Adverse event management in the TOURMALINE-MM3 study of post-transplant ixazomib maintenance in multiple myeloma

Multiple myeloma and infections in the era of novel treatment modalities

Infections are major cause of morbidity and mortality in patients with multiple myeloma. Current treatment landscape of newly-diagnosed multiple myeloma includes different classes of drugs, such as proteasome inhibitors, immunomodulatory drugs, and monoclonal antibodies, all of which are characterized by specific risk and pattern of infectious complications. Additionally, autologous and allogeneic hematopoietic cell transplantation, widely used in the treatment of multiple myeloma, are complex procedures, carrying a significant risk of complications, and mainly infections. Finally, novel treatment modalities such as bispecific T-cell engagers and chimeric antigen receptor T-lymphocytes have been changing the paradigm of myeloma treatment in relapsed-refractory setting. These agents due to unique mechanism of action carry distinct pattern of infectious complications. In this review, an attempt has been made to summarize the incidence, risk factors, and patterns of infections during different stages of myeloma treatment including novel treatment modalities, and to provide evidence underlying the current concept of infectious disease prophylaxis in this category of patients.

Ixazomib Versus Placebo as Post-Induction Maintenance Therapy in Newly Diagnosed Multiple Myeloma Patients: An Analysis by Age and Frailty Status of the TOURMALINE-MM4 Study

BACKGROUND

The TOURMALINE-MM4 trial demonstrated a significant and clinically meaningful progression-free survival (PFS) benefit with ixazomib versus placebo as postinduction maintenance in nontransplant, newly-diagnosed multiple myeloma patients, with a manageable and well-tolerated toxicity profile.

MATERIALS AND METHODS

In this subgroup analysis, efficacy and safety were assessed by age (< 65, 65-74, and ≥ 75 years) and frailty status (fit, intermediate-fit, and frail).

RESULTS

In this analysis, PFS benefit with ixazomib versus placebo was seen across age subgroups, including patients aged < 65 years (hazard ratio [HR], 0.576; 95% confidence interval [CI], 0.299-1.108; P = .095), 65-74 years (HR, 0.615; 95% CI, 0.467-0.810; P < .001), and ≥ 75 years (HR, 0.740; 95% CI, 0.537-1.019; P = .064). PFS benefit was also seen across frailty subgroups, including fit (HR, 0.530; 95% CI, 0.387-0.727; P < .001), intermediate-fit (HR, 0.746; 95% CI, 0.526-1.058; P = .098), and frail (HR, 0.733; 95% CI, 0.481-1.117; P = .147) patients. With ixazomib versus placebo, rates of grade ≥ 3 treatment-emergent adverse events (TEAEs; 28-44% vs. 10-36%), serious TEAEs (15-29% vs. 3-29%), and discontinuation due to TEAEs (7-19% vs. 5-11%) were higher or similar across age and frailty subgroups, and generally somewhat higher in older age groups and intermediate-fit/frail patients in both arms. Treatment with ixazomib versus placebo did not adversely affect patient-reported quality-of-life scores across age and frailty status subgroups.

CONCLUSION

Ixazomib is a feasible and effective maintenance option for prolonging PFS across this heterogeneous patient population.

Non-selective proteasome inhibitors in multiple myeloma and future perspectives

INTRODUCTION

: The ubiquitination system is the most important cascade of protein degradation independently of lysosomal function. The proteasome system is actively involved in cell cycle regulation. Therefore, proteasome inhibition can lead to inhibition of tumor cell proliferation, and therefore it constitutes a potential therapeutic anticancer approach especially in the therapeutic algorithm of patients with multiple myeloma.

AREAS COVERED

Three different proteasome inhibitors are currently approved, bortezomib, carfilzomib and ixazomib, and they have been investigated in multiple myeloma and other hematological malignancies. Multiple myeloma cells are extremely sensitive to this inhibition which leads to accumulation of proteins and endoplasmic reticulum stress, leading finally to apoptosis. However, these agents lack specificity, since they target both the constitutive proteasome and the immunoproteasome. Targeting the constitutive proteasome is the main reason for side toxicity due to the effect on normal tissues. In contrary, immunoproteasome inhibition may reduce the adverse events while maintaining the therapeutic efficacy. In this review the authors present the role of the available proteasome inhibitors in myeloma therapeutics and future perspectives of both selective and non-selective proteasome inhibitors.

EXPERT OPINION

The available non-selective proteasome inhibitors have changed the therapeutics of multiple myeloma the last 10 years and have significantly improved the clinical outcomes of the patients. Furthermore, selective proteasome inhibitors are now under preclinical investigation and there is hope that their optimization will come with an improved safety profile with at least comparable efficacy.

Pharmacology differences among proteasome inhibitors: Implications for their use in clinical practice

Preclinical and clinical investigation on proteasome as a druggable target in cancer has led to the development of proteasome inhibitors (PIs) with different pharmacodynamic and pharmacokinetic properties. For example, carfilzomib has a better safety profile and a lower risk of clinically relevant drug-drug interactions than bortezomib, whereas ixazomib can be orally administered on a weekly basis due to a very long elimination half-life and high systemic exposure. The purpose of this review article is to elucidate the quantitative and qualitative differences in potency, selectivity, pharmacokinetics, safety and drug-drug interactions of clinically validated PIs to provide useful information for their clinical use in real life setting.

Management of patients with multiple myeloma beyond the clinical-trial setting: understanding the balance between efficacy, safety and tolerability, and quality of life

Treatment options in multiple myeloma (MM) are increasing with the introduction of complex multi-novel-agent-based regimens investigated in randomized clinical trials. However, application in the real-world setting, including feasibility of and adherence to these regimens, may be limited due to varying patient-, treatment-, and disease-related factors. Furthermore, approximately 40% of real-world MM patients do not meet the criteria for phase 3 studies on which approvals are based, resulting in a lack of representative phase 3 data for these patients. Therefore, treatment decisions must be tailored based on additional considerations beyond clinical trial efficacy and safety, such as treatment feasibility (including frequency of clinic/hospital attendance), tolerability, effects on quality of life (QoL), and impact of comorbidities. There are multiple factors of importance to real-world MM patients, including disease symptoms, treatment burden and toxicities, ability to participate in daily activities, financial burden, access to treatment and treatment centers, and convenience of treatment. All of these factors are drivers of QoL and treatment satisfaction/compliance. Importantly, given the heterogeneity of MM, individual patients may have different perspectives regarding the most relevant considerations and goals of their treatment. Patient perspectives/goals may also change as they move through their treatment course. Thus, the 'efficacy' of treatment means different things to different patients, and treatment decision-making in the context of personalized medicine must be guided by an individual's composite definition of what constitutes the best treatment choice. This review summarizes the various factors of importance and practical issues that must be considered when determining real-world treatment choices. It assesses the current instruments, methodologies, and recent initiatives for analyzing the MM patient experience. Finally, it suggests options for enhancing data collection on patients and treatments to provide a more holistic definition of the effectiveness of a regimen in the real-world setting.