data characterizing the nature of host-related immunodeficiency in the development of MM. We show sequential changes in lymphocyte subsets from MGUS to SMM to MM. We further suggest that CD57 subsets may serve as potential markers of progression from SMM to MM. Our findings support the study of lymphocyte subsets in the search for immune biomarkers. Such markers could provide clinical guidance in managing myeloma precursor disease.

Circulating Adiponectin Levels Differ Between Patients with Multiple Myeloma and its Precursor Disease.

OBJECTIVE: An increased risk of multiple myeloma (MM) has been observed among individuals with low prediagnostic circulating levels of adiponectin, a metabolic hormone that is typically underexpressed among those with overweight or obesity. To assess whether adiponectin may influence myeloma development or progression to frank MM, circulating adiponectin levels were compared across patients with different stages of MM and its precursor, monoclonal gammopathy of undetermined significance (MGUS). METHODS: Adiponectin was measured in 213 patients with MGUS, smoldering MM, or fully developed MM. Differences in adiponectin levels across patient groups were assessed using multivariate linear regression. RESULTS: Relative to MGUS patients, adiponectin levels were statistically significantly lower among those with smoldering and fully developed MM, both overall (16%-20% decrease; P = 0.048) and among those with IgG/IgA isotypes (26%-28% decrease; P = 0.004). Among MGUS patients, adiponectin levels were significantly lower for those with the higher-risk IgM isotype compared with those who had IgG/IgA isotypes (42% decrease; P = 0.036). CONCLUSIONS: The findings of this study, the largest to investigate adiponectin levels in patients with different stages of MM and the first to evaluate associations with clinical characteristics, suggest that reduced expression of adiponectin may be associated with progression from MGUS to MM.

Enzymatic activities of circulating plasma proteasomes in newly diagnosed multiple myeloma patients treated with carfilzomib, lenalidomide and dexamethasone.

The proteasome inhibitor carfilzomib is highly effective in the treatment of multiple myeloma. It irreversibly binds the chymotrypsin-like active site in the ß5 subunit of the 20S proteasome. Despite impressive response rates when carfilzomib is used in combination with immunomodulatory agents in newly diagnosed multiple myeloma patients; no biomarker exists to accurately predict response and clinical outcomes. We prospectively assessed the activity in peripheral blood of the chymotrypsin-like (CHYM), caspase-like (CASP) and trypsin-like (TRYP) proteolytic sites in 45 newly diagnosed multiple myeloma patients treated with eight cycles of carfilzomib, lenalidomide and dexamethasone (CRd) (NCT01402284). Samples were collected per protocol and proteasome activity measured through a fluorogenic assay. Median CHYM levels after one dose of carfilzomib decreased by >70%. CHYM and CASP activity decreased throughout treatment reaching a minimum after eight cycles of treatment. Higher levels of proteasome activity associated with higher disease burden (r > 0.30; p < 0.05) and higher disease stage (0.10 < p <0.20). No association was found with the probability of achieving a complete response, minimal residual disease negativity or time to best response. Further studies evaluating proteasome activity in malignant plasma cells may help elucidate how proteasome activity can be used as a biomarker in multiple myeloma.

Baseline mutational patterns and sustained MRD negativity in patients with high-risk smoldering myeloma.

Early results of a prospective phase 2 clinical trial of carfilzomib, lenalidomide, and dexamethasone followed by lenalidomide maintenance in high-risk smoldering myeloma showed promising results that were previously published. Here, we provide novel insights into the genetic landscape of high-risk smoldering myeloma and information on sustained minimal residual disease (MRD) negativity with an expanded cohort of patients. Eighteen patients with high-risk smoldering myeloma were enrolled between 29 May 2012, and 14 January 2014. We included patients with newly diagnosed multiple myeloma enrolled in a parallel trial who received the same therapy (reference group). The overall response rate was 100%. With median potential follow-up of 43.3 months, 10 (63%) remain in MRD negativity, and the estimated 4-year progression-free and overall survival rates are 71% and 100%, respectively. Importantly, we report differences in mutational patterns in patients with high-risk smoldering myeloma and newly diagnosed multiple myeloma, reflected in a lower frequency of mutations in significant myeloma genes (6.6% vs 45%) and NFKB pathway genes (6.6% vs 25%). Treatment with carfilzomib, lenalidomide, and dexamethasone followed by lenalidomide maintenance was associated with a 100% response rate and 63% MRD negativity with a safety profile consistent with previous reports for this regimen. This study had a small numbers of participants, but there seemed to be important differences in the genetic landscape of patients with high-risk smoldering myeloma and those with newly diagnosed multiple myeloma, suggestive of a more treatment-responsive biology in early disease.

Bone marrow abnormalities and early bone lesions in multiple myeloma and its precursor disease: a prospective study using functional and morphologic imaging.

The incidence and importance of bone marrow involvement and/or early bone lesions in multiple myeloma (MM) precursor diseases is largely unknown. This study prospectively compared the sensitivity of several imaging modalities in monoclonal gammopathy of undetermined significance (MGUS), smoldering multiple myeloma (SMM) and MM. Thirty patients (10 each with MGUS, SMM and MM) were evaluated with skeletal survey, [18F]FDG-PET/CT, [18F]NaF-PET/CT and morphologic dynamic contrast enhanced (DCE)-MRI. An additional 16 SMM patients had skeletal surveys and FDG-PET/CT. Among MGUS patients, DCE-MRI found only one focal marrow abnormality; other evaluations were negative. Among 26 SMM patients, five (19%) were re-classified as MM based on lytic bone lesions on CT and six had unifocal or diffuse marrow abnormality. Among MM, marrow abnormalities were observed on FDG-PET/CT in 8/10 patients and on DCE-MRI in nine evaluable patients. Abnormal NaF uptake was observed only in MM patients with lytic lesions on CT, providing no additional clinical information.

Chemotherapy-induced nausea and vomiting: an overview and comparison of three consensus guidelines.

Chemotherapy-induced nausea and vomiting (CINV) remains one of the most debilitating toxicities associated with cancer treatment. In recent decades, significant strides have been made in our understanding of the pathophysiology of CINV, making way to more effective targeted pharmacotherapies, especially 5-hydroxytryptamine3 receptor antagonists and neurokinin-1 (NK-1) receptor antagonists. As much as 70%-80% of CINV can be prevented with appropriate administration of available antiemetics. Nevertheless, fear of CINV still may diminish cancer treatment adherence. To assimilate and summarise the rapidly growing body of clinical research literature on CINV, three professional organisations-the Multinational Association of Supportive Care in Cancer/European Society for Medical Oncology, the American Society of Clinical Oncology and the National Comprehensive Cancer Network-have created CINV management guidelines. While these respective guidelines are developed from similar consensus processes using similar clinical research literature, their results demonstrate several key differences in recommended strategies. This article aims to provide an overview of CINV pathophysiology, compare and contrast three expert guidelines and offer considerations for future clinical and research challenges.

Treatment With Carfilzomib-Lenalidomide-Dexamethasone With Lenalidomide Extension in Patients With Smoldering or Newly Diagnosed Multiple Myeloma.

IMPORTANCE: Carfilzomib-lenalidomide-dexamethasone therapy yields deep responses in patients with newly diagnosed multiple myeloma (NDMM). It is important to gain an understanding of this combination's tolerability and impact on minimal residual disease (MRD) negativity because this end point has been associated with improved survival. OBJECTIVE: To assess the safety and efficacy of carfilzomib-lenalidomide-dexamethasone therapy in NDMM and high-risk smoldering multiple myeloma (SMM). DESIGN, SETTING, AND PARTICIPANTS: Clinical and correlative pilot study at the National Institutes of Health Clinical Center. Patients with NDMM or high-risk SMM were enrolled between July 11, 2011, and October 9, 2013. Median follow-up was 17.3 (NDMM) and 15.9 months (SMM). INTERVENTIONS: Eight 28-day cycles were composed of carfilzomib 20/36 mg/m2 on days 1, 2, 8, 9, 15, and 16; lenalidomide 25 mg on days 1 through 21; and dexamethasone 20/10 mg (cycles 1-4/5-8) on days 1, 2, 8, 9, 15, 16, 22, and 23. Patients who achieved at least stable disease subsequently received 24 cycles of lenalidomide extended dosing. MAIN OUTCOMES AND MEASURES: Primary end points were neuropathy of grade 3 or greater (NDMM) and at least very good partial response rates (SMM). Minimal residual disease was also assessed. RESULTS: Of 45 patients with NDMM, none had neuropathy of grade 3 or greater. Of 12 patients with high-risk SMM, the most common of any-grade adverse events were lymphopenia (12 [100%]) and gastrointestinal disorders (11 [92%]). All patients with SMM achieved at least a very good partial response during the study period. Among the 28 patients with NDMM and the 12 with SMM achieving at least a near-complete response, MRD negativity was found in 28 of 28 (100% [95% CI, 88%-100%]), 11 of 12 (92% [95% CI, 62%-100%]) (multiparametric flow cytometry), 14 of 21 (67% [95% CI, 43%-85%]), and 9 of 12 (75% [95% CI, 43%-94%]) (next-generation sequencing), respectively. In patients with NDMM, 12-month progression-free survival for MRD-negative vs MRD-positive status by flow cytometry and next-generation sequencing was 100% vs 79% (95% CI, 47%-94%; P < .001) and 100% vs 95% (95% CI, 75%-99%; P = .02), respectively. CONCLUSIONS AND RELEVANCE: Carfilzomib-lenalidomide-dexamethasone therapy is tolerable and demonstrates high rates of MRD negativity in NDMM, translating into longer progression-free survival in patients achieving MRD negativity. Carfilzomib-lenalidomide-dexamethasone therapy also demonstrates efficacy in high-risk SMM.

High-Dose Sirolimus and Immune-Selective Pentostatin plus Cyclophosphamide Conditioning Yields Stable Mixed Chimerism and Insufficient Graft-versus-Tumor Responses.

PURPOSE: We hypothesized that lymphoid-selective host conditioning and subsequent adoptive transfer of sirolimus-resistant allogeneic T cells (T-Rapa), when combined with high-dose sirolimus drug therapy in vivo, would safely achieve antitumor effects while avoiding GVHD. EXPERIMENTAL DESIGN: Patients (n = 10) with metastatic renal cell carcinoma (RCC) were accrued because this disease is relatively refractory to high-dose conditioning yet may respond to high-dose sirolimus. A 21-day outpatient regimen of weekly pentostatin (P; 4 mg/m(2)/dose) combined with daily, dose-adjusted cyclophosphamide (C; ≤200 mg/d) was designed to deplete and suppress host T cells. After PC conditioning, patients received matched sibling, T-cell-replete peripheral blood stem cell allografts, and high-dose sirolimus (serum trough target, 20-30 ng/mL). To augment graft-versus-tumor (GVT) effects, multiple T-Rapa donor lymphocyte infusions (DLI) were administered (days 0, 14, and 45 posttransplant), and sirolimus was discontinued early (day 60 posttransplant). RESULTS: PC conditioning depleted host T cells without neutropenia or infection and facilitated donor engraftment (10 of 10 cases). High-dose sirolimus therapy inhibited multiple T-Rapa DLI, as evidenced by stable mixed donor/host chimerism. No antitumor responses were detected by RECIST criteria and no significant classical acute GVHD was observed. CONCLUSIONS: Immune-selective PC conditioning represents a new approach to safely achieve alloengraftment without neutropenia. However, allogeneic T cells generated ex vivo in sirolimus are not resistant to the tolerance-inducing effects of in vivo sirolimus drug therapy, thereby cautioning against use of this intervention in patients with refractory cancer.

Flow cytometric sensitivity and characteristics of plasma cells in patients with multiple myeloma or its precursor disease: influence of biopsy site and anticoagulation method.

Flow cytometry has increasing relevance for prognosis in myeloma and precursor disease (monoclonal gammopathy of unknown significance/smoldering myeloma), yet it has been reported that plasma cell enumeration by flow varies depending on the quality of marrow aspirate and field biopsied in patchy disease. We demonstrated increased sensitivity of flow over immunohistochemistry in abnormal-plasma cell detection in monoclonal gammopathy (n = 59)/smoldering myeloma (n = 87). We prospectively evaluated treatment-na ve smoldering myeloma (n = 9)/myeloma (n = 11) patients for the percentage of abnormal plasma cells/total plasma cell compartment, plasma cell viability/infiltration and flow immunophenotype depending on anticoagulant use, biopsy site and pull sequence in uni-and-bilateral bone marrow biopsies and aspirates. We found no statistical difference regarding the percentage of abnormal plasma cells, their immunophenotype or number/distribution in marrow samples even when obtained by different sequence in aspirates, or anticoagulants (p > 0.05). Our results show that plasma cell enumeration and immunophenotyping by flow cytometry is consistent under different conditions in these populations.

Brain metastasis in patients with adrenocortical carcinoma: a clinical series.

INTRODUCTION: Adrenocortical carcinoma (ACC) is a heterogeneous and rare disease. At presentation or at the time of a recurrence, the disease commonly spreads to the liver, lungs, lymph nodes, and bones. The brain has only rarely been reported as a site of metastases. OBJECTIVE: The aims of this report were to describe the clinical characteristics of patients with ACC who developed brain metastasis and were evaluated at the National Cancer Institute. METHODS: We describe the history and clinical presentation of six patients with ACC and metastatic disease in the brain. Images of the six patients and pathology slides were reviewed when available. RESULTS: The median age at the time of the diagnosis of ACC was 42 years. The median time from the initial diagnosis until the presentation of brain metastasis was 43 months. As a group the patients had previously received multiples lines of chemotherapy (median of three), and they presented with one to three metastatic brain lesions. Four patients underwent metastasectomy, one had radiosurgery, and one had both modalities. Two patients are still alive, three died, between 2 and 14 months after the diagnosis of brain metastases, and one was lost to follow-up. CONCLUSION: Patients with advanced ACC can rarely present with metastasis to the brain, most often long after the initial diagnosis. Timely diagnosis of brain metastasis with appropriate intervention after discussion in a multidisciplinary meeting can improve the prognosis in this particular scenario.

Altered cytokine and chemokine profiles in multiple myeloma and its precursor disease.

Currently, no reliable biomarkers are available to predict transformation from smoldering myeloma (SMM) to multiple myeloma (MM). Using an ultrasensitive enzyme-linked immunosorbent assay (ELISA) we assessed the levels of a broad range of cytokines and chemokines in the peripheral blood (PB) and bone marrow (BM) supernatant collected from 14 SMM and 38 MM patients and compared to healthy donors. We found significantly increased levels of key cytokines, in particular CXCL8 (IL-8), associated with progressive disease state (controls→SMM→MM). Cytokine profiles were found similar in PB and BM. Five of fourteen SMM patients (36%) progressed to MM. Our findings, although based on a limited number of patients, suggest that serum-based cytokines may have a future role as biomarkers for disease progression and could potentially be assessed as novel targets for treatment.

Flow cytometric differentiation of abnormal and normal plasma cells in the bone marrow in patients with multiple myeloma and its precursor diseases.

Flow cytometric (FC) enumeration of abnormal plasma cells (APCs) for diagnosis and prognostication of plasma cell dyscrasias (PCD) is challenging. We studied antigen expression in normal plasma cells (NPC) (N = 34) and APC in a series of unselected PCD (N = 59). NPC subpopulations often demonstrated CD19(-), CD20(+), CD45(-) or dim and CD56(+), an immunophenotype observed in PCD. However abnormal CD81 was only observed in APCs (APC detection sensitivity 95%; specificity 100%). We evaluated differences in antigen expression patterns among MGUS (N = 14), SMM (N = 35) and MM (N = 10), finding the combination of CD45 and CD56 helpful in differentiating MGUS from SMM and MM (p = 0.0002).

The proteasome: mechanisms of biology and markers of activity and response to treatment in multiple myeloma.

Since the early 1990s, the synthesis and subsequent clinical application of small molecule inhibitors of the ubiquitin proteasome pathway (UPP) has revolutionized the treatment and prognosis of multiple myeloma. In this review, we summarize important aspects of the biology of the UPP with a focus on its structure and key upstream/downstream regulatory components. We then review current knowledge of plasma cell sensitivity to proteasome inhibition and highlight new proteasome inhibitors that have recently entered clinical development. Lastly, we address the putative role of circulating proteasomes as a novel biomarker in multiple myeloma and provide guidance for future clinical trials using proteasome inhibitors.