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

Novel Treatment Options for Multiple Myeloma

Multiple myeloma (MM), the second most common hematologic malignancy in the United States, is characterized by repeated cycles of remission and relapse, with increasing resistance to treatment after each line of therapy. Despite the virtually incurable nature of MM, recent therapeutic breakthroughs have fundamentally reshaped its treatment landscape. This review explores evolving care paradigms, spanning from newly diagnosed MM to relapsed or refractory disease. In the frontline setting, treatment strategies have shifted beyond their traditional emphasis on autologous stem-cell transplant eligibility to a broader categorization of patients on the basis of their suitability for quadruplet therapy. In the relapsed/refractory setting, novel immunotherapies, including chimeric antigen receptor T-cell (CAR-T) therapies and bispecific antibodies, have revolutionized treatment, offering new hope for patients with previously limited options. Precision medicine is playing a growing role in MM treatment, with venetoclax showing significant efficacy in patients with t(11;14) translocation, advancing targeted therapy for this subgroup. On the horizon, investigational CAR-T products and cereblon E3 ligase modulators, such as mezigdomide and iberdomide, may provide faster, more durable responses compared with current therapies. In addition, belantamab mafodotin, an antibody-drug conjugate withdrawn from the US market in 2022, is on the verge of reapproval after positive results from recent randomized trials. While these therapies offer significant potential, challenges remain in managing toxicity, ensuring treatment accessibility, and optimizing sequencing strategies. As the therapeutic arsenal expands, the need for personalized MM treatment plans that balance efficacy with quality of life becomes even more essential.

Disparities in relapsed or refractory multiple myeloma: recommendations from an interprofessional consensus panel

Many studies have documented racial, socioeconomic, geographic, and other disparities for United States (US) patients with multiple myeloma pertaining to diagnosis and frontline management. In contrast, very little is known about disparities in the management of relapsed/refractory multiple myeloma (RRMM) despite a plethora of novel treatment options. In this review, we discuss the manifestations of disparities in RRMM and strategies to mitigate their impact. Immunomodulatory drugs can create disparities on many axes, for example inappropriately low dosing due to Duffy-null status as well as time toxicity and financial toxicity from logistical hurdles for socioeconomically vulnerable patients. Access to myeloma expertise at high-volume centers is a critical consideration given the disconnect between how drugs like carfilzomib and dexamethasone are prescribed in trials versus optimized in real-world practice to lower toxicities. Disparities in chimeric antigen receptor T-cell therapy and bispecific antibody therapy span across racial, ethnic, and socioeconomic lines in large part due to their limited availability outside of high-volume centers. Another insidious source of disparities is supportive care in RRMM, ranging from inadequate pain control in Black patients to limited primary care provider access in rural settings. We discuss the rationales and evidence base for several solutions aimed at mitigating these disparities: for example, (1) bidirectional co-management with community-based oncologists, (2) screening for risk factors based on social determinants of health, (3) strategies to build patient trust with regard to clinical trials, and (4) longitudinal access to a primary care provider. As the treatment landscape for RRMM continues to expand, these types of efforts by the field will help ensure that this landscape is equally accessible and traversable for all US patients.

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.

Beyond oncology: Selinexor's journey into anti-inflammatory treatment and long-term management

Selinexor, a selective inhibitor of nuclear export (SINE), is gaining recognition beyond oncology for its potential in anti-inflammatory therapy. This review elucidates Selinexor's dual action, highlighting its anti-tumor efficacy in various cancers including hematologic malignancies and solid tumors, and its promising anti-inflammatory effects. In cancer treatment, Selinexor has demonstrated benefits as monotherapy and in combination with other therapeutics, particularly in drug-resistant cases. Its role in enhancing the effectiveness of bone marrow transplants has also been noted. Importantly, the drug's impact on key inflammatory pathways provides a new avenue for the management of conditions like sepsis, viral infections including COVID-19, and chronic inflammatory diseases such as Duchenne Muscular Dystrophy and Parkinson's Disease. The review emphasizes the criticality of managing Selinexor's side effects through diligent dose optimization and patient monitoring. Given the complexities of its broader applications, extensive research is called upon to validate Selinexor's long-term safety and effectiveness, with a keen focus on its integration into clinical practice for a diverse spectrum of disorders.

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.