Once-per-week selinexor, bortezomib, and dexamethasone versus twice-per-week bortezomib and dexamethasone in patients with multiple myeloma (BOSTON): a randomised, open-label, phase 3 trial

Patient-Reported Outcomes in Phase 3 Clinical Trials for Blood Cancers: A Systematic Review

Importance

Published research suggests that patient-reported outcomes (PROs) are neither commonly collected nor reported in randomized clinical trials (RCTs) for solid tumors. Little is known about these practices in RCTs for hematological malignant neoplasms.

Objective

To evaluate the prevalence of PROs as prespecified end points in RCTs of hematological malignant neoplasms, and to assess reporting of PROs in associated trial publications.

Evidence Review

All issues of 8 journals known for publishing high-impact RCTs (NEJM, Lancet, Lancet Hematology, Lancet Oncology, Journal of Clinical Oncology, Blood, JAMA, and JAMA Oncology) between January 1, 2018, and December 13, 2022, were searched for primary publications of therapeutic phase 3 trials for adults with hematological malignant neoplasms. Studies that evaluated pretransplant conditioning regimens, graft-vs-host disease treatment, or radiotherapy as experimental treatment were excluded. Data regarding trial characteristics and PROs were extracted from manuscripts and trial protocols. Univariable analyses assessed associations between trial characteristics and PRO collection or reporting.

Findings

Ninety RCTs were eligible for analysis. PROs were an end point in 66 (73%) trials: in 1 trial (1%) as a primary end point, in 50 (56%) as a secondary end point, and in 15 (17%) as an exploratory end point. PRO data were reported in 26 of 66 primary publications (39%): outcomes were unchanged in 18 and improved in 8, with none reporting worse PROs with experimental treatment. Trials sponsored by for-profit entities were more likely to include PROs as an end point (49 of 55 [89%] vs 17 of 35 [49%]; P < .001) but were not significantly more likely to report PRO data (20 of 49 [41%] vs 6 of 17 [35%]; P = .69). Compared with trials involving lymphoma (18 of 29 [62%]) or leukemia or myelodysplastic syndrome (18 of 28 [64%]), those involving plasma cell disorders or multiple myeloma (27 of 30 [90%]) or myeloproliferative neoplasms (3 of 3 [100%]) were more likely to include PROs as an end point (P = .03). Similarly, compared with trials involving lymphoma (3 of 18 [17%]) or leukemia or myelodysplastic syndrome (5 of 18 [28%]), those involving plasma cell disorders or multiple myeloma (16 of 27 [59%]) or myeloproliferative neoplasms (2 of 3 [67%]) were more likely to report PROs in the primary publication (P = .01).

Conclusions and Relevance

In this systematic review, almost 3 of every 4 therapeutic RCTs for blood cancers collected PRO data; however, only 1 RCT included PROs as a primary end point. Moreover, most did not report resulting PRO data in the primary publication and when reported, PROs were either better or unchanged, raising concern for publication bias. This analysis suggests a critical gap in dissemination of data on the lived experiences of patients enrolled in RCTs for hematological malignant neoplasms.

The impact of current therapeutic options on the health-related quality of life of patients with relapse/refractory multiple myeloma: a systematic review of clinical studies

PURPOSE

Patients with relapse and/or refractory multiple myeloma (RRMM) have a high disease burden with poor health-related quality of life (HRQoL) which worsens with each additional relapse. We aimed to review the impact of triplet, doublet, monotherapies, and salvage autologous stem cell transplantation on the HRQoL of RRMM patients.

METHODS

We performed a comprehensive literature search of Medline/PubMed, Wiley Cochrane Library, EMBASE, Scopus, CINAHL, and Clinicaltrials.gov to identify clinical studies in RRMM patients with HRQoL as an outcome measure. The ISOQoL and CONSORT-PRO extension guidelines were used to assess the quality of HRQoL reporting. We synthesized the result using a qualitative analysis.

RESULTS

A total of 10,245 RRMM patients enrolled in 28 eligible studies received either a triplet, doublet regimen, monotherapy, or salvage autologous stem cell transplantation. The EORTC QLQ-C30 was the most used questionnaire, and compliance with HRQoL reporting standards is generally poor among studies without an additional HRQoL publication. Most of the current therapeutic options are at best able to maintain HRQoL at baseline but not improve it. The methodological and reporting heterogeneity among the studies complicates generalizations.

CONCLUSIONS

Many of the current treatment regimens for RRMM have demonstrated clinical effectiveness in trials. Unlike newly diagnosed MM, these regimens are less likely to result in significant improvement in HRQoL in RRMM. This should be communicated to patients before initiating therapies.

IMPLICATIONS FOR CANCER SURVIVORS

Individualized therapeutic approach for RRMM should be chosen based on a shared decision-making process that aligns clinical efficacy with patients' treatment priorities and HRQoL.

Therapeutic progress in relapsed/refractory multiple myeloma

Improvement in the therapeutics for multiple myeloma (MM) has been continuously developed owing to the application of novel drugs and technologies in the last 20 years. The standard first-line therapy for MM consists of a three-drug induction regimen based on immunomodulatory drugs and proteasome inhibitors combined with autologous stem cell transplantation. However, MM remains incurable; therefore, therapies for relapsed/refractory MM (RRMM) are emerging and evolving rapidly. This study aimed to summarize and review the results of RRMM trials over the past 5 years to provide a holistic overview and insights for practitioners in related fields and to provide additional ideas for clinical trialists. This study shows that daratumumab and isatuximab continue to significantly advance as treatment options. Additionally, novel antibody drugs, such as elotuzumab and selinexor, as well as bispecific antibodies, teclistamab and talquetamab, are currently undergoing clinical research with promising outcomes. However, chimeric antigen receptor-T cell therapy targeting B-cell maturation antigen remains the optimal approach for MM treatment.

Targeting KPNB1 with Genkwadaphnin suppresses gastric cancer progression through the Nur77-mediated signaling pathway

Gastric cancer (GC) remains a global challenge due to the lack of early detection and precision therapies. Genkwadaphnin (DD1), a natural diterpene isolated from the bud of Flos GenkWa (Thymelaeaceae), serves as a Karyopherin β1 (KPNB1) inhibitor. In this study, we investigated the anti-tumor effect of DD1 in both cell culture and animal models. Our findings reveal that KPNB1, a protein involved in nuclear import, was highly expressed in GC tissues and associated with a poor prognosis in patients. We demonstrated that DD1, alongside the established KPNB1 inhibitor importazole (IPZ), inhibited GC cell proliferation and tumor growth by enhancing both genomic and non-genomic activity of Nur77. DD1 and IPZ reduced the interaction between KPNB1 and Nur77, resulting in Nur77 cytoplasmic accumulation and triggering mitochondrial apoptosis. The inhibitors also increased the expression of the Nur77 target apoptotic genes ATF3, RB1CC1 and PMAIP1, inducing apoptosis in GC cell. More importantly, loss of Nur77 effectively rescued the inhibitory effect of DD1 and IPZ on GC cells in both in vitro and in vivo experiments. In this study, we for the first time explored the relationship between KPNB1 and Nur77, and found KPNB1 inhibition could significantly increase the expression of Nur77. Moreover, we investigated the function of KPNB1 in GC for the first time, and the results suggested that KPNB1 could be a potential target for cancer therapy, and DD1 might be a prospective therapeutic candidate.

Adverse events reporting of XPO1 inhibitor - selinexor: a real-word analysis from FAERS database

As the world's first oral nuclear export inhibitor, selinexor is increasingly being used in clinical applications for malignant tumors. However, there is no extensive exploration on selinexor's adverse events (ADEs), necessitating a real-word assessment of its clinical medication safety. FAERS data (July 2019-June 2023) were searched for selinexor ADE reports across all indications. Use the system organ class (SOC) and preferred terms (PT) from the medical dictionary for regulatory activities (MedDRA) to describe, categorize, and statistic ADEs. Disproportionality analysis was employed through calculation of reporting odds ratio (ROR) and proportional reporting ratio (PRR). Based on total of 4392 selinexor related ADE reports as the primary suspect (PS), of which 2595 instances were severe outcomes. The predominant ADEs included gastrointestinal disorders, myelosuppression symptoms, and various nonspecific manifestations. 124 signals associated with selinexor ADE were detected, and 10 of these top 15 signals were not included into the instructions. Our study provides real-world evidence regarding the drug safety of selinexor, which is crucial for clinicians to safeguard patients' health.

Targeting the ubiquitin pathway in lymphoid malignancies

Ubiquitination and related cellular processes control a variety of aspects in human cell biology, and defects in these processes contribute to multiple illnesses. In recent decades, our knowledge about the pathological role of ubiquitination in lymphoid cancers and therapeutic strategies to target the modified ubiquitination system has evolved tremendously. Here we review the altered signalling mechanisms mediated by the aberrant expression of cancer-associated E2s/E3s and deubiquitinating enzymes (DUBs), which result in the hyperactivation of oncoproteins or the frequently allied downregulation of tumour suppressors. We discuss recent highlights pertaining to the several different therapeutic interventions which are currently being evaluated to effectively block abnormal ubiquitin-proteasome pathway and the use of heterobifunctional molecules which recruit the ubiquitination system to degrade or stabilize non-cognate substrates. This review aids in comprehension of ubiquitination aberrance in lymphoid cancers and current targeting strategies and elicits further investigations to deeply understand the link between cellular ubiquitination and lymphoid pathogenesis as well as to ameliorate corresponding treatment interventions.

Efficacy and safety of once weekly selinexor 40 mg versus 60 mg with pomalidomide and dexamethasone in relapsed and/or refractory multiple myeloma

Objective

To identify the optimal dose of selinexor in combination with pomalidomide and dexamethasone (SPd).

Methods

An analysis of efficacy and safety of 2 once-weekly selinexor regimens (60 mg and 40 mg) with pomalidomide and dexamethasone (SPd-60 and SPd-40, respectively) given to patients with relapsed/refractory multiple myeloma (RRMM) in the STOMP (NCT02343042) and XPORT-MM-028 (NCT04414475) trials.

Results

Twenty-eight patients (60.7% males, median age 67.5 years) and 20 patients (35.0% males, median age 65.5 years) were analyzed in the SPd-40 and SPd-60 cohorts, respectively. Overall response rate was 50% (95% confidence interval [CI] 30.6-69.4%) and 65% (95% CI 40.8-84.6%), respectively. Very good partial response or better was reported in 28.6% (95% CI 13.2-48.7%) and 30.0% (95% CI 11.9-54.3%) of patients, respectively. Among 27 responders in both cohorts, the 12-month sustained response rate was 83.3% (95% CI 64.7-100.0%) for SPd-40 and 28.1% (95% CI 8.9-88.8%) for SPd-60. Median progression-free survival was 18.4 months (95% CI 6.5 months, not evaluable [NE]) and 9.5 months (95% CI 7.6 months-NE) for SPd-40 and SPd-60, respectively. Twenty-four-month survival rates were 64.2% (95% CI 47.7-86.3%) for SPd-40 and 51.1% (95% CI 29.9-87.5%) for SPd-60. Treatment-emergent adverse events (TEAEs) included neutropenia (all grades: SPd-40 64.3% versus SPd-60 75.0%), anemia (46.4% versus 65.0%), thrombocytopenia (42.9% versus 45.0%), fatigue (46.4% versus 75.0%), nausea (32.1% versus 70.0%) and diarrhea (28.6% versus 35.0%).

Conclusion

The all-oral combination of SPd exhibited preliminary signs of efficacy and was generally tolerable in patients with RRMM. The overall risk-benefit profile favored the SPd-40 regimen.

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.

Impact of prior treatment on selinexor, bortezomib, dexamethasone outcomes in patients with relapsed/refractory multiple myeloma: Extended follow-up subgroup analysis of the BOSTON trial

OBJECTIVES

To analyze the impact of prior therapies on outcomes with selinexor, bortezomib, and dexamethasone (SVd) versus bortezomib and dexamethasone (Vd) in 402 patients with relapsed/refractory multiple myeloma (RRMM) in the phase 3 BOSTON trial.

METHODS

Post hoc analysis of progression-free survival (PFS), overall survival (OS), and safety for lenalidomide-refractory, proteasome inhibitor (PI)-naïve, bortezomib-naïve, and one prior line of therapy (1LOT) patient subgroups.

RESULTS

At a median follow-up of over 28 months, clinically meaningful improvements in PFS were noted across all groups with SVd. The median SVd PFS was longer in all subgroups (lenalidomide-refractory: 10.2 vs. 7.1 months, PI-naïve: 29.5 vs. 9.7; bortezomib-naïve: 29.5 vs. 9.7; 1LOT: 21.0 vs. 10.7; p < .05). The lenalidomide-refractory subgroup had longer OS with SVd (26.7 vs. 18.6 months; HR 0.53; p = .015). In all subgroups, overall response and ≥very good partial response rates were higher with SVd. The manageable safety profile of SVd was similar to the overall patient population.

CONCLUSIONS

With over 2 years of follow-up, these clinically meaningful outcomes further support the use of SVd in patients who are lenalidomide-refractory, PI-naïve, bortezomib-naïve, or who received 1LOT (including a monoclonal antibody) and underscore the observed synergy between selinexor and bortezomib.

Selinexor for the treatment of patients with relapsed or refractory multiple myeloma

OBJECTIVE

Multiple myeloma cells resist standard therapies due to overexpression of the transport protein, exportin 1. Selinexor is a novel drug that targets the Exportin 1 protein in these cells.

DATA SOURCE

A comprehensive search was done, and data showing the efficacy and safety of selinexor in relapsed/refractory multiple myeloma was collected using PubMed, Google Scholar, and clincialtrials.gov.

DATA SUMMARY

Results from the clinical trials STORM, BOSTON, and STOMP were included. Parts I and II of the STORM trial revealed a progression-free survival (PFS) of 4.7 and 3.7 months, a median duration of response of 6.2 and 4.4 months, and an overall survival of 7.3 and 8.4 months, respectively. BOSTON trial's SVd arm (selinexor, bortezomib, and dexamethasone) had a median follow-up period of 13.2 months and an mPFS of 13.93 months. The Vd arm (bortezomib and dexamethasone) had a median follow-up duration of 16.5 months and an mPFS of 9.46 months. The STOMP trial is still active and has limited data available. The SKd arm (selinexor, carfilzomib, and dexamethasone) reported an overall response rate of 66.7% in patients with triple refractory multiple myeloma, and 82% in patients with high-risk cytogenetics. The SPd arm (selinexor, pomalidomide, and dexamethasone) shows an overall response rate of 54.30% in pomalidomide naïve-nonrefractory, 35.70% in pomalidomide refractory and 60% in those dosed at RP2D. SRd arm (selinexor, lenalidomide, and dexamethasone) shows an overall response rate of 91.7% in lenalidomide naïve and 12.5% in lenalidomide refractory patients. SVd (selinexor, bortezomib, and dexamethasone) arm reported an overall response rate of 63% in all patients while the SDd arm (selinexor, daratumumab, and dexamethasone) showed an overall response rate of 73%.

CONCLUSION

To improve the outcome of patients with relapsed/refractory multiple myeloma, it is critical to develop new therapies, assess potential therapeutic synergies, and overcome drug resistance by determining the efficacy of multiple myeloma therapies across multiple disease subgroups.

Once-weekly versus twice-weekly bortezomib in newly diagnosed multiple myeloma: a real-world analysis

Induction regimens for multiple myeloma (MM) commonly include bortezomib, which has typically been administered twice weekly despite studies demonstrating comparable efficacy and less peripheral neuropathy (PN) with once-weekly bortezomib. We aimed to analyze the real-world prevalence and efficacy of once-weekly versus twice-weekly bortezomib regimens in newly diagnosed MM. We analyzed 2497 US patients aged 18-70 years treated with commercial first-line bortezomib using nationwide Flatiron Health electronic health record-derived data, including 910 (36.4%) patients who received twice-weekly and 1522 (63.2%) who received once-weekly bortezomib. Once-weekly bortezomib use increased over time, from 57.7% in 2017 to 73.1% in 2022. Multivariate analysis identified worsened performance status and more recent year of diagnosis with higher odds of receiving once-weekly bortezomib. Real-world progression-free survival (median 37.2 months with once-weekly versus 39.6 months with twice-weekly, p = 0.906) and overall survival (medians not reached in either cohort, p = 0.800) were comparable. PN rates were higher in patients receiving twice-weekly bortezomib (34.7% versus 18.5%, p < 0.001). In conclusion, once-weekly bortezomib is clearly associated with similar efficacy and fewer toxicities compared to twice-weekly bortezomib. Our findings support once-weekly bortezomib as a standard-of-care regimen for newly diagnosed patients with MM.

Efficacy and safety of daratumumab with ixazomib and dexamethasone in lenalidomide-exposed patients after one prior line of therapy: Final results of the phase 2 study DARIA

The use of lenalidomide in frontline therapy for patients with newly diagnosed multiple myeloma (MM) has increased the number of those who become refractory to lenalidomide at second line. In this context, we assessed the efficacy of daratumumab in combination with ixazomib and dexamethasone (Dara-Ixa-dex) in the prospective phase 2 study DARIA. Eligible patients had relapsed/refractory MM (RRMM) after one prior line with a lenalidomide-based regimen. The primary endpoint was overall response rate (ORR). Secondary endpoints included survival outcomes, safety and changes in biomarkers of bone metabolism. Overall, 50 patients were enrolled (median age 69 years, 56% males). 32 (64%) patients were refractory to lenalidomide, and 17 (34%) had undergone autologous transplant. The ORR was 64% (n = 32); whereas 17 (34%) had a very good partial response or better. The median time to first response was 1.0 month. After a median follow-up of 23.4 months, the median PFS and OS were 8.1 and 39.2 months, respectively. Furthermore, significant changes in markers of bone metabolism became evident as early as at 6 months on treatment. Regarding safety, 21 (42%) patients had ≥1 grade 3/4 adverse event (AE); the most common was thrombocytopenia (n = 9, 18%). 14 (28%) patients had ≥1 serious AE (SAE), the most common being acute kidney injury and pneumonia (n = 2, each). Four patients died due to infections. In conclusion, second-line treatment with Dara-Ixa-dex in patients with RRMM pre-treated with a lenalidomide-based regimen resulted in rapid responses along with a favorable effect on bone metabolism.

ANCHOR: melflufen plus dexamethasone and daratumumab or bortezomib in relapsed/refractory multiple myeloma: final results of a phase I/IIa study

Melphalan flufenamide (melflufen), a first-in-class, alkylating peptide-drug conjugate, demonstrated clinical benefit in combination with dexamethasone in triple-class refractory multiple myeloma (MM). The phase I/IIa ANCHOR study evaluated melflufen (30 or 40 mg) and dexamethasone (40 mg with daratumumab; 20 mg followed by 40 mg with bortezomib; dose reduced if aged ≥75 years) in triplet combination with daratumumab (16 mg/kg; daratumumab arm) or bortezomib (1.3 mg/m2; bortezomib arm) in patients with relapsed/refractory MM refractory to an immunomodulatory agent and/or a proteasome inhibitor and who had received one to four prior lines of therapy. Primary objectives were to determine the optimal dose of melflufen in triplet combination (phase I) and overall response rate (phase IIa). In total, 33 patients were treated in the daratumumab arm and 23 patients received therapy in the bortezomib arm. No dose-limiting toxicities were reported at either melflufen dose level with either combination. With both triplet regimens, the most common grade ≥3 treatment-emergent adverse events were thrombocytopenia and neutropenia; thrombocytopenia was the most common treatment-emergent adverse event leading to treatment discontinuation. In the daratumumab arm, patients receiving melflufen 30 mg remained on treatment longer than those receiving the 40-mg dose. In the daratumumab arm, the overall response rate was 73% and median progression-free survival was 12.9 months. Notably, in the bortezomib arm, the overall response rate was 78% and median progression-free survival was 14.7 months. Considering the totality of the data, melflufen 30 mg was established as the recommended dose for use with dexamethasone and daratumumab or bortezomib for future studies in relapsed/refractory MM.

Selinexor in multiple myeloma

INTRODUCTION

Selinexor, an XPO1 inhibitor, has emerged as a promising therapeutic option in the challenging landscape of relapsed/refractory multiple myeloma (RRMM).

AREAS COVERED

This article provides a review of selinexor, with a focus on available clinical studies involving MM patients and its safety profile. Clinical trials, such as STORM and BOSTON, have demonstrated its efficacy, particularly in combination regimens, showcasing notable overall response rates (ORR) and prolonged median progressionfree survival (mPFS). Selinexor's versatility is evident across various combinations, including carfilzomibdexamethasone (XKd), lenalidomidedexamethasone (XRd), and pomalidomidedexamethasone (XPd), with efficacy observed even in tripleclass refractory and highrisk patient populations. However, challenges, including resistance mechanisms and adverse events, necessitate careful management. Realworld evidence also underscores selinexor's effectiveness in RRMM, though dose adjustments and supportive measures remain crucial. Ongoing trials are exploring selinexor in diverse combinations and settings, including pomalidomidenaïve patients and postautologous stem cell transplant (ASCT) maintenance.

EXPERT OPINION

The evolving landscape of selinexor's role in the sequencing of treatment for RRMM, its potential in highrisk patients, including those with extramedullary disease, as revealed in the most recent international meetings, and ongoing investigations signal a dynamic era in myeloma therapeutics. Selinexor emerges as a pivotal component in multidrug strategies and innovative combinations.

Safety of selinexor as the only exportin 1 (XPO1) inhibitor so far: a post-marketing study based on the world Health Organization pharmacovigilance database (Vigibase)

BACKGROUND

Exportin 1 (XPO1) inhibitors are being developed as a new agent for anti-cancer therapies. This study aimed to broadly portray the adverse event (AE) profile of selinexor, an XPO1 inhibitor, in actual clinical practice.

RESEARCH DESIGN AND METHODS

Disproportionality analyses were conducted by calculating the information component and reporting odds ratio in VigiBase over different reporting periods. All selinexor-related AEs were classified by system organ class (SOC) and preferred term (PT) according to the Medical Dictionary for Regulatory Activities.

RESULTS

A total of 116,443 AEs were identified in 2,608 patients that received selinexor. Patients with cardiac disorders had a higher propensity for death. Thirteen SOCs and 125 PTs were identified as having a potential connection with selinexor. Notably, 29 suspected signals detected in our study were defined as significant AEs by the European Medicines Agency, including febrile neutropenia, pancytopenia, and acute kidney injury. Attention should be paid to these AEs, despite most toxicities being manageable and reversible.

CONCLUSIONS

This study highlights a number of AEs associated with selinexor. Most toxicities are reversible but require careful management. The benefit of selinexor still outweighs the potential risks, indicating XPO1 inhibitors as promising agents.

New Biological Therapies for Multiple Myeloma

Multiple myeloma is a cancer of bone marrow plasma cells that represents approximately 10% of hematologic malignancies. Though it is typically incurable, a remarkable suite of new therapies developed over the last 25 years has enabled durable disease control in most patients. This article briefly introduces the clinical features of multiple myeloma and aspects of multiple myeloma biology that modern therapies exploit. Key current and emerging treatment modalities are then reviewed, including cereblon-modulating agents, proteasome inhibitors, monoclonal antibodies, other molecularly targeted therapies (selinexor, venetoclax), chimeric antigen receptor T cells, T cell-engaging bispecific antibodies, and antibody-drug conjugates. For each modality, mechanism of action and clinical considerations are discussed. These therapies are combined and sequenced in modern treatment pathways, discussed at the conclusion of the article, which have led to substantial improvements in outcomes for multiple myeloma patients in recent years.

Alterations in chromosome 1q in multiple myeloma randomized clinical trials: a systematic review

Extra copies of chromosome 1q21 (+1q: gain = 3 copies, amp >= 4 copies) are associated with worse outcomes in multiple myeloma (MM). This systematic review assesses the current reporting trends of +1q, the efficacy of existing regimens on +1q, and its prognostic implications in MM randomized controlled trials (RCTs). Pubmed, Embase and Cochrane Registry of RCTs were searched from January 2012 to December 2022. Only MM RCTs were included. A total of 124 RCTs were included, of which 29 (23%) studies reported on +1q. Among them, 10% defined thresholds for +1q, 14% reported survival data separately for gain and amp, and 79% considered +1q a high-risk cytogenetic abnormality. Amongst RCTs that met the primary endpoint showing improvement in progression free survival (PFS), lenalidomide maintenance (Myeloma XI), selinexor (BOSTON), and isatuximab (IKEMA and ICARIA) were shown to improve PFS for patients with evidence of +1q. Some additional RCT's such as Myeloma XI+ (carfilzomib), ELOQUENT-3 (elotuzumab), and HOVON-65/GMMG-HD4 (bortezomib) met their endpoint showing improvement in PFS and also showed improvement in PFS in the +1q cohort, although the confidence interval crossed 1. All six studies that reported HR for +1q patients vs. without (across both arms) showed worse OS and PFS for +1q. There is considerable heterogeneity in the reporting of +1q. All interventions that have shown to be successful in RCTs and have clearly reported on the +1q subgroup have shown concordant direction of results and benefit of the applied intervention. A more standardized approach to reporting this abnormality is needed.

Treatment of multiple myeloma with selinexor: a review

Over the last 20 years, breakthroughs in accessible therapies for the treatment of multiple myeloma (MM) have been made. Nevertheless, patients with MM resistant to immunomodulatory drugs, proteasome inhibitors, and anti-CD38 monoclonal antibodies have a very poor outcome. Therefore, it is necessary to explore new drugs for the treatment of MM. This review summarizes the mechanism of action of selinexor, relevant primary clinical trials, and recent developments in both patients with relapsed/refractory myeloma and patients with newly diagnosed myeloma. Selinexor may be useful for the treatment of refractory MM.

Therapeutic targeting of nuclear export and import receptors in cancer and their potential in combination chemotherapy

Systemic modalities are crucial in the management of disseminated malignancies and liquid tumours. However, patient responses and tolerability to treatment are generally poor and those that enter remission often return with refractory disease. Combination therapies provide a methodology to overcome chemoresistance mechanisms and address dose-limiting toxicities. A deeper understanding of tumorigenic processes at the molecular level has brought a targeted therapy approach to the forefront of cancer research, and novel cancer biomarkers are being identified at a rapid rate, with some showing potential therapeutic benefits. The Karyopherin superfamily of proteins is soluble receptors that mediate nucleocytoplasmic shuttling of proteins and RNAs, and recently, nuclear transport receptors have been recognized as novel anticancer targets. Inhibitors against nuclear export have been approved for clinical use against certain cancer types, whereas inhibitors against nuclear import are in preclinical stages of investigation. Mechanistically, targeting nucleocytoplasmic shuttling has shown to abrogate oncogenic signalling and restore tumour suppressor functions through nuclear sequestration of relevant proteins and mRNAs. Hence, nuclear transport inhibitors display broad spectrum anticancer activity and harbour potential to engage in synergistic interactions with a wide array of cytotoxic agents and other targeted agents. This review is focussed on the most researched nuclear transport receptors in the context of cancer, XPO1 and KPNB1, and highlights how inhibitors targeting these receptors can enhance the therapeutic efficacy of standard of care therapies and novel targeted agents in a combination therapy approach. Furthermore, an updated review on the therapeutic targeting of lesser characterized karyopherin proteins is provided and resistance to clinically approved nuclear export inhibitors is discussed.

Epigenetic Alterations as Vital Aspects of Bortezomib Molecular Action

Bortezomib (BTZ) is widely implemented in the treatment of multiple myeloma (MM). Its main mechanism of action is very well established. BTZ selectively and reversibly inhibits the 26S proteasome. More precisely, it interacts with the chymotryptic site of the 20S proteasome and therefore inhibits the degradation of proteins. This results in the intracellular accumulation of misfolded or otherwise defective proteins leading to growth inhibition and apoptosis. As well as interfering with the ubiquitin-proteasome complex, BTZ elicits various epigenetic alterations which contribute to its cytotoxic effects as well as to the development of BTZ resistance. In this review, we summarized the epigenetic alterations elicited by BTZ. We focused on modifications contributing to the mechanism of action, those mediating drug-resistance development, and epigenetic changes promoting the occurrence of peripheral neuropathy. In addition, there are therapeutic strategies which are specifically designed to target epigenetic changes. Herein, we also reviewed epigenetic agents which might enhance BTZ-related cytotoxicity or restore the sensitivity to BTZ of resistant clones. Finally, we highlighted putative future perspectives regarding the role of targeting epigenetic changes in patients exposed to BTZ.

Oral Selinexor as Maintenance Therapy After First-Line Chemotherapy for Advanced or Recurrent Endometrial Cancer

PURPOSE

Selinexor inhibits exportin-1 (XPO1) resulting in nuclear accumulation of tumor suppressor proteins including p53 and has clinical activity in endometrial cancer (EC). The primary end point was to assess progression-free survival (PFS) with once-weekly oral selinexor in patients with advanced or recurrent EC.

PATIENTS AND METHODS

ENGOT-EN5/GOG-3055/SIENDO was a randomized, prospective, multicenter, double-blind, placebo-controlled, phase III study at 107 sites in 10 countries. Patients 18 years or older with histologically confirmed EC were enrolled. All had completed a single line of at least 12 weeks of taxane-platinum combination chemotherapy and achieved partial or complete response. Patients were assigned to receive 80 mg oral selinexor once weekly or placebo with 2:1 random assignment (ClinicalTrials.gov identifier: NCT03555422).

RESULTS

Between January 2018 and December 2021, 263 patients were randomly assigned, with 174 allocated to selinexor and 89 to placebo. The median PFS was 5.7 months (95% CI, 3.81 to 9.20) with selinexor versus 3.8 months (95% CI, 3.68 to 7.39) with placebo (hazard ratio [HR], 0.76 [95% CI, 0.54 to 1.08]; two-sided P = .126), which did not meet the criteria for statistical significance in the intent-to-treat population. Incorrect chemotherapy response stratification data for 7 (2.7%) patients were identified. In a prespecified exploratory analysis of PFS in audited stratification data, PFS for selinexor met the threshold for statistical significance (HR, 0.71; 95% CI, 0.499 to 0.996; two-sided P = .049). Furthermore, patients with the TP53 wild-type (wt) EC had a median PFS of 13.7 and 3.7 months with selinexor and placebo. The most common grade 3 treatment-related adverse events were nausea (9%), neutropenia (9%), and thrombocytopenia (7%).

CONCLUSION

The significance level for PFS was only met in the audited analysis. However, a preliminary analysis of a prespecified exploratory subgroup of patients with TP53wt EC showed promising results with selinexor maintenance therapy.

Considerations for next therapy after anti-CD38 monoclonal antibodies used as first line

In the current treatment paradigm, the use of anti-CD38 monoclonal antibodies (mAbs) in frontline has notably increased, for both transplant-ineligible and transplant-eligible patients with newly diagnosed multiple myeloma (NDMM) patients. As a result, patients with multiple myeloma (MM) are frequently exposed to or develop resistance to anti-CD38 mAb therapy during the initial stages of treatment. Here, we review second-line (first relapse) and some third-line (second relapse) therapies for patients with MM with disease progression after exposure to anti-CD38 mAb-based therapy. We discuss therapies including B-cell maturation antigen (BCMA)-targeted and non-BCMA-targeted therapeutic options in the setting of prior anti-CD38 mAb exposure/refractoriness.

Association of Selinexor Dose Reductions With Clinical Outcomes in the BOSTON Study

BACKGROUND

Dose modifications in response to adverse events (AEs) can maintain tumor response and improve therapy tolerability. We conducted a post-hoc analysis of the efficacy and safety of reduced selinexor doses in the BOSTON trial (NCT03110562).

PATIENTS AND METHODS

Efficacy, safety, and quality of life (QoL) in 195 patients with relapsed/refractory multiple myeloma randomized to once-weekly (QW) selinexor (100 mg), QW subcutaneous bortezomib (1.3 mg/m2), and twice-weekly dexamethasone (20 mg) were compared between patients with dose reductions and those without.

RESULTS

In total, 126 patients (65%) had selinexor dose reductions (median dose 71.4 mg/wk). In patients with dose reductions versus those without median progression-free survival was 16.6 months (95% CI 12.9-not evaluable [NE]) versus 9.2 months [95% CI 6.8-15.5]), overall response rate was 81.7% (95% CI 73.9-88.1%) versus 66.7% (95% CI 54.3-77.6%), ≥very good partial response was (51.6% [95% CI 42.5-60.6%] vs. 31.9% [95% CI 21.2-44.2]), median duration of response was not reached (95% CI 13.8-NE) versus 12.0 months (95% CI 8.3-NE), and time to next treatment was 22.6 months (95% CI 14.6-NE) versus 10.5 months (95% CI 6.3-18.2). Mean best change from baseline on the EORTC QLQ-C30 Global Health Status/QoL scale was 10.0 ± 20.5 versus 4.0 ± 20.9. Duration-adjusted AE rates that were lower after selinexor dose reduction included thrombocytopenia (62.5% before vs. 47.6% after), nausea (31.6% vs. 7.3%), fatigue (28.1% vs. 9.9%), decreased appetite (21.5% vs. 6.4%), anemia (17.9% vs. 10.3%), and diarrhea (12.9% vs. 5.2%).

CONCLUSION

Appropriate dose reductions in response to AEs of the 100 mg selinexor starting dose in the BOSTON study were associated with improved efficacy, reduced AE rates and improved QoL.

Optimal timing and drug combination of selinexor in multiple myeloma: a systematic review and meta-analysis

OBJECTIVES

Multiple myeloma (MM) remains an incurable disease despite advances in treatment options. Recently, selinexor has shown promising efficacy for relapsed/refractory multiple myeloma (RRMM), whereas its optimal timing and drug combination remain unclear. In order to assess the various regimens that incorporate selinexor, a systematic review and meta-analysis was conducted.

METHODS

Clinical trials and real-world studies involving MM patients treated with selinexor were included. Pooled risk ratio (RR) was calculated to compare the rates, along with a 95% confidence interval (CI) and concurrent p-value assessment. A random-effects model was employed to provide a more conservative evaluation.

RESULTS

A total of 16 studies enrolling 817 patients were reviewed. The usage of selinexor as the fifth-line or prior therapy achieved a higher objective response rate (ORR) (65.9% versus 23.4%, p < 0.01) and longer pooled progression-free survival (PFS) (median: 12.5 months versus 2.9 months, p < 0.01) than those after the fifth-line usage. In addition, early usage also resulted in a consistent trend of pooled overall survival (median: 22.7 months versus 8.9 months, p = 0.26), compared with post-fifth-line usage. Selinexor and dexamethasone (Xd) plus either protease inhibitors (PIs) or immunomodulatory drugs (IMiDs) achieved better ORRs than the Xd-only regimen for RRMM, with ORRs of 56.1%, 52.5% and 24.6%, respectively (p < 0.01).

CONCLUSION

In conclusion, using selinexor as the fifth-line or prior therapy had a beneficial impact on RRMM. The regimen of Xd plus PIs or IMiDs was recommended.

Selinexor in patients with advanced and recurrent endometrial cancer

Selinexor is an oral inhibitor of the nuclear export protein called Exportin 1 (XPO1) with demonstrated antitumor activity in hematological and solid tumors. Selinexor, blocking XPO1, induces nuclear localization of tumor suppressor proteins (including p53, p73, BRCA1, and pRB), leading to the selective induction of apoptosis, and inhibition of DNA damage repair proteins. XPO1 overexpression is common in endometrial cancers. Phase I and II trials reported the antitumor activity of selinexor in patients with endometrial carcinoma. The preliminary results of the phase III Selinexor in ENDOmetrial Cancer (SIENDO/ENGOT-EN5/GOG-3055) trial supported the use of selinexor as maintenance therapy in advanced endometrial cancer patients achieving at least partial response after a minimum of 12 weeks of first-line platinum-based chemotherapy. Selinexor maintenance resulted in a (nonsignificant) 30% reduction in the risk of disease progression or death. Looking at the endometrial cancer molecular subgroup characterized by TP53 wild type, the antitumor activity of selinexor seemed more pronounced, resulting in approximately a 60% reduction in the risk of disease progression or death. The SIENDO and the XPORT-EC trials will clarify the benefits and risks of adding selinexor as a first-line chemotherapy maintenance treatment in all-comer and TP53 wild-type endometrial cancers. Preclinical data highlights the potential for selinexor to be synthetically lethal with PARP inhibitors and may also plan a role in overcoming acquired resistance to those therapies. Therefore, new possible combinations with PARP inhibitors and should be evaluated. Furthermore, the combination of selinexor plus immune checkpoint inhibitors deserves further investigation in clinical trials.

NK92 Expressing Anti-BCMA CAR and Secreted TRAIL for the Treatment of Multiple Myeloma: Preliminary In Vitro Assessment

Multiple myeloma (MM) has witnessed improved patient outcomes through advancements in therapeutic approaches. Notably, allogeneic stem cell transplantation, proteasome inhibitors, immunomodulatory drugs, and monoclonal antibodies have contributed to enhanced quality of life. Recently, a promising avenue has emerged with chimeric antigen receptor (CAR) T cells targeting B-cell maturation antigen (BCMA), expressed widely on MM cells. To mitigate risks associated with allogenic T cells, we investigated the potential of BCMA CAR expression in natural killer cells (NKs), known for potent cytotoxicity and minimal side effects. Using the NK-92 cell line, we co-expressed BCMA CAR and soluble tumor necrosis factor-related apoptosis-inducing ligand (sTRAIL) employing the piggyBac transposon system. Engineered NK cells (CAR-NK-92-TRAIL) demonstrated robust cytotoxicity against a panel of MM cell lines and primary patient samples, outperforming unmodified NK-92 cells with a mean difference in viability of 45.1% (±26.1%, depending on the target cell line). Combination therapy was explored with the proteasome inhibitor bortezomib (BZ) and γ-secretase inhibitors (GSIs), leading to a significant synergistic effect in combination with CAR-NK-92-TRAIL cells. This synergy was evident in cytotoxicity assays where a notable decrease in MM cell viability was observed in combinatorial therapy compared to single treatment. In summary, our study demonstrates the therapeutic potential of the CAR-NK-92-TRAIL cells for the treatment of MM. The synergistic impact of combining these engineered NK cells with BZ and GSI supports further development of allogeneic CAR-based products for effective MM therapy.

Nuclear transport proteins: structure, function, and disease relevance

Proper subcellular localization is crucial for the functioning of biomacromolecules, including proteins and RNAs. Nuclear transport is a fundamental cellular process that regulates the localization of many macromolecules within the nuclear or cytoplasmic compartments. In humans, approximately 60 proteins are involved in nuclear transport, including nucleoporins that form membrane-embedded nuclear pore complexes, karyopherins that transport cargoes through these complexes, and Ran system proteins that ensure directed and rapid transport. Many of these nuclear transport proteins play additional and essential roles in mitosis, biomolecular condensation, and gene transcription. Dysregulation of nuclear transport is linked to major human diseases such as cancer, neurodegenerative diseases, and viral infections. Selinexor (KPT-330), an inhibitor targeting the nuclear export factor XPO1 (also known as CRM1), was approved in 2019 to treat two types of blood cancers, and dozens of clinical trials of are ongoing. This review summarizes approximately three decades of research data in this field but focuses on the structure and function of individual nuclear transport proteins from recent studies, providing a cutting-edge and holistic view on the role of nuclear transport proteins in health and disease. In-depth knowledge of this rapidly evolving field has the potential to bring new insights into fundamental biology, pathogenic mechanisms, and therapeutic approaches.

Multiple Myeloma in 2023 Ways: From Trials to Real Life

Multiple myeloma is a chronic hematologic malignancy that obstinately tends to relapse. Basic research has made giant strides in better characterizing the molecular mechanisms of the disease. The results have led to the manufacturing of new, revolutionary drugs which have been widely tested in clinical trials. These drugs have been approved and are now part of the therapeutic armamentarium. As a consequence, it is essential to combine what we know from clinical trials with real-world data in order to improve therapeutic strategies. Starting with this premise, our review aims to describe the currently employed regimens in multiple myeloma and compare clinical trials with real-life experiences. We also intend to put a spotlight on promising therapies such as T-cell engagers and chimeric antigen receptor T-cells (CAR-T) which are proving to be effective in changing the course of advanced-stage disease.

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.

Real World Efficacy and Toxicity of Selinexor: Importance of Patient Characteristics, Dose Intensity and Post Progression Outcomes

BACKGOUND

Selinexor is an orally available selective inhibitor of exportin-1 that has offered a new treatment option in relapsed or refractory myeloma (RRMM) either in combination with dexamethasone (Sd) or with bortezomib and dexamethasone (SVd).

PATIENTS-METHODS

We evaluated the efficacy and toxicity of selinexor combinations in the real world, post progression therapies and their outcomes. The analysis included 44 patients with RRMM treated with Sd (N = 21, 48%) or SVd (N = 23, 52%).

RESULTS

On intent-to-treat, response rate (ORR) among all treated patients was 29.5% (13/44, of which CR: 2, VGPR: 3, PR:8); ORR was 35% for SVd and 24% for Sd. Median PFS was 3.0 months for all; 6.9 months for responders (≥PR),2.7 months for Sd and 3.4 months for SVd treated patients. In univariate analysis, serum albumin <3.5 g/dl and LDH >ULN were associated with worse PFS (P = .001 and P = .032, respectively).The OS of the whole cohort exceeded one year while serum albumin <3.5 gr/dl and LDH>ULN were associated with worse OS. After progression to Sd/SVd, 20 patients received further therapy; on ITT, the ORR was 40% (8/20) and the subsequent PFS was 3.4 months. The most common adverse events were fatigue, thrombocytopenia and nausea, while the most recorded grade 3 or 4 side effect was thrombocytopenia; 56% (25/44) of patients required dose reduction, however, this was not associated with inferior PFS.

CONCLUSION

In conclusion, selinexor-based therapy provides an additional treatment option in the real word setting and with appropriate dosing and toxicity management a subset of patients may have significant benefit.

The synergy of the XPO1 inhibitors combined with the BET inhibitor INCB057643 in high-grade B-cell lymphoma via downregulation of MYC expression

High grade B-cell lymphoma with MYC and BCL2 rearrangements (HGBCL-DH) represents an uncommon B-cell lymphoma (BCL) with aggressive clinical courses and poor prognosis. Despite revolutionary therapeutic advances in BCL, there has been limited treatment progress in HGBCL-DH, thus necessitating additional therapeutic strategies for HGBCL-DH. This study demonstrated that the BET antagonist INCB057643 synergized with the XPO1 inhibitors (selinexor and eltanexor) to decrease cell viability and increase cell apoptosis in HGBCL-DH cells with or without TP53 mutations. As anticipated, the combined treatment of INCB057643 with selinexor slowed tumor growth and reduced the tumor burden in TP53-mutated HGBCL-DH xenografts. Mechanistically, MYC functional inhibition was a potential molecular mechanism underlying the synergy of the combined INCB057643 and selinexor treatment in HGBCL-DH cells independent of TP53 mutation status. In TP53 mutated HGBCL-DH cells, inducing DNA damage and impairing the DNA damage response (DDR) were involved in the therapeutic interaction of the combined regimen. In TP53 wild-type cells, the molecular mechanism was linked with upregulation of p53 levels and activation of its targeted pathways, rather than dysregulation of the DDR. Collectively, we might provide a potential promising combination therapy regimen for the management of HGBCL-DH. Clinical evaluations are warranted to confirm this conclusion.

Anti-tumor activity of selinexor in combination with antineoplastic agents in chronic lymphocytic leukemia

Despite recent relevant therapeutic progresses, chronic lymphocytic leukemia (CLL) remains an incurable disease. Selinexor, an oral inhibitor of the nuclear export protein XPO1, is active as single agent in different hematologic malignancies, including CLL. The purpose of this study was to evaluate the anti-tumor effects of selinexor, used in combination with chemotherapy drugs (i.e. fludarabine and bendamustine) or with the PI3Kδ inhibitor idelalisib in CLL. Our results showed a significant decrease in CLL cell viability after treatment with selinexor-containing drug combinations compared to each single compound, with demonstration of synergistic cytotoxic effects. Interestingly, this drug synergism was exerted also in the presence of the protective effect of stromal cells. From the molecular standpoint, the synergistic cytotoxic activity of selinexor plus idelalisib was associated with increased regulatory effects of this drug combination on the tumor suppressors FOXO3A and IkBα compared to each single compound. Finally, selinexor was also effective in potentiating the in vivo anti-tumor effects of the PI3Kδ inhibitor in mice treated with the drug combination compared to single agents. Our data provide preclinical evidence of the synergism and potential efficacy of a combination treatment targeting XPO1 and PI3Kδ in CLL.

Real-world study of the efficacy and safety of belantamab mafodotin (GSK2857916) in relapsed or refractory multiple myeloma based on data from the nominative ATU in France: the IFM 2020-04 study

Belantamab mafodotin (BM) is an anti-BCMA antibody-drug conjugate (GSK2857916) that represents an alternative option in multiple myeloma. We sought to assess the efficacy and safety of BM in a real-world setting in patients who benefited from an early access program. We conducted an observational, retrospective, multicenter study. Eligibility criteria were treatment of relapsed or refractory multiple myeloma (RRMM) in monotherapy in adult patients who have received at least three lines of therapy previously, including at least one immunomodulatory agent (IMiD), a proteasome inhibitor (PI) and an anti-CD38 monoclonal antibody, and whose disease progressed during the last treatment period. The primary endpoint of the study is to assess the overall survival (OS). Between November 2019 and December 2020, 106 patients were treated with BM; 97 were eligible for the efficacy evaluation and 104 for safety. The median age was 66 (range, 37-82) years. High-risk cytogenetics were identified in 40.9% of patients. Fifty-five (56.7%) patients were triple-class refractory and 11 (11.3%) were penta-class refractory. The median number of prior lines of treatment was five (range, 3-12). The median number of BM cycles administered was three (range, 1-22). The overall response rate at best response was 38.1% (37/97). The median OS was 9.3 months (95% confidence interval [CI]: 5.9-15.3), and median progression-free survival was 3.5 months (95% CI: 1.9-4.7). The median duration of response was 9 months (range, 4.65-10.4). Treatment was delayed for 55 (52.9%) patients including 36.5% for treatment-related toxicity. Ophthalmic adverse events, mainly grade ≤2, were the most common toxicity (48%). The occurrence of keratopathy was 37.5%. Overall, our data are concordant with the results from DREAMM-2 in terms of efficacy and safety on a non-biased population.

Multiple Myeloma: Current Clinical Landscape and Compounding Costs

PURPOSE OF REVIEW

The treatment landscape of multiple myeloma (MM) has evolved resulting in MM becoming a chronic condition. The costs of MM therapies are substantial and compound as patients remain on long-term maintenance therapies and progress through multiple lines of high-cost therapies. MM predominantly impacts the elderly population insured by Medicare; here, we analyze how these costs impact patients and the Medicare trust fund.

RECENT FINDINGS

With the recent passing of the Inflation Reduction Act (IRA), we postulate how costs may be impacted and debate future policy initiatives that may result in sustainability. The IRA will impact drug pricing and likely reduce the costs of some treatments used in MM; there is still a lot of room for policy reform to reduce financial toxicity to patients and prevent depletion of the Medicare trust fund.

Selinexor-Based Triplet Regimens in Patients With Multiple Myeloma Previously Treated With Anti-CD38 Monoclonal Antibodies

BACKGROUND

The increasing use of anti-CD38 monoclonal antibodies (αCD38 mAbs) for newly diagnosed or early relapsed multiple myeloma (MM), especially in non-transplant eligible patients, may lead to more patients developing αCD38 mAb-refractory disease earlier in the treatment course with fewer treatment options.

PATIENTS AND METHODS

We analyzed the efficacy and safety of selinexor-based triplets (selinexor+dexamethasone [Sd] plus pomalidomide [SPd, n = 23], bortezomib [SVd, n = 16] or carfilzomib (SKd, n = 23]) in a subset of STOMP (NCT02343042) and BOSTON (NCT03110562) study patients treated previously with αCD38 mAbs.

RESULTS

Sixty-two patients (median 4 prior therapies, range 1 to 11, 90.3% refractory to αCD38 mAb) were included. Overall response rates (ORR) in the SPd, SVd and SKd cohorts were 52.2%, 56.3%, and 65.2%, respectively. Overall response rate was 47.4% among patients who had MM refractory to the third drug reintroduced in the Sd-based triplet. Median progression-free survival in the SPd, SVd, and SKd cohorts was 8.7, 6.7, and 15.0 months, respectively, and median overall survival was 9.6, 16.9, and 33.0 months, respectively. Median time to discontinuation in the SPd, SVd, and SKd cohorts was 4.4, 5.9, and 10.6 months, respectively. The most common hematological adverse events were thrombocytopenia, anemia, and neutropenia. Nausea, fatigue, and diarrhea were primarily grade 1/2. Adverse events were generally manageable with standard supportive care and dose modifications.

CONCLUSION

Selinexor-based regimens may offer effective and well-tolerated therapy to patients with relapsed and/or refractory MM who had disease previously exposed or refractory to αCD38 mAb therapy and could help address the unmet clinical need in these high-risk 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.

A safety review of recently approved and emerging drugs for patients with relapsed or refractory multiple myeloma

INTRODUCTION

Multiple new drugs have been approved over the past 5 years for the treatment of relapsed/refractory multiple myeloma (RRMM), and these are being increasingly widely used. Clinicians need to familiarize themselves with common toxicities associated with these drugs and with novel toxicities requiring specific management and supportive care.

AREAS COVERED

We review common toxicities associated with agents approved for RRMM in the past 5 years, including the anti-CD38 monoclonal antibody isatuximab, the antibody-drug conjugate belantamab mafodotin, the bispecific antibody teclistamab, the chimeric antigen receptor (CAR) T cell products idecabtagene vicleucel and ciltacabtagene autoleucel, the selective inhibitor of nuclear export compound selinexor, and the drug-peptide conjugate melflufen, as well as toxicities associated with emerging agents for RRMM including additional bispecific antibodies, the BCL-2 inhibitor venetoclax, and the cereblon E3 ligase modulators iberdomide and mezigdomide. We searched the published literature using PubMed, plus congress abstracts, for the above list of drug names or classes and 'myeloma.'

EXPERT OPINION

Optimal management of toxicities associated with these recently approved and emerging therapies will be critical in maximizing clinical benefit and aiding widespread adoption in routine clinical practice. We summarize current recommendations and guidelines and provide expert insights into supportive care requirements.

Belantamab Mafodotin: From Clinical Trials Data to Real-Life Experiences

Despite the recent approval of novel immunotherapies, such as immunomodulatory drugs, proteasome inhibitors and anti-CD38 monoclonal antibodies, Multiple Myeloma (MM) remains incurable, and the acquisition of triple-refractoriness leads to really dismal outcomes in even earlier lines of therapy. More recently, innovative therapeutic strategies targeting B cell maturation antigen (BCMA), highly expressed on the plasma cell surface, are drawing different future landscapes in terms of effectiveness and outcomes. Belantamab Mafodotin, a first-in-class anti-BCMA antibody-drug conjugate, demonstrated good efficacy and safety profile in triple-refractory patients in the phase 2 DREAMM-2 trial, and it was approved for the treatment of MM triple-exposed patients with >4 prior lines of therapy. Here, starting from Belantamab Mafodotin clinical trials and also exploring combination studies and different schedules in order to improve its efficacy and toxicity, we focused on real-life experiences all over the world, which have confirmed clinical trial data and encourage further Belantamab Mafodotin investigations.

APEX3 - an optimized tool for rapid and unbiased proximity labeling

Macromolecular interactions regulate all aspects of biology. The identification of interacting partners and complexes is important for understanding cellular processes, host-pathogen conflicts, and organismal development. Multiple methods exist to label and enrich interacting proteins in living cells. Notably, the soybean ascorbate peroxidase, APEX2, rapidly biotinylates adjacent biomolecules in the presence of biotin-phenol and hydrogen peroxide. However, during initial experiments with this system, we found that APEX2 exhibits a cytoplasmic-biased localization and is sensitive to the nuclear export inhibitor leptomycin B (LMB). This led us to identify a putative nuclear export signal (NES) at the carboxy-terminus of APEX2 (NES_APEX2), structurally adjacent to the conserved heme binding site. This putative NES is functional as evidenced by cytoplasmic localization and LMB sensitivity of a mCherry-NES_APEX2 chimeric construct. Single amino acid substitutions of multiple hydrophobic residues within NES_APEX2 eliminate cytoplasm-biased localization of both mCherry-NES_APEX2 as well as full-length APEX2. However, all but one of these NES substitutions also compromises peroxide-dependent labeling. This unique separation-of-function mutant, APEX2-L242A, is termed APEX3. Localization and functionality of APEX3 are confirmed by fusion to the nucleocytoplasmic shuttling transcriptional factor, RELA. APEX3 is therefore an optimized tool for unbiased proximity labeling of cellular proteins and interacting factors.

Current Main Topics in Multiple Myeloma

Multiple Myeloma (MM) remains a difficult to treat disease mainly due to its biological heterogeneity, of which we are more and more knowledgeable thanks to the development of increasingly sensitive molecular methods that allow us to build better prognostication models. The biological diversity translates into a wide range of clinical outcomes from long-lasting remission in some patients to very early relapse in others. In NDMM transplant eligible (TE) patients, the incorporation of mAb as daratumumab in the induction regimens, followed by autologous stem cell transplantation (ASCT) and consolidation/maintenance therapy, has led to a significant improvement of PFS and OS.; however, this outcome remains poor in ultra-high risk MM or in those who did not achieve a minimal residual disease (MRD) negativity. Several trials are exploring cytogenetic risk-adapted and MRD-driven therapies in these patients. Similarly, quadruplets-containing daratumumab, particularly when administered as continuous therapies, have improved outcome of patients not eligible for autologous transplant (NTE). Patients who become refractory to conventional therapies have noticeably poor outcomes, making their treatment a difficult challenge in need of novel strategies. In this review, we will focus on the main points regarding risk stratification, treatment and monitoring of MM, highlighting the most recent evidence that could modify the management of this still incurable disease.

Management of Relapsed-Refractory Multiple Myeloma in the Era of Advanced Therapies: Evidence-Based Recommendations for Routine Clinical Practice

Multiple myeloma (MM) is the second most common hematologic malignancy in adults worldwide. Over the past few years, major therapeutic advances have improved progression-free and overall survival, as well as quality of life. Despite this recent progress, MM remains incurable in the vast majority of cases. Patients eventually relapse and become refractory to multiple drug classes, making long-term management challenging. In this review, we will focus on the treatment paradigm of relapsed/refractory MM (RRMM) in the era of advanced therapies emphasizing the available novel modalities that have recently been incorporated into routine practice, such as chimeric antigen receptor T-cell therapy, bispecific antibodies, and other promising approaches. We will also discuss major factors that influence the selection of appropriate drug combinations or cellular therapies, such as relapse characteristics, and other disease and patient related parameters. Our goal is to provide insight into the currently available and experimental therapies for RRMM in an effort to guide the therapeutic decision-making process.

E3 ubiquitin ligase ASB8 promotes selinexor-induced proteasomal degradation of XPO1

Selinexor (KPT-330), a small-molecule inhibitor of exportin-1 (XPO1, CRM1) with potent anticancer activity, has recently been granted FDA approval for treatment of relapsed/refractory multiple myeloma and diffuse large B-cell lymphoma (DLBCL), with a number of additional indications currently under clinical investigation. Since selinexor has often demonstrated synergy when used in combination with other drugs, notably bortezomib and dexamethasone, a more comprehensive approach to uncover new beneficial interactions would be of great value. Moreover, stratifying patients, personalizing therapeutics and improving clinical outcomes requires a better understanding of the genetic vulnerabilities and resistance mechanisms underlying drug response. Here, we used CRISPR-Cas9 loss-of-function chemogenetic screening to identify drug-gene interactions with selinexor in chronic myeloid leukemia, multiple myeloma and DLBCL cell lines. We identified the TGFβ-SMAD4 pathway as an important mediator of resistance to selinexor in multiple myeloma cells. Moreover, higher activity of this pathway correlated with prolonged progression-free survival in multiple myeloma patients treated with selinexor, indicating that the TGFβ-SMAD4 pathway is a potential biomarker predictive of therapeutic outcome. In addition, we identified ASB8 (ankyrin repeat and SOCS box containing 8) as a shared modulator of selinexor sensitivity across all tested cancer types, with both ASB8 knockout and overexpression resulting in selinexor hypersensitivity. Mechanistically, we showed that ASB8 promotes selinexor-induced proteasomal degradation of XPO1. This study provides insight into the genetic factors that influence response to selinexor treatment and could support both the development of predictive biomarkers as well as new drug combinations.

Clinical evidence for immune-based strategies in early-line multiple myeloma: current challenges in decision-making for subsequent therapy

Almost all patients with multiple myeloma (MM) will eventually develop disease that has relapsed with or become refractory to available treatments and will require additional therapy. However, data are still lacking on how best to sequence regimens in the relapsed/refractory (RR) setting after the failure of early-line lenalidomide, bortezomib, and/or daratumumab, the most commonly used agents in clinical practice today. With the treatment landscape rapidly changing in response to emerging clinical trial data and approvals of several new drugs and additional combinations, it is critically important to focus on patients with RRMM. Variability in patient baseline characteristics, such as the number of prior lines of treatment, refractoriness to prior treatments, prior stem cell transplant, and timing and dosing of prior lenalidomide, makes it difficult to select the best options for patients with RRMM for whom first-line treatments have failed. The aim of this review is to provide both an overview of current therapies and future directions within the RRMM treatment landscape, and a framework for clinicians to choose the most promising next treatment option.

Relapsed/Refractory Multiple Myeloma: A Review of Available Therapies and Clinical Scenarios Encountered in Myeloma Relapse

Multiple myeloma remains an incurable disease with the usual disease course requiring induction therapy, autologous stem cell transplantation for eligible patients, and long-term maintenance. Risk stratification tools and cytogenetic alterations help inform individualized therapeutic choices for patients in hopes of achieving long-term remissions with preserved quality of life. Unfortunately, relapses occur at different stages of the course of the disease owing to the biological heterogeneity of the disease. Addressing relapse can be complex and challenging as there are both therapy- and patient-related factors to consider. In this broad scoping review of available therapies in relapsed/refractory multiple myeloma (RRMM), we cover the pharmacologic mechanisms underlying active therapies such as immunomodulatory agents (IMiDs), proteasome inhibitors (PIs), monoclonal antibodies (mAbs), traditional chemotherapy, and Venetoclax. We then review the clinical data supporting the use of these therapies, organized based on drug resistance/refractoriness, and the role of autologous stem cell transplant (ASCT). Approaches to special situations during relapse such as renal impairment and extramedullary disease are also covered. Lastly, we look towards the future by briefly reviewing the clinical data supporting the use of chimeric antigen receptor (CAR-T) therapy, bispecific T cell engagers (BITE), and Cereblon E3 Ligase Modulators (CELMoDs).

Inhibition of proteasome, but not lysosome, upregulates organic anion transporter 3 in vitro and in vivo

Organic anion transporter 3 (OAT3), an indispensable basolateral membrane transporter predominantly distributed in the kidney proximal tubules, mediated the systemic clearance of substrates including clinical drugs, nutrients, endogenous and exogenous metabolites, toxins, and critically sustains body homeostasis. Preliminary data in this study showed that classical proteasome inhibitors (e.g., MG132), but not lysosome inhibitors, significantly increased the OAT3 ubiquitination and OAT3-mediated transport of estrone sulfate (ES) in OAT3 stable expressing cells, indicating that proteasome rather than lysosome is involved in the intracellular fate of OAT3. Next, bortezomib and carfilzomib, two FDA-approved and widely applied anticancer agents through selective targeting proteasome, were further used to define the role of inhibiting proteasome in OAT3 regulation and related molecular mechanisms. The results showed that 20S proteasome activity in cell lysates was suppressed with bortezomib and carfilzomib treatment, leading to the increased OAT3 ubiquitination, stimulated transport activity of ES, enhanced OAT3 surface and total expression. The upregulated OAT3 function by proteasome inhibition was attributed to the augment in maximum transport velocity and stability of membrane OAT3. Lastly, in vivo study using Sprague Dawley rats validated that proteasome inhibition using bortezomib induced enhancement of OAT3 ubiquitination and membrane expression in kidney. These data suggest that activity of proteasome but not lysosome could have an impact on the physiological function of OAT3, and proteasome displayed a promising target for OAT3 regulation in vitro and in vivo, and could be used in restoring OAT3 impairment under pathological conditions, avoiding OAT3-associated toxicity and diseases, ensuring drug efficacy and safety.

A phase I study of selinexor combined with weekly carfilzomib and dexamethasone in relapsed/refractory multiple myeloma

We performed a phase I study of weekly selinexor, carfilzomib, and dexamethasone (wSKd) in patients with relapsed/refractory multiple myeloma (MM). The primary objective was to identify the maximum tolerated dose (MTD) of wSKd. Secondary endpoints included overall response rate (ORR), progression-free survival (PFS), and overall survival (OS). Prior exposure/refractoriness to carfilzomib was permitted. Thirty patients were enrolled; 26 (87%) had triple-class exposed disease and 6 (20%) received chimeric antigen receptor (CAR) T-cell therapy. Dose level 2 (carfilzomib 70 mg/m² Intravenous [IV] on Days 1, 8, and 15; selinexor 100 mg PO on Days 1, 8, 15, 22; dexamethasone 40 mg on Days 1, 8, 15, 22 of 28-day cycles) was chosen as the MTD, with no DLTs having occurred. The most common hematologic adverse events (AE) were thrombocytopenia (83%), anemia (70%), lymphopenia (50%), and neutropenia (50%). The most common nonhematologic AE were fatigue (70%), nausea (70%), diarrhea (53%), and anorexia (47%). The ORR was 21/30 (70%) overall and 18/23 (78%) at the MTD. At a median follow-up of 12.3 months, the median PFS was 5.3 months and median OS 23.3 months. Responses were similar in carfilzomib naïve and exposed patients. Long-term efficacy of wSKd is modest; wSKd could be employed as a bridging strategy to immunotherapies.

Recent Advances in the Applications of Small Molecules in the Treatment of Multiple Myeloma

Therapy for multiple myeloma (MM), a hematologic neoplasm of plasma cells, has undergone remarkable changes over the past 25 years. Small molecules (molecular weight of less than one kDa), together with newer immunotherapies that include monoclonal antibodies, antibody-drug conjugates, and most recently, chimeric antigen receptor (CAR) T-cells, have combined to double the disease's five-year survival rate to over 50% during the past few decades. Despite these advances, the disease is still considered incurable, and its treatment continues to pose substantial challenges, since therapeutic refractoriness and patient relapse are exceedingly common. This review focuses on the current pipeline, along with the contemporary roles and future prospects for small molecules in MM therapy. While small molecules offer prospective benefits in terms of oral bioavailability, cellular penetration, simplicity of preparation, and improved cost-benefit considerations, they also pose problems of toxicity due to off-target effects. Highlighted in the discussion are recent developments in the applications of alkylating agents, immunomodulators, proteasome inhibitors, apoptosis inducers, kinesin spindle protein inhibitors, blockers of nuclear transport, and drugs that affect various kinases involved in intracellular signaling pathways. Molecular and cellular targets are described for each class of agents in relation to their roles as drivers of MM.