Phase I/II trial assessing bortezomib and melphalan combination therapy for the treatment of patients with relapsed or refractory multiple myeloma

In the era of Bortezomib-based Induction, intensification of Melphalan-based conditioning with Bortezomib does not improve Survival Outcomes in newly diagnosed Multiple Myeloma: a study from the Chronic Malignancies Working Party of the EBMT

Bortezomib (Vel)- Melphalan 200 mg/m2 (Mel200) (Vel-Mel) has been utilised to intensify conditioning in autologous hematopoietic stem cell transplantation (AHCT) for multiple myeloma (MM). This EBMT registry-based study compared Vel-Mel with Mel200 during upfront AHCT. Between 2010 and 2017, MM patients who received Vel-Mel (n = 292) conditioning were compared with 4,096 Mel200 patients in the same 58 centres. Pre-AHCT, compared to Mel200 patients, Vel-Mel patients had similar International Staging System (ISS) scores and cytogenetic risk profiles; a similar proportion had received bortezomib-based induction (85% and 87.3%, respectively) though they were younger with a better performance status. Vel-Mel patients were more likely to achieve CR post-induction (40.6% vs 20.3%, p < 0.001) and by day 100 of AHCT (CR/VGPR: 70.2 % vs. 57.2%, p < 0.001). There was no difference in 3-year PFS (49% vs 46%, p = 0.06) or early post-AHCT mortality. In multivariable analysis, Vel-Mel associated with inferior PFS (HR: 1.69 (1.27-2.25, p < 0.001) and OS (HR:1.46 (1.14-1.86,p = 0.002), similar to negative effects on PFS of advanced ISS (HR:1.56 (1.33-1.83, p < 0.001), high-risk cytogenetics (HR:1.43(1.18-1.74, p < 0.001) and poor post-induction response(<=PR)(HR: 1.43(1.25-1.62, p < 0.001) Overall, despite superior pre- and post-AHCT responses, there was no improvement in PFS or OS following Vel-Mel. This data supports the findings of the smaller prospective IFM study.

Chemical Proteomics Reveals that the Anticancer Drug Everolimus Affects the Ubiquitin-Proteasome System

Rapamycin is a natural antifungal, immunosuppressive, and antiproliferative compound that allosterically inhibits mTOR complex 1. The ubiquitin-proteasome system (UPS) responsible for protein turnover is usually not listed among the pathways affected by mTOR signaling. However, some previous studies have indicated the interplay between the UPS and mTOR. It has also been reported that rapamycin and its analogs can allosterically inhibit the proteasome itself. In this work, we studied the molecular effect of rapamycin and its analogs (rapalogs), everolimus and temsirolimus, on the A549 cell line by expression proteomics. The analysis of differentially expressed proteins showed that the cellular response to everolimus treatment is strikingly different from that to rapamycin and temsirolimus. In the cluster analysis, the effect of everolimus was similar to that of bortezomib, a well-established proteasome inhibitor. UPS-related pathways were enriched in the cluster of proteins specifically upregulated upon everolimus and bortezomib treatments, suggesting that both compounds have similar proteasome inhibition effects. In particular, the total amount of ubiquitin was significantly elevated in the samples treated with everolimus and bortezomib, and analysis of the polyubiquitination patterns revealed elevated intensities of the ubiquitin peptide with a GG modification at the K48 residue, consistent with a bottleneck in proteasomal protein degradation. Moreover, the everolimus treatment resulted in both ubiquitin phosphorylation and generation of a significant amount of semitryptic peptides, illustrating the increase in the protease activity. These observations suggest that everolimus affects the UPS in a unique way, and its mechanism of action is different from that of its close chemical analogs, rapamycin and temsirolimus.

Optimizing high dose melphalan

Melphalan, has been a major component of myeloma therapy since the 1950s. In the context of hematopoietic cell transplantation (HCT), high dose melphalan (HDM) is the most common conditioning regimen used due to its potent anti-myeloma effects and manageable toxicities. Common toxicities associated with HDM include myelosuppression, gastrointestinal issues, and mucositis. Established approaches to reduce these toxicities encompass dose modification, nausea prophylaxis with 5HT3 receptor antagonists, cryotherapy, amifostine use, and growth factors. Optimization of melphalan exposure through personalized dosing and its combination with other agents like busulfan, or bendamustine show promise. Propylene glycol-free melphalan (Evomela) represents a novel formulation aiming to enhance drug stability and reduce adverse effects. This review explores strategies to enhance the efficacy and mitigate the toxicity of HDM in multiple myeloma. Future directions involve exploring these strategies in clinical trials to improve the safety and efficacy of HDM, thereby enhancing outcomes for multiple myeloma patients undergoing autologous HCT.

A phase 1/2 of carfilzomib and melphalan conditioning for autologous stem cell transplantation for multiple myeloma (CARAMEL)

In this phase 1/2 study, carfilzomib was added to high-dose melphalan conditioning prior to autologous stem cell transplantation (ASCT) in patients with multiple myeloma that had been treated with ≤2 prior lines of therapy. Carfilzomib was escalated at doses of 27, 36, 45, and 56 mg/m2 on days -6, -5, -2, and -1 before ASCT in the phase 1 component of the study. In addition, all the patients received melphalan 100 mg/m2 on days -4 and -3. The primary endpoint of the phase 1 component was to identify the maximum tolerated dose, and the primary endpoint of the phase 2 component was the rates of complete response (≥CR) at 1 year after ASCT. The phase 1 dose escalation cohort included 14 patients, and 35 patients were included in the phase 2 cohort. The maximum tested dose was 56 mg/m2 (MTD). The median time from diagnosis to study enrollment was 5.8 (range 3.4-88.4) months, and 16% of patients had obtained a ≥CR prior to ASCT. The best response within 1 year after ASCT was a ≥ CR rate in 22% for the entire cohort, and 22% for patients treated at the MTD. The ≥VGPR rates improved from 41% before ASCT to 77% by 1 year after ASCT. One patient had a grade 3 renal adverse event, and renal function returned to baseline with supportive care. The rate of grade 3-4 cardiovascular toxicity was 16%. The addition of carfilzomib to melphalan conditioning was safe and resulted in deep responses after ASCT.

KPT-330 and Y219 exert a synergistic antitumor effect in triple-negative breast cancer through inhibiting NF-κB signaling

Triple-negative breast cancer (TNBC) is an aggressive breast cancer subtype, which has poor prognosis due to the lack of effective targeted drugs. KPT-330, an inhibitor of the nuclear export protein CRM-1, has been widely used in clinical medicine. Y219, a novel proteasome inhibitor designed by our group, shows superior efficacy, reduced toxicity, and reduced off-target effects as compared to the proteasome inhibitor bortezomib. In this study, we investigated the synergistic effect of KPT-330 and Y219 against TNBC cells, as well as the underlying mechanisms. We report that combination treatment with KPT-330 and Y219 synergistically inhibited the viability of TNBC cells in vitro and in vivo. Further analysis revealed that the combined use of KPT-330 and Y219 induced G2-M phase arrest and apoptosis in TNBC cells, and attenuated nuclear factor kappa B (NF-κB) signaling by facilitating nuclear localization of IκB-α. Collectively, these results suggest that the combined use of KPT-330 and Y219 may be an effective therapeutic strategy for the treatment of TNBC.

Bortezomib and high-dose melphalan conditioning regimen in frontline multiple myeloma: an IFM randomized phase 3 study

High-dose melphalan (HDM) and transplantation are recommended for eligible patients with multiple myeloma. No other conditioning regimen has proven to be more effective and/or safer. We previously reported in a phase 2 study that bortezomib can safely and effectively be combined with HDM (Bor-HDM), with a 32% complete response (CR) rate after transplantation. These data supported a randomized phase 3 trial. Randomization was stratified according to risk and response to induction: 300 patients were enrolled, and 154 were allocated to the experimental arm (ie, arm A) with bortezomib (1 mg/m2 intravenously [IV]) on days -6, -3, +1, and +4 and melphalan (200 mg/m2 IV) on day -2. The control arm (ie, arm B) consisted of HDM alone (200 mg/m2 IV). There were no differences in stringent CR + CR rates at day 60 posttransplant (primary end point): 22.1% in arm A vs 20.5% in arm B (P = .844). There were also no differences in undetectable minimum residual disease rates: 41.3% vs 39.4% (P = .864). Median progression-free survival was 34.0 months for arm A vs 29.6 months for arm B (adjusted HR, 0.82; 95% CI, 0.61-1.13; P = .244). The estimated 3-year overall survival was 89.5% in both arms (hazard ratio, 1.28; 95% CI, 0.62-2.64; P = .374). Sixty-nine serious adverse events occurred in 18.7% of Bor-HDM-treated patients (vs 13.1% in HDM-treated patients). The proportion of grade 3/4 AEs was similar within the 2 groups (72.0% vs 73.1%), mainly (as expected) blood and gastrointestinal disorders; 4% of patients reported grade 3/4 or painful peripheral neuropathy in arm A (vs 1.5% in arm B). In this randomized phase 3 study, a conditioning regimen with Bor-HDM did not improve efficacy end points or outcomes compared with HDM alone. The original trial was registered at www.clinicaltrials.gov as #NCT02197221.

Low dose venetoclax in combination with bortezomib, daratumumab, and dexamethasone for the treatment of relapsed/refractory multiple myeloma patients-a single-center retrospective study

Venetoclax is a BCL-2 inhibitor currently indicated for use in treating hematologic malignancies with recommended doses ranging from 400 to 600 mg/day. Although currently not FDA-approved to treat multiple myeloma (MM) patients, there is a growing number of reports indicating its efficacy as a salvage therapy for these patients, especially for those with the t(11;14) chromosomal marker. These studies, however, have also indicated that venetoclax given at doses ≥ 400 mg/day can cause serious adverse events (SAEs) especially when administered with bortezomib, commonly related to infections. The purpose of this single-center retrospective study was to determine the efficacy of low dose venetoclax (defined as ≤ 250 mg/day) in combination with low dose bortezomib (defined as 1.0 mg/m² per dose), daratumumab, and dexamethasone (Dvvd) as a salvage therapy for relapsed/refractory myeloma (RRMM) patients. Twenty-two RRMM patients were given venetoclax orally at doses ranging from 100 to 250 mg daily using this four-drug regimen. While the low doses resulted in reduced venetoclax efficacy among those lacking t(11;14) (overall response rate [ORR] = 31%), those harboring the t(11;14) marker exhibited an ORR of 80%. Notably, this response was without frequent infection-related SAEs as reported in previous studies. Together, the results of this study demonstrate that treatment of t(11;14) positive RRMM patients with Dvvd is both effective and well-tolerated.

Bortezomib-based strategy with autologous stem cell transplantation for newly diagnosed multiple myeloma: a phase II study by the Japan Study Group for Cell Therapy and Transplantation (JSCT-MM12)

BACKGROUND

The Japan Study Group for Cell Therapy and Transplantation (JSCT) organized a phase II study to evaluate the efficacy and safety of a treatment protocol (JSCT-MM12) for multiple myeloma (MM) patients who were previously untreated and transplantation-eligible. Since bortezomib-based therapy is known to be effective for MM, the protocol is intensified more than the previous protocol (JSCT-MM10) and comprised the subsequent treatments: bortezomib + cyclophosphamide + dexamethasone (VCD) induction; bortezomib + high-dose-melphalan (B-HDM) conditioning with autologous stem cell transplantation (ASCT); bortezomib + thalidomide + dexamethasone (VTD) consolidation; and lenalidomide (LEN) maintenance.

METHODS

Sixty-four symptomatic patients aged between 20 and 65 years were enrolled for treatment and received three cycles of VCD, followed by cyclophosphamide administration for autologous stem cell harvest and B-HDM/ASCT, and subsequently two cycles of VTD, after that LEN for 1 year.

RESULTS

Complete response (CR)/stringent CR (sCR) rates for induction, ASCT, consolidation, and maintenance therapies were 20, 39, 52, and 56%, respectively. The grade 3/4 toxicities (≥ 10%) with VCD treatment included neutropenia (27%), anemia (19%), and thrombocytopenia (11%). There was no treatment-related mortality. After median follow-up of 41 months, estimated 3-year progression-free survival (PFS) and overall survival (OS) rates were 64% and 88%, respectively. The high-risk group revealed lower CR/sCR, PFS, and OS than the standard-risk group.

CONCLUSIONS

The study revealed that the treatment protocol consisting of VCD induction, B-HDM/ASCT followed by VTD consolidation, and LEN maintenance could produce highly beneficial responses and favorable tolerability in newly diagnosed MM. However, future study is required for improving treatment in the high-risk group.

Lactacystin: first-in-class proteasome inhibitor still excelling and an exemplar for future antibiotic research

Lactacystin exemplifies the role that serendipity plays in drug discovery and why “finding things without actually looking for them” retains such a pivotal role in the search for the useful properties of chemicals. The first proteasome inhibitor discovered, lactacystin stimulated new possibilities in cancer control. New and innovative uses are regularly being found for lactacystin, including as a model to study dementia, while new formulations and delivery systems may facilitate its use clinically as an anticancer agent. All this provides yet more evidence that we need a comprehensive, collaborative and coordinated programme to fully investigate all new and existing chemical compounds, especially those of microbial origin. We need to do so in order to avoid failing to detect and successfully exploit unsought yet potentially life-saving or extremely advantageous properties of microbial metabolites.

P-Glycoprotein Inhibition Sensitizes Human Breast Cancer Cells to Proteasome Inhibitors

Although effective for the treatment of hematological malignancies, the FDA approved proteasome inhibitors bortezomib and carfilzomib have limited efficacy in solid tumors including triple negative breast cancer (TNBC). Chemotherapy is the only option for treating TNBC due to the absence of specific therapeutic targets. Therefore, development of new TNBC therapeutic strategies has been warranted. We studied whether P-glycoprotein (P-gp) inhibition could sensitize TNBC cells to proteasome inhibitors. When verapamil, a P-gp inhibitor, was combined with the proteasome inhibitor MG132, bortezomib, or carfilzomib, the cytotoxic effects and apoptosis in TNBC MDA-MB-231 cells were enhanced, compared to each treatment alone. Furthermore, addition of verapamil improved proteasome-inhibitory properties of MG132, bortezomib, or carfilzomib in MDA-MB-231 cells, as shown by the increased accumulation of ubiquitinated proteins and proteasome substrates such as IκBα and p27^kip1 . Additionally, when nicardipine, another P-gp inhibitor, was combined with bortezomib or carfilzomib, enhanced inhibition of MDA-MB-231 cell proliferation was observed. These findings indicate that P-gp inhibitors could sensitize TNBC cells to structurally and functionally diverse proteasome inhibitors and might provide new treatment strategy for TNBC. J. Cell. Biochem. 118: 1239-1248, 2017. © 2016 Wiley Periodicals, Inc.

New advances in targeted gastric cancer treatment

Despite a decrease in incidence over past decades, gastric cancer remains a major global health problem. In the more recent period, survival has shown only minor improvement, despite significant advances in diagnostic techniques, surgical and chemotherapeutic approaches, the development of novel therapeutic agents and treatment by multidisciplinary teams. Because multiple genetic mutations, epigenetic alterations, and aberrant molecular signalling pathways are involved in the development of gastric cancers, recent research has attempted to determine the molecular heterogeneity responsible for the processes of carcinogenesis, spread and metastasis. Currently, some novel agents targeting a part of these dysfunctional molecular signalling pathways have already been integrated into the standard treatment of gastric cancer, whereas others remain in phases of investigation within clinical trials. It is essential to identify the unique molecular patterns of tumours and specific biomarkers to develop treatments targeted to the individual tumour behaviour. This review analyses the global impact of gastric cancer, as well as the role of Helicobacter pylori infection and the efficacy of bacterial eradication in preventing gastric cancer development. Furthermore, the paper discusses the currently available targeted treatments and future directions of research using promising novel classes of molecular agents for advanced tumours.

A novel alkylating agent Melflufen induces irreversible DNA damage and cytotoxicity in multiple myeloma cells

Our prior study utilized both in vitro and in vivo multiple myeloma (MM) xenograft models to show that a novel alkylator melphalan-flufenamide (Melflufen) is a more potent anti-MM agent than melphalan and overcomes conventional drug resistance. Here we examined whether this potent anti-MM activity of melflufen versus melphalan is due to their differential effect on DNA damage and repair signalling pathways via γ-H2AX/ATR/CHK1/Ku80. Melflufen-induced apoptosis was associated with dose- and time-dependent rapid phosphorylation of γ-H2AX. Melflufen induces γ-H2AX, ATR, and CHK1 as early as after 2 h exposure in both melphalan-sensitive and -resistant cells. However, melphalan induces γ-H2AX in melphalan-sensitive cells at 6 h and 24 h; no γ-H2AX induction was observed in melphalan-resistant cells even after 24 h exposure. Similar kinetics was observed for ATR and CHK1 in meflufen- versus melphalan-treated cells. DNA repair is linked to melphalan-resistance; and importantly, we found that melphalan, but not melflufen, upregulates Ku80 that repairs DNA double-strand breaks. Washout experiments showed that a brief (2 h) exposure of MM cells to melflufen is sufficient to initiate an irreversible DNA damage and cytotoxicity. Our data therefore suggest that melflufen triggers a rapid, robust, and an irreversible DNA damage which may account for its ability to overcome melphalan-resistance in MM cells.

A phase 1, open-label, dose-escalation study of pralatrexate in combination with bortezomib in patients with relapsed/refractory multiple myeloma

Pralatrexate inhibits folic acid metabolism, and preclinical studies have shown that it is cytotoxic to multiple myeloma cells. This phase 1 study investigated the safety and efficacy of pralatrexate in combination with bortezomib in adults with relapsed or refractory multiple myeloma. A standard 3 + 3 design was used. Patients received intravenous pralatrexate at doses ranging from 10 to 30 mg/m(2) and intravenous bortezomib at a dose of 1·3 mg/m(2) on days 1, 8 and 15 of each 4-week cycle. Eleven patients were enrolled and completed a median of two cycles. The maximum tolerated dose was 20 mg/m(2) . Two patients experienced dose-limiting toxicity of mucositis. The most frequent non-haematological toxicities were fatigue (55%) and mucositis (45%). There were three serious adverse events in three patients: rash, sepsis and hypotension. One patient (9%) had a very good partial response, 1 (9%) had a partial response, 1 (9%) had minimal response and two (18%) had progressive disease. The median duration of response was 4 months, the median time to next treatment was 3·4 months and the median time to progression was 4 months. Pralatrexate, in combination with bortezomib, was generally safe and demonstrated modest activity in relapsed or refractory multiple myeloma. Clinicaltrials.gov identifier: NCT01114282.

Synergistic inhibition of PARP-1 and NF-κB signaling downregulates immune response against recombinant AAV2 vectors during hepatic gene therapy

Host immune response remains a key obstacle to widespread application of adeno-associated virus (AAV) based gene therapy. Thus, targeted inhibition of the signaling pathways that trigger such immune responses will be beneficial. Previous studies have reported that DNA damage response proteins such as poly(ADP-ribose) polymerase-1 (PARP-1) negatively affect the integration of AAV in the host genome. However, the role of PARP-1 in regulating AAV transduction and the immune response against these vectors has not been elucidated. In this study, we demonstrate that repression of PARP-1 improves the transduction of single-stranded AAV vectors both in vitro (∼174%) and in vivo (two- to 3.4-fold). Inhibition of PARP-1, also significantly downregulated the expression of several proinflammatory and cytokine markers such as TLRs, ILs, NF-κB subunit proteins associated with the host innate response against self-complementary AAV2 vectors. The suppression of the inflammatory response targeted against these vectors was more effective upon combined inhibition of PARP-1 and NF-κB signaling. This strategy also effectively attenuated the AAV capsid-specific cytotoxic T-cell response, with minimal effect on vector transduction, as demonstrated in normal C57BL/6 and hemophilia B mice. These data suggest that targeting specific host cellular proteins could be useful to attenuate the immune barriers to AAV-mediated gene therapy.

Effect of cisplatin on proteasome activity

Cisplatin is a widely used chemotherapy drug which exerts cytotoxic activity by affecting both nuclear and cytosolic pathways. Herewith, we report, for the first time, that cisplatin inhibits proteasome activity in vitro. Cisplatin induces a dose dependent inhibition of the three enzymatic activities of proteasome (i.e., the chymotrypsin-like activity, the trypsin-like activity and the caspase-like activity). Moreover, cisplatin administration to neuroblastoma cells brings about a fast loss of proteasome particle activity, which is followed by a de novo synthesis of proteasome. Lastly, we report that the simultaneous administration of lactacystin and cisplatin enhances the cytotoxicity of cisplatin alone. The overall bulk of data opens to an intriguing scenario, concerning the biological effects of cisplatin in the control of cellular life, which goes beyond the well established genotoxic effect.

An open-label phase I/II study of cyclophosphamide, bortezomib, pegylated liposomal doxorubicin, and dexamethasone in newly diagnosed myeloma

We conducted a phase 1/2 trial evaluating the combination of cyclophosphamide, bortezomib, pegylated liposomal doxorubicin, and dexamethasone (CVDD) for newly diagnosed multiple myeloma (MM). The primary objective of the phase 1 was to evaluate the safety and tolerability of maximum planned dose (MPD) and the phase 2 was to assess the overall response rate. Patients received 6-8 cycles of CVDD at four dose levels. There were no dose-limiting toxicities. The MPD was cyclophosphamide 750 mg/m(2) IV on day 1, bortezomib 1.3 mg/m(2) IV on days 1, 4, 8, 11, pegylated liposomal doxorubicin 30 mg/m(2) IV on day 4, and dexamethasone 20 mg orally on the day of and after bortezomib (21-d cycle). Forty-nine patients were treated at the MPD of which 22% had high-risk myeloma. The most common grade ≥3 toxicities included myelosuppression, infection, and fatigue. Overall response and complete response rates were 91% and 26% in standard-risk, and 100% and 58% in high-risk cohort, respectively. After a median follow-up of 34 months, the median progression-free survival was 31.3 months. The 2-yr overall survival was 91.1% in the standard-risk and 88.9% in the high-risk cohort, respectively. CVDD regimen was well tolerated and was highly active in newly diagnosed MM.

Acetyl-L-carnitine (ALCAR) for the prevention of chemotherapy-induced peripheral neuropathy in patients with relapsed or refractory multiple myeloma treated with bortezomib, doxorubicin and low-dose dexamethasone: a study from the Wisconsin Oncology Network

Purpose

Retreatment with bortezomib (B) is often considered for patients with relapsed multiple myeloma (MM), but this strategy is hindered by uncertainty of response and emergence of B-induced peripheral neuropathy (PN). We incorporated acetyl-l-carnitine (ALCAR) to prevent PN and allow for adequate dosing. We also investigated the correlation between B-inducible NF-κB activation and response to therapy.

Methods

Nineteen patients with relapsed/refractory MM received up to 8 cycles of intravenous bortezomib, doxorubicin and oral low-dose dexamethasone (BDD) to evaluate response and toxicity. Thirteen additional patients received prophylactic ALCAR (BDD-A). Patients receiving BDD-A were evaluated by FACT-GOG-TX, FACIT-Fatigue, Neuropathic Pain index (NPI) and Grooved Pegboard (GP) testing. Primary MM cells from 11 patients were tested for B-inducible NF-κB activation.

Results

Seventy-six percent of subjects were refractory to previous treatment, 39 % refractory to bortezomib. Median cycles received were 5. CR + PR for the entire group were 53 % and did not differ between groups. Incidence of ≥3 PN was 32 % in the BDD group versus 15 % in the BDD-A group (p = ns). Patient-reported fatigue and PN measured by FACT-GOG-TX increased throughout the treatment period in the BDD-A group, although time to complete GP testing declined. In a sub-study examining constitutive bortezomib-inducible NF-κB activity in primary subject-specific MM cells, the presence of NF-κB activation correlated with lower likelihood of response.

Conclusions

Addition of ALCAR to BDD did not alter the incidence or severity of PN in relapsed MM patients receiving a B-based regimen. Bortezomib-inducible NF-κB activation in patient-derived primary MM cells may be associated with poorer response.

Metastasis review: from bench to bedside

Cancer is the final result of uninhibited cell growth that involves an enormous group of associated diseases. One major aspect of cancer is when cells attack adjacent components of the body and spread to other organs, named metastasis, which is the major cause of cancer-related mortality. In developing this process, metastatic cells must successfully negotiate a series of complex steps, including dissociation, invasion, intravasation, extravasation, and dormancy regulated by various signaling pathways. In this review, we will focus on the recent studies and collect a comprehensive encyclopedia in molecular basis of metastasis, and then we will discuss some new potential therapeutics which target the metastasis pathways. Understanding the new aspects on molecular mechanisms and signaling pathways controlling tumor cell metastasis is critical for the development of therapeutic strategies for cancer patients that would be valuable for researchers in both fields of molecular and clinical oncology.

Advances in multiple myeloma therapy during two past decades

Multiple myeloma (MM) is a clonal B-cell malignancy characterized by aberrant expansion of plasma cells within bone marrow and extramedullary sites. It is one of the most common haematological malignancies; it accounts for 1.4% of all tumours and is responsible for 2% of cancer-related mortality. Over the last decades, the paradigm of MM therapy has changed dramatically - from the conventional combination of oral melphatan + prednisone, high-dose chemotherapy with stem cell (ASCT) support for younger patients to the present paradigm with the use of one (or more) of 3 major new targeted agents - the first-in class proteasome inhibitor bortezomib, the immunomodulatory drug thalidomide, and its more potent derivative lenalidomide. Their use as a part of initial therapy is associated with high overall response rates as well as high rates of complete response (CR), both for elderly patients unable to undergo ASCT and for younger patients treated prior to ASCT. Altogether, the advent of novel agents has resulted in a 50% improvement in median survival. Moreover, the development of new drug classes based on preclinical rationale and the introduction of next-generation agents are likely to further expand treatment options and improve outcomes for especially relapsed MM. This review highlights important historic landmarks as well as more recent events that have played an important role in the evolution of myeloma targeted therapy.

Bortezomib, dexamethasone, and high-dose melphalan as conditioning for stem cell transplantation in young Japanese multiple myeloma patients: a pilot study

Autologous stem cell transplantation is recommended for younger patients with newly diagnosed multiple myeloma because of a high complete response rate and better survival. Bortezomib shows a synergistic effect with melphalan and has no prolonged hematologic toxicity, and the complete response rate after autologous stem cell transplantation is improved by combining bortezomib with melphalan for conditioning. Twelve patients were enrolled in a phase 2 study between February and November 2010, receiving bortezomib (1 mg/m(2) × 4), dexamethasone (20 mg/body × 8), and melphalan (200 mg/m(2)) for conditioning. No toxic deaths occurred. Neutrophils (absolute neutrophil count ≥0.5 × 10(9)/L) and platelets (≥20 × 10(9)/L without transfusion) recovered after a median of 5 days (range: 4-6 days) and 7 days (range: 4-8 days), respectively. No patient was admitted for exacerbation of peripheral neuropathy. Four patients obtained a stringent complete response, three patients obtained a complete response, and three patients showed a very good partial response. These results suggest that this conditioning regimen is safe and promising for young Japanese multiple myeloma patients. A prospective multicenter trial of this regimen combined with suitable induction and consolidation therapy should be performed.

Bortezomib

The ubiquitin-mediated degradation of proteins in numerous cellular processes, such as turnover and quality control of proteins, cell cycle and apoptosis, transcription and cell signaling, immune response and antigen presentation, and inflammation and development makes the ubiquitin-proteosome systems a very interesting target for various therapeutic interventions. Proteosome inhibitors were first synthesized as tools to probe the function and specificity of this particle's proteolytic activities. Most synthetic inhibitors rely on a peptide base, which mimics a protein substrate, attached at a COOH terminal "warhead." Notable warheads include boronic acids, such as bortezomib and epoxy ketones, such as carfilzomib. A variety of natural products also inhibit the proteosome that are not peptide-based, most notably lactacystin, that is related to NPI-0052, or salinosporamide A, another inhibitor in clinical trials. The possibility that proteosome inhibitors could be drug candidates was considered after studies showed that they induced apoptosis in leukemic cell lines. The first proteasome inhibitor in clinical application, bortezomib showed activity in non-small-cell lung and androgen-independent prostate carcinoma, as well as MM and mantle cell and follicular non-Hodgkin's lymphoma. It is now licensed for the treatment of newly diagnosed as well as relapsed/progressive MM and has had a major impact on the improvement in the treatment of MM in the last few years.

Choosing treatment options for patients with relapsed/refractory multiple myeloma

Multiple myeloma (MM) is a clonal plasma cell disorder that is still incurable using conventional treatments. Over the last decade, advances in front-line therapy have led to an increase in survival, but there are still some doubts in the case of relapsed/refractory disease. We searched the PubMed database for articles on treatment options for patients with relapsed/refractory MM published between 1996 and 2013. These treatments included hematopoietic cell transplantation (HCT), rechallenges using previous chemotherapy regimens, and trials of new regimens. The introduction of new agents such as the immunomodulatory drugs (IMIDs) thalidomide and lenalidomide, and the first-in-its-class proteasome inhibitor bortezomib, has greatly improved clinical outcomes in patients with relapsed/refractory MM, but not all patients respond and those that do may eventually relapse or become refractory to treatment. The challenge is therefore to select the optimal treatment for each patient by balancing efficacy and toxicity. To do this, it is necessary to consider disease-related factors, such as the quality and duration of responses to previous therapies, and the aggressiveness of the relapse, and patient-related factors such as age, comorbidities, performance status, pre-existing toxicities and cytogenetic patterns. The message from the trials reviewed in this article is that the new agents may be used to re-treat relapsed/refractory disease, and that the sequencing of their administration should be modulated on the basis of the various disease and patient-related factors. Moreover, our understanding of the pharmacology and molecular action of the new drugs will contribute to the possibility of developing tailored treatment.

Current and emerging treatment options for patients with relapsed myeloma

Multiple myeloma (MM) is a neoplastic disorder. It results from proliferation of clonal plasma cells in bone marrow with production of monoclonal proteins, which are detectable in serum or urine. MM is clinically characterized by destructive bone lesions, anemia, hypercalcemia and renal insufficiency. Its prognosis is severe, with a median survival after diagnosis of approximately 3 years due to frequent relapses. Treatments for patients with relapsed/refractory MM include hematopoietic cell transplantation, a rechallenge using a previous chemotherapy regimen or a trial of a new regimen. The introduction of new drugs such as thalidomide, lenalidomide and bortezomib has markedly improved MM outcomes. When relapse occurs, the clinician's challenge is to select the optimal treatment for each patient while balancing efficacy and toxicity. Patients with indolent relapse can be first treated with a 2-drug or a 3-drug combination. Patients with more aggressive relapse often require therapy with a combination of multiple active agents. Autologous stem cell transplantation should be considered as salvage therapy at first relapse for patients who have cryopreserved stem cells early in the disease course. The aim of this review is to provide an overview on the pharmacological and molecular action of treatments used for patients with relapsed/refractory multiple myeloma.

Phase II clinical trial for the evaluation of bortezomib within the reduced intensity conditioning regimen (RIC) and post-allogeneic transplantation for high-risk myeloma patients

The current study was designed to assess the safety and efficacy of bortezomib in combination with fludarabine and melphalan as reduced intensity conditioning before allogeneic stem cell transplantation in patients with high risk multiple myeloma. Sixteen patients were evaluable. The median number of previous line of treatment was 3; all patients had relapsed following a prior autograft and 13 had previously received bortezomib. Fifteen of them either remained stable or improved disease status at day +100 post-transplant, including 11 patients with active disease. More specifically, nine patients (56%) and five patients (31%) reached complete remission and partial response, respectively. 25% developed grade III acute graft-versus-host disease. The cumulative incidence of non-relapse mortality, relapse and overall survival were 25%, 54% and 41%, respectively, at 3 years. Regarding the non-haematological toxicity (grade>2), two patients developed peripheral neuropathy, two patients liver toxicity and 1 pulmonary toxicity early post-transplant. The haematological toxicity was only observed during the first three cycles mostly related to low haemoglobin and platelet levels. The current trial is the first one evaluating the safety and efficacy of bortezomib as part of a reduced intensity conditioning regimen among patients with high risk multiple myeloma.

In vitro and in vivo antitumor activity of a novel alkylating agent, melphalan-flufenamide, against multiple myeloma cells

PURPOSE

The alkylating agent melphalan prolongs survival in patients with multiple myeloma; however, it is associated with toxicities and development of drug-resistance. Here, we evaluated the efficacy of melphalan-flufenamide (mel-flufen), a novel dipeptide prodrug of melphalan in multiple myeloma.

EXPERIMENTAL DESIGN

Multiple myeloma cell lines, primary patient cells, and the human multiple myeloma xenograft animal model were used to study the antitumor activity of mel-flufen.

RESULTS

Low doses of mel-flufen trigger more rapid and higher intracellular concentrations of melphalan in multiple myeloma cells than are achievable by free melphalan. Cytotoxicity analysis showed significantly lower IC50 of mel-flufen than melphalan in multiple myeloma cells. Importantly, mel-flufen induces apoptosis even in melphalan- and bortezomib-resistant multiple myeloma cells. Mechanistic studies show that siRNA knockdown of aminopeptidase N, a key enzyme mediating intracellular conversion of mel-flufen to melphalan, attenuates anti-multiple myeloma activity of mel-flufen. Furthermore, mel-flufen-induced apoptosis was associated with: (i) activation of caspases and PARP cleavage; (ii) reactive oxygen species generation; (iii) mitochondrial dysfunction and release of cytochrome c; and (iv) induction of DNA damage. Moreover, mel-flufen inhibits multiple myeloma cell migration and tumor-associated angiogenesis. Human multiple myeloma xenograft studies showed a more potent inhibition of tumor growth in mice treated with mel-flufen than mice receiving equimolar doses of melphalan. Finally, combining mel-flufen with lenalidomide, bortezomib, or dexamethasone triggers synergistic anti-multiple myeloma activity.

CONCLUSION

Our preclinical study supports clinical evaluation of mel-flufen to enhance therapeutic potential of melphalan, overcome drug-resistance, and improve multiple myeloma patient outcome.

Combined bendamustine, prednisone and bortezomib (BPV) in patients with relapsed or refractory multiple myeloma

INTRODUCTION

Bortezomib (Velcade) is a proteasome inhibitor that has shown important clinical efficacy either as a single agent or in combination with other cytostatic agents in multiple myeloma (MM). In the present protocol, bortezomib was combined with other active substances like bendamustine and prednisone (BPV), in order to assess the efficacy and toxicity of the combination therapy in patients with relapsed or refractory MM.

METHODS

Between January 2005 and December 2011, 78 patients with relapsed or refractory MM were treated with bendamustine 60 (-120) mg/m(2) on days 1 and 2, bortezomib 1.3 mg/m(2) on days 1, 4, 8 and 11, and prednisone 100 mg on days 1, 2, 4, 8 and 11. The median number of prior therapies was 2 with a wide range of 1-9. Thirty-three patients had pre-existing severe thrombocytopenia and/or neutropenia (WHO grade 3 or 4).

RESULTS

A median number of two (range 1-7) BPV treatment cycles were given to the patients. The majority of the patients (n = 54; 69 %) responded after at least one cycle of chemotherapy with 3 CR, 10 nCR, 10 VGPR and 31 PR. Median PFS and OS for patients without severe hematological toxicities due to previous treatments (n = 45) were 11 and 50 months, respectively. Outcome for these patients was significantly better than that for patients with severe hematological toxicities (grade 3 or 4, n = 33) with a PFS, and OS of 3 months (p < 0.05) and 5 months (p < 0.001), respectively. The regimen was well tolerated with few significant side effects in patients without severe hematological toxicities due to previous treatments. These results indicate that the combination of bortezomib, bendamustine and prednisone is well tolerated in patients with relapsed or refractory MM.

Phosphorylation of signal transducer and activator of transcription 1 reduces bortezomib-mediated apoptosis in cancer cells

The potent and selective proteasome inhibitor bortezomib has shown remarkable antitumor activity and is now entering clinical trials for several cancers. However, the molecular mechanisms by which bortezomib induces cytotoxicity in ovarian cancer cells still remain unclear. In this study, we show that bortezomib induced apoptosis, which was demonstrated by the downregulation of antiapoptotic molecules (Bcl-2, Bcl-XL, p-Bad, and p-AKT) and the upregulation of proapoptotic proteins (p21, p27, and cleaved-Bid) in ovarian cancer cell lines. Moreover, bortezomib stimulates Janus kinase (JAK) phosphorylation and activates heat-shock transcription factor-1 (HSF-1) and heat-shock protein 70 (HSP70), ultimately leading to signal transducer and activator of transcription 1 (STAT1) phosphorylation. Phosphorylated STAT1 partially counteracted apoptosis induced by bortezomib in cancer cells. These findings suggest that the antitumor activity of bortezomib in ovarian cancer can be improved by inhibiting bortezomib-induced STAT1 phosphorylation. This effect can be achieved by STAT1 knockdown, HSP70 knockdown, JAK inhibition, or the addition of cisplatin, one of the most commonly used anticancer drugs. These results provide the first evidence that STAT1 phosphorylation can play a role in bortezomib resistance by exerting antiapoptotic effects. They also suggest the possibility to abolish or reduce bortezomib chemoresistance in ovarian cancer by the addition of cisplatin or JAK inhibitors.

Good clinical activity and favorable toxicity profile of once weekly bortezomib, fotemustine, and dexamethasone (B-MuD) for the treatment of relapsed multiple myeloma

Since multiple myeloma (MM) is still not-curable, the management of relapse remains challenging. Given the known efficacy of alkylating agents in MM, we conducted a phase I/II study to test a new three drug combination in which Fotemustine (Muphoran), an alkylating agent of nitrosurea family, was added to bortezomib + dexamethasone backbone (B-MuD) for the treatment of MM relapsed patients. Fotemustine was administered at two dose levels (80–100 mg/m² i.v.) on day 1. The original 21-day schedule was early amended for extra-hematological toxicity and a 35-day schedule was adopted (Bortezomib 1.3 mg/m² i.v. on days 1, 8, 15, and 22, Dexamethasone 20 mg i.v. on days 1, 8, 15, and 22) for a total of six courses. Twenty-four patients were enrolled. The maximum tolerated dose of Fotemustine was 100 mg/m². The overall response rate was of 62% (CR 8%, VGPR 33%, and PR 21%). The median OS was 28.5 months, the median progression-free survival (PFS) was 19.1 months. B-MuD resulted effective in patients previous exposed to bortezomib without difference of response (P = 0.25) and PFS (P = 0.87) when compared to bortezomib-naive patients. Thrombocytopenia was the most common AE overall. In conclusion, B-MuD is an effective and well tolerated combination in relapsed MM patients even in advanced disease phase. © Am. J. Hematol., 88:102–106, 2013. © 2012 Wiley Periodicals, Inc.

Bortezomib-cyclophosphamide-dexamethasone for relapsing multiple myeloma

OBJECTIVES

In vitro studies have shown synergistic antimyeloma effects with the combination of bortezomib and alkylating agents. Combinations of bortezomib, cyclophosphamide, and dexamethasone are rational with the prospect of superior antitumor activity with independent toxicity.

METHODS

Between December 2004 and April 2007, we treated 44 patients with relapsing multiple myeloma with the combination of bortezomib 1.3 mg/m intravenously on days 1, 4, 8, 11; dexamethasone 20 mg/m orally daily for 4 days beginning on days 1, 9 and 17; and cyclophosphamide 70 mg/m orally twice daily for 4 days. A second course was given 1 month later.

RESULTS

Clinical response was observed in 32 patients (73%) including 26 with disease in partial remission (59%), and 6 with disease in complete remission (14%). Side effects were uncommon and mild, except for grade 3 thrombocytopenia in 15%, infection in 5% and constipation in 2% of patients. The median remission time of responding patients was 10 months that contributed to significantly longer median survival for patients with responsive disease (33 mo) than for those with unresponsive disease (12 mo) (P < 0.01).

CONCLUSION

Bortezomib-cyclophosphamide-dexamethasone was an effective, well-tolerated combination for the treatment of relapsing multiple myeloma.

Management strategies for relapsed/refractory multiple myeloma: current clinical perspectives

In the last decade, the introduction of novel agents including the immunomodulatory drugs thalidomide and lenalidomide, and the first-in-class proteasome inhibitor bortezomib, has dramatically improved clinical outcome in patients with relapsed/refractory multiple myeloma (MM) compared to conventional chemotherapy alone. Although combination treatment approaches with traditional cytotoxic agents and novel agents have led to response rates as high as 85% in patients with relapsed/refractory disease, not all patients will respond to established novel agents, and even those who do respond will ultimately relapse or become refractory to currently available regimens. There is no generally accepted standard treatment for patients with relapsed/refractory disease; however, both disease-related (eg, quality and duration of response to previous therapies and the aggressiveness of the relapse) and patient-related (eg, preexisting toxicities, comorbid conditions, quality of life, age, and performance status) factors should be considered when selecting the best treatment option. This article will review up-to-date approaches for managing patients with relapsed/refractory MM, including the efficacy and safety of established novel agents, the use of adjunctive/supportive care, and strategies for tailored treatment.

A comparison of bortezomib, cyclophosphamide, and dexamethasone (Vel-CD) chemotherapy without and with thalidomide (Vel-CTD) for the treatment of relapsed or refractory multiple myeloma

We compared the clinical responses and toxicities between bortezomib-based salvage chemotherapy combined with cyclophosphamide, thalidomide, and dexamethasone(Vel-CTD) and without thalidomide (Vel-CD) in patients with relapsed or refractory MM. Eighty-six patients received at least two cycles of treatment with Vel-CTD (bortezomib 1.3 mg/m2 i.v. on days 1, 4, 8, and 11; cyclophosphamide 150 mg/m2 orally on days 1–4; thalidomide 50–100 mg/day orally every day; and dexamethasone 20 mg/m2 i.v. on days 1, 4, 8, and 11 every 3 weeks), and 67 patients were given at least two cycles of Vel-CD, which is the same regimen as Vel-CTD except without thalidomide. The overall response rates of the Vel-CD and Vel-CTD groups were 88% and 90% (p>0.05), respectively. There was no difference in the progression free survival (p = 0.69) and overall survival rates(p = 0.49) between the two groups. Grade 3 or more adverse hematologic events occurred in the same proportion of patients in both groups. In terms of non-hematologic toxicities, the Vel-CTD group showed a higher proportion of autonomic neuropathy, motor neuropathy, and sensory neuropathy compared to the Vel-CD group (each, p<0.05). Only three patients in the Vel-CTD group showed thrombotic events despite aspirin prophylaxis. The Vel-CD regimen inpatients with relapsed or refractory MM is an effective and more tolerable salvage therapy compared to Vel-CTD in terms of its comparable response rate and less severe of non-hematologic toxicities.

Bortezomib salvage followed by a Phase I/II study of bortezomib plus high-dose melphalan and tandem autologous transplantation for patients with primary resistant myeloma

We conducted a Phase 1/2 study of bortezomib administered in combination with high-dose melphalan followed by tandem autologous transplants in patients with primary resistant multiple myeloma. Thirty patients received two cycles of salvage bortezomib followed by stem cell mobilization with granulocyte colony-stimulating factor and harvest. Melphalan 100 mg/m(2) per day on two consecutive days was administered, immediately followed by one dose of bortezomib (dose escalation) and stem cell infusion. The median beta 2-microglobulin was 4·35 mg/l (range: 1·8-11·4); albumin was 37 g/l (range: 3·1-4·9); high-risk karyotypes were noted in 45% of patients. The maximum planned dose of bortezomib at 1·3 mg/m(2) was well tolerated and a formal maximum tolerated dose was not determined. The peak of best overall response (≥partial response) and complete response rates after tandem transplants were 84% and 36%, respectively. With a median follow-up of 48 months, the median progression-free survival was 15 [95% confidence interval (CI): 11-21] months and the median overall survival was 35 (95% CI: 22-43) months. Correlative studies demonstrated decreased expression of BRCA2 (P = 0·0072) and FANCF (P = 0·0458) mRNA following bortezomib treatment. Bortezomib combined with high-dose melphalan is a well-tolerated conditioning with some activity in patients with resistant myeloma.

Advances in the autologous and allogeneic transplantation strategies for multiple myeloma

BACKGROUND

Multiple myeloma is largely an incurable malignant plasma cell neoplasm; however, the landscape of its treatment is rapidly changing.

METHODS

The recent literature on both autologous and allogeneic transplant approaches for multiple myeloma was reviewed.

RESULTS

High-dose chemotherapy followed by autologous hematopoietic cell transplantation (HCT) remains an integral component of upfront treatment strategy, and the incorporation of novel immunomodulators and proteasome inhibitor to induction regimens improves response rates and increases overall survivals. Bortezomib and lenalidomide-based combination chemotherapy regimens have become the standard induction myeloma therapy. When myeloma patients proceed to transplant after novel combination regimens, their response rates are further improved. Despite these recent major improvements, myeloma remains incurable and long-term survival appears elusive. Due in part to a potential graft-vs-myeloma effect, allogeneic HCT is a potentially curative transplant option. However, initial attempts have been hampered by the high transplant-related mortality. With a reduction of toxicity, allogeneic transplant approaches with reduced-intensity conditioning have been utilized, although they are subject to continued disease progression and relapse following transplantation. Recent research efforts have shifted to the use of a tandem autologous-allogeneic HCT approach. The long-term follow-up of this new strategy is awaited.

CONCLUSIONS

Recent advances in HCT have improved outcomes of patients with multiple myeloma. Ongoing research activity focuses on the strategies to improve outcomes of HCT by incorporation of tandem autologous-allogeneic transplantation schema, novel conditioning regimens, and the use of consolidation and maintenance therapy.

Inhibition of the Nedd8 system sensitizes cells to DNA interstrand cross-linking agents

The Fanconi anemia pathway is required for repair of DNA interstrand cross-links (ICL). Fanconi anemia pathway-deficient cells are hypersensitive to DNA ICL-inducing drugs such as cisplatin. Conversely, hyperactivation of the Fanconi anemia pathway is a mechanism that may underlie cellular resistance to DNA ICL agents. Modulating FANCD2 monoubiquitination, a key step in the Fanconi anemia pathway, may be an effective therapeutic approach to conferring cellular sensitivity to ICL agents. Here, we show that inhibition of the Nedd8 conjugation system increases cellular sensitivity to DNA ICL-inducing agents. Mechanistically, the Nedd8 inhibition, either by siRNA-mediated knockdown of Nedd8-conjugating enzymes or treatment with a Nedd8-activating enzyme inhibitor MLN4924, suppressed DNA damage-induced FANCD2 monoubiquitination and CHK1 phosphorylation. Our data indicate that inhibition of the Fanconi anemia pathway is largely responsible for the heightened cellular sensitivity to DNA ICLs upon Nedd8 inhibition. These results suggest that a combination of Nedd8 inhibition with ICL-inducing agents may be an effective strategy for sensitizing a subset of drug-resistant cancer cells.

Proteasome inhibitors

In May 2003, the US Food and Drug Administration (FDA) granted accelerated approval for the use of the first-in-class proteasome inhibitor bortezomib as a third-line therapy in multiple myeloma, and the European Union followed suit a year later. Bortezomib has subsequently been approved for multiple myeloma as a second-line treatment on its own and as a first-line therapy in combination with an alkylating agent and a corticosteroid. Furthermore, bortezomib has also been approved as a second-line therapy for mantle cell lymphoma. In this chapter, the focus is on the current clinical research on bortezomib, its adverse effects, and the resistance of multiple myeloma patients to bortezomib-based therapy. The various applications of bortezomib in different diseases and recent advances in the development of a new generation of inhibitors that target the proteasome or other parts of the ubiquitin-proteasome system are also reviewed.

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.

Bortezomib-Dexamethasone or Vincristine-Doxorubicin-Dexamethasone as Induction Therapy Followed by Thalidomide as Maintenance Therapy in Untreated Multiple Myeloma Patients

This randomized, retrospective study evaluated the effect of thalidomide combined with bortezomib-dexamethasone (TBD) or vincristine-doxorubicin-dexamethasone (T-VAD) on 46 patients with multiple myeloma. Newly diagnosed patients were randomly allocated to receive TBD ( n = 24) or T-VAD ( n = 22). The high-quality response rate (complete response plus very good partial response) was 62.5% in the TBD group and 45.4% for T-VAD. The complete response rate was 29.2% for TBD and 13.6% for T-VAD. Overall survival at 2 and 3 years, respectively, was 91.7% and 62.5% for TBD versus 86.4% and 54.5% for T-VAD. Most of the toxic effects of treatment were well tolerated. Both regimens were effective in the treatment of newly diagnosed multiple myeloma patients. Further studies are required to determine the role of thalidomide in these two regimens.