Bortezomib in combination with pegylated liposomal doxorubicin and thalidomide is an effective steroid independent salvage regimen for patients with relapsed or refractory multiple myeloma: results of a phase II clinical trial

Bortezomib retreatment for relapsed and refractory multiple myeloma in real-world clinical practice

AIMS

Studies have shown that bortezomib retreatment is effective in relapsed/refractory multiple myeloma (MM). The observational, prospective electronic VELCADE® OBservational Study (eVOBS) study assessed bortezomib-based therapies for patients with MM in everyday practice. Here, we report on those patients receiving retreatment with bortezomib.

METHODS

Consenting adults scheduled to receive bortezomib for MM were enrolled at 162 sites across Europe, Canada, Brazil, Russia, and Turkey between 2006 and 2010. Retrospective data on prior therapies and prospective observational data after bortezomib initiation were captured electronically at baseline, after every bortezomib cycle, and every 12 weeks after discontinuation or progression. Investigator-assessed responses and adverse events (AEs) were evaluated.

RESULTS

Ninety-six of 873 patients enrolled to eVOBS received bortezomib as first retreatment for progressive disease during the prospective observation period. Median age was 62 years, 53% were male, and median number of prior therapies at retreatment was 4. Overall, 41% of patients initiated bortezomib retreatment in combination with dexamethasone, 16% in combination with lenalidomide, and 21% received monotherapy. Rate of partial response or better (≥PR) was 75% at initial bortezomib therapy, including 44% complete response (CR)/near CR (nCR); at retreatment, ≥PR rate was 46%, including 15% CR/nCR. Median progression-free survival was 11.4 months (95% confidence interval [CI]: 9.1-12.7) from start of initial bortezomib treatment and 6.4 months (95% CI: 4.4-7.2) from start of retreatment. Median overall survival from start of retreatment was 17.6 months (95% CI: 14.4-23.5). Of the 96 patients retreated with bortezomib, 77% reported an AE. Peripheral neuropathy during bortezomib retreatment occurred in 49% of patients, including 10% grade 3/4.

CONCLUSION

These data suggest that retreatment with bortezomib is a feasible option for patients with relapsed/refractory MM.

Computational identification and validation of alternative splicing in ZSF1 rat RNA-seq data, a preclinical model for type 2 diabetic nephropathy

Obese ZSF1 rats exhibit spontaneous time-dependent diabetic nephropathy and are considered to be a highly relevant animal model of progressive human diabetic kidney disease. We previously identified gene expression changes between disease and control animals across six time points from 12 to 41 weeks. In this study, the same data were analysed at the isoform and exon levels to reveal additional disease mechanisms that may be governed by alternative splicing. Our analyses identified alternative splicing patterns in genes that may be implicated in disease pathogenesis (such as Shc1, Serpinc1, Epb4.1l5, and Il-33), which would have been overlooked in standard gene-level analysis. The alternatively spliced genes were enriched in pathways related to cell adhesion, cell–cell interactions/junctions, and cytoskeleton signalling, whereas the differentially expressed genes were enriched in pathways related to immune response, G protein-coupled receptor, and cAMP signalling. Our findings indicate that additional mechanistic insights can be gained from exon- and isoform-level data analyses over standard gene-level analysis. Considering alternative splicing is poorly conserved between rodents and humans, it is noted that this work is not translational, but the point holds true that additional insights can be gained from alternative splicing analysis of RNA-seq data.

Pharmacokinetic study of bortezomib administered intravenously in Taiwanese patients with multiple myeloma

This phase 4, single-arm, non-randomized, open-label, post approval commitment study evaluated the pharmacokinetics and safety of bortezomib in Taiwanese patients with multiple myeloma. Patients (≥20 years) with measurable secretory multiple myeloma (serum monoclonal IgG ≥10, IgA/IgE ≥5, IgD ≥0.5 g/L, IgM present [regardless of level], and urine M protein of ≥200 mg/24 h) received intravenous bortezomib 1.3 mg/m² , twice weekly for 2 weeks, followed by a 10-day resting phase (days 12 to 21). Pharmacokinetics and safety were assessed at pre-specified time points. All enrolled patients (n = 18, men: 11; women: 7) completed the study. Mean (SD) C_max (maximum observed plasma concentration) on day 11 was 266 (77.5) ng/mL, approximately 60% higher compared with non-Asian patients receiving a similar bortezomib regimen but with overlapping ranges. Because of the protracted terminal phase, half-life (t_1/2 ), area under the plasma concentration-time curve from time 0 to infinity (AUC_∞ ), volume of distribution (V_z ), and systemic clearance were not assessable. All patients experienced treatment-emergent adverse events (TEAEs); 78% were drug-related. Most commonly reported TEAEs were thrombocytopenia (n = 11 [61%]), neutropenia (n = 9 [50%]), leukopenia (n = 6 [33%]), and diarrhoea (n = 6 [33%]); the most common serious adverse event was pneumonia (n = 2 [11%]). One patient had a dose reduction due to a TEAE of thrombocytopenia. Overall, bortezomib exposure (AUC) in Taiwanese patients (AUC_last [SD]: 230 [147] ng·h/mL) with twice weekly intravenous administration was comparable with non-Asian population (AUC_last [SD]: 241 [82] ng·h/mL). Bortezomib treatment was associated with manageable toxicity profile and did not limit the continuity of therapy.

Modified bortezomib, adriamycin and dexamethasone (PAD) regimen in advanced multiple myeloma

The PAD regime, composed of bortezomib, adriamycin and dexamethasone, improves the outcomes of patients with advanced multiple myeloma (MM), but at the same time produces high frequency of serious toxic side effects. For the first time, we evaluated the efficacy and safety of a bortezomib-dose-reduced PAD regime in the treatment of relapsed/refractory MM in this clinical study. Forty-five patients were treated with two to six 21-day cycles of PAD, comprising bortezomib at 1.3 mg/m(2) (P1AD, n = 21) or 1.0 mg/m(2) (P2AD, n = 24) (days 1, 4, 8, 11), adriamycin at 9 mg/m(2) (days 1-4) and dexamethasone at 40 mg/day (days 1-4). Overall, 36 patients (80 %) showed at least partial remission (PR), in which 9 cases (20 %) showed complete remission (CR) and 10 cases (22 %) showed very good partial remission (VGPR). The efficacy of PAD regimen in advanced MM patients was not related to the traditional prognostic factors. There was no significant difference between P1AD and P2AD in the rates of PR, CR or VGPR, 1.5-year progression-free survival (PFS), and overall survival (OS) (81 % vs. 79 %, 48 % vs. 38 %, 64 % vs. 59 %, and 85 % vs. 73 %, respectively). However, the grade 3-4 toxic effects, including thrombocytopenia (13 % vs. 38 %), peripheral neuropathy (8 % vs. 33 %) and 3-4 grade gastrointestinal reaction (13 % vs. 43 %), were markedly inhibited after P2AD compared to P1AD (P < 0.05). The bortezomib-dose-reduced PAD regime reduced the incidence of adverse reactions without affecting the treatment efficacy in patients with advanced MM.

Current strategies for treatment of relapsed/refractory multiple myeloma

In spite of significant advances in the management of multiple myeloma (MM), the disease remains incurable and nearly all patients ultimately relapse and require salvage chemotherapy. As such, relapsed and relapsed-refractory MM remains a critical area of research pertaining to biological mechanisms of progression and chemotherapy resistance, as well as to the development of new pharmacologic agents and immunologic approaches for the disease. The immunomodulatory agents and proteasome inhibitors represent the cornerstone of treatment in this setting, with combination regimens incorporating these drugs demonstrating encouraging rates and duration of response, including the newer agents, pomalidomide and carfilzomib. In addition, novel drug classes have shown promising activity in RR MM, including the orally-administered proteasome inhibitors ixazomib and oprozomib; monoclonal antibodies such as the anti-CS1 monoclonal antibody elotuzumab and anti-CD38 monoclonal antibody daratumumab; and histone deacetylase inhibitors such as panobinostat and rocilinostat.

Podocyte dedifferentiation: a specialized process for a specialized cell

The podocyte is one of the two cell types that contribute to the formation of the glomerular filtration barrier (GFB). It is a highly specialized cell with a unique structure. The key feature of the podocyte is its foot processes that regularly interdigitate. A structure known as the slit diaphragm can be found bridging the interdigitations. This molecular sieve comprises the final layer of the GFB. It is well accepted that the podocyte is the target cell in the pathogenesis of nephrotic syndrome. In nephrotic syndrome, the GFB no longer restricts the passage of macromolecules and protein is lost into the urine. A number of phenotypic and morphological changes are seen in the diseased podocyte and in the literature these have been described as an epithelial-mesenchymal transition (EMT). However, there is a growing appreciation that this term does not accurately describe the changes that are seen. Definitions of type-2 EMT are based on typical epithelial cells. While the podocyte is known as a visceral epithelial cell, it is not a typical epithelial cell. Moreover, podocytes have several features that are more consistent with mesenchymal cells. Therefore, we suggest that the term podocyte disease transformation is more appropriate.

A prospective, international phase 2 study of bortezomib retreatment in patients with relapsed multiple myeloma

Multiple myeloma (MM) typically follows a relapsing course with many patients requiring multiple therapies. This single-arm phase 2 study prospectively evaluated the efficacy and safety of bortezomib retreatment in MM patients who had relapsed after achieving at least a partial response (≥ PR) to prior bortezomib-based therapy. Patients aged ≥ 18 years, with measurable, secretory MM, who relapsed ≥ 6 months after prior bortezomib treatment were eligible. Patients received up to eight cycles of bortezomib (± dexamethasone). The primary endpoint was best confirmed response at retreatment; secondary endpoints included duration of response (DOR), time to progression (TTP), and safety. Adverse events (AEs) were graded by National Cancer Institute Common Terminology Criteria for Adverse Events version 3.0. A total of 130 patients (median of two prior lines of therapy) were enrolled and received retreatment. At retreatment, 28% and 72% of patients received bortezomib and bortezomib-dexamethasone, respectively. Overall response rate was 40%. In patients who achieved ≥ PR, median DOR and TTP were 6.5 and 8.4 months, respectively. Thrombocytopenia was the most common grade ≥ 3 AE (35%). Forty percent of patients experienced neuropathy events, which improved and resolved in a median of 1.5 and 8.9 months, respectively. In conclusion, bortezomib retreatment was effective and tolerable in relapsed MM patients, with no evidence of cumulative toxicities.

Renal complications in multiple myeloma and related disorders: survivorship care plan of the International Myeloma Foundation Nurse Leadership Board

Kidney dysfunction is a common clinical feature of symptomatic multiple myeloma. Some degree of renal insufficiency or renal failure is present at diagnosis or will occur during the course of the disease and, if not reversed, will adversely affect overall survival and quality of life. Chronic insults to the kidneys from other illnesses, treatment, or multiple myeloma itself can further damage renal function and increase the risk for additional complications, such as anemia. Patients with multiple myeloma who have light chain (Bence Jones protein) proteinuria may experience renal failure or progress to end-stage renal disease (ESRD) and require dialysis because of light chain cast nephropathy. Kidney failure in patients with presumed multiple myeloma also may result from amyloidosis, light chain deposition disease, or acute tubular necrosis caused by nephrotoxic agents; therefore, identification of patients at risk for kidney damage is essential. The International Myeloma Foundation's Nurse Leadership Board has developed practice recommendations for screening renal function, identifying positive and negative contributing risk and environmental factors, selecting appropriate therapies and supportive care measures to decrease progression to ESRD, and enacting dialysis to reduce and manage renal complications in patients with multiple myeloma.

Multiple myeloma preparative regimens for high-dose therapy and autologous transplantation: what's new?

High-dose chemotherapy and autologous stem cell transplantation remains a standard procedure in relatively young and selected older patients with multiple myeloma. High-dose melphalan has remained the chemotherapeutic agent of choice based on earlier prospective randomized trials. Despite investigations involving different combinations of chemotherapeutics, radiation and novel agents with and without melphalan, none of these alternative preparative regimens have demonstrated superiority to high-dose melphalan used as a single agent in multiple published studies. In this article, we review the published literature regarding preparative regimens used in patients with multiple myeloma undergoing autologous stem cell transplantation.

Chemotherapy-induced weakness and fatigue in skeletal muscle: the role of oxidative stress

SIGNIFICANCE

Fatigue is one of the most common symptoms of cancer and its treatment, manifested in the clinic through weakness and exercise intolerance. These side effects not only compromise patient's quality of life (QOL), but also diminish physical activity, resulting in limited treatment and increased morbidity.

RECENT ADVANCES

Oxidative stress, mediated by cancer or chemotherapeutic agents, is an underlying mechanism of the drug-induced toxicity. Nontargeted tissues, such as striated muscle, are severely affected by oxidative stress during chemotherapy, leading to toxicity and dysfunction.

CRITICAL ISSUES

These findings highlight the importance of investigating clinically applicable interventions to alleviate the debilitating side effects. This article discusses the clinically available chemotherapy drugs that cause fatigue and oxidative stress in cancer patients, with an in-depth focus on the anthracycline doxorubicin. Doxorubicin, an effective anticancer drug, is a primary example of how chemotherapeutic agents disrupt striated muscle function through oxidative stress.

FUTURE DIRECTIONS

Further research investigating antioxidants could provide relief for cancer patients from debilitating muscle weakness, leading to improved quality of life.

A steroid-independent regimen of bortezomib, liposomal doxorubicin and thalidomide demonstrate high response rates in newly diagnosed multiple myeloma patients

Novel agents have provided a new foundation for multiple myeloma therapies. When combined with other anti-myeloma agents, these compounds significantly enhance clinical efficacy. High-dose steroids are frequently used in anti-myeloma combination regimens; however, the doses employed are often poorly tolerated, especially in patients with concurrent comorbid conditions. We hypothesized that a steroid-independent combination regimen could be developed without significant compromise of efficacy. The availability of such a regimen will be important for patients whose concurrent ailments make them poor candidates for steroid containing anti-myeloma regimens. A phase II single institute, non-randomized clinical trial was conducted to investigate a novel steroid-free three-drug combination of bortezomib (V), pegylated liposomal doxorubicin (D), and thalidomide (T), the VDT regimen. Forty-three newly diagnosed multiple myeloma patients requiring treatment were enrolled on this study. The overall response rate and complete response (CR) + near complete response (nCR) rate was 78% and 35%, respectively. Median time to progression was 29·5 months. Fatigue, rash, neuropathy, constipation and infections were the most common side effects. We concluded that VDT is a tolerable and an effective regimen capable of inducing high response rates and can be employed in patients considered to be poor candidates for steroid-based treatment regimens.

Single agent lenalidomide in newly diagnosed multiple myeloma: a retrospective analysis

Recently, lenalidomide and low dose dexamethasone were found to result in superior overall survival compared to lenalidomide and high dose dexamethasone. The immune suppressive effects of dexamethasone can antagonize lenalidomide immunomodulatory activity and may explain this observation. We conducted a retrospective analysis to evaluate the single agent activity of lenalidomide in newly diagnosed myeloma. Records of patients with newly diagnosed symptomatic multiple myeloma treated with single agent lenalidomide at H. Lee Moffitt Cancer Center and Roswell Park Cancer Institute were reviewed. Data were collected on disease characteristics, demographics, and treatment outcomes. Responses were assessed as per the International Myeloma Working Group criteria. From March 2007 to July 2009, 17 patients with newly diagnosed multiple myeloma were treated with single agent lenalidomide at both institutions. The median age was 70 years (range 46-84 years). Lenalidomide was generally well tolerated and no grade 4 hematologic toxicities were noted. The overall response rate (> or =partial remission) to lenalidomide alone was 47% at a median follow-up of 7 months (range 1-26). This experience suggests that lenalidomide alone can induce an anti-myeloma effect in previously untreated patients who are considered poor candidates for concurrent dexamethasone.

Treatment of relapsed and refractory multiple myeloma in the era of novel agents

The introduction of the Immunomodulatory drugs (IMiDs) and proteasome inhibitors, used either as a single-agent or combined with classic anti-myeloma therapies, has improved the outcome for patients with relapsed myeloma. However, there is currently no generally accepted standard treatment for relapsed/refractory myeloma patients, partly because of the absence of trials comparing the efficacy of the novel agents in relapsed/refractory myeloma. Choice of a new treatment regimen depends on both patient and disease-specific characteristics. A lenalidomide-based regimen is the first choice in patients with neuropathy, while bortezomib has the highest efficacy in patients with renal insufficiency and is not associated with increased risk of thromboembolism. A second autologous stem cell transplantation (auto-SCT) can be applied in patients with a progression-free period of ≥ 18-24 months after the first auto-SCT. In high-risk relapse such as occurring early after auto-SCT consolidation with allogeneic SCT can be considered. In this review we provide an overview of the various salvage regimens and give recommendations for treatment of patients with relapsed/refractory myeloma in different clinical settings.

Advances in treatment for relapses and refractory multiple myeloma

Recent advances in the treatment of multiple myeloma have resulted in improved response rates and overall survival in patients with multiple myeloma. These advances are largely due to thalidomide-, lenalidomide-, and bortezomib-based combinations that have improved response rates, not only in patients with untreated disease, but also in those with relapsed and/or refractory myeloma, in some cases producing response rates up to 85%. Eventually, however, nearly all patients relapse, emphasizing a continuing role for the introduction of investigational agents that overcome drug resistance. This article will review the current role for thalidomide, lenalidomide, and bortezomib-based combinations, as well as some preliminary findings for promising investigational agents currently in clinical trials for patients with relapsed and/or refractory disease.

Evidence-based mini-review: treatment options for patients with relapsed/refractory myeloma previously treated with novel agents and high-dose chemotherapy and autologous stem-cell transplantation

A 64 year-old man with a history of multiple myeloma presents with new back pain. He has a history of International Staging System stage 1, IgG kappa multiple myeloma with normal cytogenetics which was diagnosed 4 years ago when he presented with a pathological fracture of the left humerus. He was initially managed with mechanical stabilization and 4 cycles of bortezomib-dexamethasone, as well as 2 years of bisphosphanates. Following induction therapy he achieved a very good partial response (VGPR). He subsequently received high-dose melphalan and autologous stem cell transplantation (auto-SCT) and achieved a complete reponse (CR) post-transplant. He did not receive maintenance therapy and had been lost-to follow-up for about a year. He now presents 5 years after initial diagnosis with back pain and is noted to have a new lytic lesion with a compression fracture at T8. A serum protein electrophoresis demonstrates reappearance of his original monoclonal protein. After appropriate stabilization he comes to you to discuss additional treatment options.

Novel agents for relapsed and/or refractory multiple myeloma

The introduction of novel agents, such as thalidomide, bortezomib, and lenalidomide, has altered the landscape of therapeutic options for multiple myeloma by offering new mechanisms for targeting this disease. Combinations of these agents, with each other and/or traditional chemotherapeutics, have vastly increased the treatment options for patients both frontline, and at relapse, providing higher response rates, and importantly, increasing median overall survival. In this review, we will discuss the use of these novel agents and their combinations in patients with relapsed and/or refractory multiple myeloma.

Finishing off fibrils

Bortezomib shows high activity in light chain amyloidosis. Responses occur rapidly and are seen in cardiac, renal, and hepatic disease. Toxicity in this fragile population is significant.