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Journal of Clinical Oncology : Official... Dec 2020Maintenance therapy prolongs progression-free survival (PFS) in patients with newly diagnosed multiple myeloma (NDMM) not undergoing autologous stem cell transplantation... (Randomized Controlled Trial)
Randomized Controlled Trial
Ixazomib as Postinduction Maintenance for Patients With Newly Diagnosed Multiple Myeloma Not Undergoing Autologous Stem Cell Transplantation: The Phase III TOURMALINE-MM4 Trial.
PURPOSE
Maintenance therapy prolongs progression-free survival (PFS) in patients with newly diagnosed multiple myeloma (NDMM) not undergoing autologous stem cell transplantation (ASCT) but has generally been limited to immunomodulatory agents. Other options that complement the induction regimen with favorable toxicity are needed.
PATIENTS AND METHODS
The phase III, double-blind, placebo-controlled TOURMALINE-MM4 study randomly assigned (3:2) patients with NDMM not undergoing ASCT who achieved better than or equal to partial response after 6-12 months of standard induction therapy to receive the oral proteasome inhibitor (PI) ixazomib or placebo on days 1, 8, and 15 of 28-day cycles as maintenance for 24 months. The primary endpoint was PFS since time of randomization.
RESULTS
Patients were randomly assigned to receive ixazomib (n = 425) or placebo (n = 281). TOURMALINE-MM4 met its primary endpoint with a 34.1% reduction in risk of progression or death with ixazomib versus placebo (median PFS since randomization, 17.4 9.4 months; hazard ratio [HR], 0.659; 95% CI, 0.542 to 0.801; < .001; median follow-up, 21.1 months). Ixazomib significantly benefitted patients who achieved complete or very good partial response postinduction (median PFS, 25.6 12.9 months; HR, 0.586; < .001). With ixazomib versus placebo, 36.6% versus 23.2% of patients had grade ≥ 3 treatment-emergent adverse events (TEAEs); 12.9% versus 8.0% discontinued treatment because of TEAEs. Common any-grade TEAEs included nausea (26.8% 8.0%), vomiting (24.2% 4.3%), and diarrhea (23.2% 12.3%). There was no increase in new primary malignancies (5.2% 6.2%); rates of on-study deaths were 2.6% versus 2.2%.
CONCLUSION
Ixazomib maintenance prolongs PFS with no unexpected toxicity in patients with NDMM not undergoing ASCT. To our knowledge, this is the first PI demonstrated in a randomized clinical trial to have single-agent efficacy for maintenance and is the first oral PI option in this patient population.
Topics: Aged; Antineoplastic Agents; Boron Compounds; Double-Blind Method; Female; Glycine; Humans; Maintenance Chemotherapy; Male; Middle Aged; Multiple Myeloma; Placebos; Progression-Free Survival; Proteasome Inhibitors; Stem Cell Transplantation; Treatment Outcome
PubMed: 33021870
DOI: 10.1200/JCO.20.02060 -
Biomolecules Dec 2021Bortezomib (BTZ) is the first proteasome inhibitor approved by the Food and Drug Administration. It can bind to the amino acid residues of the 26S proteasome, thereby... (Review)
Review
Bortezomib (BTZ) is the first proteasome inhibitor approved by the Food and Drug Administration. It can bind to the amino acid residues of the 26S proteasome, thereby causing the death of tumor cells. BTZ plays an irreplaceable role in the treatment of mantle cell lymphoma and multiple myeloma. Moreover, its use in the treatment of other hematological cancers and solid tumors has been investigated in numerous clinical trials and preclinical studies. Nevertheless, the applications of BTZ are limited due to its insufficient specificity, poor permeability, and low bioavailability. Therefore, in recent years, different BTZ-based drug delivery systems have been evaluated. In this review, we firstly discussed the functions of proteasome inhibitors and their mechanisms of action. Secondly, the properties of BTZ, as well as recent advances in both clinical and preclinical research, were reviewed. Finally, progress in research regarding BTZ-based nanoformulations was summarized.
Topics: Adult; Antineoplastic Agents; Bortezomib; Cell Line, Tumor; Drug Delivery Systems; Humans; Multiple Myeloma; Proteasome Inhibitors
PubMed: 35053199
DOI: 10.3390/biom12010051 -
British Journal of Haematology Jul 2018The number of novel therapies for the treatment of myeloma is rapidly increasing, as are the clinical trials evaluating them in combination with other novel and... (Review)
Review
The number of novel therapies for the treatment of myeloma is rapidly increasing, as are the clinical trials evaluating them in combination with other novel and established therapies. Proteasome inhibitors, immunomodulatory agents and monoclonal antibodies are the most well known and studied classes of novel agents targeting myeloma, with histone deacetylase inhibitors, nuclear export inhibitors and several other approaches also being actively investigated. However, in parallel with the development and clinical use of these novel myeloma therapies is the emergence of novel mechanisms of resistance, many of which remain elusive, particularly for more recently developed agents. Whilst resistance mechanisms have been best studied for proteasome inhibitors, particularly bortezomib, class effects do not universally apply to all class members, and within-class differences in efficacy, toxicity and resistance mechanisms have been observed. Although immunomodulatory agents share the common cellular target cereblon and thus resistance patterns relate to cereblon expression, the unique cell surface antigens to which monoclonal antibodies are directed means these agents frequently exhibit unique within-class differences in clinical efficacy and resistance patterns. This review describes the major classes of novel therapies for myeloma, highlights the major clinical trials within each class and discusses known resistance mechanisms.
Topics: Antibodies, Monoclonal; Antineoplastic Agents; Drug Resistance, Neoplasm; Humans; Immunologic Factors; Multiple Myeloma; Mutation; Proteasome Endopeptidase Complex; Proteasome Inhibitors; Ubiquitin
PubMed: 29676460
DOI: 10.1111/bjh.15210 -
Cancer Metastasis Reviews Dec 2017The clinical efficacy of proteasome inhibitors in the treatment of multiple myeloma has encouraged application of proteasome inhibitor containing therapeutic... (Review)
Review
The clinical efficacy of proteasome inhibitors in the treatment of multiple myeloma has encouraged application of proteasome inhibitor containing therapeutic interventions in (pediatric) acute leukemia. Here, we summarize the positioning of bortezomib, as first-generation proteasome inhibitor, and second-generation proteasome inhibitors in leukemia treatment from a preclinical and clinical perspective. Potential markers for proteasome inhibitor sensitivity and/or resistance emerging from leukemia cell line models and clinical sample studies will be discussed focusing on the role of immunoproteasome and constitutive proteasome (subunit) expression, PSMB5 mutations, and alternative mechanisms of overcoming proteolytic stress.
Topics: Acute Disease; Animals; Bortezomib; Cell Line, Tumor; Drug Resistance, Neoplasm; Humans; Leukemia; Molecular Targeted Therapy; Proteasome Endopeptidase Complex; Proteasome Inhibitors
PubMed: 29071527
DOI: 10.1007/s10555-017-9699-4 -
Molecules (Basel, Switzerland) Feb 2020The proteasome is the central component of the main cellular protein degradation pathway. During the past four decades, the critical function of the proteasome in... (Review)
Review
The proteasome is the central component of the main cellular protein degradation pathway. During the past four decades, the critical function of the proteasome in numerous physiological processes has been revealed, and proteasome activity has been linked to various human diseases. The proteasome prevents the accumulation of misfolded proteins, controls the cell cycle, and regulates the immune response, to name a few important roles for this macromolecular "machine." As a therapeutic target, proteasome inhibitors have been approved for the treatment of multiple myeloma and mantle cell lymphoma. However, inability to sufficiently inhibit proteasome activity at tolerated doses has hampered efforts to expand the scope of proteasome inhibitor-based therapies. With emerging new modalities in myeloma, it might seem challenging to develop additional proteasome-based therapies. However, the constant development of new applications for proteasome inhibitors and deeper insights into the intricacies of protein homeostasis suggest that proteasome inhibitors might have novel therapeutic applications. Herein, we summarize the latest advances in proteasome inhibitor development and discuss the future of proteasome inhibitors and other proteasome-based therapies in combating human diseases.
Topics: Antineoplastic Agents; Boron Compounds; Bortezomib; Glycine; Humans; Lactones; Molecular Targeted Therapy; Multiple Myeloma; Oligopeptides; Proteasome Inhibitors; Proteostasis; Pyrroles
PubMed: 32033280
DOI: 10.3390/molecules25030671 -
Molecular Cancer Research : MCR Oct 2020We generated eight multiple myeloma cell lines resistant to bortezomib; five acquired mutations. In 1,500 patients such mutations were rare clinically. To better...
We generated eight multiple myeloma cell lines resistant to bortezomib; five acquired mutations. In 1,500 patients such mutations were rare clinically. To better understand disruption of proteasomes on multiple myeloma viability and drug sensitivity, we systematically deleted the major proteasome catalytic subunits. Multiple myeloma cells without PSMB5 were viable. Drug-resistant, PSMB5-mutated cell lines were resensitized to bortezomib by PSMB5 deletion, implying PSMB5 mutation is activating in its drug resistance function. In contrast, PSMB6 knockout was lethal to multiple myeloma cell lines. Depleting PSMB6 prevented splicing of the major catalytic subunits PSMB5, PSMB7, PSMB8, and PSMB10; however, PSMB6 engineered without splicing function or catalytic activity, also restored viability, inferring the contribution of PSMB6 to proteasome structure to be more important than functional activity. Supporting this, bortezomib sensitivity was restored in drug-resistant multiple myeloma cell lines by low level expression of mutated PSMB6 lacking splicing function. Loss of PSMB8 and PSMB9 was neither lethal nor restored bortezomib sensitivity. Significant codependency of PSMB5, PSMB6, and PSMB7 expression was observed. We demonstrated elevated levels of PSMB6 and 7, but not 8 and 9, in some, but not all, serial patient samples exposed to proteasome inhibitors. In summary, we show PSMB6 and PSMB7, but not PSMB5, to be essential for multiple myeloma cell survival, this dependency is structural and that upregulation or activating mutation of PSMB5, 6, and 7 confers proteasome inhibitor resistance, while depletion confers sensitivity. IMPLICATIONS: These findings support modulation of PSMB5, PSMB6, or PSMB7 expression as a new therapeutic strategy.
Topics: Cell Differentiation; Cell Survival; Humans; Multiple Myeloma; Proteasome Inhibitors
PubMed: 32561655
DOI: 10.1158/1541-7786.MCR-19-1026 -
The FEBS Journal May 2017Proteasomes are multisubunit protease complexes responsible for degrading most intracellular proteins. In addition to removing damaged proteins, they regulate many... (Review)
Review
Proteasomes are multisubunit protease complexes responsible for degrading most intracellular proteins. In addition to removing damaged proteins, they regulate many important cellular processes through the controlled degradation of transcription factors, cell cycle regulators, and enzymes. Eukaryotic proteasomes have three catalytic subunits, β1, β2, and β5, that each has different substrate specificities. Additionally, although we know that diverse cell types express proteasome variants with distinct activity and specificity profiles, the functions of these different pools of proteasomes are not fully understood. Covalent inhibitors of the protease activity of the proteasome have been developed as drugs for hematological malignancies and are currently under investigation for other diseases. Therefore, there is a need for tools that allow direct monitoring of proteasome activity in live cells and tissues. Activity-based probes have proven valuable for biochemical and cell biological studies of the role of individual proteasome subunits, and for evaluating the efficacy and selectivity of proteasome inhibitors. These probes react covalently with the protease active sites, and contain a reporter tag to identify the probe-labeled proteasome subunits. This review will describe the development of broad-spectrum and subunit-specific proteasome activity-based probes, and discuss how these probes have contributed to our understanding of proteasome biology, and to the development of proteasome inhibitors.
Topics: Peptide Hydrolases; Proteasome Inhibitors; Proteolysis; Substrate Specificity
PubMed: 28107776
DOI: 10.1111/febs.14016 -
Trends in Pharmacological Sciences Aug 2023Proteasome inhibitors (PIs) are a fascinating class of small molecules that disrupt protein homeostasis and are highly efficacious in the blood cancer multiple myeloma.... (Review)
Review
Proteasome inhibitors (PIs) are a fascinating class of small molecules that disrupt protein homeostasis and are highly efficacious in the blood cancer multiple myeloma. However, PIs are not curative, and overcoming PI resistance to extend patient survival remains a major unmet need. Recent strategies to overcome PI resistance, including inhibiting alternative protein homeostasis pathways and targeting the mitochondrion as a nexus of metabolic adaptation to PIs, are gaining momentum. However, these focused approaches may be surpassed or even obviated by quickly emerging immunotherapy strategies that do not selectively target PI resistance mechanisms but are highly efficacious in PI-resistant disease, nonetheless. Informed by insights from these promising areas of research moving in parallel, we propose that pharmacological strategies to enforce immunotherapeutic vulnerabilities in resistant disease may provide a unified outlook to overcome PI resistance in a 'new era' of myeloma treatment.
Topics: Humans; Proteasome Inhibitors; Multiple Myeloma; Mitochondria; Immunotherapy; Drug Resistance, Neoplasm
PubMed: 37344251
DOI: 10.1016/j.tips.2023.05.006 -
Bioscience Reports Feb 2022Proteasome-addicted neoplastic malignancies present a considerable refractory and relapsed phenotype with patients exhibiting drug resistance and high mortality rates....
Proteasome-addicted neoplastic malignancies present a considerable refractory and relapsed phenotype with patients exhibiting drug resistance and high mortality rates. To counter this global problem, novel proteasome-based therapies are being developed. In the current study, we extensively characterize TIR-199, a syrbactin-class proteasome inhibitor derived from a plant virulence factor of bacterium Pseudomonas syringae pv syringae. We report that TIR-199 is a potent constitutive and immunoproteasome inhibitor, capable of inducing cell death in multiple myeloma, triple-negative breast cancer, (TNBC) and non-small cell lung cancer lines. TIR-199 also effectively inhibits the proteasome in primary myeloma cells of patients, and bypasses the PSMB5 A49T+A50V bortezomib-resistant mutant. TIR-199 treatment leads to accumulation of canonical proteasome substrates in cells, it is specific, and does not inhibit 50 other enzymes tested in vitro. The drug exhibits synergistic cytotoxicity in combination with proteasome-activating kinase DYRK2 inhibitor LDN192960. Furthermore, low-doses of TIR-199 exhibits in vivo activity by delaying myeloma-mediated bone degeneration in a mouse xenograft model. Together, our data indicates that proteasome inhibitor TIR-199 could indeed be a promising next-generation drug within the repertoire of proteasome-based therapeutics.
Topics: Amides; Animals; Antineoplastic Agents; Azoles; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Drug Resistance, Neoplasm; Humans; Lung Neoplasms; Mice; Multiple Myeloma; Proteasome Endopeptidase Complex; Proteasome Inhibitors
PubMed: 35088066
DOI: 10.1042/BSR20212721 -
Cells Jun 2021The ubiquitin-proteasome system (UPS) is a central part of protein homeostasis, degrading not only misfolded or oxidized proteins but also proteins with essential... (Review)
Review
The ubiquitin-proteasome system (UPS) is a central part of protein homeostasis, degrading not only misfolded or oxidized proteins but also proteins with essential functions. The fact that a healthy hematopoietic system relies on the regulation of protein homeostasis and that alterations in the UPS can lead to malignant transformation makes the UPS an attractive therapeutic target for the treatment of hematologic malignancies. Herein, inhibitors of the proteasome, the last and most important component of the UPS enzymatic cascade, have been approved for the treatment of these malignancies. However, their use has been associated with side effects, drug resistance, and relapse. Inhibitors of the immunoproteasome, a proteasomal variant constitutively expressed in the cells of hematopoietic origin, could potentially overcome the encountered problems of non-selective proteasome inhibition. Immunoproteasome inhibitors have demonstrated their efficacy and safety against inflammatory and autoimmune diseases, even though their development for the treatment of hematologic malignancies is still in the early phases. Various immunoproteasome inhibitors have shown promising preliminary results in pre-clinical studies, and one inhibitor is currently being investigated in clinical trials for the treatment of multiple myeloma. Here, we will review data on immunoproteasome function and inhibition in hematopoietic cells and hematologic cancers.
Topics: Hematologic Neoplasms; Hematopoiesis; Humans; Proteasome Endopeptidase Complex; Proteasome Inhibitors; Signal Transduction
PubMed: 34206607
DOI: 10.3390/cells10071577