Impact of prior therapy on the efficacy and safety of oral ixazomib-lenalidomide-dexamethasone vs. placebo-lenalidomide-dexamethasone in patients with relapsed/refractory multiple myeloma in TOURMALINE-MM1

Proceedings from the First Onco Summit: LATAM Chapter, 19-20 May 2023, Rio de Janeiro, Brazil

The Onco Summit 2023: The Latin American (LATAM) Chapter took place over two days, from 19-20 May 2023, in Brazil. The event aimed to share the latest updates across various oncology disciplines, address critical clinical challenges, and exchange best practices to ensure optimal patient treatment. More than 30 international and regional speakers and more than 300 oncology specialists participated in the Summit. The Summit discussions centered on common challenges and therapeutic advances in cancer care, with a specific focus on the unique obstacles faced in LATAM and examples of adaptable strategies to address these challenges. The Summit also facilitated the establishment of a network of oncologists, hematologists, and scientists in LATAM, enabling collaboration to improve cancer care, both in this region and globally, through drug development and clinical research. This report summarizes the key discussions from the Summit for the global and LATAM oncology community.

Impact of prior lenalidomide or proteasome inhibitor exposure on the effectiveness of ixazomib-lenalidomide-dexamethasone for relapsed/refractory multiple myeloma: A pooled analysis from the INSURE study

OBJECTIVES

To characterize the impact of prior exposure and refractoriness to lenalidomide or proteasome inhibitors (PIs) on the effectiveness and safety of ixazomib-lenalidomide-dexamethasone (IRd) in relapsed/refractory multiple myeloma (RRMM).

METHODS

INSURE is a pooled analysis of adult RRMM patients who had received IRd in ≥2 line of therapy from three studies: INSIGHT MM, UVEA-IXA, and REMIX.

RESULTS

Overall, 391/100/68 were lenalidomide-naïve/-exposed/-refractory and 37/411/110 were PI-naïve/-exposed/-refractory. Median duration of therapy (DOT) was 15.3/15.6/4.7 months and median progression-free survival (PFS) was 21.6/25.8/5.6 months in lenalidomide-naïve/exposed/refractory patients. Median DOT and PFS in PI-naïve/exposed/refractory patients were 20.4/15.2/6.9 months and not reached/19.8/11.4 months, respectively. The proportion of lenalidomide-naïve/exposed/refractory patients in INSIGHT and UVEA-IXA who discontinued a study drug due to adverse events (AEs) was ixazomib, 31.6/28.2/28.0% and 18.6/6.7/10.5%; lenalidomide, 21.9/28.2/16.0% and 16.1/6.7/10.5%; dexamethasone, 18.4/20.5/16.0% and 10.6/0/10.5%, respectively. The proportion of PI-naïve/exposed/refractory patients in INSIGHT and UVEA-IXA who discontinued a study drug due to AEs was: ixazomib, 44.4/28.8/27.8% and 22.2/16.7/15.7%; lenalidomide, 33.3/22.0/19.4% and 16.7/15.9/11.8%; dexamethasone, 33.3/17.4/16.7% and 16.7/9.5/7.8%, respectively. REMIX AE discontinuation rates were unavailable.

CONCLUSION

IRd appeared to be effective in RRMM patients in routine clinical practice regardless of prior lenalidomide or PI exposure, with better outcomes seen in lenalidomide- and/or PI-nonrefractory versus refractory patients.

Real-world data on the effectiveness and safety of Ixazomib-Lenalidomide-Dexamethasone therapy in relapsed/refractory multiple myeloma patients: a multicenter experience in Turkey

A multicenter, retrospective, observational study was conducted to explore effectiveness and safety of ixazomib plus lenalidomide with dexamethasone (IRd) in relapsed/refractory multiple myeloma (RRMM) patients following at least ≥ two lines of therapy. Patients' treatment responses, overall response rate, progression-free survival rate, and adverse events were recorded. Mean age of 54 patients was 66.5 ± 9.1 years. There were 20 patients (37.0%) with progression. Median progression-free survival was 13 months in patients who received a median of three therapy lines in a 7.5-month follow-up period. Overall response rate was 38.5%. Of 54 patients, 19 (40.4%) had at least one adverse event, and nine (19.1%) had an adverse event of at least grade 3 or more. Of 72 adverse events observed in 47 patients, 68% were grade 1 or 2. Treatment was not stopped in any patient due to adverse events. IRd combination therapy was effective and safe in heavily treated RRMM patients.

Effect modification in network meta-analyses for relapsed/refractory multiple myeloma: systematic review and meta-analysis

OBJECTIVES

To systematically review and meta-analyse the evidence for effect modification by refractory status and number of treatment lines in relapsed/refractory multiple myeloma (RRMM); and to assess whether effect modification is likely to invalidate network meta-analyses (NMA) that assume negligible modification.

DESIGN

Systematic review, meta-analysis and simulation.

DATA SOURCES

We systematically searched the literature (e.g., OVID Medline) to identify eligible publications in February 2020 and regularly updated the search until January 2022. We also contacted project stakeholders (including industry) ELIGIBILITY CRITERIA: Phase 2 and 3 randomised controlled trials reporting stratified estimates for comparisons with at least one of a prespecified set of treatments relevant for use in Norwegian RRMM patients.

OUTCOMES

We used meta-analysis to estimate relative HRs (RHRs) for overall survival (OS) and progression-free survival (PFS) with respect to refractory status and number of treatment lines. We used the estimated RHRs in simulations to estimate the percentage of NMA results expected to differ significantly in the presence versus absence of effect modification.

RESULTS

Among the 42 included publications, stratified estimates were published by and extracted from up to 18 (43%) publications and on as many as 8364 patients. Within-study evidence for effect modification is very weak (p>0.05 for 47 of 49 sets of stratified estimates). The largest RHR estimated was 1.32 (95% CI 1.18 to 1.49) for the modifying effect of refractory status on HR for PFS. Simulations suggest that, in the worst case, this would result in only 4.48% (95% CI 4.42% to 4.54%) of NMA estimates differing statistically significantly in the presence versus absence of effect modification.

CONCLUSIONS

Based on the available evidence, effect modification appears to be sufficiently small that it can be neglected in adequately performed NMAs. NMAs can probably be relied on to provide estimates of HRs for OS and PFS in RRMM, subject to caveats discussed herein.

Real-world effectiveness of ixazomib combined with lenalidomide and dexamethasone in relapsed/refractory multiple myeloma: the REMIX study

Ixazomib (IXA) is an oral proteasome inhibitor (PI) used in combination with lenalidomide and dexamethasone (IXA-Rd) for patients with relapsed and/or refractory multiple myeloma (RRMM). The REMIX study is one of the largest prospective, real-world analysis of the effectiveness of IXA-Rd in the setting of RRMM. Conducted in France between August 2017 and October 2019, the REMIX study, a non-interventional prospective study, included 376 patients receiving IXA-Rd in second line or later and followed for at least 24 months. Primary endpoint was the median progression-free survival (mPFS). Median age was 71 years (Q1-Q3 65.0 - 77.5) with 18.4% of participants older than 80 years. IXA-Rd was initiated in L2, L3 and L4 + for 60.4%, 18.1% and 21.5%, respectively. mPFS was 19.1 months (95% CI [15.9, 21.5]) and overall response rate (ORR) was 73.1%. mPFS was 21.5, 21.9 and 5.8 months in patients receiving IXA-Rd as L2, L3, L4 + respectively. Among patients receiving IXA-Rd in L2 and L3, mPFS was similar for patients previously exposed to lenalidomide (19.5 months) than for those lenalidomide naive (not exposed, 22.6 months, p = 0.29). mPFS was 19.1 months in patients younger than 80 years and 17.4 months in those 80 years or older (p = 0.06) with similar ORR (72.4% and 76.8%) in both subgroups. Adverse events (AEs) were reported in 78.2% of patients including 40.7% of treatment-related AE. IXA discontinuation was due to toxicity in 21% of patients. To conclude, the results of the REMIX study are consistent with the results of Tourmaline-MM1 and confirm the benefit of IXA-Rd combination in real life. It shows the interest of IXA-Rd in an older and frailer population, with an acceptable effectiveness and tolerance.

Real-world toxicity and effectiveness of ixazomib, lenalidomide, and dexamethasone in Korean patients with relapsed and/or refractory multiple myeloma

BACKGROUND/AIM

Ixazomib, lenalidomide, and dexamethasone (IRd) have proven efficacy and an excellent safety profile in relapsed and/or refractory multiple myeloma (RRMM). However, there are limited reports on the real-world safety and effectiveness of IRd regimens in Asian patients with RRMM.

PATIENTS AND METHODS

This was a retrospective study of 60 patients with RRMM who were treated with IRd.

RESULTS

The median patient age was 68 years. Forty percent of patients did not meet the eligibility criteria for the TOURMALINE-MM1 trial. Patients received a median of one prior line of therapy. Non-hematologic adverse events (AEs) were more common than hematologic AEs. The most common AE was skin rash, followed by gastrointestinal toxicities. Most grade 3 or higher AEs were observed in less than 5% of the patients, except for skin rashes and infections. IRd therapy did not aggravate peripheral neuropathy (PN) in 20 of the 24 patients with pre-existing peripheral neuropathy. The overall response rate was 85%. After a median follow-up of 26.3 months, the median progression-free survival was 25.9 months and overall survival was not reached.

CONCLUSION

Ixazomib and Rd combination therapy had a comparable toxicity profile and effectiveness in real-world RRMM patients.

Isatuximab Plus Carfilzomib and Dexamethasone Versus Carfilzomib and Dexamethasone in Patients with Relapsed Multiple Myeloma: IKEMA Subgroup Analysis by Prior Transplantation

In the era of highly active novel agents for multiple myeloma (MM), the role, ideal timing, and impact of transplantation on further therapy after relapse remains a matter of debate. The impact of prior transplantation on treatment benefit from monoclonal antibodies in patients with relapsed/refractory MM (RRMM) is largely unknown. Few Phase 3 studies of monoclonal antibody combinations with proteasome inhibitors or immunomodulatory agents have reported outcomes according to transplantation status. This subgroup analysis examined efficacy and safety in patients from the Phase 3 IKEMA study with and without previous transplantation. IKEMA (NCT03275285) was a randomized, open-label, multinational, parallel-group Phase 3 study that investigated isatuximab (Isa), an anti-CD38 monoclonal antibody, combined with carfilzomib and dexamethasone (Isa-Kd; experimental group) versus Kd (control group) in 302 patients with RRMM and 1 to 3 prior lines of therapy. Patients were randomized in a 3:2 ratio to either Isa-Kd or Kd, with stratification by number of prior lines (1 versus more than 1) and Revised International Staging System (R-ISS) stage (I or II versus III versus not classified). Treatment was given until progressive disease, unacceptable adverse events, or patient choice. Of the 302 randomized patients in IKEMA, 185 (61.3%) had received a prior transplant, comprising 116 of 179 (64.8%) patients in the Isa-Kd arm and 69 of 123 (56.1%) patients in the Kd arm. After a median follow-up of 20.6 months, median progression-free survival (PFS) in patients with prior transplant was not reached with Isa-Kd versus 19.15 months with Kd (hazard ratio [HR] = 0.60; 99% confidence interval [CI], 0.31-1.16). After a median follow-up of 20.8 months, median PFS in patients without prior transplant was not reached with Isa-Kd versus 18.99 months with Kd (HR = 0.44; 99% CI, 0.18-1.05). The overall response rate in patients with prior transplant was 87.9% (Isa-Kd) versus 85.5% (Kd). More patients in the Isa-Kd arm achieved a complete response or better compared with the Kd arm (43.1% versus 29.0%). The overall response rate in patients without prior transplant was 84.1% (Isa-Kd) versus 79.6% (Kd). More patients in the Isa-Kd arm achieved a complete response or better compared with the Kd arm (33.3% versus 25.9%). The minimal residual disease negativity rate was higher with Isa-Kd versus Kd in patients with (31.9% versus 13.0%) and without prior transplantation (25.4% versus 13.0%). In patients with prior transplant, Grade 3 or higher treatment-emergent adverse events (TEAEs) were more common with Isa-Kd; however, no increases in serious TEAEs or definitive treatment discontinuations were seen versus Kd. Among patients without prior transplant, serious treatment-related TEAEs were similar, and there were fewer TEAEs leading to definitive discontinuation with Isa-Kd. The most common Grade 3 or higher TEAEs in patients with and without prior transplant were hypertension and pneumonia. For patients who underwent prior transplantation, Isa-Kd is an effective treatment option. Overall, these data demonstrate that Isa-Kd represents a standard of care for patients with RRMM, regardless of prior transplant status.

The emerging therapeutic landscape of relapsed/refractory multiple myeloma

From a historic lens, treatment for patients with relapsed/refractory multiple myeloma (R/R MM) has advanced significantly since the advent of immunomodulatory agents (IMiDs) in the 1990s, proteasome inhibitors in the 2000s, monoclonal antibodies in the 2010s, and CAR-T treatments in the 2020s. However, the availability of multiple new therapies has also created significant ambiguity regarding therapy selection and sequencing, as consensus guidelines are limited, and cross-trial comparisons of the novel agents are challenging. In this focused review, we discuss the novel Food & Drug Administration (FDA)-approved medications for R/R MM, including the recently approved first-in-class BCMA-directed bispecific antibody teclistamab. We highlight the seminal clinical trials data and discuss optimal sequencing considerations based on the goal of treatment, with an emphasis on the two novel CAR-T cell products. We consider the limited tolerability of certain agents, prospects for our aging population, and financial aspects of these therapies. Finally, we spotlight ongoing trials involving promising agents making their way through the pharmacologic pipeline including the BCMA-directed bispecific antibody elranatamab and the GPRC5D-directed bispecific antibody talquetamab. We summarize our recommendations based on the best available evidence as we enter 2023.

Kinase Inhibition in Multiple Myeloma: Current Scenario and Clinical Perspectives

Multiple myeloma (MM) is a blood cell neoplasm characterized by excessive production of malignant monoclonal plasma cells (activated B lymphocytes) by the bone marrow, which end up synthesizing antibodies or antibody fragments, called M proteins, in excess. The accumulation of this production, both cells themselves and of the immunoglobulins, causes a series of problems for the patient, of a systemic and local nature, such as blood hyperviscosity, renal failure, anemia, bone lesions, and infections due to compromised immunity. MM is the third most common hematological neoplasm, constituting 1% of all cancer cases, and is a disease that is difficult to treat, still being considered an incurable disease. The treatments currently available cannot cure the patient, but only extend their lifespan, and the main and most effective alternative is autologous hematopoietic stem cell transplantation, but not every patient is eligible, often due to age and pre-existing comorbidities. In this context, the search for new therapies that can bring better results to patients is of utmost importance. Protein tyrosine kinases (PTKs) are involved in several biological processes, such as cell growth regulation and proliferation, thus, mutations that affect their functionality can have a great impact on crucial molecular pathways in the cells, leading to tumorigenesis. In the past couple of decades, the use of small-molecule inhibitors, which include tyrosine kinase inhibitors (TKIs), has been a hallmark in the treatment of hematological malignancies, and MM patients may also benefit from TKI-based treatment strategies. In this review, we seek to understand the applicability of TKIs used in MM clinical trials in the last 10 years.

How I Treat Relapsed Multiple Myeloma

Despite recent advances multiple myeloma remains an incurable disease for most of the patients and initial remission will be followed by relapses requiring therapy. For many, there will be several remissions and relapses until resistance develops to all available therapies. With the introduction of several new agents, myeloma treatment has changed drastically and there are new options for the management of relapsed or refractory disease, including new drug classes with distinct mechanisms of action and cellular therapies. However, resistance to major drug classes used in first line remain the most critical factor for the choice of treatment at relapse. Continuous lenalidomide-based therapy is used extensively at first line and resistance to lenalidomide has become the key factor for the choice of salvage therapy. Daratumumab is increasingly used in first line and soon patients that relapse while on daratumumab will become a common challenge. Three-drug regimens are standard approach to manage relapsed disease. Adding drugs with new mechanisms of activity can improves outcomes and overcomes class resistance but, until now, while the biology is important, can offer only limited guidance for the choice of therapy.

The changing landscape of relapsed and/or refractory multiple myeloma (MM): fundamentals and controversies

The increase in the number of therapeutic alternatives for both newly diagnosed and relapsed/refractory multiple myeloma (RRMM) patients has widened the clinical scenario, leading to a level of complexity that no algorithm has been able to cover up to date. At present, this complexity increases due to the wide variety of clinical situations found in MM patients before they reach the status of relapsed/refractory disease. These different backgrounds may include primary refractoriness, early relapse after completion of first-line therapy with latest-generation agents, or very late relapse after chemotherapy or autologous transplantation. It is also important to bear in mind that many patient profiles are not fully represented in the main randomized clinical trials (RCT), and this further complicates treatment decision-making. In RRMM patients, the choice of previously unused drugs and the number and duration of previous therapeutic regimens until progression has a greater impact on treatment efficacy than the adverse biological characteristics of MM itself. In addition to proteasome inhibitors, immunomodulatory drugs, anti-CD38 antibodies and corticosteroids, a new generation of drugs such as XPO inhibitors, BCL-2 inhibitors, new alkylators and, above all, immunotherapy based on conjugated anti-BCMA antibodies and CAR-T cells, have been developed to fight RRMM. This comprehensive review addresses the fundamentals and controversies regarding RRMM, and discusses the main aspects of management and treatment. The basis for the clinical management of RRMM (complexity of clinical scenarios, key factors to consider before choosing an appropriate treatment, or when to treat), the arsenal of new drugs with no cross resistance with previously administered standard first line regimens (main phase 3 clinical trials), the future outlook including the usefulness of abandoned resources, together with the controversies surrounding the clinical management of RRMM patients will be reviewed in detail.

Ixazomib-lenalidomide-dexamethasone in routine clinical practice: effectiveness in relapsed/refractory multiple myeloma

Aim: To evaluate the effectiveness and safety of ixazomib-lenalidomide-dexamethasone (IRd) in relapsed/refractory multiple myeloma in routine clinical practice. Patients & methods: Patient-level data from the global, observational INSIGHT MM and the Czech Registry of Monoclonal Gammopathies were integrated and analyzed. Results: At data cut-off, 263 patients from 13 countries were included. Median time from diagnosis to start of IRd was 35.8 months; median duration of follow-up was 14.8 months. Overall response rate was 73%, median progression-free survival, 21.2 months and time-to-next therapy, 33.0 months. Ixazomib/lenalidomide dose reductions were required in 17%/36% of patients; 32%/30% of patients discontinued ixazomib/lenalidomide due to adverse events. Conclusion: The effectiveness and safety of IRd in routine clinical practice are comparable to those reported in TOURMALINE-MM1. Clinical trial registration: NCT02761187 (ClinicalTrials.gov).

Improving outcomes for patients with relapsed multiple myeloma: Challenges and considerations of current and emerging treatment options

Despite the recent introduction of new therapies for multiple myeloma (MM), it remains an incurable disease. As MM progresses, patients experience cycles of relapse and remission, with remission periods becoming increasingly shorter as the disease becomes less treatment-sensitive. The treatment of relapsed refractory MM (RRMM) remains a significant clinical challenge. Patients with RRMM are a highly heterogeneous group and choosing the most appropriate treatment requires careful consideration. Furthermore, the number of treatment options for MM is continually growing with no definitive consensus to guide treating clinicians. The emergence of second-generation proteasome inhibitors (e.g., carfilzomib and ixazomib), immunomodulatory drugs (e.g., pomalidomide) and monoclonal antibodies (e.g., isatuximab) has expanded an already complex treatment landscape. This review provides a clear summary of the available treatments for MM and discusses how to tailor treatments to individual patients' needs. Novel treatments currently under clinical development, including venetoclax, melflufen and CAR T-cell therapies, are also discussed.

Survival benefit of ixazomib, lenalidomide and dexamethasone (IRD) over lenalidomide and dexamethasone (Rd) in relapsed and refractory multiple myeloma patients in routine clinical practice

BACKGROUND

We have performed a head to head comparison of all-oral triplet combination of ixazomib, lenalidomide and dexamethasone (IRD) versus lenalidomide and dexamethasone (RD) in patients with relapsed and refractory multiple myeloma (RRMM) in the routine clinical practice.

METHODS

A total of 344 patients treated with IRD (N = 127) or RD (N = 217) were selected for analysis from the Czech Registry of Monoclonal Gammopathies (RMG). Descriptive statistics were used to assess patient's characteristics associated with the respective therapy. The primary endpoint was progression free survival (PFS), secondary end points included response rates and overall survival (OS). Survival endpoints were plotted using Kaplan-Meier methodology at 95% Greenwood confidence interval. Univariable and multivariable Cox proportional hazards models were used to evaluate the effect of treatment regimens and the significance of uneven variables. Statistical tests were performed at significance level 0.05.

RESULTS

In the whole cohort, median PFS for IRD was 17.5 and for RD was 11.5 months favoring the all-oral triplet, p = 0.005; in patients within relapse 1-3, the median PFS was 23.1 vs 11.6 months, p = 0.001. The hazard ratio for PFS was 0.67 (95% confidence interval [CI] 0.51-0.89, p = 0.006). The PFS advantage translated into improved OS for patients treated with IRD, median 36.6 months vs 26.0 months (p = 0.008). The overall response rate (ORR) was 73.0% in the IRD group vs 66.2% in the RD group with a complete response rate (CR) of 11.1% vs 8.8%, and very good partial response (VGPR) 22.2% vs 13.9%, IRD vs RD respectively. The IRD regimen was most beneficial in patients ≤75 years with ISS I, II, and in the first and second relapse. Patients with the presence of extramedullary disease did not benefit from IRD treatment (median PFS 6.5 months). Both regimens were well tolerated, and the incidence of total as well as grade 3/4 toxicities was comparable.

CONCLUSIONS

Our analysis confirms the results of the TOURMALINE-MM1 study and shows benefit of all-oral triplet IRD treatment versus RD doublet. It demonstrates that the addition of ixazomib to RD improves key survival endpoints in patients with RRMM in a routine clinical setting.

Ixazomib, lenalidomide, and dexamethasone is effective and well tolerated in multiply relapsed (≥2nd relapse) refractory myeloma: a multicenter real world UK experience

There are limited real world data on ixazomib, lenalidomide, and dexamethasone (IRd) in multiply relapsed myeloma. We analyzed outcomes of 116 patients who received IRd predominantly at second and subsequent relapse including those refractory to proteasome inhibitors (PIs). With a median follow up 16.3 months, the overall response rate was 66.9%; median progression-free survival (PFS) was 17.7 months with median overall survival (OS) not reached (NR). PFS and OS were significantly shorter in advanced disease (PFS; 12.6 vs. 21.2 months (p = .01), OS; 15.9 months vs. NR (p = .01) for ISS3 vs. ISS 1&2, respectively). PFS and OS were significantly shorter in clinical high risk (CHR) compared to standard risk (SR) patients (PFS; 9.3 months vs. NR (p = .001), OS; 11.5 months vs. NR (p < .001), respectively). There was a trend toward shorter PFS in PI-refractory patients 13.7 vs. 19.6 months for non-PI refractory (p = .2). The triplet combination was generally well tolerated.

Melphalan and Exportin 1 Inhibitors Exert Synergistic Antitumor Effects in Preclinical Models of Human Multiple Myeloma

High-dose chemotherapy with melphalan followed by autologous transplantation is a first-line treatment for multiple myeloma. Here, we present preclinical evidence that this treatment may be significantly improved by the addition of exportin 1 inhibitors (XPO1i). The XPO1i selinexor, eltanexor, and KOS-2464 sensitized human multiple myeloma cells to melphalan. Human 8226 and U266 multiple myeloma cell lines and melphalan-resistant cell lines (8226-LR5 and U266-LR6) were highly sensitized to melphalan by XPO1i. Multiple myeloma cells from newly diagnosed and relapsed/refractory multiple myeloma patients were also sensitized by XPO1i to melphalan. In NOD/SCIDγ mice challenged with either parental 8226 or U266 multiple myeloma and melphalan-resistant multiple myeloma tumors, XPO1i/melphalan combination treatments demonstrated stronger synergistic antitumor effects than single-agent melphalan with minimal toxicity. Synergistic cell death resulted from increased XPO1i/melphalan-induced DNA damage in a dose-dependent manner and decreased DNA repair. In addition, repair of melphalan-induced DNA damage was inhibited by selinexor, which decreased melphalan-induced monoubiquitination of FANCD2 in multiple myeloma cells. Knockdown of FANCD2 was found to replicate the effect of selinexor when used with melphalan, increasing DNA damage (γH2AX) by inhibiting DNA repair. Thus, combination therapies that include selinexor or eltanexor with melphalan may have the potential to improve treatment outcomes of multiple myeloma in melphalan-resistant and newly diagnosed patients. The combination of selinexor and melphalan is currently being investigated in the context of high-dose chemotherapy and autologous transplant (NCT02780609). SIGNIFICANCE: Inhibition of exportin 1 with selinexor synergistically sensitizes human multiple myeloma to melphalan by inhibiting Fanconi anemia pathway-mediated DNA repair.

Multiple myeloma-A painful disease of the bone marrow

Multiple myeloma is a bone marrow neoplasia with an incidence of 6/100,000/year in Europe. While the disease remains incurable, the development of novel treatments such as autologous stem cell transplantation, proteasome inhibitors and monoclonal antibodies has led to an increasing subset of patients living with long-term myeloma. However, more than two thirds of patients suffer from bone pain, often described as severe, and knowledge on the pain mechanisms and its effect on their health-related quality of life (HRQoL) is limited. In this review, we discuss the mechanisms of myeloma bone disease, the currently available anti-myeloma treatments and the lessons learnt from clinical studies regarding HRQoL in myeloma patients. Moreover, we discuss the mechanisms of cancer-induced bone pain and the knowledge that animal models of myeloma-induced bone pain can provide to identify novel analgesic targets. To date, information regarding bone pain and HRQoL in myeloma patients is still scarce and an effort should be made to use standardised questionnaires to assess patient-reported outcomes that allow inter-study comparisons of the available clinical data.

Efficacy of proteasome inhibitor-based maintenance following autologous transplantation in multiple myeloma: A systematic review and meta-analysis

INTRODUCTION

Lenalidomide maintenance, commonly prescribed in the postautologous transplantation (AHCT) setting for multiple myeloma (MM), is associated with development of secondary primary malignancies (SPM). Proteasome inhibitor maintenance (PIM) has also been evaluated in MM. We conduct a systematic review/meta-analysis to assess the efficacy of PIM in MM.

METHODS

Performing a comprehensive search of the medical literature using PubMed/Medline and EMBASE on September 11, 2019, we extracted data on clinical outcomes related to benefits (OS, PFS, and depth of hematologic response [DOHR]) and harms (SPM and adverse events). 2144 references were identified; three studies were eligible for inclusion.

RESULTS

A total of 1760 patients were included in the analysis; 507 patients received bortezomib and 395 received ixazomib maintenance. Control arms were either placebo (n = 261) or thalidomide (n = 358). PIM did not improve OS (HR 0.88, 95% CI 0.73-1.05, P = .15) but improved PFS (HR 0.77, 95% CI 0.69-0.86, P ≤ .00001) and DOHR (HR 0.88, 95% CI 0.79-0.98, P = .02) compared with control. There were no significant differences between PIM and control regarding SPM (p = NS) and ≥grade 3 peripheral neuropathy (PN) (p = NS).

CONCLUSIONS

PIM following AHCT in MM improves PFS and DOHR without an increase in development of SPM or severe PN compared with placebo/thalidomide.

The proteasome as a druggable target with multiple therapeutic potentialities: Cutting and non-cutting edges

Ubiquitin Proteasome System (UPS) is an adaptable and finely tuned system that sustains proteostasis network under a large variety of physiopathological conditions. Its dysregulation is often associated with the onset and progression of human diseases; hence, UPS modulation has emerged as a promising new avenue for the development of treatments of several relevant pathologies, such as cancer and neurodegeneration. The clinical interest in proteasome inhibition has considerably increased after the FDA approval in 2003 of bortezomib for relapsed/refractory multiple myeloma, which is now used in the front-line setting. Thereafter, two other proteasome inhibitors (carfilzomib and ixazomib), designed to overcome resistance to bortezomib, have been approved for treatment-experienced patients, and a variety of novel inhibitors are currently under preclinical and clinical investigation not only for haematological malignancies but also for solid tumours. However, since UPS collapse leads to toxic misfolded proteins accumulation, proteasome is attracting even more interest as a target for the care of neurodegenerative diseases, which are sustained by UPS impairment. Thus, conceptually, proteasome activation represents an innovative and largely unexplored target for drug development. According to a multidisciplinary approach, spanning from chemistry, biochemistry, molecular biology to pharmacology, this review will summarize the most recent available literature regarding different aspects of proteasome biology, focusing on structure, function and regulation of proteasome in physiological and pathological processes, mostly cancer and neurodegenerative diseases, connecting biochemical features and clinical studies of proteasome targeting drugs.

Clinical benefit of ixazomib plus lenalidomide-dexamethasone in myeloma patients with non-canonical NF-κB pathway activation

OBJECTIVES

Evaluating potential relationships between progression-free survival (PFS) and tumor gene expression patterns and mutational status was an exploratory objective of the phase 3 TOURMALINE-MM1 study (NCT01564537) of ixazomib-lenalidomide-dexamethasone (IRd) vs placebo-Rd in 722 patients with relapsed/refractory multiple myeloma (MM).

METHODS

We utilized gene expression and mutation data from screening bone marrow aspirates to identify tumors with non-canonical nuclear factor-κB (NF-κB) signaling pathway activation.

RESULTS

DNA/RNA sequencing data were available for 339 (47.0%)/399 (55.2%) patients; 49/339 (14.5%) patients had non-canonical NF-κB pathway gene mutations (tumor-necrosis-factor receptor-associated factor 2, 3 [TRAF2, TRAF3], baculoviral-inhibitor-of-apoptosis repeat-containing 2/3 [BIRC2/3]), and PFS was significantly longer with IRd vs placebo-Rd in these patients (hazard ratio [HR] 0.23). In patients with lower TRAF3 expression (median not reached vs 11 months, HR 0.47) and higher NF-κB-inducing kinase (NIK) expression (median not reached vs 14 months, HR 0.45), both associated with non-canonical NF-κB pathway activation, PFS was significantly longer with IRd vs placebo-Rd. TRAF3 expression was decreased in patients harboring t(4;14) and 1q21 amplification, suggesting increased non-canonical NF-κB pathway activation.

CONCLUSIONS

Adding ixazomib to Rd provides clinical benefit in MM tumors with increased non-canonical NF-κB pathway activity. This is a potential mechanism for activity in 1q21 amplified high-risk tumors.

c-MYC expression and maturity phenotypes are associated with outcome benefit from addition of ixazomib to lenalidomide-dexamethasone in myeloma

OBJECTIVES

In the TOURMALINE-MM1 phase 3 trial in relapsed/refractory multiple myeloma, ixazomib-lenalidomide-dexamethasone (IRd) showed different magnitudes of progression-free survival (PFS) benefit vs placebo-Rd according to number and type of prior therapies, with greater benefit seen in patients with >1 prior line of therapy or 1 prior line of therapy without stem cell transplantation (SCT).

METHODS

RNA sequencing data were used to investigate the basis of these differences.

RESULTS

The PFS benefit of IRd vs placebo-Rd was greater in patients with tumors expressing high c-MYC levels (median not reached vs 11.3 months; hazard ratio [HR] 0.42; 95% CI, 0.26, 0.66; P < .001) compared with in those expressing low c-MYC levels (median 20.6 vs 16.6 months; HR 0.75; 95% CI, 0.42, 1.2). Expression of c-MYC in tumors varied based on the number and type of prior therapy received, with the lowest levels observed in tumors of patients who had received 1 prior line of therapy including SCT. These tumors also had higher expression levels of CD19 and CD81.

CONCLUSIONS

PFS analyses suggest that lenalidomide and ixazomib target tumors with different levels of c-MYC, CD19, and CD81 expression, thus providing a potential rationale for the differential benefits observed in the TOURMALINE-MM1 study. This trial was registered at www.clinicaltrials.gov as: NCT01564537.

Efficacy of ixazomib for the treatment of relapsed/refractory multiple myeloma: A protocol of systematic review and meta-analysis

BACKGROUND

Over the past years, ixazomib has been increasingly explored for the treatment of relapsed/refractory multiple myeloma (RRMM). However, its results are still contradictory. This study will explore the efficacy and safety of ixazomib for patients with RRMM.

METHODS

A systematic records search of Cochrane Library, PUBMED, EMBASE, CINAHL, ACMD, PsycINFO, WANGFANG, and China National Knowledge Infrastructure will be carried out from their origin to March 31, 2020 with no limitations of language and publication status. Trials will be selected by titles/abstracts, and full manuscripts by 2 independent authors. Data collection will be carried out from eligible trials based on the previous designed criteria. Study quality will be checked using Cochrane risk of bias, and statistical analysis will be administered by RevMan 5.3 software.

RESULTS

This study will summarize the current high-quality trials investigating the efficacy and safety of ixazomib for the treatment of patients with RRMM.

CONCLUSION

The results of this study may provide convinced evidence on the evidence-based medicine level, and guidance for clinical practice and future studies.

INPLASY REGISTRATION NUMBER

INPLASY202040027.

Mass Spectrometry-Based Method Targeting Ig Variable Regions for Assessment of Minimal Residual Disease in Multiple Myeloma

Multiple myeloma is a systemic malignancy of monoclonal plasma cells that accounts for 10% of hematologic cancers. With development of highly effective therapies for multiple myeloma, minimal residual disease (MRD) assessment has emerged as an important end point for management decisions. Currently, serologic assays lack the sensitivity for MRD assessment, and invasive bone marrow sampling with flow cytometry or molecular methods has emerged as the gold standard. We report a sensitive and robust targeted mass spectrometry proteomics method to detect MRD in serum, without the need of invasive, sequential bone marrow aspirates. The method detects Ig-derived clonotypic tryptic peptides predicted by sequencing the clonal plasma cell Ig genes. A heavy isotope-labeled Ig internal standard is added to patient serum at a known concentration, the Ig is enriched in a light chain type specific manner, and proteins are digested and analyzed by targeted mass spectrometry. Peptides from the constant regions of the λ or κ light chains, Ig heavy chains, and clonotypic peptides unique to the patient monoclonal Igs are targeted. This technique is highly sensitive and specific for the patient-specific monoclonal Igs, even in samples negative by multiparametric flow cytometry. Our method can accurately and precisely detect monoclonal protein in serum of patients treated for myeloma and has broad implications for management of hematologic patients.

Real-world effectiveness and safety of ixazomib-lenalidomide-dexamethasone in relapsed/refractory multiple myeloma

Real-world data on regimens for relapsed/refractory multiple myeloma (RRMM) represent an important component of therapeutic decision-making. This multi-centric, retrospective, observational study conducted by the treating physicians evaluated the effectiveness and safety of ixazomib-lenalidomide-dexamethasone (IRd) in 155 patients who received ixazomib via early access programs in Greece, the UK, and the Czech Republic. Median age was 68 years; 17% had an Eastern Cooperative Oncology Group performance status ≥ 2; median number of prior therapies was 1 (range 1-7); 91%, 47%, and 17% had received prior bortezomib, thalidomide, and lenalidomide, respectively. Median duration of exposure to ixazomib was 9.6 months. Overall response rate was 74%, including 35% very good partial response or better (16% complete response). Median progression-free survival (PFS) was 27.6 months (27.6 and 19.9 months in patients with 1 or > 1 prior lines, respectively). IRd treatment for ≥ 6 months was associated with longer PFS (hazard ratio 0.06). Fourteen patients (9%) discontinued IRd due to adverse events/toxicity in the absence of disease progression. Peripheral neuropathy was reported in 35% of patients (3% grades 3-4). These findings support the results of the phase III TOURMALINE-MM1 trial in a broader real-world RRMM population.

Different roles of bortezomib and ONX 0914 in acute kidney injury

Proteasome inhibitor bortezomib offers one more option for acute or chronic antibody-mediated rejection after kidney transplantation, but aggravated acute kidney injury (AKI) in some cases early after surgery using bortezomib bring new problem. Here, we evaluated the effects of bortezomib and ONX-0914 on renal tubule injury in a mouse model of ischemia-reperfusion injury. After treated with bortezomib, serum creatinine, usea nitrogen and tubular necrosis significantly increased compared with vehicle-treated mice, but decreased in ONX-0914 group mildly. Infiltration of neutrophil and macrophage were less in bortezomib and ONX-0914-treated mice than vehicle-treated group, and the same was observed on oxidative stress in the kidneys. Furthermore, the apoptosis of renal tubular epithelial cells increased in bortezomib-treated mice' kidneys compared with ONX-0914 and vehicle-treated controls. In vitro HK2 cell experiments also demonstrated the proapoptotic effect of bortezomib. The mRNA expression of several proapoptotic factors increased in kidneys of bortezomib-treated mice. In brief, bortezomib, as a proteasome inhibitor, shows a certain cytotoxicity to renal tubular epithelial cell during ischemia/reperfusion injury (IRI) through increased apoptosis. ONX-0914, as an immunoproteasome inhibitor, showed equal potency on anti-inflammation and oxidative stress relieving compared with bortezomib, while less cytotoxicity. The results render the immunoproteasome is a better target for anti-rejection and protecting kidney function in the field of organ transplantation.

How I treat a refractory myeloma patient who is not eligible for a clinical trial

Myeloma patients not eligible for clinical trials have many treatment options. Choosing the next best therapy starts with careful assessment of the biology and dynamics of the disease at relapse, as well as the condition and situation of the patient. Fit patients should be considered for triplet regimens, whereas intermediate and frail patients warrant dose-reduced triplets or doublets. An indolent serologic relapse may be treated with dose intensification, especially in a maintenance situation, whereas a rapid relapse requires a more aggressive approach with drug class change or a second-generation immunomodulatory drug (IMID) or proteasome inhibitor (PI). Monoclonal antibodies, in combination with PIs and IMIDs, have proven highly efficacious in early and late relapse. Key elements of supportive care include infection prevention, bone health, thromboprophylaxis, and management of active symptoms, such as pain and distress.

Real World Efficacy and Safety Results of Ixazomib Lenalidomide and Dexamethasone Combination in Relapsed/Refractory Multiple Myeloma: Data Collected from the Hungarian Ixazomib Named Patient Program

Ixazomib-Revlimid-Dexamethasone is an all-oral treatment protocol for multiple myeloma with a manageable tolerability profile which was available through a named patient program for Hungarian patients from December 2015 to April 2017. We analyzed the clinical characteristics and survival of 77 patients treated at 7 centers within this program. The majority of patients responded, we found complete response in 9, very good partial response in 8, partial response in 32, minor response or stable disease in 13 and progressive disease in 11 patients. Progression free survival was 11.4 months. There was a trend of longer progression free survival in those with 1 vs. >1 prior treatment, with equally good effectivity in standard risk and high risk cytogenetic groups. The adverse events were usually mild, none leading to permanent drug interruptions. There were 5 fatalities: 3 infections and 2 pulmonary embolisms. Our real word data support the use of Ixazomib-Revlimid-Dexamethasone as a highly effective and well tolerated oral treatment protocol for relapsed myeloma.

Lenalidomide Augments the Antitumor Activities of Eps8 Peptide-Specific Cytotoxic T Lymphocytes against Multiple Myeloma

Cancer immunotherapy is a promising new approach to cancer treatment. It has been demonstrated that a high number of tumor-specific cytotoxic T cells (CTL) is associated with increased survival in patients with multiple myeloma. Here, we focused on EGFR pathway substrate 8 (Eps8) as a candidate tumor-associated antigen (TAA) in multiple myeloma. Previous work has shown that Eps8-based immunotherapy in HLA-A2⁺ cancer patients may result in efficient antitumor immune responses against diverse tumor types. To improve immunotherapy for patients with multiple myeloma, we constructed a cocktail vaccine by combining several HLA-A2-restricted epitopes derived from Eps8 (Eps8_cocktail), including Eps8_101-2L (WLQDMILQV), Eps8_276-1Y9V (YLDDIEFFV), and Eps8_455-1Y (YLAESVANV). The CTLs induced by Eps8_cocktail (Eps8_cocktail-CTLs) showed highly effective anti-multiple myeloma activity, including Th1 cytokines production, cell proliferation, and cytotoxicity against HLA-A2⁺ multiple myeloma cells. This study highlights the importance of using a cocktail vaccine instead of a single-peptide vaccine to induce a robust response. Importantly, we revealed that lenalidomide effectively stimulated the antitumor activity of the Eps8_cocktail-CTLs, with increasing expression trends for T-cell markers (CD28, CD40L, 41BB, and OX40). Compared with unstimulated CTLs and Eps8_cocktail-CTLs, lenalidomide-treated Eps8_cocktail-CTLs showed superior anti-multiple myeloma activity in humanized multiple myeloma models, including delaying tumor burden increases due to enhanced immune function. These results provide the framework for an Eps8 cocktail vaccination therapy to induce effective Eps8-specific CTLs in HLA-A2⁺ patients with multiple myeloma. Moreover, these studies further demonstrate that lenalidomide augments the immune response, providing a possibility for its use in combination with peptide vaccines to improve patient outcomes.

A Phase Ib/II Study of Oprozomib in Patients with Advanced Multiple Myeloma and Waldenström Macroglobulinemia

PURPOSE

The oral proteasome inhibitor oprozomib has shown preclinical antitumor activity. Here, we report phase Ib/II study results investigating single-agent oprozomib in patients with relapsed multiple myeloma and Waldenström macroglobulinemia.

PATIENTS AND METHODS

The primary objectives were to determine the MTD, safety, and tolerability of oprozomib (phase Ib) as well as overall response rate (ORR; phase II). Oprozomib was administered once daily on days 1, 2, 8, and 9 (2/7 schedule) or days 1 to 5 (5/14 schedule) of a 14-day cycle.

RESULTS

In patients with multiple myeloma or Waldenström macroglobulinemia (n = 71), the determined MTDs were 300 mg/day (2/7 schedule) and 240 mg/day (5/14 schedule). Median oprozomib treatment duration for patients with multiple myeloma was 11.4 weeks (2/7 schedule, 240/300 mg/day), 5.4 weeks (5/14, 240 mg/day), and 10.1 weeks (5/14, 150/180 mg/day). For patients with Waldenström macroglobulinemia, these values were 34.6 weeks (2/7 schedule, 240/300 mg/day) and 8.1 weeks (5/14 schedule, 240 mg/day). The most common grade ≥3 adverse events (AE) in phase Ib included gastrointestinal and hematologic AEs. Three AE-related deaths in phase II prompted enrollment into 2/7 and 5/14 step-up dosing schedules (240/300 mg/day and 150/180 mg/day, respectively). In phase II, ORRs in 95 response-eligible multiple myeloma patients were 41.0%, 28.1%, and 25.0% in the 2/7, 240/300-mg/day; 5/14, 150/180-mg/day; and 5/14, 240-mg/day cohorts, respectively. ORRs in 31 response-eligible Waldenström macroglobulinemia patients were 71.4% and 47.1% for the 2/7 and 5/14 cohorts, respectively.

CONCLUSIONS

This study demonstrated promising efficacy of single-agent oprozomib in patients with relapsed multiple myeloma and Waldenström macroglobulinemia.

A Practical Review of Proteasome Pharmacology

The ubiquitin proteasome system (UPS) degrades individual proteins in a highly regulated fashion and is responsible for the degradation of misfolded, damaged, or unneeded cellular proteins. During the past 20 years, investigators have established a critical role for the UPS in essentially every cellular process, including cell cycle progression, transcriptional regulation, genome integrity, apoptosis, immune responses, and neuronal plasticity. At the center of the UPS is the proteasome, a large and complex molecular machine containing a multicatalytic protease complex. When the efficiency of this proteostasis system is perturbed, misfolded and damaged protein aggregates can accumulate to toxic levels and cause neuronal dysfunction, which may underlie many neurodegenerative diseases. In addition, many cancers rely on robust proteasome activity for degrading tumor suppressors and cell cycle checkpoint inhibitors necessary for rapid cell division. Thus, proteasome inhibitors have proven clinically useful to treat some types of cancer, especially multiple myeloma. Numerous cellular processes rely on finely tuned proteasome function, making it a crucial target for future therapeutic intervention in many diseases, including neurodegenerative diseases, cystic fibrosis, atherosclerosis, autoimmune diseases, diabetes, and cancer. In this review, we discuss the structure and function of the proteasome, the mechanisms of action of different proteasome inhibitors, various techniques to evaluate proteasome function in vitro and in vivo, proteasome inhibitors in preclinical and clinical development, and the feasibility for pharmacological activation of the proteasome to potentially treat neurodegenerative disease.

Ixazomib, lenalidomide, and dexamethasone in patients with newly diagnosed multiple myeloma: long-term follow-up including ixazomib maintenance

Triplet combinations containing a proteasome inhibitor are a standard of care in newly diagnosed multiple myeloma (NDMM). We examined the long-term efficacy and safety of the all-oral combination of weekly ixazomib plus lenalidomide-dexamethasone (IRd), followed by single-agent ixazomib maintenance in NDMM patients. Of 65 enrolled patients, 53 received ixazomib 4 mg (days 1, 8, and 15) plus lenalidomide 25 mg (days 1–21) and dexamethasone 40 mg (days 1, 8, 15, and 22) for up to twelve 28-day induction cycles. Twenty-three patients discontinued induction for stem cell transplantation (SCT). In the remaining 42 patients, overall response rate was 80%, including 63% ≥very good partial response (VGPR) and 32% complete responses. At a median follow-up of 56 months, median progression-free survival (PFS) was 35.4 months in the total population. Twenty-five patients received ixazomib maintenance; eight deepened their response (76% ≥VGPR), and median PFS was 37.2 months in this subgroup. Nine of 42 patients who did not proceed to SCT (14% of total population) had an adverse event requiring discontinuation. Ixazomib (median ≥ 96%) and lenalidomide (median 88–94%) relative dose intensities were maintained throughout treatment. Weekly IRd, followed by ixazomib maintenance, was highly active with acceptable toxicity, enabling long-term administration with no evidence of cumulative toxicities.

New proteasome inhibitors in the treatment of multiple myeloma

The treatment of patients with relapsed and/or refractory multiple myeloma has improved considerably in the last 15 years, after the introduction of proteasome inhibitors and immunomodulatory drugs. The first clinical trials with new proteasome inhibitors have produced exciting results, particularly those comparing triplet regimens with standard doublet regimens, with a gain in progression-free survival accompanied by an acceptable safety profile and either similar or better health-related quality of life. New proteasome inhibitors hold the potential to fill unmet needs in multiple myeloma management regarding improvement of clinical outcomes, including delayed progression of disease in high-risk patients. This review summarizes the main pharmacological properties and clinical outcomes of these agents, and discusses their potential to change the whole multiple myeloma therapeutic landscape.

Curcumin-induced promoter hypermethylation of the mammalian target of rapamycin gene in multiple myeloma cells

Curcumin, a polyphenol derived from the rhizome of Curcuma, is a potential tumor inhibitor through affecting signaling pathways and epigenetic regulation. The mammalian target of rapamycin (mTOR) gene serves a crucial role in the carcinogenesis of multiple myeloma. The curcumin-induced epigenetic regulation of mTOR, including promoter DNA methylation in multiple myeloma, has not yet been fully elucidated. In the present study, antitumor effects of curcumin were investigated in RPMI-8226 and NCI-H929 cells using an MTT assay and flow cytometry. The expression of mTOR and DNA methyltransferase proteins were determined by western blot analysis, and the methylation status of the mTOR promoter were detected by sequencing following bisulfite conversion. The results of the present study revealed that the half-maximal inhibitory concentration of curcumin was 10 µM in myeloma cells. Following curcumin treatment, the mRNA and protein expression levels of mTOR were decreased by 43.31 and 39.34% in NCI-H929 cells, respectively. The promoter of mTOR, located in chromosome 1 (chromosome position, 11262153-11263153), contains a CpG island that was hypermethylated in myeloma cells following curcumin treatment. The expression levels of DNA methyltransferase (DNMT)3a and DNMT3b were increased in curcumin-treated cells. Collectively, these results indicate that curcumin serves a role in the epigenetic regulation of mTOR expression, and that mTOR downregulation is due to promoter hypermethylation, which may be associated with DNMT3a and DNMT3b upregulation. The results of the present study contribute towards improving the understanding of curcumin treatment in multiple myeloma and provide novel insights into the molecular mechanisms underlying the epigenetic regulation of mTOR.

Ixazomib promotes CHOP-dependent DR5 induction and apoptosis in colorectal cancer cells

BACKGROUND

Ixazomib (Ninlaro), a novel proteasome inhibitor, has been developed for the treatment of many cancers and has demonstrated anti-tumor efficacy against various malignancies. However, the mechanism of the anti-tumor effect of ixazomib in colorectal cancer (CRC) cells remains unclear.

METHODS

MTS and flow cytometry were performed to determine the effect of ixazomib on CRC cells. Western blotting and real-time RT-PCR were performed to detect ixazomib-induced DR5 upregulation. ChIP was performed to detect CHOP binding to DR5 promoter. Finally, xenograft experiments were carried out to measure the antitumor effect of ixazomib in vivo.

RESULTS

In this study, we revealed the mechanism by which ixazomib inhibits the growth of CRC cells. Our findings indicated that ixazomib treatment induces CHOP-dependent DR5 induction, irrespective of p53 status. Furthermore, DR5 is necessary for ixazomib-mediated apoptosis. Ixazomib also synergized with TRAIL to induce marked apoptosis via DR5 in CRC cells.

CONCLUSIONS

Our findings further suggested that ixazomib sensitizes TRAIL/death receptor signaling pathway-targeted CRC and suggested that DR5 induction could be a valuable indicator of ixazomib sensitivity.

Is re-challenge still an option as salvage therapy in multiple myeloma? The case of REal-life BOrtezomib re-Use as secoND treatment for relapsed patients exposed frontline to bortezomib-based therapies (the REBOUND Study)

Therapeutic re-challenge is currently a debated issue in the field of multiple myeloma (MM), given the recent availability of several new drugs and combinations. However, very few specific evidences are available about bortezomib re-use at first relapse. This multicenter, observational, retrospective study enrolled 134 MM patients with significant response after bortezomib-based frontline regimens and who had received a first salvage treatment containing bortezomib at relapse. The overall response rate was 71%, including 40% partial responses, 24% very good partial responses, and 7% complete responses. Re-treatment was well-tolerated, with no significant new or unexpected toxicities observed. The median duration of second progression-free survival (PFS) was 15 months, while median PFS2 was 55 months. With a median follow-up of 56 months, overall survival was 94 months for the entire series, without significant differences between patients undergoing or not undergoing transplant procedures. This real-life survey indicates that re-treatment including bortezomib as a first salvage therapy could be still considered in MM patients achieving durable response after initial exposure to bortezomib.

Healthcare resource utilization with ixazomib or placebo plus lenalidomide-dexamethasone in the randomized, double-blind, phase 3 TOURMALINE-MM1 study in relapsed/refractory multiple myeloma

AIMS

The aim of this analysis was to assess healthcare resource utilization in the pivotal phase 3 TOURMALINE-MM1 study of the oral proteasome inhibitor ixazomib or placebo plus lenalidomide and dexamethasone (Rd) in relapsed and/or refractory multiple myeloma (RRMM).

METHODS

In this double-blind, placebo-controlled, randomized study (NCT01564537), 722 patients with RRMM following 1-3 prior lines of therapy received Rd plus ixazomib (ixazomib-Rd; n = 360) or matching placebo (placebo-Rd; n = 362) until disease progression or unacceptable toxicity. Healthcare resource utilization data were captured on Day 1 of each 28-day cycle, every 4 weeks during follow-up for progression-free survival, and every 12 weeks during subsequent follow-up, and included medical encounters (length of stay, inpatient, outpatient, and reason) and number of missing days from work or other activities for patients and caregivers.

RESULTS

Exposure-adjusted rates of hospitalization were similar between the ixazomib-Rd and placebo-Rd arms, at 0.530 and 0.564 per patient year (ppy), respectively, as were outpatient visit rates (3.305 and 3.355 ppy). Mean length of hospitalization per patient was 10.0 and 10.8 days, respectively. In both arms, hospitalization and outpatient visit rates were higher in patients with two or three prior lines of treatment (ixazomib-Rd: 0.632 and 3.909 ppy; placebo-Rd: 0.774 and 3.539 ppy) compared with patients with one prior line (ixazomib-Rd: 0.460 and 2.888 ppy; placebo-Rd: 0.436 and 3.243 ppy). Patients and their caregivers who missed any work or other activity missed a median of 7 and 5 days in the ixazomib-Rd arm, respectively, vs 8 and 4 days with placebo-Rd.

LIMITATIONS

The study was not powered for a statistical comparison of healthcare resource utilization between treatment arms, nor did it capture costs associated with utilization of the identified healthcare resources.

CONCLUSIONS

This pre-specified analysis demonstrated that the all-oral triplet regimen of ixazomib added to Rd did not increase healthcare resource utilization compared with placebo-Rd.

Ixazomib in the management of relapsed multiple myeloma

The development of proteasome inhibitors contributed to the dramatic life expectancy improvement observed in myeloma patients over the past decades. Ixazomib is a boron-containing selective and reversible proteasome inhibitor that demonstrated antimyeloma activity with excellent safety profile. Ixazomib is the first orally available proteasome inhibitor approved in combination with lenalidomide and dexamethasone for the treatment of myeloma patients who received at least one prior therapy. The present review addresses the current knowledge regarding the clinical use of ixazomib in relapsed myeloma patients.

[Pharmacological characteristics and clinical study results of the oral proteasome inhibitor ixazomib (NINLARO® capsules; 2.3 mg, 3 mg, and 4 mg)]

Ixazomib (Ninlaro^® capsule) is an oral small molecule 20S proteasome inhibitor created by Millennium Pharmaceuticals, Inc (Takeda Oncology Company). Ubiquitin proteasome system is a major regulatory system for maintaining protein homeostasis, and an important mechanism for degrading proteins, such as those involved in proliferation regulation, cell cycle regulation and apoptosis, in cells. Ixazomib selectively and reversibly binds to the β5 subunit of the 20S proteasome, inhibits its chymotrypsin-like activity, and thereby accumulates ubiquitinated proteins. It induces ER stress and apoptosis of myeloma cells. The phase 3, randomized, double-blind, multicenter global study (TOURMALINE-MM1) in patients with relapsed and/or refractory multiple myeloma, who have received 1 to 3 prior lines of therapy, showed that addition of ixazomib to lenalidomide-dexamethasone (ixazomib-Rd) demonstrated significant improvement in progression-free survival (hazard ratio = 0.742, P = 0.012) versus placebo-Rd (20.6 vs. 14.7 months in the median) (data cut-off as of October 30, 2014). Ixazomib has been approved by the United States Food and Drug Administration in November 2015, and the European Medicines Agency in November 2016 for the treatment of multiple myeloma (MM) patients who have received at least one prior therapy. In Japan, ixazomib was approved for the treatment of relapsed and/or refractory MM in March, 2017. It is expected to demonstrate that the oral proteasome inhibitor ixazomib is an effective and convenient treatment option in clinical practice.