Ixazomib significantly prolongs progression-free survival in high-risk relapsed/refractory myeloma patients

ctDNA improves prognostic prediction for patients with relapsed/refractory MM receiving ixazomib, lenalidomide, and dexamethasone

ABSTRACT

It remains elusive how driver mutations, including those detected in circulating tumor DNA (ctDNA), affect prognosis in relapsed/refractory multiple myeloma (RRMM). Here, we performed targeted-capture sequencing using bone marrow plasma cells (BMPCs) and ctDNA of 261 RRMM cases uniformly treated with ixazomib, lenalidomide, and dexamethasone in a multicenter, prospective, observational study. We detected 24 and 47 recurrently mutated genes in BMPC and ctDNA, respectively. In addition to clonal hematopoiesis-associated mutations, varying proportion of driver mutations, particularly TP53 mutations (59.2% of mutated cases), were present in only ctDNA, suggesting their subclonal origin. In univariable analyses, ctDNA mutations of KRAS, TP53, DIS3, BRAF, NRAS, and ATM were associated with worse progression-free survival (PFS). BMPC mutations of TP53 and KRAS were associated with inferior PFS, whereas KRAS mutations were prognostically relevant only when detected in both BMPC and ctDNA. A total number of ctDNA mutations in the 6 relevant genes was a strong prognostic predictor (2-year PFS rates: 57.3%, 22.7%, and 0% for 0, 1, and ≥2 mutations, respectively) and independent of clinical factors and plasma DNA concentration. Using the number of ctDNA mutations, plasma DNA concentration, and clinical factors, we developed a prognostic index, classifying patients into 3 categories with 2-year PFS rates of 57.9%, 28.6%, and 0%. Serial analysis of ctDNA mutations in 94 cases revealed that TP53 and KRAS mutations frequently emerge after therapy. Thus, we clarify the genetic characteristics and clonal architecture of ctDNA mutations and demonstrate their superiority over BMPC mutations for prognostic prediction in RRMM. This study is a part of the C16042 study, which is registered at www.clinicaltrials.gov as #NCT03433001.

The numerous facets of 1q21+ in multiple myeloma: Pathogenesis, clinicopathological features, prognosis and clinical progress (Review)

Multiple myeloma (MM) is a malignant neoplasm characterized by the clonal proliferation of abnormal plasma cells (PCs) in the bone marrow and recurrent cytogenetic abnormalities. The incidence of MM worldwide is on the rise. 1q21+ has been found in ~30-40% of newly diagnosed MM (NDMM) patients.1q21+ is associated with the pathophysiological mechanisms of disease progression and drug resistance in MM. In the present review, the pathogenesis and clinicopathological features of MM patients with 1q21+ were studied, the key data of 1q21+ on the prognosis of MM patients were summarized, and the clinical treatment significance of MM patients with 1q21+ was clarified, in order to provide reference for clinicians to develop treatment strategies targeting 1q21+.

Anti-CD38 monoclonal antibodies in multiple myeloma with gain/amplification of chromosome arm 1q: a review of the literature

INTRODUCTION

Gain/amplification of 1q (+1q) represents one of the most prevalent cytogenetic abnormalities (CAs) observed in multiple myeloma (MM). Historical studies predating the advent of anti-CD38 monoclonal antibodies (moAbs) implicated + 1q in poor prognoses, prompting its integration into novel staging systems. However, with the emergence of daratumumab and isatuximab, two pivotal anti-CD38 moAbs, the landscape of MM therapy has undergone a profound transformation.

AREAS COVERED

This review encompasses a comprehensive analysis of diverse study methodologies, including observational investigations, clinical trials, meta-analyses, and real-world database analyses. By synthesizing these data sources, we aim to provide an overview of the current understanding of + 1q in the context of anti-CD38 moAbs therapies.

EXPERT OPINION

Despite the paucity of available data, evidence suggests a potential mitigating effect of daratumumab on the adverse prognostic implications of + 1q. However, this benefit seems to diminish in patients harboring ≥ 4 copies or with concurrent high-risk CAs. On the other hand, isatuximab demonstrated promising outcomes in the relapsed-refractory setting for + 1q MM patients. Nevertheless, direct comparison between the two compounds is currently challenging. The current evidence firmly supports the integration of anti-CD38 moAb-based therapies as the standard of care for + 1q patients, pending further elucidation.

Assessment of prolonged proteasome inhibition through ixazomib-based oral regimen on newly diagnosed and first-relapsed multiple myeloma: A real-world Chinese cohort study

OBJECTIVE

To evaluate the effectiveness, safety, and convenience of in-class transition (iCT) from intravenous bortezomib-based induction to ixazomib-based oral regimens.

METHODS

This retrospective real-world study was conducted in 16 Chinese hospitals between October 2017 and April 2023 and analyzed newly diagnosed (NDMM) and first-line relapsed multiple myeloma (FRMM) patients who attained at least a partial response from bortezomib-based induction therapy, followed by an ixazomib-based oral regimen for 2 year or until disease progression or intolerable toxicity.

RESULTS

The study enrolled 199 patients, median age: 63 years old, male 55.4%, 53% as high risk (HR), and 47% as standard risk. Cytogenetic risk stratification by metaphase fluorescence in situ hybridization (M-FISH), based on the Mayo Clinic risk stratification system. The median duration of total PI therapy was 11 months, with ixazomib-based treatment spanning 6 months. At the 20-month median follow-up, 53% of patients remained on therapy. The 24-month PFS rate was 84.3% from the initiation of bortezomib-based induction and 83.4% from the start of ixazomib-based treatment. Overall response rate (ORR) was 100% post-bortezomib induction and 90% following 6 cycles of the ixazomib-based regimen. Based on the Sankey diagrams, 89.51% of patients maintained or improved their disease response after 2 cycles of iCT, 6 cycles (90.14%), and 12 cycles (80%). The HR level of Mayo was found to be a significant independent factor in a worse remission (hazard ratio (HR) 2.55; p = 0.033). Ixazomib's safety profile aligned with previous clinical trial data, with 49% of patients experiencing at least one AE of any grade. The most common AEs included peripheral neuropathy, nausea and vomiting, diarrhea, thrombocytopenia, and granulocytopenia.

CONCLUSION

In the real-world Chinese MM population, NDMM and FRMM patients responded favorably to PI-based continuous therapy, demonstrating substantial response rates. The ixazomib-based iCT allows for sustained PI-based treatment, offering promising efficacy and tolerable AEs.

Minor clone of del(17p) provides a reservoir for relapse in multiple myeloma

The deletion of chromosome 17p (del(17p)) is considered a crucial prognostic factor at the time of diagnosis in patients with multiple myeloma (MM). However, the impact of del(17p) on survival at different clonal sizes at relapse, as well as the patterns of clonal evolution between diagnosis and relapse and their prognostic value, has not been well described. To address these issues, we analyzed the interphase fluorescence in situ hybridization (iFISH) results of 995 newly diagnosed MM (NDMM) patients and 293 patients with MM at their first relapse. Among these patients, 197 had paired iFISH data at diagnosis and first relapse. Our analysis of paired iFISH revealed that a minor clone of del(17p) at relapse but not at diagnosis was associated with poor prognosis in MM (hazard ratio for median overall survival 1.64 vs. 1.44). Fifty-six and 12 patients developed one or more new cytogenetic abnormalities at relapse, mainly del(17p) and gain/amp(1q), respectively. We classified the patients into six groups based on the change patterns in the clonal size of del(17p) between the two time points. Patients who did not have del(17p) during follow-up showed the best outcomes, whereas those who acquired del(17p) during their disease course, experienced compromised survival (median overall survival: 61.3 vs. 49.4 months; hazard ratio =1.64; 95% confidence interval: 1.06-2.56; P<0.05). In conclusion, our data confirmed the adverse impact of a minor clone of del(17p) at relapse and highlighted the importance of designing optimal therapeutic strategies to eliminate high-risk cytogenetic abnormalities (clinicaltrials gov. identifier: NCT04645199).

A prospective, multicenter, observational study of ixazomib plus lenalidomide-dexamethasone in patients with relapsed/refractory multiple myeloma in Japan

Real-world studies permit inclusion of a more diverse patient population and provide more information on the effectiveness of treatments used in routine clinical practice. This prospective, multicenter, observational study investigated the effectiveness and safety of ixazomib plus lenalidomide and dexamethasone (IRd) in 295 patients with relapsed/refractory multiple myeloma (RRMM) in routine clinical practice in Japan. Patients had a median age of 74 years, 80.0% were aged ≥ 65 years, 42.0% had received ≥ 3 lines of prior treatment, and 28.5% were "frail" according to the International Myeloma Working Group frailty score. After a median follow-up of 25.0 months, median progression-free survival (PFS) was 15.3 (95% CI 12.4-19.5) months, while median overall survival was not reached. The overall response rate was 53.9%, and 31.5% of patients had a very good partial response or better. In the subgroup analysis, median PFS was better in patients with 1 versus 2 or ≥ 3 lines of prior treatment (29.0 vs 19.2 or 6.9 months) and paraprotein versus clinical relapse (16.0 vs 7.9 months), but median PFS was not notably affected by frailty score or age group. Dose adjustment was more frequent among patients aged > 75 years, especially early after IRd treatment initiation. Treatment-emergent adverse events (TEAEs) of any grade occurred in 84.4% of patients and 24.7% of patients discontinued treatment due to TEAEs; no new safety concerns were found. These findings suggest that oral IRd triplet regimen is an effective and tolerable treatment option for RRMM patients in real-world settings outside of clinical trials.ClinicalTrials.gov identifier: NCT03433001; Date of registration: 14 February 2018.

Difficult-to-treat patients with relapsed/refractory multiple myeloma: A review of clinical trial results

Overall outcomes for multiple myeloma have improved due to the availability of new therapies, but patients with relapsed/refractory multiple myeloma harbouring certain factors continue to pose a therapeutic challenge. These challenging features include high-risk cytogenetics, renal impairment, patient characteristics such as age and frailty, and extramedullary disease. Prior refractory status and number of prior lines add further complexity to the treatment of these patients. While newer regimens are available and have suggested efficacy in these patient populations through subgroup analyses, differences in trial definitions and cut-offs make meaningful comparisons difficult. This review aims to examine the available clinical trial data for patients with high-risk cytogenetics, renal impairment, age and frailty and extramedullary disease.

Pathogenesis, clinical characteristics and personalized managements of multiple myeloma with chromosome 1 abnormalities

Multiple myeloma (MM) is a biologically heterogeneous malignancy defined by the proliferation of monoclonal plasma cells. Despite the tremendous advancement in MM treatment over the past decades, relapse remains a major problem which is inevitable for most patients. In particular, a partial of patients with early relapse and poor outcomes are classified as a high-risk group. Apart from the clinical stage, genetic aberrations are now recognized as important prognostic factors for identifying high-risk patients. Chromosome 1 abnormalities (C1As), particularly 1q21 gain or amplification, have been identified as common genetic aberrations in patients with MM and are often considered unfavorable prognostic markers for progression-free survival and overall survival. However, more effective therapeutic approaches are still needed to overcome the negative impact of C1As. Therefore, we summarize the prevalence, pathogenesis, clinical significance and present therapeutic condition of C1As in MM, and attempt to conclude the precise and personalized management for patients with C1As.

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.

A pooled analysis of outcomes according to cytogenetic abnormalities in patients receiving ixazomib- vs placebo-based therapy for multiple myeloma

Some cytogenetic abnormalities (CAs) are associated with poorer prognosis in multiple myeloma (MM); proteasome inhibitors appear to benefit patients with high-risk CAs. We evaluated 2247 MM patients from the TOURMALINE-MM1/-MM2/-MM3/-MM4 trials to assess the PFS benefit of ixazomib plus lenalidomide-dexamethasone (Rd) vs placebo-Rd (TOURMALINE-MM1/-MM2) or ixazomib vs placebo (TOURMALINE-MM3/-MM4) in specific high-risk CAs. After a pooled median follow-up of 25.6 months, the hazard ratio (HR) for PFS with ixazomib- vs placebo-based therapy for high-risk patients was 0.74 (95% confidence interval [CI]: 0.59-0.93; median PFS [mPFS] 17.8 vs 13.2 months), and 0.70 (95% CI: 0.62-0.80; mPFS 26.3 vs 17.6 months) for complementary standard-risk patients. The HR for expanded high-risk patients was 0.75 (95% CI: 0.64-0.87; mPFS 18.1 vs 14.1 months), and 0.71 (95% CI: 0.59-0.85; mPFS 36.1 vs 21.4 months) for complementary standard-risk patients. The HR for PFS with ixazomib- vs placebo-based therapy was 0.68 in patients with t(4;14) (95% CI: 0.48-0.96; mPFS 22.4 vs 13.2 months), and 0.77 for patients with amp1q21 (95% CI: 0.63-0.93; mPFS 18.8 vs 14.5 months). A PFS benefit was demonstrated with ixazomib- vs placebo-based therapy regardless of cytogenetic status, with greatest benefit observed in patients with t(4;14) and amp1q21.

Carfilzomib induction, consolidation, and maintenance with or without autologous stem-cell transplantation in patients with newly diagnosed multiple myeloma: pre-planned cytogenetic subgroup analysis of the randomised, phase 2 FORTE trial

BACKGROUND

Patients with newly diagnosed multiple myeloma and high-risk cytogenetic abnormalities (HRCA) represent an unmet medical need. In the FORTE trial, lenalidomide and dexamethasone plus carfilzomib (KRd) induction resulted in a higher proportion of patients with at least a very good partial response as compared with carfilzomib, cyclophosphamide, and dexamethasone (KCd), and carfilzomib plus lenalidomide maintenance prolonged progression-free survival compared with lenalidomide maintenance. In this prespecified analysis of the FORTE trial, we described the outcomes of enrolled patients according to their cytogenetic risk.

METHODS

The UNITO-MM-01/FORTE was a randomised, open-label, phase 2 trial done at 42 Italian academic and community practice centres, which enrolled transplant-eligible patients with newly diagnosed multiple myeloma aged 18-65 years. Eligible patients had newly diagnosed multiple myeloma based on standard International Myeloma Working Group criteria, a Karnofsky performance status of at least 60%, and had not received any previous treatment with anti-myeloma therapy. At enrolment, patients were stratified according to International Staging System stage (I vs II/III) and age (<60 years vs 60-65 years) and randomly assigned (1:1:1) to KRd plus autologous stem-cell transplantation (ASCT; four 28-day induction cycles with KRd, melphalan at 200 mg/m² and ASCT [MEL200-ASCT], followed by four 28-day KRd consolidation cycles), 12 28-day KRd cycles, or KCd plus ASCT (four 28-day induction cycles with KCd, MEL200-ASCT, and four 28-day KCd consolidation cycles), using a web-based system (block randomisation, block size of 12). Carfilzomib was administered at 20 mg/m² on days 1 and 2 of cycle 1, followed by 36 mg/m² intravenously administered on days 8, 9, 15, and 16 of cycle 1, and then 36 mg/m² intravenously administered for all subsequent doses on days 1, 2, 8, 9, 15, 16; lenalidomide 25 mg was administered orally on days 1-21; cyclophosphamide 300 mg/m² was administered orally on days 1, 8, and 15; and dexamethasone 20 mg was administered orally or intravenously on days 1, 2, 8, 9, 15, 16, 22, and 23. After the consolidation phase, patients were stratified according to induction-consolidation treatment and randomly assigned (1:1; block size of 8) to maintenance treatment with carfilzomib plus lenalidomide or lenalidomide alone. Carfilzomib 36 mg/m² was administered intravenously on days 1-2 and days 15-16, every 28 days for up to 2 years, and lenalidomide 10 mg was administered orally on days 1-21 every 28 days until progression or intolerance in both groups. The primary endpoints were the proportion of patients with at least a very good partial response after induction with KRd versus KCd and progression-free survival with carfilzomib plus lenalidomide versus lenalidomide alone as maintenance treatment. In this preplanned analysis, we included patients enrolled in the FORTE trial with complete cytogenetic data on del(17p), t(4;14), t(14;16), del(1p), gain(1q) (3 copies), and amp(1q) (≥4 copies) assessed by fluorescence in-situ hybridisation analysis on CD138-positive sorted cells. We assessed progression-free survival, overall survival, minimal residual disease negativity, and 1-year sustained minimal residual disease negativity according to the presence of zero, one, and two or more HRCA across treatment groups. The FORTE trial is ongoing, and registered with ClinicalTrials.gov, NCT02203643.

FINDINGS

Between Feb 23, 2015, and April 5, 2017, 477 patients were enrolled, of whom 396 (83%) had complete cytogenetic data and were analysed (176 [44%] of whom were women and 220 [56%] were men). The median follow-up from first randomisation was 51 months (IQR 46-56). 4-year progression-free survival was 71% (95% CI 64-78) in patients with zero HRCA, 60% (95% CI 52-69) in patients with one HRCA, and 39% (95% CI 30-50) in patients with two or more HRCA. Compared with patients with zero HRCA, the risk of progression or death was similar in patients with one HRCA (hazard ratio [HR] 1·33 [95% CI 0·90-1·97]; p=0·15) and higher in patients with two or more HRCA (HR 2·56 [95% CI 1·74-3·75]); p<0·0001) across the induction-intensification-consolidation groups. Moreover, the risk of progression or death was also higher in patients with two or more HRCA versus those with one HRCA (HR 1·92 [95% CI 1·34-2·76]; p=0·0004). 4-year overall survival from the first randomisation was 94% (95% CI 91-98) in patients with zero HRCA, 83% (95% CI 76-90) in patients with one HRCA, and 63% (95% CI 54-74) in patients with two or more HRCA. Compared with patients with zero HRCA, the risk of death was significantly higher in patients with one HRCA (HR 2·55 [95% CI 1·22-5·36]; p=0·013) and two or more HRCA (HR 6·53 [95% CI 3·24-13·18]; p<0·0001). Patients with two or more HRCA also had a significantly higher risk of death than those with one HRCA (HR 2·56 [95% CI 1·53-4·28]; p=0·0004). The rates of 1-year sustained minimal residual disease negativity were similar in patients with zero HRCA (53 [35%] of 153] and with one HRCA (57 [41%] of 138) and were lower in patients with two or more HRCA (25 [24%] of 105). The median duration of follow-up from second randomisation was 37 months (IQR 33-42). 3-year progression-free survival from the second randomisation was 80% (95% CI 74-88) in patients with zero HRCA, 68% (95% CI 59-78) in patients with one HRCA, and 53% (95% CI 42-67) in patients with two or more HRCA. The risk of progression or death was higher in patients with one HRCA (HR 1·68 [95% CI 1·01-2·80]; p=0·048) and two or more HRCA (2·74 [95% CI 1·60-4·69], p=0·0003) than in patients with zero HRCA.

INTERPRETATION

This preplanned analysis of the FORTE trial showed that carfilzomib-based induction-intensification-consolidation regimens are effective strategies in patients with standard risk (zero HRCA) and high-risk (one HRCA) myeloma, resulting in similar rates of progression-free survival and 1-year sustained minimal residual disease negativity. Despite promising progression-free survival, patients with ultra-high-risk disease (those with 2 or more HRCA) still have an increased risk of progression and death and therefore represent an unmet medical need.

FUNDING

Amgen and Celgene/Bristol Myers Squibb.

How to Manage Patients with Lenalidomide-Refractory Multiple Myeloma

Although lenalidomide-based combinations, such as lenalidomide plus a proteasome inhibitor or an anti-CD38 monoclonal antibody, improve the overall response rate, progression-free survival, and overall survival of patients with relapsed/refractory multiple myeloma (RRMM), there is a tendency to use these regimens as a frontline treatment. This strategy has led to the development of refractoriness early in the disease course, usually after the patient's first treatment. Since lenalidomide-free regimens have so far shown limited efficacy in lenalidomide-refractory patients, there is an unmet need for other treatment options. In this review, we discuss the therapeutic options available to treat the general population of lenalidomide-refractory patients (mono, double and triple refractory) and the subpopulation of patients with other high-risk features such as renal failure, extramedullary disease, and high-risk cytogenetics. Moreover, new promising individual therapies and the possible impact of immunotherapy in RRMM patients are debated.

The first relapse in multiple myeloma: how to pick the next best thing

The choice of treatment for patients with multiple myeloma (MM) at first relapse/progression is based on many factors: (1) treatment-related factors, which include the regimen used during first induction, the quality and duration of first response achieved, toxicities from the first treatment, whether the patient underwent autologous stem cell transplant, and whether the patient was on maintenance at the time of relapse/progression; (2) disease-related factors, including disease presentation and pace of progression; and (3) patient-related factors, including functional age and performance status. The learning objectives are to present the treatment options for patients with MM upon their first relapse and to learn about various strategies for selecting an optimal treatment regimen.

Risk and response adapted therapy following autologous stem cell transplant in patients with newly diagnosed multiple myeloma (RADAR (UK-MRA Myeloma XV Trial): study protocol for a phase II/III randomised controlled trial

INTRODUCTION

Multiple myeloma is a plasma cell malignancy that accounts for 1%-2% of newly diagnosed cancers.At diagnosis, approximately 20% of patients can be identified, using cytogenetics, to have inferior survival (high-risk). Additionally, standard-risk patients, with detectable disease (minimal residual disease (MRD)-positive) postautologus stem cell transplant (ASCT), fare worse compared with those who do not (MRD-negative). Research is required to determine whether a risk-adapted approach post-ASCT could further improve patient outcomes.

METHODS

RADAR is a UK, multicentre, risk-adapted, response-guided, open-label, randomised controlled trial for transplant-eligible newly diagnosed multiple myeloma patients, using combinations of lenalidomide (R), cyclophosphamide (Cy), bortezomib (Bor), dexamethasone (D) and isatuximab (Isa).Participants receive RCyBorD(x4) induction therapy, followed by high-dose melphalan and ASCT. Post-ASCT, there are three pathways as follows:A phase III discontinuation design to assess de-escalating therapy in standard-risk MRD-negative patients. Participants receive 12 cycles of Isa maintenance. Those who remain MRD-negative are randomised to either continue or stop treatment.A phase II/III multiarm multistage design to test treatment strategies for treatment escalation in standard-risk MRD-positive patients. Participants are randomised to either; R, RBorD(x4) +R, RIsa, or RBorIsaD(x4) + RIsa.A phase II design to assess the activity of intensive treatment strategies in high-risk patients. Participants are randomised to RBorD(x4) +R or RBorIsaD(x4) + RIsa.1400 participants will be registered to allow for 500, 450 and 172 participants in each pathway. Randomisations are equal and treatment is given until disease progression or intolerance.

ETHICS AND DISSEMINATION

Ethical approval was granted by the London-Central Research Ethics Committee (20/LO/0238) and capacity and capability confirmed by the appropriate local research and development department for each participating centre prior to opening recruitment. Participant informed consent is required before trial registration and reconfirmed post-ASCT. Results will be disseminated by conference presentations and peer-reviewed publications.

TRIAL REGISTRATION NUMBER

ISCRTN46841867.

Population pharmacokinetic/pharmacodynamic joint modeling of ixazomib efficacy and safety using data from the pivotal phase III TOURMALINE‐MM1 study in multiple myeloma patients

Ixazomib is an oral proteasome inhibitor approved in combination with lenalidomide and dexamethasone for the treatment of relapsed/refractory multiple myeloma (MM). Approval in the United States, Europe, and additional countries was based on results from the phase III TOURMALINE‐MM1 (C16010) study. Here, joint population pharmacokinetic/pharmacodynamic time‐to‐event (TTE) and discrete time Markov models were developed to describe key safety (rash and diarrhea events, and platelet counts) and efficacy (myeloma protein [M‐protein] and progression‐free survival [PFS]) outcomes observed in TOURMALINE‐MM1. Models reliably described observed safety and efficacy results; prior immunomodulatory drug therapy and race were significant covariates for diarrhea and rash events, respectively, whereas M‐protein dynamics were sufficiently characterized using TTE models of relapse and dropout. Moreover, baseline M‐protein was identified as a significant covariate for observed PFS. The developed framework represents an integrated approach to describing safety and efficacy with MM therapy, enabling the simulation of prospective trials and potential alternate dosing regimens.

The Importance of FISH Signal Cut-off Value and Copy Number Variation for 1q21 in Newly Diagnosed Multiple Myeloma: Is it Underestimated?

BACKGROUND

The cut-off value for gain/amplification of 1q21(1q21+) was 20% according to the recommendations of the European Myeloma Network and there were limited studies concerning less than 20%. Meanwhile, the copy number variation of 1q21+ remains controversial. Our purpose was to evaluate the significance of clone size and copy numbers of 1q21+ in Chinese newly diagnosed multiple myeloma (NDMM).

PATIENTS AND METHODS

We retrospectively analyzed 161 consecutive NDMM patients who were tested for common cytogenetic abnormalities at diagnosis by fluorescence in-situ hybridization and 5% was set for the threshold for 1q21+ by a comparative study.

RESULTS

Ninety-six (59.6%) patients were determined for 1q21+ by fluorescence in-situ hybridization including 38 had ≥4 copies. In clone size analyses, the 2-year progression-free survival (PFS) in <5% group was superior in comparison with 5% to 20% (65.2% vs. 47.0%, P = .041) and >20% group (65.2% vs. 37.5%, P < .001), whereas there was no significant difference between the 2 latter groups. Patients with ≥ 4 copies of 1q21 had inferior 2-year PFS compared to patients with 3 copies (23.3% vs. 50.6%, P = .028) and 2 copies (23.3% vs. 65.2%, P < .001). Bortezomib-based treatment might benefit the PFS for patients with 3 copies but could not improve the adverse effect of ≥ 4 copies. 1q21+ was an independent risk factor for inferior PFS and OS in multivariate analysis (P < .001 and P = .028).

CONCLUSION

Our results demonstrated that 5% was a reliable cut-off value for 1q21+, and 1q21+ was an adverse prognostic factor in NDMM, especially when ≥ 4 copies were present.

Pathogenesis and treatment of multiple myeloma

Multiple myeloma (MM) is the second‐ranking malignancy in hematological tumors. The pathogenesis of MM is complex with high heterogeneity, and the development of the disease is a multistep process. Chromosomal translocations, aneuploidy, genetic mutations, and epigenetic aberrations are essential in disease initiation and progression. The correlation between MM cells and the bone marrow microenvironment is associated with the survival, progression, migration, and drug resistance of MM cells. In recent decades, there has been a significant change in the paradigm for the management of MM. With the development of proteasome inhibitors, immunomodulatory drugs, monoclonal antibodies, chimeric antigen receptor T‐cell therapies, and novel agents, the survival of MM patients has been significantly improved. In addition, nanotechnology acts as both a nanocarrier and a treatment tool for MM. The properties and responsive conditions of nanomedicine can be tailored to reach different goals. Nanomedicine with a precise targeting property has offered great potential for drug delivery and assisted in tumor immunotherapy. In this review, we summarize the pathogenesis and current treatment options of MM, then overview recent advances in nanomedicine‐based systems, aiming to provide more insights into the treatment of MM.

Update on primary plasma cell leukemia

Plasma cell leukemia (PCL) is a rare and highly aggressive plasma cell neoplasm developing in 0.5?4% of patients with multiple myeloma (MM). The diagnostic criteria were recently revised from 20% to ≥5% of circulating plasma cells in peripheral blood smears. PCL is classified as primary or secondary; primary PCL is when it presents in patients with no MM. Primary PCL shows clinical and laboratory features at presentation that differ from MM and exhibits a dismal prognosis even with the use of effective agents against MM. Therefore, intensive chemotherapy should be initiated immediately after diagnosis, and autologous stem cell transplantation is recommended for transplant-eligible patients. Maintenance therapy after transplantation may reduce the rate of early relapses. We reviewed the definitions of PCL, revised diagnostic criteria, clinical features, and appropriate initial treatments for primary PCL.

Efficacy and follow-up of humanized anti-BCMA CAR-T cell therapy in relapsed/refractory multiple myeloma patients with extramedullary-extraosseous, extramedullary-bone related, and without extramedullary disease

The prognosis of patients with multiple myeloma (MM) with extramedullary disease (EMD) remains poor. A high overall response rate (ORR) has been reported following anti‐B‐cell maturation antigen (BCMA) chimeric antigen receptor (CAR)‐T cell therapy in relapsed/refractory (R/R) patients with MM; however, data on patients with EMD remain limited. Herein, we compared and analyzed the efficacy and long‐term follow‐up of anti‐BCMA CAR‐T cell therapy in R/R MM patients with extramedullary‐extraosseous (EM‐E), extramedullary‐bone related (EM‐B), and without extramedullary disease. No difference in the ORR was observed between the three groups. The long‐term efficacy of anti‐BCMA CAR‐T cell therapy in the EM‐E group was worse than that in patients without EMD and with EM‐B. In the EM‐E group, disease progression was the reappearance of extramedullary lesions without an increase in the MM cell percentage or M protein level. Although no difference in the proportion of CAR‐T cells was detected among the three groups, the EM‐E group might exhibit a relatively high grade of cytokine release syndrome following anti‐BCMA CAR‐T therapy. Interleukin‐6 levels in the without EMD group were lower than those in the EM‐E and EM‐B groups. However, given the small number of cases in the three groups, statistical analysis was not performed.(ChiCTR1800017051 and ChiCTR2000033925).

Efficacy and safety of ixazomib maintenance therapy for patients with multiple myeloma: a meta-analysis

OBJECTIVES

Multiple myeloma(MM) is a malignant plasma cell disease. Maintenance treatment is beneficial to prolong survival time in patients with MM. Ixazomib was approved for the treatment of relapsed or refractory MM in combination with lenalidomide and dexamethasone. Here, we carried out a meta-analysis to determine the efficacy and safety of ixazomib maintenance therapy.

METHODS

Several databases were searched including PubMed, Web of Science, Embase, the Cochrane Library, etc. The last search dated back to July, 2020. Three clinical trials with a total of 1440 participants with newly diagnosed MM were included.

RESULTS AND CONCLUSION

The pooled HR of progression-free survival (PFS) was 0.69 (95% CI = 0.59-0.79), which suggested ixazomib maintenance therapy could prolong PFS remarkably. In addition, ixazomib was effective in deepening remission (RR = 1.57, 95% CI = 1.26-1.96). But it could not significantly prolong PFS in cytogenetic high-risk patients (HR = 0.74, 95% CI = 0.47-1.00). In terms of adverse reactions, our analysis revealed higher incidences of grade 3-4 thrombocytopenia (RR = 7.47, 95% CI = 2.06-27.06), neuropathy (RR = 1.48, 95% CI = 1.14-1.92), grade 3-4 infections (RR = 1.77, 95% CI = 1.21-2.59) and gastrointestinal disorders (RR = 1.48, 95% CI = 1.32-1.66). There was no significant correlation between the use of ixazomib and grade 3-4 neutropenia (RR = 1.46, 95% CI = 0.77-2.78, p = 0.25) or the occurrence of new primary malignant tumor (RR = 0.88, 95% CI = 0.53-1.46, p = 0.62). Additionally, more RCTs are needed for better choice of treatment regimen.

How I Treat High-risk Multiple Myeloma

Survival of multiple myeloma (MM) has significantly improved over the last decade; however, a composed group of patients (15-20%), named high-risk (HR) MM, still experience reduced survival. Both tumor biology and suboptimal/absent responses to therapy may underlie HR definition and a clear uniform identification of risk factors is crucial for a proper management of these patients. In biologic-HRMM, MRD negativity attainment and sustain, inside and outside BM, should be the primary goal and therapy should be adapted in patients with frailty to reduce toxicity and improve quality of life. MM treatment has traditionally been tailored on age and more recently frailty or comorbidities, but very rarely on the biology of the disease, mainly because of the lack of a clear benefit derived from a specific drug/combination, inhomogeneity in HR definition and lack of data coming from prospective, properly designed clinical trials. Some attempts have been successfully made recently in this direction. In this review, we are discussing the current different definitions of HR and the need for a consensus, the results of available trials in HR patients and the way through risk-adapted treatment strategies. For this purpose, we are proposing several clinical cases of difficult-to-treat patients throughout different treatment phases.

Chromosomal 1q21 abnormalities in multiple myeloma: a review of translational, clinical research, and therapeutic strategies

INTRODUCTION

Multiple myeloma (MM) remains an incurable disease with a median overall survival of approximately 5 years. Gain or amplification of 1q21 (1q21+) occurs in around 40% of patients with MM and generally portends a poor prognosis. Patients with MM who harbor 1q21+ are at increased risk of drug resistance, disease progression, and death. New pharmacotherapies with novel modes of action are required to overcome the negative prognostic impact of 1q21+. Areas covered: This review discusses the detection, biology, prognosis, and therapeutic targeting of 1q21+ in newly diagnosed and relapsed MM. Patients with MM and 1q21+ tend to present with higher tumor burden, greater end-organ damage, and more co-occurring high-risk cytogenetic abnormalities than patients without 1q21+. The chromosomal rearrangements associated with 1q21+ result in dysregulation of genes involved in oncogenesis. Identification and characterization of the 1q21+ molecular targets are needed to inform on prognosis and treatment strategy. Clinical trial data are emerging that addition of isatuximab to combination therapies may improve outcomes in patients with 1q21+ MM. Expert opinion: In the next 5 years, the results of ongoing research and trials are likely to focus on the therapeutic impact and treatment decisions associated with 1q21+ in MM.

Survival prediction and treatment optimization of multiple myeloma patients using machine-learning models based on clinical and gene expression data

Multiple myeloma (MM) remains mostly an incurable disease with a heterogeneous clinical evolution. Despite the availability of several prognostic scores, substantial room for improvement still exists. Promising results have been obtained by integrating clinical and biochemical data with gene expression profiling (GEP). In this report, we applied machine learning algorithms to MM clinical and RNAseq data collected by the CoMMpass consortium. We created a 50-variable random forests model (IAC-50) that could predict overall survival with high concordance between both training and validation sets (c-indexes, 0.818 and 0.780). This model included the following covariates: patient age, ISS stage, serum B2-microglobulin, first-line treatment, and the expression of 46 genes. Survival predictions for each patient considering the first line of treatment evidenced that those individuals treated with the best-predicted drug combination were significantly less likely to die than patients treated with other schemes. This was particularly important among patients treated with a triplet combination including bortezomib, an immunomodulatory drug (ImiD), and dexamethasone. Finally, the model showed a trend to retain its predictive value in patients with high-risk cytogenetics. In conclusion, we report a predictive model for MM survival based on the integration of clinical, biochemical, and gene expression data with machine learning tools.

Efficacy of Humanized Anti-BCMA CAR T Cell Therapy in Relapsed/Refractory Multiple Myeloma Patients With and Without Extramedullary Disease

In recent years, many new treatments for relapsed/refractory (R/R) multiple myeloma (MM) have improved patient prognosis, but the prognosis of patients with extramedullary MM is still particularly poor. Therefore, more efficacious therapies and novel strategies are urgently needed for these patients. The aim of this study was to observe and compare the efficacy and safety of humanized anti-B cell maturation antigen (anti-BCMA) chimeric antigen receptor (CAR) T cell therapy in R/R MM patients with and without extramedullary disease. Seven R/R MM patients with extramedullary disease and 13 without extramedullary disease received humanized anti-BCMA CAR T cell therapy. The overall response rate was not different between patients with and without extramedullary disease. There was no difference in the progression-free survival (PFS) or overall survival (OS) rates between the two groups at 180 days, but the PFS and OS rates in patients with extramedullary disease were lower at 360 days than those in patients without extramedullary disease. Although some patients with extramedullary disease experienced further disease progression, their M protein level did not increase. We did not see this change trend of M protein in patients without extramedullary disease. However, this was not observed in patients without extramedullary disease. Among patients who responded to CAR T cell therapy, the grades of cytokine release syndrome (CRS) and immune effector cell-associated neurotoxic syndrome (ICANS) were much higher among patients with extramedullary disease. In summary, R/R MM patients with extramedullary disease could benefit from humanized anti-BCMA CAR T cell therapy in the short term, although the CRS and ICANS grades were much higher in patients with extramedullary disease. Therefore, anti-BCMA CAR T cell therapy allows for a remission time for R/R MM patients with extramedullary disease, which could be maintained by bridging hematopoietic stem cell transplantation, radiotherapy, and other therapies.

Clinical Trial Registration

http://www.chictr.org.cn/index.aspx, identifiers ChiCTR1800017051 and ChiCTR2000033925.

[The efficacy and safety profile of ixazomib/lenalidomide/dexamethasone in relapsed/refractory multiple myeloma: a multicenter real-world study in China]

Objective: To evaluate the efficacy and safety profile of ixazomib/lenalidomide/dexamethasone (IRd) in Chinese patients with relapsed/refractory multiple myeloma (MM) . Methods: This study comprising 14 medical centers in China included patients with relapsed/refractory MM who received at least. Ixazomib at an initial oral dose of 4 mg was administered. Seven patients had dose adjustment to 3 mg at the time of first dose. The lenalidomide doses were adjusted according to creatinine clearance rate. The efficacy and safety were evaluated every cycle. Results: In the study cohort of 74 patients, the median age was 65 years and 11 (14.9% ) patients received over three lines of therapy. Overall response rate (ORR) was 54.1% (40/74) , and 7 (9.5% ) , 14 (18.9% ) , and 19 (25.7% ) patients achieved stringent complete response or complete response, very good partial response, and partial response, respectively. The median progression-free survival and overall survival were 9.9 and 20 months, respectively. The median time to response was 1 month. The efficacy and survival outcome were similar to those reported in the Tourmaline-MM1 China Continuous Study. The ORR of patients refractory to bortezomib, lenalidomide, and bortezomib plus lenalidomide were 52.0% (13/25) , 57.1% (4/7) , and 33.3% (6/18) , respectively. The rate of grade 3-4 adverse events was 36.5% (27/74) . Common hematological toxicities were anemia, thrombocytopenia, lymphopenia, and neutropenia. Common non-hematological toxicities were fatigue, gastrointestinal symptoms, and infections. Two cases of grade 3 peripheral neuropathy were reported. The patients eligible for the Tourmaline-MM1 China Continuous Study had a higher ORR than the ineligible patients [77.8% (14/18) vs 46.4% (26/56) , P=0.020]. There was no difference in the rate of grade 3-4 adverse events [33.3% (6/18) vs 37.5% (21/56) , P=0.749]. Conclusion: The IRd regimen had good efficacy and acceptable toxicity in Chinese patients with relapsed/refractory MM.

Autologous Stem-Cell Transplantation for Multiple Myeloma in the Era of Novel Therapies

Despite the evolution of the therapeutic arsenal for the treatment of multiple myeloma (MM) over the past decade, autologous stem-cell transplantation (ASCT) remains an integral part of the treatment of patients with both newly diagnosed and relapsed MM. The advent of novel therapies, such as immunomodulatory agents, proteasome inhibitors, and monoclonal antibodies, has led to unprecedented levels of deep hematologic responses. Nonetheless, studies show that ASCT has an additive effect leading to additional deepening of responses. As the therapeutic agents for MM continue to evolve, the timing, duration, and sequence of their use in combination with ASCT will be crucial to understand to obtain the deepest response and survival benefit for patients with MM. This review aims to discuss the role of ASCT for the management of MM, with a particular focus on the role of ASCT in the context of novel therapies and minimal residual disease.

Final Overall Survival Analysis of the TOURMALINE-MM1 Phase III Trial of Ixazomib, Lenalidomide, and Dexamethasone in Patients With Relapsed or Refractory Multiple Myeloma

PURPOSE

The double-blind, placebo-controlled, phase III TOURMALINE-MM1 study demonstrated a statistically significant improvement in progression-free survival with ixazomib-lenalidomide-dexamethasone (ixazomib-Rd) versus placebo-Rd in patients with relapsed or refractory multiple myeloma. We report the final analyses for overall survival (OS).

PATIENTS AND METHODS

Patients were randomly assigned to ixazomib-Rd (n = 360) or placebo-Rd (n = 362), stratified by number of prior therapies (1 v 2 or 3), previous proteasome inhibitor (PI) exposure (yes v no), and International Staging System disease stage (I or II v III). OS (intent-to-treat population) was a key secondary end point.

RESULTS

With a median follow-up of 85 months, median OS with ixazomib-Rd versus placebo-Rd was 53.6 versus 51.6 months (hazard ratio, 0.939; P = .495). Lower hazard ratios, indicating larger magnitude of OS benefit with ixazomib-Rd versus placebo-Rd, were seen in predefined subgroups: refractory to any (0.794) or last (0.742) treatment line; age > 65-75 years (0.757); International Staging System stage III (0.779); 2/3 prior therapies (0.845); high-risk cytogenetics (0.870); and high-risk cytogenetics and/or 1q21 amplification (0.862). Following ixazomib-Rd versus placebo-Rd, 71.7% versus 69.9% of patients received ≥ 1 anticancer therapy, of whom 24.7% versus 33.9% received daratumumab and 71.8% versus 76.9% received PIs (next-line therapy: 47.5% v 55.8%). Rates of new primary malignancies were similar with ixazomib-Rd (10.3%) and placebo-Rd (11.9%). There were no new or additional safety concerns.

CONCLUSION

Median OS values in both arms were the longest reported in phase III studies of Rd-based triplets in relapsed or refractory multiple myeloma at the time of this analysis; progression-free survival benefit with ixazomib-Rd versus placebo-Rd did not translate into a statistically significant OS benefit on intent-to-treat analysis. OS benefit was greater in subgroups with adverse prognostic factors. OS interpretation was confounded by imbalances in subsequent therapies received, especially PIs and daratumumab.

A phase II trial of continuous ixazomib, thalidomide and dexamethasone for relapsed and/or refractory multiple myeloma: the Australasian Myeloma Research Consortium (AMaRC) 16-02 trial

We evaluated the efficacy and tolerability of continuous ixazomib-thalidomide-dexamethasone (ITd: 4 mg, day 1, 8, 15; 100 mg daily; and 40 mg weekly). A total of 39 patients with relapsed/refractory multiple myeloma (RRMM) aged ≥18 years with one to three prior lines of therapy were enrolled from two tertiary centres in Victoria and South Australia, Australia. The overall response rate (ORR) was 56·4% with a clinical benefit rate of 71·8%. The median progression-free survival was 13·8 months [95% confidence interval (CI) 8·2-22·2] and median overall survival was not reached. The median time to best response and duration of response was 3·7 months (95% CI 2·8-10·5) and 18·4 months (95% CI 10·2-31·0) respectively. Prior immunomodulatory drug (IMID) exposure was associated with a lower ORR (40% vs. 73·7%, P = 0·03). Survival outcomes in patients with prior proteasome inhibitor (PI) and/or IMID exposure were similar. Patients received a median (range) of 11 (1-31) cycles of therapy and six patients (15%) remained on therapy at the time of final analysis. Grade 3/4 haematological and non-haematological adverse events were reported in 7·7% and 20·6% of patients respectively. ITd dose reductions were required in 15·4%, 48·7% and 35·9% of patients respectively. The present study demonstrates promising effectiveness and tolerability of ITd as an affordable all-oral PI-IMID approach for RRMM.

Genetic Predictors of Mortality in Patients with Multiple Myeloma

Multiple myeloma (MM) is a heterogeneous disease featured by clonal plasma cell proliferation and genomic instability. The advent of next-generation sequencing allowed unraveling the complex genomic landscape of the disease. Several recurrent genomic aberrations including immunoglobulin genes translocations, copy number abnormalities, complex chromosomal events, transcriptomic and epigenomic deregulation, and mutations define various molecular subgroups with distinct outcomes. In this review, we describe the recurrent genomic events identified in MM impacting patients’ outcome and survival. These genomic aberrations constitute new markers that could be incorporated into a prognostication model to eventually guide therapy at every stage of the disease.

Carfilzomib, cyclophosphamide and dexamethasone for newly diagnosed, high-risk myeloma patients not eligible for transplant: a pooled analysis of two studies

Despite remarkable advances in the treatment of multiple myeloma (MM) in the last decades, the prognosis of patients harboring highrisk cytogenetic abnormalities remains dismal as compared to that of standard-risk patients. Proteasome inhibitors have been demonstrated to partially ameliorate the prognosis of high-risk patients. We pooled together data from two phase I/II trials on transplant-ineligible patients with MM receiving upfront carfilzomib cyclophosphamide and dexamethasone followed by carfilzomib maintenance. The aim of this analysis was to compare treatment outcomes in patients with standard-risk versus high-risk cytogenetic abnormalities detected by fluorescence in situ hybridization (FISH) analysis. High risk was defined by the presence of at least one chromosomal abnormality, including t(4;14), del17p and t(14;16). Overall, 94 patients were included in the analysis: 57 (61%) in the standard-risk and 37 (39%) in the high-risk group. Median follow-up was 38 months. In standard- risk versus high-risk patients, we observed similar progression-free survival (PFS) (3-year PFS: 52% vs. 43%, respectively; P=0.50), overall survival (OS) (3-year OS: 78% vs. 73%; P=0.38), and overall response rate (88% vs. 95%; P=0.47), with no statistical differences between the two groups. No difference in terms of PFS was observed between patients with or without del17p. Carfilzomib, used both as induction and maintenance agent for transplant-ineligible newly diagnosed MM patients, mitigated the poor prognosis carried by high-risk cytogenetics and resulted in similar PFS and OS as in standard-risk patients. (Registered at clinicaltrials.gov identifiers: NCT01857115 [IST-CAR-561] and NCT01346787 [IST-CAR-506].)

Oral ixazomib, lenalidomide, and dexamethasone for transplant-ineligible patients with newly diagnosed multiple myeloma

Addition of ixazomib to Rd in nontransplant NDMM patients resulted in a nonstatistically significant increase in PFS (HR, 0.830; P = .073).

Ixazomib-Rd is a feasible and tolerable all-oral triplet regimen in this setting, with a well-characterized and manageable safety profile.

Continuous lenalidomide-dexamethasone (Rd)-based regimens are among the standards of care in transplant-ineligible newly diagnosed multiple myeloma (NDMM) patients. The oral proteasome inhibitor ixazomib is suitable for continuous dosing, with predictable, manageable toxicities. In the double-blind, placebo-controlled TOURMALINE-MM2 trial, transplant-ineligible NDMM patients were randomized to ixazomib 4 mg (n = 351) or placebo (n = 354) plus Rd. After 18 cycles, dexamethasone was discontinued and treatment was continued using reduced-dose ixazomib (3 mg) and lenalidomide (10 mg) until progression/toxicity. The primary endpoint was progression-free survival (PFS). Median PFS was 35.3 vs 21.8 months with ixazomib-Rd vs placebo-Rd, respectively (hazard ratio [HR], 0.830; 95% confidence interval, 0.676-1.018; P = .073; median follow-up, 53.3 and 55.8 months). Complete (26% vs 14%; odds ratio [OR], 2.10; P < .001) and ≥ very good partial response (63% vs 48%; OR, 1.87; P < .001) rates were higher with ixazomib-Rd vs placebo-Rd. In a prespecified high-risk cytogenetics subgroup, median PFS was 23.8 vs 18.0 months (HR, 0.690; P = .019). Overall, treatment-emergent adverse events (TEAEs) were mostly grade 1/2. With ixazomib-Rd vs placebo-Rd, 88% vs 81% of patients experienced grade ≥3 TEAEs, 66% vs 62% serious TEAEs, and 35% vs 27% TEAEs resulting in regimen discontinuation; 8% vs 6% died on study. Addition of ixazomib to Rd was tolerable with no new safety signals and led to a clinically meaningful PFS benefit of 13.5 months. Ixazomib-Rd is a feasible option for certain patients who can benefit from an all-oral triplet combination. This trial was registered at www.clinicaltrials.gov as #NCT01850524.

Outcomes of ixazomib/lenalidomide/dexamethasone for multiple myeloma: A multicenter retrospective analysis

OBJECTIVES

This study aimed to investigate real-world data of ixazomib plus lenalidomide and dexamethasone (IRd) therapy for patients with relapsed and refractory multiple myeloma (RRMM).

METHODS

We retrospectively analyzed 122 patients treated with IRd at 16 centers from May 2017 to January 2019 by using the Kansai Myeloma Forum database.

RESULT

At the start of IRd, the median age was 72 years, 66.7% of patients had IgG type, and the median number of prior therapies was 4, comprising bortezomib (85.4%) and lenalidomide (89.3%)-based regimens. Disease progression and adverse events accounted for treatment discontinuation in 46 and 32 patients, respectively. The median overall survival (OS) was not reached, and the median progression-free survival (PFS) was 11.9 months. Sensitivity to bortezomib did not affect the PFS, whereas lenalidomide-refractory patients had significantly lower PFS than lenalidomide-sensitive patients, who were comparable to TOURMALINE-MM1 study. The patients with IgG type had significantly better PFS and OS than those with non-IgG type.

CONCLUSION

This study presents the largest real-world data of patients treated with IRd in Asia. However, in real clinical practice, the patient background is different from the TOURMALINE-MM1 study, and IRd showed poor efficacy, especially in the non-IgG type and lenalidomide-refractory patients with RRMM.

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.

Gain/Amplification of Chromosome Arm 1q21 in Multiple Myeloma

Simple Summary

Multiple myeloma (MM), a plasma cell neoplasm, is an incurable hematological malignancy. Gain/amplification of chromosome arm 1q21 (1q21+) is the most common adverse genomic abnormality associated with disease progression and drug resistance. While possible mechanisms of 1q21+ occurrence and candidate genes in the 1q21 amplicon have been suggested, the precise pathogenesis of MM with 1q21+ is unknown. Herein, we review the current knowledge about the clinicopathological features of 1q21+ MM, which can assist in effective therapeutic approaches for MM patients with 1q21+.

Abstract

Multiple myeloma (MM), a plasma cell neoplasm, is an incurable hematological malignancy characterized by complex genetic and prognostic heterogeneity. Gain or amplification of chromosome arm 1q21 (1q21+) is the most frequent adverse chromosomal aberration in MM, occurring in 40% of patients at diagnosis. It occurs in a subclone of the tumor as a secondary genomic event and is more amplified as the tumor progresses and a risk factor for the progression from smoldering multiple myeloma to MM. It can be divided into either 1q21 gain (3 copies) or 1q21 amplification (≥4 copies), and it has been suggested that the prognosis is worse in cases of amplification than gain. Trisomy of chromosome 1, jumping whole-arm translocations of chromosome1q, and tandem duplications lead to 1q21+ suggesting that its occurrence is not consistent at the genomic level. Many studies have reported that genes associated with the malignant phenotype of MM are situated on the 1q21 amplicon, including CKS1B, PSMD4, MCL1, ANP32E, and others. In this paper, we review the current knowledge regarding the clinical features, prognostic implications, and the speculated pathology of 1q21+ in MM, which can provide clues for an effective treatment approach to MM patients with 1q21+.

Activation of Serum/Glucocorticoid Regulated Kinase 1/Nuclear Factor-κB Pathway Are Correlated with Low Sensitivity to Bortezomib and Ixazomib in Resistant Multiple Myeloma Cells

Multiple myeloma (MM) is an incurable malignancy often associated with primary and acquired resistance to therapeutic agents, such as proteasome inhibitors. However, the mechanisms underlying the proteasome inhibitor resistance are poorly understood. Here, we elucidate the mechanism of primary resistance to bortezomib and ixazomib in the MM cell lines, KMS-20, KMS-26, and KMS-28BM. We find that low bortezomib and ixazomib concentrations induce cell death in KMS-26 and KMS-28BM cells. However, high bortezomib and ixazomib concentrations induce cell death only in KMS-20 cells. During Gene Expression Omnibus analysis, KMS-20 cells exhibit high levels of expression of various genes, including anti-phospho-fibroblast growth factor receptor 1 (FGFR1), chemokine receptor type (CCR2), and serum and glucocorticoid regulated kinase (SGK)1. The SGK1 inhibitor enhances the cytotoxic effects of bortezomib and ixazomib; however, FGFR1 and CCR2 inhibitors do not show such effect in KMS-20 cells. Moreover, SGK1 activation induces the phosphorylation of NF-κB p65, and an NF-κB inhibitor enhances the sensitivity of KMS-20 cells to bortezomib and ixazomib. Additionally, high levels of expression of SGK1 and NF-κB p65 is associated with a low sensitivity to bortezomib and a poor prognosis in MM patients. These results indicate that the activation of the SGK1/NF-κB pathway correlates with a low sensitivity to bortezomib and ixazomib, and a combination of bortezomib and ixazomib with an SGK1 or NF-κB inhibitor may be involved in the treatment of MM via activation of the SGK1/NF-κB pathway.

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.

Risk and Response-Adapted Treatment in Multiple Myeloma

Simple Summary

Therapeutic strategies in multiple myeloma have been adapted only to age and comorbidities for a long time. Given the currently available therapeutic and technologic arsenal, the time may have come to refine this adaptation. First, high-risk patients should benefit from the most intensive and efficient combinations from diagnosis. Here, we review these different strategies and how to define and identify high-risk myeloma patients in current clinical practice. In addition, the advent of technologies detecting minimal residual disease gives us this opportunity to define the quality of response to treatment with an unpreceded sensitivity and adapt treatment accordingly. Finally, even if molecular targeting is still nascent in myeloma, some molecular features are interesting to detect at relapse to determine optimal salvage treatments.

Abstract

Myeloma therapeutic strategies have been adapted to patients’ age and comorbidities for a long time. However, although cytogenetics and clinical presentations (plasmablastic cytology; extramedullary disease) are major prognostic factors, until recently, all patients received the same treatment whatever their initial risk. No strong evidence allows us to use a personalized treatment according to one cytogenetic abnormality in newly diagnosed myeloma. Retrospective studies showed a benefit of a double autologous transplant in high-risk cytogenetics according to the International Myeloma Working Group definition (t(4;14), t(14;16) or del(17p)). Moreover, this definition has to be updated since other independent abnormalities, namely gain 1q, del(1p32), and trisomies 5 or 21, as well as TP53 mutations, are also prognostic. Another very strong predictive tool is the response to treatment assessed by the evaluation of minimal residual disease (MRD). We are convinced that the time has come to use it to adapt the strategy to a dynamic risk. Many trials are ongoing to answer many questions: when and how should we adapt the therapy, its intensity and duration. Nevertheless, we also have to take into account the clinical outcome for one patient, especially adverse events affecting his or her quality of life and his or her preferences for continuous/fixed duration treatment.

Daratumumab, lenalidomide, and dexamethasone in relapsed/refractory myeloma: a cytogenetic subgroup analysis of POLLUX

High cytogenetic risk abnormalities confer poor outcomes in multiple myeloma patients. In POLLUX, daratumumab/lenalidomide/dexamethasone (D-Rd) demonstrated significant clinical benefit versus lenalidomide/dexamethasone (Rd) in relapsed/refractory multiple myeloma (RRMM) patients. We report an updated subgroup analysis of POLLUX based on cytogenetic risk. The cytogenetic risk was determined using fluorescence in situ hybridization/karyotyping; patients with high cytogenetic risk had t(4;14), t(14;16), or del17p abnormalities. Minimal residual disease (MRD; 10^–5) was assessed via the clonoSEQ^® assay V2.0. 569 patients were randomized (D-Rd, n = 286; Rd, n = 283); 35 (12%) patients per group had high cytogenetic risk. After a median follow-up of 44.3 months, D-Rd prolonged progression-free survival (PFS) versus Rd in standard cytogenetic risk (median: not estimable vs 18.6 months; hazard ratio [HR], 0.43; P < 0.0001) and high cytogenetic risk (median: 26.8 vs 8.3 months; HR, 0.34; P = 0.0035) patients. Responses with D-Rd were deep, including higher MRD negativity and sustained MRD-negativity rates versus Rd, regardless of cytogenetic risk. PFS on subsequent line of therapy was improved with D-Rd versus Rd in both cytogenetic risk subgroups. The safety profile of D-Rd by cytogenetic risk was consistent with the overall population. These findings demonstrate the improved efficacy of daratumumab plus standard of care versus standard of care in RRMM, regardless of cytogenetic risk.

Anti-tumor activities of the new oral pan-RAF inhibitor, TAK-580, used as monotherapy or in combination with novel agents in multiple myeloma

Many RAS pathway inhibitors, including pan-RAF inhibitors, have shown significant anti-tumor activities in both solid and hematological tumors. The pan-RAF inhibitor, TAK-580, is a representative of the novel RAF inhibitors that act by disrupting RAF homo- or heterodimerization. In this study, we examined the anti-tumor effects of TAK-580 used as monotherapy or in combination with bortezomib, lenalidomide, or other novel agents in multiple myeloma (MM) cells in vitro. TAK-580 monotherapy potently targeted proteins in the RAS-RAF-MEK-ERK signaling pathway and induced potent cytotoxicity and apoptosis in MM cell lines and myeloma cells from patients with newly diagnosed and relapsed and/or refractory MM, compared with a representative RAF inhibitor, dabrafenib. Normal donor peripheral blood B lymphocytes and cord blood CD34-positive cells were not affected. Importantly, TAK-580 significantly inhibited phospho-FOXO3 and induced upregulation of Bim_L and Bim_S in a dose-dependent manner, finally leading to apoptosis in MM cells. Moreover, TAK-580 enhanced bortezomib-induced cytotoxicity and apoptosis in MM cells via the FOXO3-Bim axis and the terminal unfolded protein response. Importantly, TAK-580 also enhanced lenalidomide-induced cytotoxicity and apoptosis in MM cells. Taken together, our results provide the rationale for TAK-580 monotherapy and/or treatment in combination with novel agents to improve outcomes in patients with MM.

Evaluation of Daratumumab for the Treatment of Multiple Myeloma in Patients With High-risk Cytogenetic Factors: A Systematic Review and Meta-analysis

Importance

The addition of daratumumab to backbone multiple myeloma (MM) regimens is associated with improved response rates and progression-free survival (PFS). Whether improved outcomes are also associated with this regimen among patients with cytogenetically defined high-risk MM (HRMM) remains unclear.

Objective

To measure PFS associated with adding daratumumab to backbone MM regimens among patients with HRMM.

Data Sources

For this systematic review and meta-analysis, MEDLINE, Embase, PubMed, Scopus, Web of Science Core Collection, Cochrane Library, clinical trials registries, and meeting libraries were searched from inception to January 2, 2020, using terms reflecting multiple myeloma and daratumumab.

Study Selection

Included studies were phase 3 randomized clinical trials that compared backbone MM regimens with the same regimen plus daratumumab in newly diagnosed or relapsed or refractory MM, such that the only difference between the intervention and control groups was use of daratumumab and reported outcomes by cytogenetic risk. High-risk MM was defined as the presence of t(4;14), t(14;16), or del(17p).

Data Extraction and Synthesis

Using the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline, 2 investigators independently extracted study data, with disagreements resolved by a third investigator. Quality was assessed by the Cochrane risk-of-bias method.

Main Outcomes and Measures

Data on effectiveness were extracted using hazard ratios (HRs) for PFS. Relative log-HRs were pooled using a DerSimonian-Laird random-effects model. Heterogeneity was assessed using the Cochran Q and the I2 statistic.

Results

Of 5194 studies screened, 6 phase 3 trials were eligible, including 3 trials for newly diagnosed MM (2528 patients; 358 with HRMM) and 3 trials for relapsed or refractory MM (1533 patients; 222 with HRMM). Among patients with newly diagnosed HRMM, the addition of daratumumab to backbone regimens was associated with improved PFS (pooled HR, 0.67; 95% CI, 0.47-0.95; P = .02), with little evidence of heterogeneity (Cochran Q, P = .77; I2 = 0%). Similar results were seen among patients with relapsed or refractory HRMM (pooled HR, 0.45; 95% CI, 0.30-0.67; P < .001), again with little evidence of heterogeneity (Cochran Q, P = .63; I2 = 0%).

Conclusions and Relevance

This study suggests that incorporating daratumumab to backbone regimens may be associated with improved PFS among patients with newly diagnosed HRMM or relapsed or refractory HRMM.

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.

Impact of acquired del(17p) in multiple myeloma

The high-risk abnormality del(17p) can be detected by fluorescence in situ hybridization on malignant plasma cells (PCs) and has an adverse prognostic impact in patients with multiple myeloma (MM). Patients with del(17p) have reduced overall survival (OS). Patients who acquire del(17p) later during the disease course are not well described. The disease characteristics at diagnosis predicting for acquired del(17p) and its overall impact on patient survival is not known. We compared 76 patients with MM who were negative for del(17p) at diagnosis and acquired it later with 152 control MM patients who did not acquire del(17p) at a comparable time point. Patients acquired del(17p) at a median of 35.6 months (range, 4.6-116.1 months) from diagnosis of MM after a median of 2 lines of therapy (range, 1-10 lines of therapy). When compared with controls, patients with acquired del(17p) had shorter median progression-free survival (PFS) (30.1 vs 23.0 months; P = .032) and OS (106.1 vs 68.2 months; P < .001) from diagnosis. After the detection of del(17p), the median PFS was 5.4 months and the median OS was 18.1 months. High lactate dehydrogenase level (odds ratio [OR], 3.69; 95% confidence interval [CI], 1.11-12.24) and presence of t(4;14) (OR, 2.66; 95% CI, 1.09-6.48) or any high-risk translocation (OR, 2.23; 95% CI, 1.00-4.95) at diagnosis predicted acquisition of del(17p). High PC proliferative rate predicted shorter OS from detection of del(17p) (hazard ratio, 2.28; 95% CI, 1.31-3.96; P = .004). Our study shows that acquisition of del(17p) is an important molecular event associated with reduction in OS in MM. Certain baseline factors may predict acquisition of del(17p). This needs validation in prospective data sets.

Prognostic Value and Efficacy Evaluation of Novel Drugs for Multiple Myeloma Patients with 1q21 Amplification (Amp1q21) Only: A Systematic Review of Randomized Controlled Trials

Background: Multiple myeloma (MM) is a heterogeneous disease characterized by chromosomal translocation, deletion, and amplification in plasma cells, resulting in a huge heterogeneity in its outcomes. Of all these cytogenetic abnormalities, Amp1q21 is most commonly detected, which is always associated with significantly shorter progression-free survival (PFS) and overall survival (OS) than normal 1q copy number status. In the era of novel agents such as bortezomib, ixazomib, lenalidomide, a head-to-head comparison of all these agents is still absent, especially in the patients with Amp1q21 alone. So, aiming to explore the optimum therapy to the patients with Amp1q21 only, we conduct this study.

Patients and Methods: We searched the PubMed, the Cochrane Library, PMC and the Embase databases, and we selected all the randomized controlled trials (RCTs) in English about MM with Amp1q21 up to April, 2019. A total of 72 papers were full screened and finally 2 literatures can be included in our study.

Results: Of the two studies, the one is about IRd (ixazomib, lenalidomide, dexamethasone) vs. placebo-Rd (HR, 0.781; 95% CI, 0.492-1.240), another is about VAD (vincristine, adriamycin, dexamethasone) vs. PAD (bortezomib, adriamycin, dexamethasone) (3-year survival rate: 59% vs. 83%, p=0.016).

Conclusion: From this review, MM patients with Amp1q21 may somewhat benefit from ixazomib but the evidence is still stuffless. What's more, a head-to-head comparison between ixazomib and other agents among MM patients with Amp1q21 is also absent. So, we sincerely expect this review can attract some attention for the therapy of this special part of patients. This study was registered in https://www.crd.york.ac.uk/prospero/#recordDetails.

Latest treatment strategies aiming for a cure in transplant-eligible multiple myeloma patients: how I cure younger MM patients with lower cost

This article presents a practical overview of the treatment of younger, newly diagnosed multiple myeloma patients, focusing on novel treatment strategies. With the introduction of effective new agents, multiple myeloma is one of the most active and changing fields in clinical oncology. In addition, monitoring technology has become reliable and practical. Achieving and sustaining minimal residual disease negativity (MRD- ), such as multiparameter flow cytometry (MFC) < 10^-5, is one of the goals of therapy. MRD-  is significantly associated with prolonged progression-free survival, whereas MRD persistence (MRD +) is an independent factor for poor progression-free survival. Evidence from several recent studies evaluating modern therapy has further supported the positive correlation between depth of response and outcomes. Multiple myeloma can become a chronic illness with sustained MRD- in a significant number of patients. Our ultimate hope is to leverage tumoricidal-immunomodulatory sequential therapies and to cure a subset of our patients.

Medication Adherence, Health Care Utilization, and Costs Among Patients Initiating Oral Oncolytics for Multiple Myeloma or Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma

BACKGROUND

Oral oncolytic therapies have improved survival in hematologic cancers, such as chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) and multiple myeloma (MM), which are now being managed like chronic conditions. However, compared with other cancers, there is a lack of studies assessing adherence, health care resource utilization, and costs in patients with these cancers.

OBJECTIVE

To assess factors associated with adherence to oral oncolytic therapies, health care utilization, and costs in patients with CLL/SLL or MM.

METHODS

A retrospective database study was conducted using the IBM MarketScan Commercial Claims and Medicare Supplement databases. Adults (aged ≥ 18 years) diagnosed with and prescribed an oral oncolytic for CLL/SLL (ibrutinib or idelalisib) or MM (thalidomide, lenalidomide, or pomalidomide) between 2013 and 2016 and with continuous eligibility 6 months before and 12 months after oral oncolytic initiation were identified. Adherence to oral oncolytics was measured using the proportion of days covered (PDC) metric. Multiple linear regression and multivariable logistic regression were used to identify adherence predictors. Count models assessed the relationship between adherence and resource utilization, and generalized linear models assessed the relationship between adherence and health care costs.

RESULTS

A total of 701 and 2,385 patients were identified with CLL/SLL or MM, respectively. Mean PDC (SD) for CLL/SLL and MM patients was 75.3 (22.5) and 57.6 (26.5), respectively. For CLL/SLL patients, those aged ≥ 65 years (beta [B] = -4.00) had lower medication use. Among MM patients, multiple predictors of higher medication use emerged: aged ≥ 65 years (B = 3.44), higher than average outpatient resource utilization (B = 3.53), insurance plan other than preferred provider organization (PPO; B = -2.58), previous cancer therapy (B = -2.81), higher number of concurrent unique therapeutic classes (B = -0.35), and higher comorbidity burden (B = -2.55). Patients with CLL/SLL and enrolled in plans other than a PPO were more likely to be adherent (OR = 1.41, 95% CI = 1.01-1.98), whereas patients who were aged ≥ 65 years, were residents of the southern United States, and had visited the emergency department in the baseline period were less likely to be adherent. For MM patients, those aged ≥ 65 years (OR = 1.68, 95% CI = 1.38-2.04) and with higher than average outpatient services utilization (OR = 1.24, 95% CI = 1.01-1.52) were more likely to be adherent, whereas those enrolled in plans other than a PPO, previously treated with cancer therapy, and with higher comorbidity burden were less likely to be adherent. In both cohorts, adherent patients had significantly lower odds of health care utilization and incurred lower medical costs, but higher prescription costs, following oncolytic initiation; however, total costs were not significantly lower in those adherent.

CONCLUSIONS

Factors were identified that influenced adherence at the patient, treatment, and health system levels. These factors can be used to identify patients requiring interventions for improving medication-taking behavior and associated health care burden.

DISCLOSURES

This study received no outside funding. Dashputre was recently employed by Novartis; K. Gatwood has received speaker fees from Jazz Pharmaceuticals; and J. Gatwood has received research funding from Merck & Co. and GlaxoSmithKline, unrelated to this study..

Prognosis, Biology, and Targeting of TP53 Dysregulation in Multiple Myeloma

Multiple myeloma (MM) is the second most common hematological cancer and is characterized by genetic features including translocations, chromosomal copy number aberrations, and mutations in key oncogene and tumor suppressor genes. Dysregulation of the tumor suppressor TP53 is important in the pathogenesis of many cancers, including MM. In newly-diagnosed MM patients, TP53 dysregulation occurs in three subsets: monoallelic deletion as part of deletion of chromosome 17p (del17p) (~8%), monoallelic mutations (~6%), and biallelic inactivation (~4%). Del17p is an established high-risk feature in MM and is included in current disease staging criteria. Biallelic inactivation and mutation have also been reported in MM patients but are not yet included in disease staging criteria for high-risk disease. Emerging clinical and genomics data suggest that the biology of high-risk disease is complex, and so far, traditional drug development efforts to target dysregulated TP53 have not been successful. Here we review the TP53 dysregulation literature in cancer and in MM, including the three segments of TP53 dysregulation observed in MM patients. We propose a reverse translational approach to identify novel targets and disease drivers from TP53 dysregulated patients to address the unmet medical need in this setting.

Proteasome inhibition in multiple myeloma: lessons for other cancers

Cellular protein homeostasis (proteostasis) depends on the controlled degradation of proteins that are damaged or no longer required by the ubiquitin-proteasome system (UPS). The 26S proteasome is the principal executer of substrate-specific proteolysis in eukaryotic cells and regulates a myriad of cellular functions. Proteasome inhibitors were initially developed as chemical tools to study proteasomal function but rapidly became widely used anticancer drugs that are now used at all stages of treatment for the bone marrow cancer multiple myeloma (MM). Here, we review the mechanisms of action of proteasome inhibitors that underlie their preferential toxicity to MM cells, focusing on endoplasmic reticulum stress, depletion of amino acids, and effects on glucose and lipid metabolism. We also discuss mechanisms of resistance to proteasome inhibition such as autophagy and metabolic rewiring and what lessons we may learn from the success and failure of proteasome inhibition in MM for treating other cancers with proteostasis-targeting drugs.