Bortezomib-induced Peripheral Neuropathy Research Articles

A genetic variant study of bortezomib-induced peripheral neuropathy in Chinese multiple myeloma patients.

Bortezomib results in peripheral neuropathy (PN) in approximately 50% of patients, during multiple myeloma (MM) treatment, a complication known as Bortezomib-induced peripheral neuropathy (BIPN). The drug response varies among individuals. Genetic factor may play an important role in BIPN. A next-generation sequencing (NGS) panel containing 1659 targets from 233 genes was used to identify risk variants for developing BIPN in 204 MM patients who received bortezomib therapy. mRNA expression of MTHFR and ALDH1A1 in 62 peripheral blood samples was detected by real-time quantitative PCR (RT-qPCR). Serum homocysteine (Hcy) levels were detected in 40 samples by chemiluminescent microparticle immunoassay (CMIA). Compared with the non-BIPN group (n = 89), a total of 8 significantly associated single nucleotide polymorphisms (SNPs) were identified in the BIPN group (n = 115): MTHFR (rs1801131, rs1801133, rs17421511), EPHX1 (rs1051740), MME (rs2016848), ALDH1A1 (rs6151031), HTR7 (rs1935349) and CYP2A6 (rs8192720). The mRNA expression level of MTHFR in newly diagnosed patients with peripheral neuritis after treatment (NP group) was lower than that of newly diagnosed patients without peripheral neuritis after treatment (NnP group) (1.70 ± 0.77 vs. 2.81 ± 0.97, p= 0.009). Serum Hcy levels were significantly higher in BIPN group than in non-BIPN group (11.66 ± 1.79 μmol/L vs. 8.52 ± 3.29 μmol/L, p= 0.016) and healthy controls (11.66 ± 1.79 μmol/L vs. 8.55 ± 2.13 μmol/L, p≤ 0.001). CYP2A6, EPHX1, MTHFR, ALDH1A1, HTR7, MME and BIPN are linked in Chinese MM patients. BIPN is more likely to occur in patients with lower MTHFR mRNA expression, which might result in higher serum Hcy levels.

Neurotropin Alleviates Bortezomib-Induced Neurotoxicity Via Microglial Neuroinflammation

Objective: To investigate the effect of neurotropin (NTP) on the prevention and amelioration of neurotoxicity induced by bortezomib (BTZ)-based chemotherapy regimens and the possible mechanism of action, and to provide new ideas for the prevention mechanism and treatment of bortezomib-induced peripheral neuropathy (BIPN). Methods: The BIPN model was constructed by injecting bortezomib （ BTZ group ）or bortezomib+saline ( BTZ+NS group)into the tail vein of C57BL/6 mice. After successful modeling, NTP was added to take intraperitoneal injections for 4 weeks, which were defined to be NTP group. In order to assess the severity of BIPN, systemic toxicity, pain behavioral and sensorimotor kinetic changes in mice of different group were observed while transmission electron microscopy examination was used to observe the damage of peripheral nerve ultrastructure and myelin thickness. Immunofluorescence staining method was used to detected the activation of spinal cord microglial and their expression level of inflammatory factors such as IL-1β, IL-6 and TNF-α. ELISA was used to detected the expression of IL-1β, IL-6 and TNF-α in the dorsal horn homogenate of the spinal cord; Western blot to detect the protein expression of pathway-associated proteins JAK/STAT. Results: The Compared with the Control group, the BTZ and BTZ+NS groups showed significant decreases in mechanical, thermal pain thresholds and motor coordination compared with the Control group (P<0.05), and ultrastructural damage to the peripheral nerves, with demyelinating lesions and a significant reduction in the overall thickness of myelin sheaths in myelinated fibers (0.62±0.08 Vs 0.56±0.12, P＜0.01). NTP administration significantly improved pain behavioral changes, reduced ultrastructural damage, reversed demyelinating lesions and significantly increased myelin thickness (0.56±0.06 Vs 0.62±0.08, P＜0.01) in model mice compared with BTZ group. Immunofluorescence staining suggested that microglia in the dorsal horn of the spinal cord of mice in the BTZ group and the BTZ+NS group were significantly activated, which were shown the fluorescence ratio of IBA-1 + was significantly increased (2.55±0.61 Vs 0.55±0.04，2.42±0.89 Vs 0.55±0.04，P＜0.0001), while NTP significantly improved the activation of microglia in the model mice (0.71±0.13 Vs 2.55±0.61, 0.71±0.13 Vs 2.42±0.89, P<0.0001). The co-staining results suggest that the increase in inflammatory factors may originate from microglia. ELISA results that the expression level of IL-6 and TNF-α in NTP administration group significantly decreased compared with the group of BTZ group (IL-6: 37.87±23.2 Vs 111.8±6.0, P＜0.05; TNF-α: 547.9±17.11 Vs 998.8±333.4, P＜0.05) and the BTZ+NS group (IL-6: 37.87±23.2 Vs 88.3±15.58, P<0.05; TNF-α: 547.9±17.11 Vs 768.3±37.45, P<0.05) in the dorsal horn homogenate of the spinal cord. The results of spinal cord proteomics showed that neurotropin could induce the changes of differential proteins, such as PI3K-AKT, MAPK, JAK/STAT, which were related to inflammation. Moreover, these differential proteins can be significantly enriched in the JAK/STAT KEGG Pathway. The KEGG pathway of differential protein enrichment in the spinal cord of differential BIPN mice was detected by proteomics chip after NTP treatment, and the JAK/STAT pathway was significantly down-regulated after NTP treatment. Western blot showed that the protein expression of JAK1/STAT3 decreased after NTP administration. Conclusion: Neurotropin alleviates bortezomib induced neurotoxicity through microglial neuroinflammation, and may reduce the release of glial inflammation by regulating JAK1/STAT3 signaling pathway, thus playing a therapeutic role in BIPN. Repeated experiments are needed for further research. Keywords: Neurotropin, Bortezomib, Peripheral neuropathy, Neuroinflammation

Impact of Black Race on Peripheral Neuropathy in Patients With Newly Diagnosed Multiple Myeloma Receiving Bortezomib Induction.

The incidence of multiple myeloma (MM) is two to three times higher in Black patients compared with other races, making it the most common hematologic malignancy in this patient population. Current treatment guidelines recommend the combination of a proteasome inhibitor, an immunomodulatory agent, and a corticosteroid as preferred induction therapy. Bortezomib use comes with the risk of peripheral neuropathy (PN) and potential need for dose reduction, therapy interruption, and additional supportive medications. Known risk factors for bortezomib-induced peripheral neuropathy (BIPN) include diabetes mellitus, previous thalidomide, advanced age, and obesity. We aimed to determine the potential association between Black race and incidence of BIPN. We identified a cohort of 748 patients with newly diagnosed MM who received induction with bortezomib, lenalidomide, and dexamethasone from 2007 to 2016. One hundred forty Black patients were matched with 140 non-Black patients on age, sex, BMI, and route of bortezomib administration. Incidence of BIPN was a binary event defined as new use of a neuropathy medication, bortezomib dose reduction, dose omission, or discontinuation because of PN. The incidence of BIPN was higher in Black patients (46%) compared with non-Black patients (34%; P = .05) in both univariate (odds ratio [OR], 1.61; 95% CI, 1.00 to 2.61; P = .052) and multivariable analyses (OR, 1.64; 95% CI, 1.01 to 2.67; P = .047). No significant differences in BIPN were seen when stratified by route of administration. These data indicate that Black race is an independent risk factor for the development of BIPN. Additional prevention strategies, close monitoring, and appropriate supportive care measures are warranted for these patients.

Inhibitors of the Mechanistic Target of Rapamycin Can Ameliorate Bortezomib-Induced Peripheral Neuropathy.

Bortezomib, an anticancer drug for multiple myeloma and mantle cell lymphoma, causes severe adverse events and leads to peripheral neuropathy. The associated neuropathy limits the use of bortezomib and could lead to discontinuation of the treatment; therefore, effective intervention is crucial. In the present study, we statistically searched for a drug that could alleviate bortezomib-induced peripheral neuropathy using adverse event self-reports. We observed that specific inhibitors of the mechanistic target of rapamycin (mTOR) lowered the incidence of bortezomib-induced peripheral neuropathy. These findings were experimentally validated in mice, which exhibited long-lasting mechanical hypersensitivity after repeated bortezomib treatment. This effect was inhibited for hours after a systemic injection with rapamycin or everolimus in a dose-dependent manner. Bortezomib-induced allodynia was accompanied by the activation of spinal astrocytes, and intrathecal injection of mTOR inhibitors or an inhibitor of ribosomal protein S6 kinase 1, a downstream target of mTOR, exhibited considerable analgesic effects in a dose-dependent manner. These results suggest that mTOR inhibitors, which are readily available to patients prescribed bortezomib, are one of the most effective therapeutics for bortezomib-induced peripheral neuropathy.

Feasibility of cryocompression for bortezomib-induced peripheral neuropathy (BIPN) among patients with multiple myeloma (MM).

e24147 Background: BIPN is a dose-limiting side effect of bortezomib therapy occurring in over three-quarters of bortezomib-treated patients and results in increased morbidity secondary to decreased quality of life and increased mortality due to treatment discontinuation or dose-reduction. Cryocompression therapy acts at the level of the nerve and does not limit bortezomib anti-tumor activity, making it ideal for clinical testing in patients with BIPN. This study evaluated the feasibility of cryocompression therapy in MM patients with BIPN. Methods: MM patients with Common Terminology Criteria for Adverse Event (CTCAE) Grade 1-3 BIPN who previously received a bortezomib-containing regimen (Arm 1) or were currently receiving a bortezomib-containing regimen (Arm 2) were enrolled at a Comprehensive Cancer Center outpatient clinic. Patients were instructed to complete daily home cryocompression treatments on non-dominant hand and foot for 30 continuous minutes for 8-weeks. Primary outcome was compliance measured by device-recorded data and defined as completion of at least 25 of 30 minutes, 60% of prescribed treatment days. Change in patient reported symptoms was assessed by the European Organization for Research and Treatment of Cancer (EORTC) QLQ-CIPN20 questionnaire. Proportion of compliant patients was calculated. Spearman’s rank correlation coefficients were used to evaluate the association between treatment compliance and QLQ-CIPN20 scores. Here we report on Arm 1. Results: 12 patients (median age 63.9+11.8 years, 41.7% female, 66.7% white, 25.0% black) participated in Arm 1. 75% of patients were compliant. The mean proportion of treatment-compliant days was 65.8% (95% CI 46.5% – 85.0%). Patient-reported BIPN symptoms improved with QLQ-CIPN20 total and sensory sub scores of 39.2+9.2 and 22.5+4.7 at baseline, 33.7+6.2 and 19+3.5 at week 4, and 34.1+7.8 and 19.9+5.5 at week 8. This accounted for a statistically significant decline in total QLQ-CIPN20 score at week 4 (-5.9+9.1, p = 0.035), week 8 (-4.6+5.0, p = 0.020), and sensory sub score at week 4 (-3.5+3.4, p = 0.008) and week 8 (-2.6+3.5, p = 0.050). There was no correlation between compliance and change in total QLQ-CIPN20 score (r = -0.31, p = 0.380) or sensory sub score (r = -.054, p = 0.109) in the per protocol analysis (N = 10). Using a last-time-point available analysis, no correlation was observed for total QLQ-CIPN20 score (r = -0.44, p = 0.149) but a moderate-to-strong inverse correlation was observed between amount of cryocompression use and change in QLQ-CIPN20 sensory sub score (r = -0.62, p = 0.031). Conclusions: Cryocompression therapy is feasible in MM patients with BIPN who previously received a bortezomib-containing regimen. The observed biologic gradient with greater improvement in patient-reported sensory neuropathy with longer duration of cryocompression treatment supports the rationale and further study. Clinical trial information: NCT03870451 .

The nonlinear association between red blood cell distribution width (RDW) and bortezomib-related peripheral neurotoxicity (PN): A retrospective cohort study

BackgroundPrevious evidence on the association of red blood cell distribution width (RDW) with bortezomib-induced peripheral neuropathy (BIPN) is limited. As a result, in this single-center retrospective cohort analysis, the link between RDW and BIPN was investigated. MethodsThis study4 comprised 376 patients with primary multiple myeloma (MM) who attended the Department of Haematology at Guizhou Provincial People's Hospital between 2013 and 2021. RDW and the occurrence of BIPN were the exposure and outcome variables, respectively. Demographic characteristics, pharmacological agents, co-morbidities, and MM-related indicators were all included as covariates. To investigate the relationship between RDW and BIPN, binary logistic regression and two-piecewise linear regression were utilized. ResultsThe relationship between RDW and BIPN was found to be non-linear. RDW was not significantly associated with the risk of BIPN (odds ratio (OR): 0.99; 95% confidence interval (CI): 0.95 to 1.02; p-value: 0.4810) to the left of the inflection point (RDW = 72.3); to the right of the inflection point, each 1 ft increase in RDW was associated with an 7% increase in the risk of BIPN (OR: 1.07; 95% CI: 1.01 to 1.15; p-value: 0.046). ConclusionThe relationship between RDW and the risk of BIPN demonstrated a threshold effect, with RDW exceeding 72.3 fl, indicating a relatively significant risk of BIPN.

Impact of Concomitant Use of Azoles on Bortezomib-related Adverse Drug Reactions Using JADER.

Azoles are widely used for prophylaxis in patients with haematologic malignancies and are well known as selective cytochrome P450 isoenzyme 3A4 inhibitors. Although the interaction between bortezomib and azoles has been reported, most previous studies were case reports or small clinical studies. Hence, we conducted a pharmacoepidemiological study to elucidate the impact of azoles on bortezomib-related adverse reactions, using the Japanese adverse drug event report database (JADER). We extracted 19,567 reports on patients prescribed bortezomib and/or azoles. We classified cases into three groups, namely bortezomib, bortezomib and azoles, and azoles groups. We estimated the odds ratios (OR) for the impact of concomitant azole use on five bortezomib-related adverse drug reactions (peripheral neuropathy, thrombocytopenia, neutropenia, leukopenia, and interstitial lung disease) using logistic regression. The OR for peripheral neuropathy in the 'bortezomib and azoles' group was higher than that in the bortezomib group [OR=2.02, 95% confidence interval (CI)=1.32-3.08]. The magnitude of the interaction was stronger with itraconazole than that with fluconazole (itraconazole, OR=3.22, 95% CI=1.78-5.70; fluconazole, OR=1.56, 95% CI=0.86-2.72). We found an association between concomitant administration of azoles with bortezomib and peripheral neuropathy. Azoles may enhance bortezomib-induced peripheral neuropathy based on their pharmacokinetic properties.

Animal models of chemotherapy-induced peripheral neuropathy for hematological malignancies: A review.

Chemotherapy is one of the main treatments for hematologic malignancies. However, chemotherapy-induced peripheral neuropathy (CIPN) is one of the most common long-term toxic reactions in chemotherapy, and the occurrence of CIPN affects patients' quality of life and can cause interruption of chemotherapy in severe cases, thus reducing the efficacy of chemotherapy. We currently summarize the existing CIPN animal models, including the characteristics of several common animal models such as bortezomib-induced peripheral neuropathy, vincristine-induced peripheral neuropathy, and oxaliplatin-induced peripheral neuropathy. It was found that CIPN may lead to behavioral, histopathological, and neurophysiological changes inducing peripheral neuropathy. However, the mechanism of CIPN has not been fully elucidated, especially the prevention and treatment protocols need to be improved. Therefore, this review article summarizes the progress of research on CIPN animal models and the possible mechanisms and treatment of CIPN.

Bortezomib-induced neurotoxicity in human neurons is the consequence of nicotinamide adenine dinucleotide depletion.

The proteosome inhibitor bortezomib has revolutionized the treatment of multiple hematologic malignancies, but in many cases, its efficacy is limited by a dose-dependent peripheral neuropathy. We show that human induced pluripotent stem cell (hiPSC)-derived motor neurons and sensory neurons provide a model system for the study of bortezomib-induced peripheral neuropathy, with promising implications for furthering the mechanistic understanding of and developing treatments for preventing axonal damage. Human neurons in tissue culture displayed distal-to-proximal neurite degeneration when exposed to bortezomib. This process coincided with disruptions in mitochondrial function and energy homeostasis, similar to those described in rodent models of bortezomib-induced neuropathy. Moreover, although the degenerative process was unaffected by inhibition of caspases, it was completely blocked by exogenous nicotinamide adenine dinucleotide (NAD+), a mediator of the SARM1-dependent axon degeneration pathway. We demonstrate that bortezomib-induced neurotoxicity in relevant human neurons proceeds through mitochondrial dysfunction and NAD+ depletion-mediated axon degeneration, raising the possibility that targeting these changes might provide effective therapeutics for the prevention of bortezomib-induced neuropathy and that modeling chemotherapy-induced neuropathy in human neurons has utility.

Investigation of the frequency of bortezomib neuropathy in patients with multiple myeloma diagnosis with normal and abnormal genetic characteristics.

Bortezomib-induced peripheral neuropathy in patients with multiple myeloma is an undesirable and sometimes severe side effect. Our study aimed to examine whether there was a difference in bortezomib-induced peripheral neuropathy between multiple myeloma patients with normal and abnormal genetic characteristics. This retrospective analysis is based on the assessment of bortezomib-induced peripheral neuropathy frequency in newly-diagnosed multiple myeloma patients with normal (n = 68) and abnormal (n = 45) genetic profiles. A total of 113 patients diagnosed with multiple myeloma according to the International Myeloma Working Group criteria, between 2016 and 2021, were included in this study. Neuropathy was detected in 42 (37.1%) patients. The most common genetic anomalies were 13q del (in 28.9%), t(4.14) (in 22.2%), and trisomy 7 (in 20.0%). When patients with and without bortezomib-induced peripheral neuropathy were compared, the only significant differences were observed for age (p = 0.032) and genetic grouping (p = 0.001); whereas other characteristics that could be associated with bortezomib-induced peripheral neuropathy were similarly distributed in both groups. Bortezomib-induced peripheral neuropathy was significantly more frequent in multiple myeloma patients with normal genetic characteristics (p = 0.001). As a result of our study, it was observed that the frequency of bortezomib neuropathy was significantly higher in patients with normal genetic features compared to those with abnormal genetic features. This result suggested that factors other than genetic factors should be investigated to clarify the etiology of bortezomib-associated neuropathy in patients with multiple myeloma.

Mechanistic Involvement of Inflammation in Bortezomib-induced Peripheral Neuropathy.

The aim of the study was to establish the role of inflammation in bortezomibinduced peripheral neuropathy (BIPN). Peripheral neuropathy is the dose-limiting toxicity of bortezomib that can lead to discontinuation of the treatment. There are multiple mechanisms involved in the disposition of BIPN. However, the role of inflammatory mediators is still under investigation. A complete understanding of inflammatory markers in relation to BIPN can lead to the development of effective therapy for prophylaxis and treatment of peripheral neuropathy. Based on the available data, the role of inflammatory mediators in the development of peripheral neuropathy due to bortezomib has been postulated. The "Pubmed" and "Google Scholar" were used as the search engines with terms like "peripheral neuropathy", "bortezomib-induced peripheral neuropathy" and "inflammation". Original research, case reports and review articles were considered. Bortezomib use is associated with the development of peripheral neuropathy. This effect is due to the damage to Schwann cells and dorsal root ganglion neurons, mitochondrial damage, increased ion channel susceptibility, and higher infiltration of macrophages in the spinal cord. All these factors collectively increase the secretion of inflammatory mediators and lead to the development of neuropathic pain. Targeting inflammatory mediators may be helpful in the treatment of bortezomibinduced peripheral neuropathy.

Paeoniflorin Ameliorates BiPN by Reducing IL6 Levels and Regulating PARKIN-Mediated Mitochondrial Autophagy.

BackgroundBortezomib-induced peripheral neuropathy (BiPN) is a common complication of multiple myeloma (MM) treatment that seriously affects the quality of life of patients. The purpose of the present study was to explore the therapeutic effect of paeoniflorin on BiPN and its possible mechanism.MethodsELISA was used to measure the level of interleukin-6 (IL6) in the plasma of MM patients, and bioinformatics analysis was used to predict the mechanism underlying the effect of paeoniflorin on peripheral neuropathy. Cell and animal models of BiPN were constructed to evaluate mitochondrial function by measuring cell viability and mitochondrial quality and labeling mitochondria with MitoTracker Green. Nerve injury in mice with BiPN was assessed by behavioral tests, evaluation of motor nerve conduction velocity, hematoxylin-eosin (HE) staining, electron microscopy and analysis of the levels of reactive oxygen species (ROS). Western blotting and immunohistochemistry (IHC) were used to assess the expression of autophagy-related proteins.ResultsIn MM patients, IL6 levels were positively correlated with the degree of PN. The results of bioinformatics analysis suggested that paeoniflorin ameliorated PN by altering inflammation levels and mitochondrial autophagy. Paeoniflorin increased PC12 cell viability and mitochondrial autophagy levels, alleviated mitochondrial damage, and reduced IL6 levels. In addition, paeoniflorin effectively improved the behavior of mice with BiPN, relieved sciatic nerve injury in mice, increased the expression of LC3II/I, beclin-1, and Parkin in sciatic nerve cells, and increased the expression of LC3B and Parkin in the nerve tissue.ConclusionThe present study confirmed that paeoniflorin significantly ameliorated peripheral neuropathy (PN) caused by bortezomib, possibly by reducing IL6 levels to regulate PARKIN-mediated mitochondrial autophagy and mitochondrial damage.

Baseline peripheral neuropathy was associated with age and a prognostic factor in newly diagnosed multiple myeloma patients

Multiple myeloma (MM) is an incurable plasma cell hematological malignancy. Bortezomib has become the primary drug in the treatment of patients with MM. However, its negative effects, especially peripheral neuropathy (PN), affect the patients’ life quality and treatment continuity. However, there are few studies on baseline PN of MM, and little is known of the impact of baseline PN on the prognosis of MM patients. Therefore, we reviewed the clinical data of newly diagnosed MM patients in our center, explored the influencing factors of baseline PN, and evaluated PN’s influence on the prognosis of MM patients undergoing induction therapy with bortezomib. According to the inclusion and exclusion criteria, 155 MM patients were eligible for the retrospective study. The multivariate regression analysis, generalized additive fitting smooth curve, the receiver operating characteristic curve (ROC) and K-M curve were conducted in this study. We found that baseline PN in patients with MM was age-related; MM patients with baseline PN have more severe bortezomib induced PN (BiPN) during the four courses of induction therapy with bortezomib as the primary regimen and worse PN outcome after induction therapy. Additionally, the progression-free survival (PFS) and overall survival (OS) of MM patients with baseline PN were worse than those of the MM patients without baseline PN.

Prevention and management of bortezomib-induced peripheral neuropathy in patients with multiple myeloma

Proteasome inhibitors and immunomodulators (IMiDs), primarily bortezomib and lenalidomide, are essential components of treatment for both newly diagnosed and relapsed/refractory multiple myeloma (MM), producing high response rates and resulting in improved overall survival. However, bortezomib often induces a dose-limiting toxicity in the form of peripheral neuropathy (PN). Neurotoxicity often affects patient’s quality of life and requires dose modification or withdrawal of therapy, with a possible effect on the overall response. A prompt recognition of predisposing factors (such as diabetes mellitus, vitamin B 12 deficiencies, or viral infections) and appearance of signs and symptoms, through a periodic neurological assessment with appropriate scales, is extremely important. Usually, bortezomib-induced PN is a sensory axonopathy characterized by numbness, tingling, and severe neuropathic pain in stocking and glove distribution while motor neuropathy is less frequently observed. Dose adjustment of bortezomib could be necessary during treatment. Anticonvulsants (pregabalin, gabapentin, carbamazepine, etc.) and tricyclic antidepressants (amitriptyline) are most often used to relieve neurological pain. In this review we focus on the clinical manifestations of bortezomibinduced PN, current understanding of the pathophysiological mechanisms as well as clinical and pharmacological aspects of prevention and management this complication. New proteasome inhibitors such as ixazomib and carfilzomib do not have the neurotoxicity of bortezomib. An early switch within the class of proteasome inhibitors from bortezomib to oral ixazomib appears to be an important approach to prevent severe PN. Our own clinical case of an early switch from bortezomib-based induction to IRd triplet (ixazomib, lenalidomide, dexamethasone) is cited as an illustration of the success of this approach.

Specific Attenuation of Purinergic Signaling during Bortezomib-Induced Peripheral Neuropathy In Vitro.

Human peripheral neuropathies are poorly understood, and the availability of experimental models limits further research. The PeriTox test uses immature dorsal root ganglia (DRG)-like neurons, derived from induced pluripotent stem cells (iPSC), to assess cell death and neurite damage. Here, we explored the suitability of matured peripheral neuron cultures for the detection of sub-cytotoxic endpoints, such as altered responses of pain-related P2X receptors. A two-step differentiation protocol, involving the transient expression of ectopic neurogenin-1 (NGN1) allowed for the generation of homogeneous cultures of sensory neurons. After >38 days of differentiation, they showed a robust response (Ca2+-signaling) to the P2X3 ligand α,β-methylene ATP. The clinical proteasome inhibitor bortezomib abolished the P2X3 signal at ≥5 nM, while 50–200 nM was required in the PeriTox test to identify neurite damage and cell death. A 24 h treatment with low nM concentrations of bortezomib led to moderate increases in resting cell intracellular Ca2+ concentration but signaling through transient receptor potential V1 (TRPV1) receptors or depolarization-triggered Ca2+ influx remained unaffected. We interpreted the specific attenuation of purinergic signaling as a functional cell stress response. A reorganization of tubulin to form dense structures around the cell somata confirmed a mild, non-cytotoxic stress triggered by low concentrations of bortezomib. The proteasome inhibitors carfilzomib, delanzomib, epoxomicin, and MG-132 showed similar stress responses. Thus, the model presented here may be used for the profiling of new proteasome inhibitors in regard to their side effect (neuropathy) potential, or for pharmacological studies on the attenuation of their neurotoxicity. P2X3 signaling proved useful as endpoint to assess potential neurotoxicants in peripheral neurons.

Bortezomib-Induced Epigenetic Alterations in Nerve Cells: Focus on the Mechanisms Contributing to the Peripheral Neuropathy Development.

Bortezomib-induced peripheral neuropathy (BiPN) occurs in approximately 40% of patients with multiple myeloma. The induction of severe neuropathy entails the dose reduction or complete elimination of bortezomib (BTZ). Interestingly, discontinuation of BTZ mostly results in a reduction or complete resolution of peripheral neuropathy (PN) symptoms. Therefore, it is likely that the BiPN mechanisms are based on temporary/reversible changes such as epigenetic alterations. In this study, we examined the effect of treating nerve cells, differentiated from the Lund human mesencephalic (dLUHMES) cell line, with several low-dose BTZ (0.15 nM) applications. We showed a significant decrease in global histone H3 acetylation as well as histone H3 lysine 9 acetylation. Moreover, analysis of the genetic microarray showed changes mainly in epigenetic processes related to chromatin rearrangement, chromatin silencing, and gene silencing. GSEA analysis revealed three interesting signaling pathways (SIRT1, B-WICH and, b-Catenin) that may play a pivotal role in PN development. We also performed an analysis of the miRNA microarray which showed the interactions of miR-6810-5p with the genes MSN, FOXM1, TSPAN9, and SLC1A5, which are directly involved in neuroprotective processes, neuronal differentiation, and signal transduction. The study confirmed the existence of BTZ-induced complex epigenetic alterations in nerve cells. However, further studies are necessary to assess the reversibility of epigenetic changes and their potential impact on the induction/resolution of PN.

Immune-mediated neuropathy related to bortezomib in a patient with multiple myeloma

Treatment options in multiple myeloma (MM) based on novel agents are often limited by dose-related neurotoxicity. Bortezomib, a highly active reversible proteasome inhibitor, frequently causes peripheral neuropathy (PN). Bortezomib-induced PN (BIPN) is characterized by a length-dependent, sensory, axonal polyneuropathy (PNP) with predominant small fiber-affection. Following dose reduction or drug discontinuation, BIPN resolves within 3-4 months in the majority of patients. The pathophysiological mechanisms of BIPN are unclear. Rare cases of a severe demyelinating or mixed BIPN with prominent motor involvement have been attributed to autoimmune or inflammatory reactions. A case report, including nerve pathology, is presented of a 59-year-old man with stage III IgG-κ MM who was treated with bortezomib on the occurrence of progressive disease. After the fourth cycle, he developed a painful distal symmetric sensory PNP followed by gait instability and muscle weakness increasing over 3 months despite early cessation of bortezomib. Neurological examination revealed a distal flaccid tetraparesis mainly of the lower limbs with sensory loss and severe ataxia, electrophysiological features of a mixed axonal-demyelinating PNP, and pathomorphological evidence of neuritis. Steroid treatment was initiated, and partial recovery of the neurological symptoms within 6 months was observed. While a neurotoxic effect may explain the initial distal sensory disturbances, the worsening of neurological dysfunction after bortezomib withdrawal and the clinical pattern with steroid-responsive muscle weakness predominantly of the legs are consistent with an immune-mediated mechanism. This is in line with the sural nerve biopsy findings. Toxic BIPN followed by an immune-mediated BIPN in the same patient has not been reported before.

Prevention of Bortezomib-Induced Peripheral Neuropathy in Newly Multiple Myeloma Patients Using Nervonic Acid, Curcuma Rizoma, and L-Arginine Compound: A Pilot Study.

Introduction:This is a phase II pilot study to evaluate the efficacy of a nutraceutical compound composed of nervonic acid, curcuma rizoma, and l-Arginine to prevent the onset of bortezomib-induced peripheral neuropathy (BIPN) in 16 newly diagnosed multiple myeloma (MM) patients treated with bortezomib (BTZ) over 6 months.Materials and methods:Assessments included neurological examination and electroneurography, Common Terminology Criteria for Adverse Events (NCI-CTCAE), reduced version of Total Neuropathic Score (TNSr), pain evaluation, functional autonomy scales, self-perceived symptoms and quality of life questionnaires at baseline and after 6 months.Results:No patients were symptomatic at baseline, despite neurophysiological data and TNSr evidence of peripheral neuropathy (PN) in 11 of them. After 6 months, only 9 patients completed the study. All had modifications in neurological examination with 8 out of 9 showing neurophysiological data of PN (2 of which had a NCI-CTCAE grade of neurotoxicity ≥2); 4 patients dropped out due to BIPN, 2 because of MM progression, 1 for scarce compliance.Discussion:In our study, the compound was not adequate to prevent BIPN. The incidence of subclinical PN in MM patients is a risk factor for the development of severe neurotoxicity during BTZ treatment. For this reason to evaluate the efficacy of any preventive compound, as well as to manage MM patients, it should be mandatory to include neurophysiological study as a standard procedure.

Bortezomib-Pomalidomide-Dexamethasone (VPD) As Novel Induction Therapy in Newly-Diagnosed Multiple Myeloma: Early Safety Data from an Ongoing Single Arm Phase-II Investigator-Initiated Clinical Trial (PRIME Study)

Introduction: Pomalidomide is a third-generation immunomodulatory drug approved for relapsed and/or refractory Multiple Myeloma (RRMM). In the phase 3 OPTIMISMM trial, pomalidomide, bortezomib, and dexamethasone demonstrated superior efficacy in patients with RRMM. PRIME study (CTRI/2019/10/021618) is testing this combination in Newly Diagnosed Multiple Myeloma (NDMM)Aim: To determine safety of Pomalidomide in combination with Bortezomib and dexamethasone (VPD) in NDMMStudy design: A prospective, single arm, phase II study from a tertiary center. Both transplant eligible and ineligible patients with NDMM aged between 18-70 years are being recruited in the study. Patients with Plasma cell leukemia, POEMS and amyloidosis were excluded. The regimen consists of weekly Bortezomib 1.3mg/sq.m (subcutaneous), Tab. Pomalidomide 2-4mg once daily for 21days, and Tab Dexamethasone 20mg twice weekly, with the cycle repeating every 28 days, 9-12 cycles. Here we report the adverse events (AE) by NCI CTCAE v5.0, upon recruiting 26 patients, as predetermined in the study.Results: Of the proposed 45-50 patients, 26 patients were enrolled in the study between April 2020 to May 2021 and 23 (88.4%) have completed 4 cycles of VPD. The median age is 55years (18-70), and gender ratio 1:1. At disease presentation, bone lesions were the commonest (96.2%, n=25), IMWG high risk cytogenetics were seen in 42.4% (n=11), RISS-2 in 69.3% (n=18), IgG kappa paraproteinemia in 54% (n=14) patients and ECOG performance score 2-3 in 57.6%(n=15). Ten (38.5%) patients have completed 9 cycles, and 3 underwent auto-transplant (between Cycle 4 & 6). Protocol adherence was 96.1% (25/26 patients).Table-1 shows drug-induced toxicity, hematological toxicities were the commonest. Two patients withdrew consent in view of bortezomib-induced peripheral neuropathy. Serious adverse events (SAE) were reported in 9 (34.6%) patients and were considered unrelated to the regimen by the safety committee (PSVT=1, Bony pain=2, dyspnea=1, pneumonia=1, constipation=1, diarrhea=1, hypotension=1) and one death due to SARS-CoV2 pneumonia. Treatment delays of 2 weeks in 4 patients (SARS-CoV2 = 3, Syncope = 1)After 4 cycles (n=23), 6 (26%) patients were in stringent Complete Response (sCR), 17(74%) in Very Good partial response (VGPR) and 13 (56.5%) are Measurable Residual Disease (MRD) negative. Of 10 patients who completed cycle 9, 9 were MRD negative and 1 showed disease progression.Conclusion: Safety data from the PRIME study demonstrates that VPD regimen has a favorable tolerance profile in patients with NDMM. Early efficacy signals are encouraging, and recruitment continues. [Display omitted] DisclosuresRadhakrishnan: Dr Reddy's Laboratories: Honoraria, Membership on an entity's Board of Directors or advisory committees; Emcure Pharmaceuticals: Research Funding; Intas Pharmaceuticals: Research Funding; Janssen India: Honoraria; NATCO Pharmaceuticals: Research Funding; Novartis India: Membership on an entity's Board of Directors or advisory committees; Roche India: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; AstraZeneca India: Honoraria, Speakers Bureau; Bristol-Myers-Squibb India: Membership on an entity's Board of Directors or advisory committees, Research Funding; Cipla Pharmaceuticals India: Research Funding; Aurigene: Speakers Bureau. Garg: Dr Reddys Laboratories: Honoraria, Speakers Bureau. Nair: Dr Reddy's Laboratories: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Intas pharmaceuticals: Honoraria, Speakers Bureau; Mylan pharmaceuticals: Honoraria; Novartis India: Honoraria; Fresenius Kabi India: Honoraria; Cipla Pharmaceuticals: Honoraria, Speakers Bureau; Janssen India: Honoraria, Speakers Bureau. Chandy: Janssen: Honoraria; Pfizer: Honoraria; Intas Pharmaceuticals: Research Funding.

Foot drop in patients treated with bortezomib – a case series and review of the literature

Bortezomib-induced peripheral neuropathy (BIPN) has a profound impact on quality of life, which is an important issue considering the growing number of survivors of multiple myeloma and amyloidosis. BIPN is typically symmetric, distal, "stocking and glove" distribution and predominantly consists of sensory rather than motor symptoms. In this case series, we report an acute neurotoxicity syndrome induced by bortezomib, which is clinically distinct from BIPN by not being peripheral and distal. We describe six patients that developed unilateral or bilateral foot drop attributed to bortezomib. With bortezomib discontinuation symptoms improved gradually over months to years.