Inhibition of proteasome, a proteolytic complex responsible for the degradation of ubiquitinated proteins, has emerged as a powerful strategy for treatment of multiple myeloma (MM), a plasma cell ...malignancy. First‐in‐class agent, bortezomib, has demonstrated great positive therapeutic efficacy in MM, both in pre‐clinical and in clinical studies. However, despite its high efficiency, a large proportion of patients do not achieve sufficient clinical response. Therefore, the development of a second‐generation of proteasome inhibitors (PIs) with improved pharmacological properties was needed. Recently, several of these new agents have been introduced into clinics including carfilzomib, marizomib and ixazomib. Further, new orally administered second‐generation PI oprozomib is being investigated. This review provides an overview of main mechanisms of action of PIs in MM, focusing on the ongoing development and progress of novel anti‐proteasome therapeutics.
Summary Background Bortezomib with dexamethasone is a standard treatment option for relapsed or refractory multiple myeloma. Carfilzomib with dexamethasone has shown promising activity in patients in ...this disease setting. The aim of this study was to compare the combination of carfilzomib and dexamethasone with bortezomib and dexamethasone in patients with relapsed or refractory multiple myeloma. Methods In this randomised, phase 3, open-label, multicentre study, patients with relapsed or refractory multiple myeloma who had one to three previous treatments were randomly assigned (1:1) using a blocked randomisation scheme (block size of four) to receive carfilzomib with dexamethasone (carfilzomib group) or bortezomib with dexamethasone (bortezomib group). Randomisation was stratified by previous proteasome inhibitor therapy, previous lines of treatment, International Staging System stage, and planned route of bortezomib administration if randomly assigned to bortezomib with dexamethasone. Patients received treatment until progression with carfilzomib (20 mg/m2 on days 1 and 2 of cycle 1; 56 mg/m2 thereafter; 30 min intravenous infusion) and dexamethasone (20 mg oral or intravenous infusion) or bortezomib (1·3 mg/m2 ; intravenous bolus or subcutaneous injection) and dexamethasone (20 mg oral or intravenous infusion). The primary endpoint was progression-free survival in the intention-to-treat population. All participants who received at least one dose of study drug were included in the safety analyses. The study is ongoing but not enrolling participants; results for the interim analysis of the primary endpoint are presented. The trial is registered at ClinicalTrials.gov , number NCT01568866. Findings Between June 20, 2012, and June 30, 2014, 929 patients were randomly assigned (464 to the carfilzomib group; 465 to the bortezomib group). Median follow-up was 11·9 months (IQR 9·3–16·1) in the carfilzomib group and 11·1 months (8·2–14·3) in the bortezomib group. Median progression-free survival was 18·7 months (95% CI 15·6–not estimable) in the carfilzomib group versus 9·4 months (8·4–10·4) in the bortezomib group at a preplanned interim analysis (hazard ratio HR 0·53 95% CI 0·44–0·65; p<0·0001). On-study death due to adverse events occurred in 18 (4%) of 464 patients in the carfilzomib group and in 16 (3%) of 465 patients in the bortezomib group. Serious adverse events were reported in 224 (48%) of 463 patients in the carfilzomib group and in 162 (36%) of 456 patients in the bortezomib group. The most frequent grade 3 or higher adverse events were anaemia (67 14% of 463 patients in the carfilzomib group vs 45 10% of 456 patients in the bortezomib group), hypertension (41 9% vs 12 3%), thrombocytopenia (39 8% vs 43 9%), and pneumonia (32 7% vs 36 8%). Interpretation For patients with relapsed or refractory multiple myeloma, carfilzomib with dexamethasone could be considered in cases in which bortezomib with dexamethasone is a potential treatment option. Funding Onyx Pharmaceuticals, Inc., an Amgen subsidiary.
The addition of the oral proteasome inhibitor ixazomib to a regimen of lenalidomide plus dexamethasone led to a significant prolongation of progression-free survival of almost 6 months, as compared ...with placebo, with a small increase in the risk of thrombocytopenia.
Outcomes of multiple myeloma have improved substantially over the past 15 years with the introduction of proteasome inhibitors and immunomodulatory drugs,
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,
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and these agents now form the backbone of therapy for multiple myeloma.
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In phase 3 studies, triplet regimens based on these agents were shown to be more efficacious than doublet regimens when these regimens were used as a first-line treatment
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–
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and in relapsed disease.
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,
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In addition, there has been a shift in treatment patterns toward the use of extended treatment to further improve long-term outcomes,
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and this shift highlights the need for additional effective agents with . . .
Even in the era of new drugs, multiple myeloma patients with extramedullary relapse have a poor prognosis. Our goal was to analyze the frequency and outcome of extramedullary relapse occurring in ...relapsed multiple myeloma patients. In total, we analyzed the prognosis of 226 relapsed multiple myeloma patients treated between 2005 and 2008 and evaluated them for presence of extramedullary relapse. We found evidence of extramedullary relapse in 24% (55 of 226) of relapsed multiple myeloma patients. In 14% (32 of 226) of patients, the lesions were not adjacent to the bone, while extramedullary relapse adjacent to the bone was documented in 10% (23 of 226) of cases. Patients without extramedullary relapse had significantly longer overall survival than patients with extramedullary relapse (109 vs. 38 months; P<0.001). Moreover, patients with soft tissue-related extramedullary relapse had significantly poorer overall survival compared to bone-related extramedullary relapse patients (30 vs. 45 months; P=0.022). Also, overall survival from diagnosis was as low as five months for soft tissue-related extramedullary relapse patients when compared to 12 months overall survival for bone-related extramedullary relapse. This is the first study that shows a significant difference in prognosis for different types of extramedullary relapse. If the extramedullary myeloma infiltration was not bone-related, overall survival after relapse was extremely short (5 months).
The reason why a few myeloma cells egress from the bone marrow (BM) into peripheral blood (PB) remains unknown. Here, we investigated molecular hallmarks of circulating tumor cells (CTCs) to identify ...the events leading to myeloma trafficking into the bloodstream. After using next-generation flow to isolate matched CTCs and BM tumor cells from 32 patients, we found high correlation in gene expression at single-cell and bulk levels (r ≥ 0.94, P = 10
), with only 55 genes differentially expressed between CTCs and BM tumor cells. CTCs overexpressed genes involved in inflammation, hypoxia, or epithelial-mesenchymal transition, whereas genes related with proliferation were downregulated in CTCs. The cancer stem cell marker CD44 was overexpressed in CTCs, and its knockdown significantly reduced migration of MM cells towards SDF1-α and their adhesion to fibronectin. Approximately half (29/55) of genes differentially expressed in CTCs were prognostic in patients with newly-diagnosed myeloma (n = 553; CoMMpass). In a multivariate analysis including the R-ISS, overexpression of CENPF and LGALS1 was significantly associated with inferior survival. Altogether, these results help understanding the presence of CTCs in PB and suggest that hypoxic BM niches together with a pro-inflammatory microenvironment induce an arrest in proliferation, forcing tumor cells to circulate in PB and seek other BM niches to continue growing.
Certain cytogenetic abnormalities are known to adversely impact outcomes in patients with multiple myeloma (MM). The phase 3 TOURMALINE-MM1 study demonstrated a significant improvement in ...progression-free survival (PFS) with ixazomib-lenalidomide-dexamethasone (IRd) compared with placebo-lenalidomide-dexamethasone (placebo-Rd). This preplanned analysis assessed the efficacy and safety of IRd vs placebo-Rd according to cytogenetic risk, as assessed using fluorescence in situ hybridization. High-risk cytogenetic abnormalities were defined as del(17p), t(4;14), and/or t(14;16); additionally, patients were assessed for 1q21 amplification. Of 722 randomized patients, 552 had cytogenetic results; 137 (25%) had high-risk cytogenetic abnormalities and 172 (32%) had 1q21 amplification alone. PFS was improved with IRd vs placebo-Rd in both high-risk and standard-risk cytogenetics subgroups: in high-risk patients, the hazard ratio (HR) was 0.543 (95% confidence interval CI, 0.321-0.918; P = .021), with median PFS of 21.4 vs 9.7 months; in standard-risk patients, HR was 0.640 (95% CI, 0.462-0.888; P = .007), with median PFS of 20.6 vs 15.6 months. This PFS benefit was consistent across subgroups with individual high-risk cytogenetic abnormalities, including patients with del(17p) (HR, 0.596; 95% CI, 0.286-1.243). PFS was also longer with IRd vs placebo-Rd in patients with 1q21 amplification (HR, 0.781; 95% CI, 0.492-1.240), and in the “expanded high-risk” group, defined as those with high-risk cytogenetic abnormalities and/or 1q21 amplification (HR, 0.664; 95% CI, 0.474-0.928). IRd demonstrated substantial benefit compared with placebo-Rd in relapsed and/or refractory MM (RRMM) patients with high-risk and standard-risk cytogenetics, and improves the poor PFS associated with high-risk cytogenetic abnormalities. This trial was registered at www.clinicaltrials.gov as #NCT01564537.
•IRd was associated with a consistent PFS benefit vs placebo-Rd in RRMM patients with high-risk and standard-risk cytogenetics.•The addition of ixazomib to Rd overcomes the poor PFS associated with high-risk cytogenetics in patients with RRMM.
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Infections are the primary cause of morbidity and mortality in multiple myeloma (MM) patients (pts). The aim of our retrospective analysis was to evaluate incidence and course of COVID-19 infection ...in a cohort of 351 MM outpatients treated with novel drugs. COVID-19 disease was detected in 50/351 pts (14%); median age was 68 years. Gender, ISS stage, and last treatment lines were as follows: male 32, female 18; ISS-I 19, ISS-II 20, ISS-III 11; daratumumab-based 15, lenalidomide-based 12, bortezomib-based 17, other 6. Positive PCR test at COVID-19 diagnosis was present in all pts; anti-myeloma treatment was interrupted. Hospitalizations for COVID-19 pneumonia were necessary for 28/50 pts (56%), 18/50 pts (36%) in standard unit (SU) 10/50 pts (20%) in intensive care unit (ICU), and 9/50 pts (18%) died. The statistically significant parameters for COVID-19 hospitalization were as follows: responsive versus non-responsive disease (
p
= 0.027), ECOG performance status 0–2 versus ≥ 3 (
p
= 0.014), presence of comorbidities (0–1 versus ≥ 2,
p
= 0.043). The statistically significant factors for COVID-19 death were as follows: ECOG 0–2 versus ≥ 3 (
p
= 0.001), presence of comorbidities (0–1 versus ≥ 2,
p
= 0.007), serious course of COVID-19 disease with ICU hospitalization (SU versus ICU,
p
= 0.001). None of the other studied risk factors was associated with poor outcome (age, gender, ISS stage, immunoparesis, type of anti-myeloma treatment). Full recovery from COVID-19 infection was observed in 41/50 pts (82%) in median of 32 days. The course of COVID-19 disease in MM pts was mostly moderate or serious with 56% of hospitalizations and 18% of deaths.
Renal impairment (RI) is common in patients with multiple myeloma (MM) and new therapies that can improve renal function are needed. The phase III IKEMA study (clinicaltrials gov. Identifier: ...NCT03275285) investigated isatuximab (Isa) with carfilzomib and dexamethasone (Kd) versus Kd in relapsed MM. This subgroup analysis examined results from patients with RI, defined as estimated glomerular filtration rate <60 mL/min/1.73 m². Addition of Isa prolonged progression-free survival (PFS) in patients with RI (hazard ratio: 0.27; 95% confidence interval CI: 0.11-0.66; median PFS not reached for Isa-Kd versus 13.4 months for Kd 20.8-month follow-up). Complete renal responses occurred more frequently with Isa-Kd (52.0%) versus Kd (30.8%) and were durable in 32.0% versus 7.7% of patients, respectively. Treatment exposure was longer with Isa-Kd, with median number of started cycles and median duration of exposure of 20 versus 9 cycles and 81.0 versus 35.7 weeks for Isa-Kd versus Kd, respectively. Among patients with RI, the incidence of patients with grade ≥3 treatment-emergent adverse events was similar between the two arms (79.1% in Isa-Kd vs. 77.8% in Kd). In summary, the addition of Isa to Kd improved clinical outcomes with a manageable safety profile in patients with RI, consistent with the benefit observed in the overall IKEMA study population.
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