Exploring the time-dependent regulatory potential of microRNAs in breast cancer cells treated with proteasome inhibitors

PURPOSE

Breast cancer (BrCa) is a predominant type of cancer with a disparate molecular nature. MicroRNAs (miRNAs) have emerged as promising key players in the regulation of pathological processes in BrCa. Proteasome inhibitors (PIs) emerged as promising anticancer agents for several human malignancies, including BrCa, inhibiting the function of the proteasome. Aiming to shed light on the miRNA regulatory effect in BrCa after treatment with PIs, we used two PIs, namely bortezomib and carfilzomib.

MATERIALS AND METHODS

Four BrCa cell lines of distinct molecular subtypes were treated with these PIs. Cell viability and IC50 concentrations were determined. Total RNA was extracted, polyadenylated, and reversely transcribed. Next, the levels of specific miRNAs with a significant role in BrCa were determined using relative quantification, and their regulatory effect was assessed.

RESULTS

High heterogeneity was discovered in the levels of miRNAs in the four cell lines, after treatment. The miRNA levels fluctuate with distinct patterns, in 24, 48, or 72 hours. Interestingly, miR-1-3p, miR-421-3p, and miR-765-3p appear as key molecules, as they were found deregulated, in almost all combinations of cell lines and PIs. In the SK-BR-3 cell line, the majority of the miRNAs were significantly downregulated in treated compared to untreated cells, with miR-21-5p being the only one upregulated. Finally, various significant biological processes, molecular functions, and pathways were predicted to be affected.

CONCLUSIONS

The diversity of pathways predicted to be affected by the diversity in miRNA expression after treatment with PIs paves the way for the recognition of new regulatory axes in BrCa.

lenalidomide-sparing pomalidomide-containing triplet regimens for relapsed/refractory multiple myeloma: an indirect treatment comparison

Nearly all patients with multiple myeloma eventually relapse or become refractory to treatment. Lenalidomide is increasingly administered in the frontline until disease progression or intolerance to therapy, resulting in the need for highly effective, lenalidomide-sparing options. In this study, carfilzomib plus daratumumab and dexamethasone were evaluated against lenalidomide-sparing, pomalidomide-containing triplets using matching-adjusted indirect comparison in the absence of head-to-head data. The analyses utilized long-term follow-up data from the CANDOR study (NCT03158688). Treatment with carfilzomib, daratumumab, and dexamethasone resulted in significantly longer progression-free survival (hazard ratio 0.60 [95% confidence interval: 0.37, 0.88])vs. pomalidomide plus bortezomib and dexamethasone, and numerically longer progression-free survival (hazard ratio 0.77 [95% confidence interval: 0.50, 1.08]) vs. daratumumab plus pomalidomide and dexamethasone in patients with relapsed/refractory multiple myeloma and previous lenalidomide exposure, the majority of whom were lenalidomide refractory. Carfilzomib plus daratumumab and dexamethasone offers a highly effective, lenalidomide-sparing treatment option for this population.

An open-label phase 2 study treating patients with first or second relapse of multiple myeloma with carfilzomib, pomalidomide, and dexamethasone (KPd): SELECT study

Once-weekly carfilzomib at 56 mg/m2 plus immunomodulatory drugs and dexamethasone has shown efficacy and tolerability treating early relapsed/refractory multiple myeloma (RRMM). The phase 2 SELECT study (NCT04191616) evaluated efficacy/safety of weekly carfilzomib, pomalidomide, and dexamethasone (KPd) in early RRMM patients refractory to lenalidomide. All 52 treated patients were refractory to prior treatment, and 19 (37%) were triple-class refractory. Overall response rate (ORR; primary endpoint) was 58% (35% ≥ very good partial response, 6% ≥ complete response); median response duration was 20.3 months. Minimal residual disease negativity (10-5) was achieved in 10% of patients. Median progression-free survival was 11.1 months; median overall survival was 18.8 months. Adverse events (AEs) were consistent with the known safety profile including grade ≥3 treatment-emergent AEs reported in 67% of patients. Although the primary endpoint of ORR was not met, KPd showed meaningful clinical benefits in lenalidomide-refractory RRMM patients, including those who were daratumumab-refractory and/or triple-class refractory.

Acute suppression of translation by hyperthermia enhances anti-myeloma activity of carfilzomib

Hyperthermia is a unique treatment option for cancers. Multiple myeloma (MM) remains incurable and innovative therapeutic options are needed. We investigated the efficacy of hyperthermia and carfilzomib in combination against MM cells. Although MM cell lines exhibited different susceptibilities to pulsatile carfilzomib treatment, mild hyperthermia at 43℃ induced MM cell death in all cell lines in a time-dependent manner. Hyperthermia and carfilzomib cooperatively induced MM cell death even under suboptimal conditions. The pro-survival mediators PIM2 and NRF2 accumulated in MM cells due to inhibition of their proteasomal degradation by carfilzomib; however, hyperthermia acutely suppressed translation in parallel with phosphorylation of eIF2α to reduce these proteins in MM cells. Recovery of β5 subunit enzymatic activity from its immediate inhibition by carfilzomib was observed at 24 h in carfilzomib-insusceptible KMS-11, OPM-2, and RPMI8226 cells, but not in carfilzomib-sensitive MM.1S cells. However, heat treatment suppressed the recovery of β5 subunit activity in these carfilzomib-insusceptible cells. Therefore, hyperthermia re-sensitized MM cells to carfilzomib. Our results support the treatment of MM with hyperthermia in combination with carfilzomib. Further research is warranted on hyperthermia for drug-resistant extramedullary plasmacytoma.

Genome-wide analysis in PC6 electroacupuncture to ameliorate carfilzomib-induced cardiotoxicity in mice

Carfilzomib (CFZ), a proteasome inhibitor commonly used in the treatment of multiple myeloma (MM), exhibits limited clinical application due to its cardiotoxicity. In our study, electroacupuncture (EA) at Neiguan acupoint (PC6) effectively reversed CFZ-induced reduction in ejection fraction (EF) and fractional shortening (FS), demonstrating great potential effect for heart protection. Through comparative analysis of the transcriptome profile from heart samples of mice treated with DMSO control, CFZ injection, and EA stimulation, we identified a total of 770 differentially expressed genes (DEGs) in CFZ (vs. Control) group and 329 DEGs in EA (vs. CFZ) group. Specifically, CFZ (vs. Control) group exhibited 65 up-regulated DEGs and 705 down-regulated DEGs, while EA (vs. CFZ) group displayed 251 up-regulated DEGs and 78 down-regulated DEGs. Metascape analysis revealed that among these treatment groups, there were 137 co-expressed DEGs remarkably enriched in skeletal system development, cellular response to growth factor stimulus, negative regulation of Wnt signaling pathway, and muscle contraction. The expression patterns of miR-8114, Myl4, Col1a1, Tmem163, Myl7, Sln, and Fxyd3, which belong to the top 30 DEGs, were verified by quantitative real-time PCR (RT-qPCR). In summary, this study firstly discloses novel insights into the regulatory mechanisms underlying PC6-based EA therapy against CFZ-induced cardiotoxicity, potentially serving as a theoretical foundation for further clinical applications.

Health-related quality of life and quality-adjusted progression free survival for carfilzomib and dexamethasone maintenance following salvage autologous stem-cell transplantation in patients with multiple myeloma: a randomized phase 2 trial by the Nordic Myeloma Study Group

BACKGROUND

Decisions regarding maintenance therapy in patients with multiple myeloma should be based on both treatment efficacy and health-related quality of life (HRQL) consequences. In the CARFI trial, patients with first relapse of multiple myeloma underwent salvage autologous stem cell transplantation (salvage ASCT) before randomization to carfilzomib-dexamethasone maintenance therapy (Kd) or observation. The primary clinical endpoint was time to progression, which was extended by 8 months by Kd. The aim of this paper is to present the all HRQL endpoints of the CARFI trial including the HRQL effect of Kd maintenance therapy relative to observation. The primary HRQL endpoint was assessed by EORTC QLQ-C30 Summary score (QLQ-C30-sum) at 8 months follow-up. A key secondary HRQL endpoint was quality-adjusted progression-free-survival (QAPFS).

METHODS

HRQL was assessed with EORTC QLQ-C30, EORTC QLQ-MY20 and FACT/GOG-Ntx at randomization and every second month during follow-up. HRQL data were analyzed with linear mixed effect models until 8 months follow-up. QAPFS per individual was calculated by multiplying progression-free survival (PFS) by two quality-adjustment metrics, the QLQ-C30-sum and EORTC Quality of Life Utility Measure-Core 10 dimensions (QLU-C10D). The QAPFS per treatment group was estimated with the Kaplan-Meier method. P < 0.05 was used for statistical significance, and a between-group minimal important difference of 10 points was interpreted as clinically relevant for the QLQ-C30-sum.

RESULTS

168 patients were randomized. HRQL questionnaire compliance was 93%. For the QLQ-C30-sum, the difference of 4.62 points (95% confidence interval (CI) -8.9: -0.4, p = 0.032) was not clinically relevant. PFS was 19.3 months for the Kd maintenance group and 16.8 months for the observation group; difference = 2.5 months (95% CI 0.5; 4.5). QAPFS based on the QLQ-C30-sum for the Kd maintenance group was 18.0 months (95% CI 16.4; 19.6) and for the observation group 15.0 months (95% CI 13.5; 16.5); difference = 3.0 months (95% CI 0.8-5.3). QAPFS based on the QLU-C10D for the Kd maintenance group was 17.5 months (95% CI 15.9; 19.2) and 14.0 months (95% CI 12.4; 15.5) for the observation group; difference = 3.5 months (95% CI 1.1-5.9).

CONCLUSIONS

Kd maintenance therapy after salvage ASCT did not adversely affect overall HRQL, but adjustment for HRQL reduced the PFS compared to unadjusted PFS. PFS of maintenance therapy should be quality-adjusted to balance the benefits and HRQL impact.

Oxyphenbutazone ameliorates carfilzomib induced cardiotoxicity in rats via inhibition of oxidative free radical burst and NF-κB/IκB-α pathway

Carfilzomib (CFZ), a chemotherapeutic agent used for multiple myeloma treatments reported to cause high incidence of cardiac events either new onset and/or exacerbate formerly diagnosed heart failure with ventricular and myocardial dysfunction. Purpose: Current research designed to explore and examine the preventive effect of oxyphenbutazone in the CFZ -instigated cardiotoxicity. Methodology: Female Wistar Rats weighing 200-250 g selected randomly and grouped as follows: Group 1 designated as the Normal control and receive normal saline only. Group 2 served toxic control and exposed to CFZ (4 mg/kg, intraperitoneally [i.p.]). Group 3 & 4 served as treatment groups and administered with CFZ concomitantly orally fed with oxyphenbutazone at doses of 35 and 70 mg/kg/three times a week, respectively. The total duration of experimental protocol was of 21 days. After completion of the experiments animals subjected to blood collection using light ether anesthesia and serum was separated for biochemical analysis further. The serum levels of Mg+2, Ca+2 and cardiac enzymes (aspartate transaminase (AST), lactate dehydrogenase (LDH), creatine kinase (CK) and creatine kinase-MB (CK-MB) levels were estimated. Later animals sacrificed and heart tissue isolated for further examinations. Intracellular proteins NFkB and IkBα were estimated by western blot. Results: The serum analysis revealed that CFZ administration significantly elevated the levels of LDH, CK and CKMB in CFZ exposed animals when compared to normal animals while administration of oxyphenbutazone significantly reduced these biochemical changes, Intracellular antioxidant enzymes and NF-kB in treatment groups as compared to disease control animals. Conclusion: Findings of the research protocol suggests significant injuries to cardiac tissues when animals exposed to CFZ and Oxyphenbutazone protected the cardiac tissues.

Carfilzomib suppressed LDHA-mediated metabolic reprogramming by targeting ATF3 in esophageal squamous cell carcinoma

Carfilzomib, a second-generation proteasome inhibitor, has been approved as a treatment for relapsed and/or refractory multiple myeloma. Nevertheless, the molecular mechanism by which Carfilzomib inhibits esophageal squamous cell carcinoma (ESCC) progression largely remains to be determined. In the present study, we found that Carfilzomib demonstrated potent anti-tumor activity against esophageal squamous cell carcinoma both in vitro and in vivo. Mechanistically, carfilzomib triggers mitochondrial apoptosis and reprograms cellular metabolism in ESCC cells. Moreover, it has been identified that activating transcription factor 3 (ATF3) plays a crucial cellular target role in ESCC cells treated with Carfilzomib. Overexpression of ATF3 effectively antagonized the effects of carfilzomib on ESCC cell proliferation, apoptosis, and metabolic reprogramming. Furthermore, the ATF3 protein is specifically bound to lactate dehydrogenase A (LDHA) to effectively suppress LDHA-mediated metabolic reprogramming in response to carfilzomib treatment. Research conducted in xenograft models demonstrates that ATF3 mediates the anti-tumor activity of Carfilzomib. The examination of human esophageal squamous cell carcinoma indicated that ATF3 and LDHA have the potential to function as innovative targets for therapeutic intervention in the treatment of ESCC. Our findings demonstrate the novel function of Carfilzomib in modulating ESCC metabolism and progression, highlighting the potential of Carfilzomib as a promising therapeutic agent for the treatment of ESCC.

Identification of TNFRSF1A as a novel regulator of carfilzomib resistance in multiple myeloma

Multiple myeloma (MM) is a hematological tumor with high mortality and recurrence rate. Carfilzomib is a new-generation proteasome inhibitor that is used as the first-line therapy for MM. However, the development of drug resistance is a pervasive obstacle to treating MM. Therefore, elucidating the drug resistance mechanisms is conducive to the formulation of novel therapeutic therapies. To elucidate the mechanisms of carfilzomib resistance, we retrieved the GSE78069 microarray dataset containing carfilzomib-resistant LP-1 MM cells and parental MM cells. Differential gene expression analyses revealed major alterations in the major histocompatibility complex (MHC) and cell adhesion molecules. The upregulation of the tumor necrosis factor (TNF) receptor superfamily member 1A (TNFRSF1A) gene was accompanied by the downregulation of MHC genes and cell adhesion molecules. Furthermore, to investigate the roles of these genes, we established a carfilzomib-resistant cell model and observed that carfilzomib resistance induced TNFRSF1A overexpression and TNFRSF1A silencing reversed carfilzomib resistance and reactivated the expression of cell adhesion molecules. Furthermore, TNFRSF1A silencing suppressed the tumorigenesis of MM cells in immunocompetent mice, indicating that TNFRSF1A may lead to carfilzomib resistance by dampening antitumor immunity. Furthermore, our results indicated that TNFRSF1A overexpression conferred carfilzomib resistance in MM cells and suppressed the expression of MHC genes and cell adhesion molecules. The suppression of MHC genes and cell adhesion molecules may impair the interaction between immune cells and cancer cells to impair antitumor immunity. Future studies are warranted to further investigate the signaling pathway underlying the regulatory role of TNFRSF1A in MM cells.

Lactoferrin ameliorates carfilzomib-induced renal and pulmonary deficits: Insights to the inflammasome NLRP3/NF-κB and PI3K/Akt/GSK-3β/MAPK axes

AIMS

Carfilzomib, an irreversible proteasome inhibitor, has been increasingly used to treat multiple myeloma worldwide. However, case studies showed its treatment has been associated with cardiac, renal, and pulmonary deleterious effects. Lactoferrin is an iron-binding glycoprotein present in milk. It is a multifunctional protein with antimicrobial activity, antitumor, antioxidant, and anti-inflammatory effects. Thus, this study aimed to assess the protective effects of lactoferrin against carfilzomib-induced nephrotoxicity and pulmonary toxicity, in addition to identifying the possible underlying molecular mechanisms.

MAIN METHODS

Mice were treated with lactoferrin (300 mg/kg/day) concomitantly with carfilzomib (4 mg/kg, i.p.) twice weekly for three weeks. Kidney and lung indices, serum creatinine, blood urea nitrogen (BUN), uric acid, kidney injury molecule-1 (KIM-1), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and histological examination were assessed. In addition, biochemical analyses of the inflammasome NLRP3/NF-κB and PI3K/Akt/GSK-3β/MAPK axes were conducted.

KEY FINDINGS

Treatment with lactoferrin decreased serum levels of creatinine, BUN, uric acid, KIM-1, ALP, AST, and LDH and reversed carfilzomib-induced histological changes in both kidney and lung. The inflammatory markers NLRP3, p65 NF-kB, caspases1, interleukin-1β, and interleukin-18, as well as the MAPK signaling pathway, were significantly reduced in renal and pulmonary tissues of mice following lactoferrin administration. Moreover, lactoferrin significantly counteracted carfilzomib-induced reduced expression of pAkt and pGSK-3β in both renal and pulmonary tissues.

SIGNIFICANCE

The current study suggests lactoferrin might be a promising candidate for ameliorating carfilzomib-induced nephrotoxicity and pulmonary toxicity.

Carfilzomib-induced life-threatening lung injury in refractory multiple myeloma

INTRODUCTION

Carfilzomib is a second-generation selective proteasome inhibitor that is commonly used in the treatment of relapsed or refractory multiple myeloma. Carfilzomib is associated with respiratory side effects, such as cough, dyspnea, and upper respiratory tract infection. However, severe pulmonary toxicity is rare and is only reported in a few case reports.

CASE REPORT

Here, we present a case of a 65-year-old male with refractory multiple myeloma who developed a life-threatening lung injury during his third cycle of carfilzomib. The patient presented with a decreased level of consciousness and was found to have Type I respiratory failure. He was admitted to the intensive care unit, where he was intubated. Blood cultures and viral panel were negative. The patient received a prolonged course of antibiotics with 2 days of hydrocortisone.

MANAGEMENT AND OUTCOMES

After discharge, repeated myeloma workup showed disease progression and carfilzomib was reintroduced. The next day, he presented with fever, vomiting, and hypoxia. Chest x-ray showed congestive lung changes with patchy airspace opacities. Repeated echocardiography showed normal ejection fraction with moderate pulmonary hypertension (RVSP 46 mm Hg). The patient was transferred again to the ICU and kept on continuous positive airway pressure. Antibiotics were started, and blood cultures and respiratory viral panels were negative for any infectious organism. The patient improved in terms of inflammatory markers and oxygen requirements. Treatment with carfilzomib was stopped permanently.

DISCUSSION

Pulmonary toxicity associated with carfilzomib in patients with multiple myeloma can be potentially life-threatening. The mechanism with which carfilzomib induces lung-related AEs is still not fully understood. In our patient, carfilzomib-induced lung injury was evident after rechallenging the patient with carfilzomib, in the radiographic x-ray changes and the new onset moderate pulmonary hypertension. Healthcare providers should be encouraged to report rare adverse events in order to identify the risk factors that can predispose patients to the development of these adverse events.

Real-world treatment outcomes of carfilzomib plus dexamethasone in patients with relapsed and/or refractory multiple myeloma, focusing on the impact of trial-fitness: CAtholic REsearch network for Multiple Myeloma study (CAREMM-2203)

INTRODUCTION

Carfilzomib plus dexamethasone (Kd) is widely used in patients with relapsed and/or refractory multiple myeloma (RRMM). However, the treatment outcomes of Kd, especially in trial-unfit patients, have not been extensively studied in the real-world setting.

METHODS

We analyzed the outcomes of 152 RRMM patients who received Kd at our hospitals from April 2018 to March 2022.

RESULTS

At the commencement of Kd, patients received a median of two (range 1-7) lines of prior anti-myeloma therapy. According to the ENDEAVOR study criteria, 93 (61.2%) and 59 (38.8%) patients were classified as the trial-fit and the trial-unfit group, respectively. The overall response (OR) rate for the entire cohort was 71.1% (95% CI 63.2-78.1%). Progression-free survival (PFS) and overall survival (OS) were 5.6 months (95% CI 3.9-6.9 months) and 24.0 months (95% CI 13.4-38.0 months), respectively. There was no significant difference in the OR rate between the trial-fit and the trial-unfit groups (76.3% vs. 62.7%; P = 0.105). However, the median PFS (3.6 months vs. 7.3 months; P < 0.001) and OS (15.0 vs. 36.8 months; P = 0.009) were significantly shorter in the trial-unfit group. On multivariate analysis, trial-fitness (unfit vs. fit) remained a significant covariate influencing the TRM (HR: 4.84, 95% CI 1.66-14.06; P = 0.004) and PFS (HR: 1.82, 95% CI 1.27-2.62; P = 0.001).

CONCLUSION

Our data suggest that the treatment outcomes of Kd are acceptable in the real-world setting with significant differences between the trial-fit and the trial-unfit groups, although they are relatively inferior to those of a pivotal trial.

A phase 1b dose-escalation study of carfilzomib in combination with thalidomide and dexamethasone in patients with relapsed/refractory systemic immunoglobulin light chain amyloidosis

INTRODUCTION

Proteasome inhibitors are the backbone of AL amyloidosis treatment - bortezomib being most widely used. Carfilzomib is a proteasome inhibitor licenced to treat multiple myeloma; autonomic and peripheral neuropathy are uncommon toxicities with carfilzomib. There is limited data on the use of carfilzomib in AL amyloidosis. Here, we report the results of a phase Ib dose-escalation study of Carfilzomib-Thalidomide-Dexamethasone (KTD) in relapsed/refractory AL amyloidosis.

RESULTS

The trial registered 11 patients from 6 UK centres from September 2017 to January 2019; 10 patients received at least one dose of trial treatment. 80 adverse events were reported from 10 patients in the 1st three cycles. One patient experienced dose-limiting toxicity (acute kidney injury) at a dose of 45 mg/m2, and another patient had a SAR (fever). Five patients experienced an AE ≥ grade 3. There were no haematologic, infectious, or cardiac AE ≥ grade 3. The overall haematological response rate (ORR) at the end of three cycles of treatment was 60%.

CONCLUSION

Carfilzomib 45 mg/m2 weekly can be safely given with thalidomide and dexamethasone. The efficacy and tolerability profile appears comparable to other agents in relapsed AL amyloidosis. These data provide a framework for further studies of carfilzomib combinations in AL amyloidosis.

Microangiopathy in multiple myeloma: a case of carfilzomib-induced secondary thrombotic microangiopathy successfully treated with plasma exchange and complement inhibition

BACKGROUND

Thrombotic microangiopathy (TMA) is a potentially organ and life-threatening condition affecting patients with multiple myeloma (MM). Cases of proteasome inhibitor-induced TMA and specifically carfilzomib-induced TMA have been rarely reported and standards for diagnostic workup and treatment are not available.

CASE PRESENTATION

We describe a case of a male MM patient under salvage therapy including proteasome inhibitor carfilzomib following chemotherapy and autologous stem cell transplantation. The patient then developed acute kidney injury with clinical and laboratory signs of TMA. Hemodialysis became necessary and treatment with plasma exchange was initiated followed by therapy with C5 complement inhibitor eculizumab which led to amelioration of kidney function and hemolysis parameters.

CONCLUSION

We report a patient with suspected proteasome inhibitor-induced secondary thrombotic microangiopathy that has been successfully treated with plasma exchange and eculizumab, a monoclonal antibody targeting complement factor C5.

Canagliflozin mitigates carfilzomib-induced endothelial apoptosis via an AMPK-dependent pathway

Carfilzomib (CFZ) is a proteasome inhibitor approved for relapsed/refractory multiple myeloma (MM) but its clinical use is limited by cardiovascular toxicity. The mechanisms of CFZ-induced cardiovascular toxicity are not fully understood but endothelial dysfunction may be a common denominator. Here, we first characterized the direct toxic effects of CFZ on endothelial cells (HUVECs and EA.hy926 cells) and tested whether SGLT2 inhibitors, known to have cardioprotective effects, can protect against CFZ-induced toxicity. To determine the chemotherapeutic effect of CFZ in the presence of SGLT2 inhibitors, MM and lymphoma cells were treated with CFZ with or without canagliflozin. CFZ decreased cell viability and induced apoptotic cell death in endothelial cells in a concentration-dependent manner. CFZ also upregulated ICAM-1 and VCAM-1 and downregulated VEGFR-2. These effects were associated with the activation of Akt and MAPK pathways, inhibition of p70s6k, and downregulation of AMPK. Canagliflozin, but not empagliflozin or dapagliflozin, protected endothelial cells from CFZ-induced apoptosis. Mechanistically, canagliflozin abrogated CFZ-induced JNK activation and AMPK inhibition. AICAR (an AMPK activator) protected from CFZ-induced apoptosis, and compound C (an AMPK inhibitor) abrogated the protective effect of canagliflozin, strongly suggesting that AMPK mediates these effects. Canagliflozin did not interfere with the anticancer effect of CFZ in cancer cells. In conclusion, our findings demonstrate for the first time the direct toxic effects of CFZ in endothelial cells and the associated signaling changes. Canagliflozin abrogated the apoptotic effects of CFZ in endothelial cells in an AMPK-dependent mechanism, without interfering with its cytotoxicity in cancer cells.

Proteasome Inhibitor-Based Regimens in the Frontline Management of Waldenström Macroglobulinemia

Proteasome inhibitors (PIs) have long been used in myeloma therapy but also for Waldenström macroglobulinemia. Their use has been successful and has also been investigated for the frontline management of the disease. Bortezomib was effective either as a single agent or in combination with other regimens with high response rates observed in most studies, despite its adverse effects, especially neurotoxicity, which remains a major concern. Clinical trials with second-generation PIs such as carfilzomib and ixazomib have also been conducted, always in combination with immunotherapy in previously untreated patients. They have been shown to be active and neuropathy-sparing treatment options.

Hyperfractionated Cyclophosphamide and Dexamethasone Alone or in Combination with Daratumumab and/or Carfilzomib for the Treatment of Relapsed or Refractory Multiple Myeloma: A Single-Center Retrospective Analysis

BACKGROUND

Hyperfractionated cyclophosphamide and dexamethasone (HyperCd) alone, or with carfilzomib(K) and/or daratumumab(D), represents a potential treatment option when rapid disease control is needed for patients with aggressive presentations of relapsed/refractory multiple myeloma (RRMM).

PATIENTS AND METHODS

This is a single-center, retrospective analysis of adult patients with RRMM who received HyperCd with or without K and/or D between May 1, 2016 and August 1, 2019 at the University of Texas MD Anderson Cancer Center. We here report treatment response and safety outcomes.

RESULTS

Data from 97 patients, 12 with plasma cell leukemia (PCL), were reviewed in this analysis. Patients had had a median of 5 prior lines of therapy and received a median of 1 consecutive cycle of hyperCd-based therapy. The overall response rate (ORR) of all patients was 71.8% (HyperCd 75%, HyperCdK 64.3%, D-HyperCd 73.3%, and D-HyperCdK 76.9%). Median progression-free survival and overall survival among all patients was 4.3 months (HyperCd 3.1 months, HyperCdK 4.5 months, D-HyperCd 3.3 months, and D-HyperCdK 6 months) and 9.0 months (HyperCd 7.4 months, HyperCdK 9.0 months, D-HyperCd 7.5 months, and D-HyperCdK 15.2 months), respectively. Grade 3/4 hematologic toxicities were common, thrombocytopenia being the most frequent at 76%. Notably, 29-41% of patients per treatment group had existing grade 3/4 cytopenias at initiation of hyperCd-based therapy.

CONCLUSION

HyperCd-based regimens provided rapid disease control among MM patients, even when heavily pre-treated and with few remaining treatment options. Grade 3/4 hematologic toxicities were frequent, but manageable with aggressive supportive care.

Inhibition of proteasome, but not lysosome, upregulates organic anion transporter 3 in vitro and in vivo

Organic anion transporter 3 (OAT3), an indispensable basolateral membrane transporter predominantly distributed in the kidney proximal tubules, mediated the systemic clearance of substrates including clinical drugs, nutrients, endogenous and exogenous metabolites, toxins, and critically sustains body homeostasis. Preliminary data in this study showed that classical proteasome inhibitors (e.g., MG132), but not lysosome inhibitors, significantly increased the OAT3 ubiquitination and OAT3-mediated transport of estrone sulfate (ES) in OAT3 stable expressing cells, indicating that proteasome rather than lysosome is involved in the intracellular fate of OAT3. Next, bortezomib and carfilzomib, two FDA-approved and widely applied anticancer agents through selective targeting proteasome, were further used to define the role of inhibiting proteasome in OAT3 regulation and related molecular mechanisms. The results showed that 20S proteasome activity in cell lysates was suppressed with bortezomib and carfilzomib treatment, leading to the increased OAT3 ubiquitination, stimulated transport activity of ES, enhanced OAT3 surface and total expression. The upregulated OAT3 function by proteasome inhibition was attributed to the augment in maximum transport velocity and stability of membrane OAT3. Lastly, in vivo study using Sprague Dawley rats validated that proteasome inhibition using bortezomib induced enhancement of OAT3 ubiquitination and membrane expression in kidney. These data suggest that activity of proteasome but not lysosome could have an impact on the physiological function of OAT3, and proteasome displayed a promising target for OAT3 regulation in vitro and in vivo, and could be used in restoring OAT3 impairment under pathological conditions, avoiding OAT3-associated toxicity and diseases, ensuring drug efficacy and safety.

[Thrombotic microangiopathy with gastrointestinal hemorrhage during carfilzomib therapy for multiple myeloma]

A 70-year-old woman was admitted to the hospital with loss of appetite and melena. She was diagnosed with multiple myeloma 7 years ago and had been on carfilzomib, lenalidomide, and dexamethasone (KRd) therapy for a month because her disease had a relapsed/refractory. On admission, her laboratory tests revealed hemolytic anemia with schizocytes, thrombocytopenia, and acute renal dysfunction. TMA (thrombotic microangiography) caused by carfilzomib was suspected. The possibility of thrombotic thrombocytopenia was considered, and steroid pulse therapy was initiated. Her condition improved significantly after she stopped taking carfilzomib, plasma exchange, hemodiafiltration, steroid pulse therapy, and abstaining from food. The previously reported cases of carfilzomib-induced TMA included fever, gastrointestinal symptoms (nausea/vomiting, diarrhea), and acute renal disorders (lower extremity edema, decreasing urine output). As far as we know, this is the first case of carfilzomib-induced TMA with bleeding as the first symptom.

Systematic molecular profiling of acute leukemia cancer stem cells allows identification of druggable targets

Acute myeloid leukemia (AML) is one of the most prevalent and acute blood cancers with a poor prognosis and low overall survival rate, especially in the elderly. Although several new AML markers and drug targets have been recently identified, the rate of long-term cancer eradication has not improved significantly due to the presence and drug resistance of AML cancer stem cells (CSCs). Here we develop a novel computational pipeline to analyze the transcriptomic profiles of AML cancer (stem) cells and identify novel candidate AML CSC markers and drug targets. In our novel pipeline we apply a top-down meta-analysis strategy to integrate The Cancer Genome Atlas data with CSC datasets to infer cell stemness features. As a result, a set of genes termed the "AML key CSC genes" along with all the available drugs/compounds that could target them were identified. Overall, our novel computational pipeline could retrieve known cancer drugs (Carfilzomib) and predicted novel drugs such as Zonisamide, Amitriptyline, and their targets amongst the top ranked drugs and drug targets for targeting AML. Additionally, the pipeline applied in this study could be used for the identification of CSC-specific markers, drivers and their respective targeting drugs in other cancer types.

Carfilzomib versus rituximab for treatment of de novo donor-specific antibodies in lung transplant recipients

INTRODUCTION

De novo donor-specific antibodies (DSAs) increase the risk of chronic lung allograft dysfunction (CLAD) in lung transplant recipients (LTRs). Both carfilzomib (CFZ) and rituximab (RTX) lower the mean fluorescent intensity (MFI) of DSAs, but comparative data are lacking. We compared CLAD-free survival and the degree and duration of DSA depletion after treatment of LTRs with CFZ or RTX.

METHODS

LTRs that received CFZ or RTX for DSA depletion between 08/01/2015 and 08/31/2020 were included. The primary outcome was CLAD-free survival. Secondary outcomes were change in MFI at corresponding loci within 6 months of treatment (ΔMFI), time to DSA rebound, and change in % predicted FEV₁ 6 months after treatment (ΔFEV₁).

RESULTS

Forty-four LTRs were identified, 7 of whom had ≥2 drug events; therefore, 53 drug events were divided into 2 groups, CFZ (n = 17) and RTX (n = 36). Use of plasmapheresis, immunoglobulin, and mycophenolate augmentation was equivalent in both groups. CLAD-free survival with a single RTX event was superior to that after ≥2 drug events (p = 0.001) but comparable to that with a single CFZ event (p = 0.399). Both drugs significantly lowered the MFI at DQ locus, and the median ΔMFI was comparable. Compared to the RTX group, the CFZ group had a shorter median interval to DSA rebound (p = 0.015) and a lower ΔFEV₁ at 6 months (p = 0.014).

CONCLUSION

Although both CFZ and RTX reduced the MFI of circulating DSAs, RTX prolonged the time to DSA rebound. Despite more pronounced improvement in FEV₁ with RTX, comparable CLAD-free survival between the 2 groups suggests that both drugs offer a reasonable treatment strategy for DSAs in LTRs.

Carfilzomib-induced thrombotic microangiopathy is underestimated in clinical practice: A report of five patients and literature review

Carfilzomib (Cfz) is widely used to treat multiple myeloma. However, real-world data of the incidence of thrombotic microangiopathy (TMA) caused by Cfz is inconsistent (<1-5%). We evaluated 96 consecutive patients who received Cfz to evaluate the incidence of TMA in clinical practice. TMA developed in five patients (5.2%) who were mainly receiving high-dose Cfz (≥56 mg/m²). Based on a literature review, precaution should be taken for Cfz-induced TMA in male patients receiving high-dose Cfz irrespective of the combination therapy, Cfz administration period, and complement level. In conclusion, Cfz-induced TMA might be underestimated in clinical practice, and early intervention should be considered.

Clinical impacts of frailty, poor performance status, and advanced age in carfilzomib-containing treatment for relapsed/refractory multiple myeloma: post hoc investigation of the KOTOSG multicenter pilot prospective observational study

We conducted a post hoc analysis of our previous pilot observational study on the efficacy and safety of carfilzomib (CFZ)-containing therapy in 50 patients with relapsed/refractory multiple myeloma in routine practice to clarify the relationships between three major criteria for vulnerability (frailty, poor performance status [PS], and advanced age [≥ 75 years]) and their clinical impact on efficacy and adverse events (AEs). Sixteen patients fulfilled at least one and five patients fulfilled all three criteria. The overall response rate was not significantly affected by frailty, poor PS, and/or advanced age; however, frailty and advanced age were significantly associated with shorter progression-free survival (PFS). In contrast, no significant difference in PFS was observed between patients with PS0-1 or PS2-4. The three criteria for vulnerability were associated with more frequent hematologic AEs: frailty, poor PS, and/or advanced age significantly increased the risk of grade 3-4 anemia and lymphopenia. However, these criteria were not associated with increased risk of other non-hematologic AEs except infection. Collectively, these results demonstrate the need to carefully manage severe hematologic AEs in vulnerable patients and perform disease-specific assessment of frailty to predict prognosis.

Management of Patients with Relapsed and/or Refractory Multiple Myeloma Treated with Novel Combination Therapies in Routine Clinical Practice in Germany

INTRODUCTION

Multiple myeloma remains an incurable plasma cell malignancy which, despite improvements in overall survival over the last decade, is characterized by recurrent relapse and is associated with a poor prognosis. This study investigates the use of novel agents in current real-world clinical practice in the management of relapsed and/or refractory multiple myeloma (RRMM) in Germany over different lines of therapy.

METHODS

A retrospective chart review was conducted for patients with RRMM treated at multiple centers across Germany between May 2017 and June 2018. Variables included patient demographics and clinical characteristics, current and prior treatment regimens, treatment response, cytogenetic abnormalities, testing methodology, and resource utilization.

RESULTS

Data were analyzed from 484 patients from 47 centers across Germany (60% male; average age over 70 years; majority at International Staging System stage 2 or 3). Bone pain and anemia were the most common symptoms at diagnosis, with 63% of patients receiving osteoprotective drugs. Approximately one-third (32%) of patients had received autologous stem cell transplantation and approximately 70% underwent cytogenetic testing. After failure to respond to first-line treatment, most patients received regimens containing second-generation proteasome inhibitors and monoclonal antibodies, with overall response rates greater than 90% in second line (95% and 90% for daratumumab-based and carfilzomib-based therapies, respectively). The incidence of unplanned hospitalization ranged from 11% to 16% across all treatment lines, with longer hospital stays required for treatment administration than for treatment-related toxicity.

CONCLUSION

Although treatment patterns for RRMM in Germany differ by line of therapy and are adapted as disease progresses, patients mostly receive combination regimens with carfilzomib or daratumumab in second and third lines, with high overall response rates achieved in all lines.

Cecal volvulus associated with carfilzomib use for al amyloidosis

INTRODUCTION

Proteasome inhibitors have emerged as quintessential therapies for light-chain (AL) amyloidosis and multiple myeloma in the last decade. While these agents are highly effective, reports have also documented toxicities affecting various organ systems. Whereas gastrointestinal (GI) toxicities are a relatively common occurrence with proteasome inhibitors, severe GI complications are exceedingly rare.

CASE REPORT

We describe a unique case of a patient with AL amyloidosis who developed cecal volvulus after four weeks of treatment with carfilzomib. This severe GI manifestation has not been previously described in the literature.

MANAGEMENT AND OUTCOME

The patient required right hemicolectomy. After clinical recovery, she restarted reduced-dose carfilzomib. She did not have any severe GI side effects following dose reduction, and continues with the current treatment regimen to the present day.

DISCUSSION/CONCLUSION

The causality between volvulus and the treatment with carfilzomib was probable, with a documented score of 6 on the Naranjo probability nomogram. The exact mechanism behind this effect of carfilzomib has yet to be elucidated.

Carfilzomib alleviated osteoporosis by targeting PSME1/2 to activate Wnt/β-catenin signaling

Osteoporosis (OP) is characterized by decreased bone mineral density and impaired bone strength. Carfilzomib (CFZ) is a new-generation proteasome inhibitor and has been found to affect bone metabolism. However, the effect and mechanism of CFZ on OP has not been investigated systematically. In this study, we found that protein levels of proteasome activator subunit 1/2 (PSME1/2) increased in OP, and accumulated mostly in osteoblasts and osteoclasts. Treatment with PSME1/2 recombinant protein inhibited osteogenesis and promoted osteoclast formation in vitro. Also, PSME1/2 inhibited the expression of β-catenin protein, resulting in limitation of Wnt/β-catenin signaling. CFZ inhibited PSME1 and PSME2 proteasome activities and increased β-catenin protein level, resulting in the translocation of β-catenin to the nucleus and activation of canonical Wnt/β-catenin signaling, further promoting osteogenesis and inhibiting osteoclastic differentiation. In vivo, we conducted ovariectomy (OVX) to create a model of OVX-induced postmenopausal OP in mice. When analyzed by micro-CT scanning, enhancement of bone mineral density, bone volume, trabecular number, and thickness was seen in the CFZ-treated mice. Also, we noticed increased osteogenesis and decreased osteoclastogenesis, diminished expression of PSME1 and PSME2 and activated Wnt/β-catenin signaling in bone sections from OP mice treated with CFZ. Overall, our data indicated that PSME1/2 may serve as new targets for the treatment of OP, and targeting PSME1/2 with CFZ provides a candidate therapeutic molecule for postmenopausal OP.

[Rapid response of secondary plasma cell leukemia after carfilzomib and dexamethasone therapy]

An 83-year-old man was admitted to our hospital due to a recurrence of multiple myeloma, accompanied by the appearance of plasma cells in the peripheral blood (PB). Subsequently, he was diagnosed with secondary plasma cell leukemia (sPCL). A chemotherapy regimen of carfilzomib and dexamethasone (Cd) combination therapy was selected, and 15 days later, plasma cells completely disappeared from the PB. Cd therapy was continued, and the free kappa chain levels normalized. Three months later, M-protein could not be detected using serum electrophoresis. This is a valuable report wherein Cd combination therapy was successful in treating sPCL.

The development of a home-based therapeutic platform for multiple myeloma

BACKGROUND

Multiple Myeloma (MM) accounts for 1-2% of all malignancies but is the second commonest haematological malignancy. It is characterized by a proliferation of malignant plasma cells. The treatment paradigm of MM in Australia is traditionally hospital-based, complex and costly. While MM comprises 1-2% of cancer diagnoses, it appears in the top ten cancer diagnoses requiring hospital admission. The cumulative time spent receiving treatment is a significant burden for patients. The ability to receive treatment at home and maximize time away from hospital-based settings is a key preference for patients receiving anticancer therapies over a prolonged period of time.

METHODS

The Peter MacCallum Cancer Centre and Royal Melbourne Hospital's combined Clinical Hematology Unit has collaborated with their Hospital in the Home departments to develop several innovative programs to address this.

RESULTS

We describe our current active programs and potential developments in home-based MM therapy.

CONCLUSION

We have enabled large numbers of patients to receive complex therapies in their own home and the COVID-19 pandemic has increased the pace of the roll out without any compromise in safety. We anticipate that the next raft of immunotherapies will be able to transition into the @Home treatment setting in the coming years.

3D Printing of Tricalcium Phosphate/Poly Lactic-co-glycolic Acid Scaffolds Loaded with Carfilzomib for Treating Critical-sized Rabbit Radial Bone Defects

The rapid development of scaffold-based bone tissue engineering strongly relies on the fabrication of advanced scaffolds and the use of newly discovered functional drugs. As the creation of new drugs and their clinical approval often cost a long time and billions of U.S. dollars, producing scaffolds loaded with repositioned conventional drugs whose biosafety has been verified clinically to treat critical-sized bone defect has gained increasing attention. Carfilzomib (CFZ), an approved clinical proteasome inhibitor with a much fewer side effects, is used to replace bortezomib to treat multiple myeloma. It is also reported that CFZ could enhance the activity of alkaline phosphatase and increase the expression of osteogenic transcription factors. With the above consideration, in this study, a porous CFZ/β-tricalcium phosphate/poly lactic-co-glycolic acid scaffold (designated as “cytidine triphosphate [CTP]”) was produced through cryogenic three-dimensional (3D) printing. The hierarchically porous CTP scaffolds were mechanically similar to human cancellous bone and can provide a sustained CFZ release. The implantation of CTP scaffolds into critical-sized rabbit radius bone defects improved the growth of new blood vessels and significantly promoted new bone formation. To the best of our knowledge, this is the first work that shows that CFZ-loaded scaffolds could treat nonunion of bone defect by promoting osteogenesis and angiogenesis while inhibiting osteoclastogenesis, through the activation of the Wnt/β-catenin signaling. Our results suggest that the loading of repositioned drugs with effective osteogenesis capability in advanced bone tissue engineering scaffold is a promising way to treat critical-sized defects of a long bone.

Evaluation of Cardiac Adverse Events Associated with Carfilzomib Using a Japanese Real-World Database

BACKGROUND

Carfilzomib is a proteasome inhibitor widely used for the treatment of multiple myeloma. However, cardiac adverse events (CAEs) are a serious side effect of carfilzomib administration. Observational studies based on systematic reviews and real-world data have revealed that the risk of CAEs tends to be high. However, there have been no reports on the incidence of CAEs associated with carfilzomib in Japanese patients. Furthermore, there have been no reports on the timing and post-event outcomes of CAEs.

OBJECTIVES

The purpose of this study was to identify the trends in carfilzomib-associated adverse events, the time to onset of CAEs, and the clinical outcomes after the occurrence of CAEs using the Japanese Adverse Drug Event Report (JADER) database.

METHOD

We analyzed data from the JADER database, which contains reports of spontaneous adverse events submitted to the Pharmaceutical and Medical Device Agency, between April 2004 and December 2020. The relative risk of adverse events was estimated using the reporting odds ratio. The time to onset and post-event outcomes were evaluated for adverse cardiotoxic events with >10 reports.

RESULTS

The reporting rate was significantly higher for all 6 detected CAEs. A time-to-onset histogram of the 6 CAEs showed that they all occurred early after carfilzomib administration. The median time of onset of heart failure, congestive heart failure, and acute heart failure was approximately 2 weeks after treatment. The adverse events with the largest proportion of fatal clinical outcomes were acute heart failure (26%) and heart failure (9.5%).

CONCLUSIONS

This study suggests that the early signs and symptoms of potential fatal heart failure should be monitored during carfilzomib treatment.

Phase 1 trial of carfilzomib in relapsed/refractory peripheral T-cell lymphoma

Peripheral T-cell lymphomas (PTCL) are a unique subset of lymphomas with a poor prognosis due to limited treatment options. We performed a phase 1 study of carfilzomib in patients with relapsed/refractory PTCL to determine the safety profile and the maximum tolerated dose (MTD) of this agent. The study was a classical 3 + 3 phase 1 design with intra-patient dose escalation allowed beginning on day 8 of cycle 1 and subsequently. Dose-limiting toxicity (DLT) was defined as the occurrence of any grade 3/4 adverse event. Carfilzomib was given on days 1, 2, 8, 9, 15, and 16 of a 28-day cycle. Fifteen patients were enrolled from 3 centers. The median age of patients was 62. The median number of prior therapies for subjects on this trial was five. The MTD of carfilzomib was 36 mg/m². Dose-limiting toxicities included anemia and sepsis. Serious adverse events were seen in 45% of patients. Single-agent carfilzomib leads to a complete response in one patient and a partial response in one patient. Overall, the drug was reasonably tolerated for a heavily pretreated population, but the limited response rate and short duration of response demonstrate a lack of promise for carfilzomib as a single agent in this patient population.

A combination of carfilzomib, dexamethasone, and daratumumab for treatment of adult patients with relapsed/refractory multiple myeloma in two dosing regimens: once-weekly and twice-weekly

INTRODUCTION

Despite the development of new therapeutic agents, relapsed/refractory multiple myeloma (RRMM) is associated with poor survival outcomes. Furthermore, many patients develop resistance to immunomodulatory drugs (IMiD), creating a need for IMiD-free regimens. Areas covered: This review focuses on the combination of carfilzomib, dexamethasone, and daratumumab (KdD or DKd) which has shown promising results in patients with RRMM who have tried multiple lines of therapy, and has been approved in the U.S., EU, and Japan. The KdD triplet has two recommended dosage regimens, carfilzomib once-weekly (KdD70 QW) and carfilzomib twice-weekly (KdD56 BIW), with comparable efficacy and safety profiles. Expert opinion: These options provide flexibility to patients and healthcare providers, especially in the era of COVID-19. Carfilzomib-based regimens remain a standard of care based on multiple randomized phase 3 studies. Additional studies are currently underway investigating carfilzomib-based regimens such as KdD combined with novel agents. Nevertheless, KdD is one of the most efficacious options for patients with RRMM.

Effects of Organic Acids on Drug Release From Ternary Polypeptide Nanoparticles Entrapping Carfilzomib

Carfilzomib (CFZ) is an FDA-approved proteasome inhibitor with antineoplastic properties against various cancers, yet its short blood retention time after intravenous injection (< 30 min) makes clinical applications limited to multiple myeloma. We previously developed ternary polypeptide nanoparticles (tPNPs) as a new nanoparticle formulation of CFZ to overcome these limitations. The formulation was prepared by polyion complexation between poly(ethylene glycol)-poly(L-glutamate) block copolymers (PEG-PLE) and CFZ-cyclodextrin (CD) inclusion complexes, where CDs were positively charged with 7 primary amines attached while PEG-PLE carried 100 carboxyl groups per polymer chain. Although tPNPs greatly improved biostability of CFZ, CFZ-loaded tPNPs (CFZ-tPNPs) still showed burst drug release and mediocre drug retention under physiological conditions. To address these issues, organic acids are tested as stabilizers in this study to improve particle stability and drug retention for tPNPs. Charge densities in the core of CFZ-tPNPs were optimized with selected organic acids such as citric acid (CA) and lactic acid (LA) at varying mixing ratios. Organic acids successfully maintained small particle size suitable for intravenous injection and drug delivery (diameters < 60 nm), improved CFZ solubility (> 1 mg/mL), allowed for lyophilization and easy reconstitution in various buffers, enhanced drug retention (> 60% post 24 h incubation), and suppressed burst drug release in the first 6 h following solubilization. These results demonstrate that organic acid stabilized tPNPs are useful as an injection formulation of CFZ, which may expand the utility of the proteasome inhibitor.

Carfilzomib, dexamethasone, and daratumumab in Asian patients with relapsed or refractory multiple myeloma: post hoc subgroup analysis of the phase 3 CANDOR trial

BACKGROUND

Due to increasing use of frontline lenalidomide, effective and safe lenalidomide-free therapies for relapsed/refractory multiple myeloma (RRMM) are needed in Asia. This subgroup analysis of phase 3 CANDOR study evaluated efficacy and safety of KdD vs Kd in Asian patients with RRMM.

METHODS

Self-identified Asian patients with RRMM (KdD = 46; Kd = 20) with 1‒3 prior therapies were included. The primary endpoint of progression-free survival was estimated by stratified Cox regression.

RESULTS

Baseline demographics and patient characteristics were balanced in both arms. KdD reduced the risk of progression or death by 25% vs Kd [hazard ratio (HR) = 0.75; 95% CI 0.259, 2.168] in the Asian subgroup, compared with 37% vs Kd (0.63; 0.464, 0.854) in the overall CANDOR population. Percentage of patients who reported grade ≥ 3 treatment-emergent adverse events (TEAEs) in the KdD and Kd arms was 95.7 and 90.0%, respectively. Serious AEs were observed in 58.7 and 40.0% of patients in the KdD and Kd arms, respectively. There were two (4.3%) fatal TEAEs in the KdD arm due to infections.

CONCLUSIONS

There was a trend toward better efficacy and a favorable benefit-risk profile for KdD vs Kd in Asian patients with RRMM. Cautious interpretation is warranted due to small patient size.

Retrospective Study of Carfilzomib-Pomalidomide-Dexamethasone in Relapsed/Refractory Multiple Myeloma Patients in a Tertiary Care Hospital in India

Carfilzomib is a second-in class Proteosome Inhibitor and has been approved for Relapsed/Refractory Multiple Myeloma (RRMM). We retrospectively retrieved and analyzed data of KPd combination both biweekly and weekly regimens at our centre from 1 st August 2017 and 31 st May 2020. Sixty-nine patients were treated with KPd with median age of 58 years. Median prior lines of chemotherapy were 2(1-15). Twenty-eight (40.5%) patients underwent autoSCT. Median no. of cycles was 4(1-12) and 3(1-13) with median time to response of 4(2-12) and 2(2-6) months in biweekly and once weekly regimen cohorts respectively. At last follow-up, overall response rate (ORR) was 65.2%{CR-n = 10 (14.5%), VGPR-n = 19 (27.5%), PR-n = 16 (23.2%)} with n = 13(18.8%) patients had PD and relapse was observed in n = 24(34.8%). Thirty (43.4%) patients received maintenance therapy {n = 21(70%)} or autoSCT {n = 9(30%)}. Common toxicities were anemia {n = 11(15.9 %)}, thrombocytopenia (n = 15(21.7%) and neutropenia (n = 16 (23.2%)}, hypertension {n = 28(40.5%)}, peripheral neuropathy (grade1/2) {n = 15(21.7%)}, infections [n = 18(26%) {bacterial [n = 9(13%),viral n = 7(10.1%), fungal n = 8(11.6%)}]. At a median follow-up of 18 months, the estimated median PFS was 11.3 months (95%C.I. 8.3– 14.2) whereas the estimated median OS was 28 months (95%C.I. 20.4-35.5) for the entire cohort. Mortality rate of 2.5% and 10% in two cohorts respectively. Commonest cause of death was PD and sepsis. KPD is a well-tolerated regimen for RRMM, which can be a bridge to ASCT, however with significant side effects.

Proteasome inhibitor-induced coronary vasospasm in multiple myeloma: a case report

BACKGROUND

Coronary vasospasm is an increasingly recognized cause of myocardial infarction or myocardial ischaemia in patients without obstructive coronary artery disease. A thorough medication review may identify drugs or toxins that could trigger coronary vasospasm. This case provides mechanistic insight into the off-target effect of proteasome inhibition leading to coronary vasospasm in a patient referred with chest pain consistent with typical angina.

CASE SUMMARY

A 72-year-old lady presented with anginal chest pain at rest with electrocardiogram evidence of myocardial ischaemia who was referred for invasive coronary angiography. This demonstrated minor coronary disease without an obstructive lesion. Vasoreactivity testing revealed diffuse coronary vasospasm of the left anterior descending artery. Carfilzomib was identified as the trigger for coronary vasospasm. Symptoms resolved without recurrence after appropriate treatment including cessation of the triggering agent.

CONCLUSION

Coronary spasm is a rare but important adverse reaction to proteasome inhibitors. This case supports the clinical utility of invasive coronary vasoreactivity testing in patients with ischaemia with no obstructive coronary artery disease.

Severe Right-Sided Heart Failure and Pulmonary Hypertension with Carfilzomib Treatment in Multiple Myeloma

Carfilzomib, a second-generation irreversible proteasome inhibitor, is currently considered the preferred therapy for relapsed and refractory multiple myeloma. There are several cardiovascular adverse effects described with carfilzomib chemotherapy most commonly being hypertension, dyspnea and decreased cardiac ejection fraction. We report a case of newonset pulmonary hypertension with right ventricular (RV) heart failure in a patient receiving carfilzomib. Awareness of this rare side effect of this drug is essential for prompt diagnosis and management. We also propose close monitoring of RV and pulmonary artery pressures along with left ventricular function in echocardiographic assessment in patients with carfilzomib chemotherapy.

Real-world comparative effectiveness of triplets containing bortezomib (B), carfilzomib (C), daratumumab (D), or ixazomib (I) in relapsed/refractory multiple myeloma (RRMM) in the US

Multiple available combinations of proteasome inhibitors, immunomodulators (IMIDs), and monoclonal antibodies are shifting the relapsed/refractory multiple myeloma (RRMM) treatment landscape. Lack of head-to-head trials of triplet regimens highlights the need for real-world (RW) evidence. We conducted an RW comparative effectiveness analysis of bortezomib (V), carfilzomib (K), ixazomib (I), and daratumumab (D) combined with either lenalidomide or pomalidomide plus dexamethasone (Rd or Pd) in RRMM. A retrospective cohort of patients initiating triplet regimens in line of therapy (LOT) ≥ 2 on/after 1/1/2014 was followed between 1/2007 and 3/2018 in Optum's deidentified US electronic health records database. Time to next treatment (TTNT) was estimated using Kaplan-Meier methods; regimens were compared using covariate-adjusted Cox proportional hazard models. Seven hundred forty-one patients (820 patient LOTs) with an Rd backbone (VRd, n = 349; KRd, n = 218; DRd, n = 99; IRd, n = 154) and 348 patients (392 patient LOTs) with a Pd backbone (VPd, n = 52; KPd, n = 146; DPd, n = 149; IPd, n = 45) in LOTs ≥2 were identified. More patients ≥75 years received IRd (39.6%), IPd (37.8%), and VRd (36.7%) than other triplets. More patients receiving VRd/VPd were in LOT2 vs other triplets. Unadjusted median TTNT in LOT ≥ 2: VRd, 13.9; KRd, 8.7; IRd, 11.4; DRd, not estimable (NE); and VPd, 12.0; KPd, 6.7; IPd, 9.5 months; DPd, NE. In covariate-adjusted analysis, only KRd vs DRd was associated with a significantly higher risk of next LOT initiation/death (HR 1.72; P = 0.0142); no Pd triplet was significantly different vs DPd in LOT ≥ 2. Our data highlight important efficacy/effectiveness gaps between results observed in phase 3 clinical trials and those realized in the RW.

Incidence and Management of Carfilzomib-induced Cardiovascular Toxicity; A Systematic Review and Meta-analysis

BACKGROUND

The ASPIRE and ENDEAVOUR trials have shown cardiovascular adverse effects in patients treated with carfilzomib-based regimens. Therefore, we conducted this meta-analysis of published clinical trials to identify the cumulative incidence and risk of cardiovascular adverse effects due to carfilzomib.

METHODS

A systematic search of PubMed, Embase, Web of Science, and Cochrane library was performed, and we identified 45 prospective trials of carfilzomib with data on 5583 patients. Among all patients being treated with carfilzomib (N=5,583), 8.9% sustained all grade cardiotoxicity, while 4.4% sustained high-grade cardiotoxicity. All-grade hypertension was present in 13.2%, while the incidence of high-grade hypertension was 5.3%.

RESULT

The observed incidences of all-grade heart failure, edema, and ischemia were 5.1%, 20.7%, and 4.6% respectively. Likewise, for high-grade heart failure and edema observed incidence was 3.2%, and 2.7% respectively. There was no difference in the event rate of all and high-grade cardiotoxicity between newly diagnosed multiple myeloma and relapsed/refractory (p-value 0.42 and 0.86 respectively). Likewise, we did not observe any difference in the event rate of all and high-grade cardiotoxicity when carfilzomib was used as a single agent versus when used in combination therapy with other agents (p-value 0.43 and 0.73 respectively).

CONCLUSION

Carfilzomib is associated with a significant risk of cardiovascular toxicity and hypertension. With the increasing utilization of carfilzomib, it is critical for primary care physicians, oncologists and cardiologists to be aware of the risk of cardiotoxicity associated with the use of carfilzomib to recognize and treat baseline cardiovascular risk factors in such patients.

KD-PACE Salvage Therapy for Aggressive Relapsed Refractory Multiple Myeloma, Plasma Cell Leukemia and Extramedullary Myeloma

BACKGROUND

Patients with advanced/aggressive multiple myeloma have limited treatment options to achieve rapid disease control. In eligible patients, bortezomib, dexamethasone, thalidomide, cisplatin, doxorubicin, cyclophosphamide, and etoposide is often used. However, many patients are refractory to or have toxicities from bortezomib and there is a need for bridging therapy. We have used a modified regimen incorporating the second-generation proteasome inhibitor carfilzomib (carfilzomib, dexamethasone, thalidomide, cisplatin, doxorubicin, cyclophosphamide and etoposide [KD-PACE]) instead of bortezomib for relapsed/refractory multiple myeloma.

PATIENTS AND METHODS

This 2-center retrospective study included consecutive patients receiving KD-PACE for relapsed or refractory multiple myeloma, plasma cell leukemia, or extramedullary myeloma. The primary outcome was the feasibility of KD-PACE as a bridging therapy to a more definitive treatment option.

RESULTS

Fifty-two patients were included. The median age was 57 years, and 67% were male. Thirty-one patients were bridged with KD-PACE to autologous hematopoietic stem cell transplant (29%), allogenic hematopoietic stem cell transplant (27%), or a clinical trial (12%). Patients bridged to autologous hematopoietic stem cell transplant, allogenic hematopoietic stem cell transplant, or a clinical trial had a superior progression-free survival (8.3 months vs 2.3 months in the nonbridged group; P < .001) and overall survival (median, 16.7 months vs 4.3 months in the nonbridged group; P < .001). No unexpected toxicities occurred from the treatment regimen.

CONCLUSION

KD-PACE is a promising treatment option for select patients with advanced/aggressive forms of myeloma requiring rapid disease control before a more definitive salvage therapy such as auto/allotransplantation or a clinical trial.

Carfilzomib-induced pulmonary hypertension with associated right ventricular dysfunction: A case report

Carfilzomib, a selective proteasome inhibitor, is approved for use in relapsed and refractory multiple myeloma. Its link to left ventricular dysfunction is well established but little is known about its effects on the right ventricle. One of its rare complications is pulmonary hypertension, which at its extreme may result in right ventricular dysfunction. Here, we present a case of an elderly male veteran with multiple myeloma status post various failed therapies who developed acute dyspnea after four cycles of carfilzomib and subsequently found to have severe pulmonary hypertension with resultant acute right ventricular failure, which recovered after cessation of carfilzomib. This case highlights the need for careful cardiovascular surveillance while on carfilzomib and the importance of knowing even its rarest complications as these cardiotoxicities are reversible with discontinuation of the drug.

Two cases of carfilzomib-induced thrombotic microangiopathy successfully treated with Eculizumab in multiple myeloma

BACKGROUND

Treatment with proteasome inhibitors like carfilzomib in patients with multiple myeloma (MM) can induce thrombotic microangiopathy (TMA) characterized by neurological symptoms, acute kidney injury, hemolysis and thrombocytopenia. Successful treatment with the monoclonal antibody eculizumab was described for these patients, but reports of ideal management and definitive treatment protocols are lacking.

CASE PRESENTATION

The first case describes a 43-years-old IgG-kappa-MM patient that developed TMA during the first course of carfilzomib-lenalidomide-dexamethasone (KRd) consolidation after autologous stem cell transplantation (ASCT). In the second case, a 59-years-old IgG-kappa-MM patient showed late-onset TMA during the fourth and last cycle of elotuzumab-KRd consolidation within the DSMM XVII study of the German study group MM (DSMM; clinicalTrials.gov Identifier: NCT03948035). Concurrently, he suffered from influenza A/B infection. Both patients had a high TMA-index for a poor prognosis of TMA. Therapeutically, in both patients plasma exchange (TPE) was initiated as soon as TMA was diagnosed. In patient #1, dialysis became necessary. For both patients, only when the complement inhibitor eculizumab was administered, kidney function and blood values impressively improved.

CONCLUSION

In this small case series, two patients with MM developed TMA due to carfilzomib treatment (CFZ-TMA), the second patient as a late-onset form. Even though TMA could have been elicited by influenza in the second patient and occurred after ASCT in both patients, with cases of TMA post-transplantation in MM being described, a relation of TMA and carfilzomib treatment was most likely. In both patients, treatment with eculizumab over two months efficiently treated TMA without recurrence and with both patients remaining responsive months after TMA onset. Taken together, we describe two cases of TMA in MM patients on carfilzomib-combination treatment, showing similar courses of this severe adverse reaction, with good responses to two months of eculizumab treatment.

Carfilzomib in addition to lenalidomide and dexamethasone in Asian patients with RRMM outside of a clinical trial

Carfilzomib, lenalidomide, and dexamethasone (KRd) effectively improve survival in patients with relapsed and refractory multiple myeloma (RRMM). However, the outcome of KRd treatment in Asian patients reflecting a general RRMM population outside of a clinical trial has not been reported. Fifty-five RRMM patients who were treated with carfilzomib in combination with Rd from the time of the first approval of KRd in the Republic of Korea were analyzed. The median age was 61 years. The percentage of patients with an ECOG performance status ≥ 3, creatinine clearance < 50 mL/min, high-risk cytogenetics, and ≥ 4 lines of prior treatment were 9%, 22%, 31%, and 27%, respectively. Forty-one patients started treatment with KRd, whereas the remaining 14 patients (25%) were added carfilzomib during the Rd treatment. In the whole cohort, the overall response rate was 73% and progression-free survival was 8.8 months. The addition of carfilzomib in patients who were refractory or had disease progression during Rd treatment reattained a response in half of the patients. The advantage of carfilzomib with Rd was significant in patients in the first relapse. Toxicity profile was acceptable, excluding severe infections. Carfilzomib in combination with Rd is effective and has a reasonable adverse event rate in Asian patients with RRMM.

A study of carfilzomib and dexamethasone in patients with relapsed and refractory multiple myeloma in China

The second-generation proteasome inhibitor carfilzomib produces superior outcomes in relapsed or refractory multiple myeloma (MM). We conducted a single-arm trial of twice-weekly carfilzomib (27 mg/m²)-dexamethasone (Kd27) for relapsed and refractory MM in China. Kd27 was administered in 28-day cycles to 123 patients previously treated with ≥ 2 other regimens, including treatment with bortezomib and an immunomodulatory drug, and refractory to their most recent therapy. Overall response rate (ORR) was the primary endpoint; progression-free survival (PFS) and overall survival (OS) were key secondary endpoints. Primary analysis was conducted when all patients received ≥ 6 cycles of Kd27 or discontinued Kd27. Median age was 60 years; median number of prior regimens was 4; 74% were refractory to proteasome inhibitors and immunomodulatory drugs. ORR was 35.8% (95% CI 27.3-44.9), median PFS was 5.6 (95% CI 4.6-6.5) months, and median OS was 16.6 (95% CI 12.2-NE) months. Grade ≥ 3 adverse events (AEs) occurred in 76.4% of patients. Grade ≥ 3 AEs of interest included hypertension (13.8%), acute renal failure (3.3%), cardiac failure (0.8%), ischemic heart disease (0.0%), and peripheral neuropathy (0.0%); 5.7% of patients discontinued carfilzomib due to AEs. Carfilzomib-dexamethasone produced a clinically meaningful response without new safety findings in Chinese patients with previously treated MM.Trial registration: NCT03029234.

Suppression of proteasome induces apoptosis in APL cells and increases chemo-sensitivity to arsenic trioxide: Proposing a perception in APL treatment

In the last three decades, the pathogenesis of acute promyelocytic leukemia (APL) has been mostly studied with regard to the oncogenic role of PML/RAR fusion protein; however, the latest discoveries have stated that the concerns with the treatment of APL patients would not be resolved until the role of aberrant networks is overlooked. The present study was designed to evaluate the anti-cancer property of second-generation of the proteasome inhibitors carfilzomib (CFZ) on APL-derived NB4 cells. Our results showed that pharmacologic targeting of proteasome in NB4 reduced the proliferative rate of malignant cells through a c-Myc-mediated G2/M cell cycle arrest. Moreover, we found that the suppression of proteasome was coupled with the induction of apoptotic NB4 cell death, which is probably mediated through down-regulation of anti-apoptotic target genes. Interestingly, our results suggested that the suppression of the autophagy system using chloroquine could serve as a mechanism through which the cytotoxicity of CFZ in APL cells was ameliorated. Finally, and consistent with the favorable efficacy of single agent of CFZ, we also noted an intensifying effect of the inhibitor on the anti-leukemic activity of arsenic trioxide (ATO) when it was used in combination. Overall, this study suggests that pharmaceutical targeting of proteasome using CFZ, either as a single agent or in combination with ATO, could be a promising mechanism through which the obstacle on the way of APL would be tackled; however, further investigations are needed to determine the advantages of the inhibitor in clinical applications.

[Hypomagnesemia induced by gastrointestinal losses due to carfilzomib]

A 67-year-old man with multiple myeloma had been treated with carfilzomib, lenalidomide, and dexamethasone (KRd) therapy. During the second course, he developed dyspnea, which gradually worsened. After admission, gastrointestinal losses of magnesium were confirmed, and intravenous magnesium was administered, which consequently improved his symptoms. Although KRd therapy was resumed, hypomagnesemia was recurring. Therefore, carfilzomib was replaced with ixazomib, which improved the patient's hypomagnesemia. The major causes of hypomagnesemia are gastrointestinal and renal losses; our case appeared to have gastrointestinal losses of magnesium and was successfully treated by discontinuing carfilzomib. Hypomagnesemia should be considered in patients receiving carfilzomib; furthermore, clinicians should consider discontinuing carfilzomib as its treatment.