Elotuzumab plus lenalidomide/dexamethasone for relapsed or refractory multiple myeloma: ELOQUENT-2 follow-up and post-hoc analyses on progression-free survival and tumour growth

Going the distance: Are we losing patients along the multiple myeloma treatment pathway?

Despite data suggesting that individuals with multiple myeloma can benefit from receiving several lines of therapy, and guidelines recommending treatment after relapse, a recent European patient chart review found that only 61% of patients receive second-line treatment. The review found that factors such as old age and previous adverse events lead to physicians deciding not to treat after relapse. However, given the large number of regimens available, treatment can be tailored to individual patients' needs and supportive care measures can help with the management of adverse effects. If approved therapies are not suitable for a patient, guidelines recommend registration in a clinical trial, yet only 7% of patients in the review were participating in such studies. A need for better education on the range of treatments available and their risk-benefit profiles is suggested. Access to new drugs should be examined to maximise the number of patients benefitting from them.

Anti-CD38 and anti-SLAMF7: the future of myeloma immunotherapy

INTRODUCTION

the high expression of a number of surface antigens on malignant plasma cells, the bone marrow micro-environment and immune effector T cells, makes these appealing targets for immune therapy with monoclonal antibodies (mAbs). Areas covered: Two mAbs, anti-CD38 daratumumab (Dara) and anti-SLAMF7 elotuzumab (Elo), have achieved recent regulatory approval for relapsed or refractory MM (RRMM) and are currently being explored as possible treatment options in novel combinations and different settings. This review discusses the current landscape and possible development of anti-CD38 and anti-SLAMF7 mAbs. Expert commentary: Three phase III trials demonstrated a significant advantage in terms of response and PFS when Dara or Elo are combined with lenalidomide-dexamethsone (Rd) or bortezomib-dexamethsone (Vd), in comparison to doublet regimens, for patients with RRMM. Treatment algorithms including Dara- or Elo-based triplets may be defined on the basis of disease and patients' characteristics, as well as of their prior exposure to different classes of novel agents. Evaluation of these agents in new combination regimens, including second and third generation PIs and IMiDs, are under investigation. Moreover, use of mAbs in phases of the disease where the immune system is less compromised, such as newly diagnosed MM or even high-risk smoldering myeloma, appears logical.

Improvement in Overall Survival With Carfilzomib, Lenalidomide, and Dexamethasone in Patients With Relapsed or Refractory Multiple Myeloma

Purpose

In the ASPIRE study of carfilzomib, lenalidomide, and dexamethasone (KRd) versus lenalidomide plus dexamethasone (Rd) in patients with relapsed or refractory multiple myeloma, progression-free survival was significantly improved in the carfilzomib group (hazard ratio, 0.69; two-sided P < .001). This prespecified analysis reports final overall survival (OS) data and updated safety results.

Patients and Methods

Adults with relapsed multiple myeloma (one to three prior lines of therapy) were eligible and randomly assigned at a one-to-one ratio to receive KRd or Rd in 28-day cycles until withdrawal of consent, disease progression, or occurrence of unacceptable toxicity. After 18 cycles, all patients received Rd only. Progression-free survival was the primary end point; OS was a key secondary end point. OS was compared between treatment arms using a stratified log-rank test.

Results

Median OS was 48.3 months (95% CI, 42.4 to 52.8 months) for KRd versus 40.4 months (95% CI, 33.6 to 44.4 months) for Rd (hazard ratio, 0.79; 95% CI, 0.67 to 0.95; one-sided P = .0045). In patients receiving one prior line of therapy, median OS was 11.4 months longer for KRd versus Rd; it was 6.5 months longer for KRd versus Rd among patients receiving ≥ two prior lines of therapy. Rates of treatment discontinuation because of adverse events (AEs) were 19.9% (KRd) and 21.5% (Rd). Grade ≥ 3 AE rates were 87.0% (KRd) and 83.3% (Rd). Selected grade ≥ 3 AEs of interest (grouped terms; KRd v Rd) included acute renal failure (3.8% v 3.3%), cardiac failure (4.3% v 2.1%), ischemic heart disease (3.8% v 2.3%), hypertension (6.4% v 2.3%), hematopoietic thrombocytopenia (20.2% v 14.9%), and peripheral neuropathy (2.8% v 3.1%).

Conclusion

KRd demonstrated a statistically significant and clinically meaningful reduction in the risk of death versus Rd, improving survival by 7.9 months. The KRd efficacy advantage is most pronounced at first relapse.

CD38-targeting antibodies in multiple myeloma: mechanisms of action and clinical experience

INTRODUCTION

Multiple myeloma (MM) is generally an incurable hematological malignancy with heterogeneous overall survival rates ranging from a few months to more than 10 years. Survival is especially poor for patients who developed disease that is refractory to immunomodulatory drugs and proteasome inhibitors. Areas covered: This review will discuss the importance of CD38-targeting antibodies for the treatment of MM patients to improve their outcome. Expert commentary: Intense immuno-oncological laboratory research has resulted in the development of functionally active monoclonal antibodies against cell surface markers present on MM cells. In this respect, CD38-targeting antibodies such as daratumumab, MOR202, and isatuximab, have high single agent activity in heavily pretreated MM patients by virtue of their pleiotropic mechanisms of action including Fc-dependent effector mechanisms and immunomodulatory activities. Importantly, CD38-targeting antibodies are well tolerated, with infusion reactions as most frequent adverse event. Altogether, this makes them attractive combination partners with other anti-MM agents. Daratumumab is already approved as monotherapy and in combination with lenalidomide-dexamethasone as well as bortezomib-dexamethasone in pretreated MM patients. Furthermore, results from studies evaluating CD38-targeting antibodies in newly diagnosed MM patients are also promising, indicating that CD38-targeting antibodies will be broadly used in MM, resulting in further improvements in survival.

Elotuzumab for the Treatment of Relapsed or Refractory Multiple Myeloma, with Special Reference to its Modes of Action and SLAMF7 Signaling

Elotuzumab, targeting signaling lymphocytic activation molecule family 7 (SLAMF7), has been approved in combination with lenalidomide and dexamethasone (ELd) for relapsed/refractory multiple myeloma (MM) based on the findings of the phase III randomized trial ELOQUENT-2 (NCT01239797). Four-year follow-up analyses of ELOQUENT-2 have demonstrated that progression-free survival was 21% in ELd versus 14% in Ld. Elotuzumab binds a unique epitope on the membrane IgC2 domain of SLAMF7, exhibiting a dual mechanism of action: natural killer (NK) cell-mediated antibody-dependent cellular cytotoxicity (ADCC) and enhancement of NK cell activity. The ADCC is mediated through engagement between Fc portion of elotuzumab and FcgRIIIa/CD16 on NK cells. Enhanced NK cell cytotoxicity results from phosphorylation of the immunoreceptor tyrosine-based switch motif (ITSM) that is induced via elotuzumab binding and recruits the SLAM-associated adaptor protein EAT-2. The coupling of EAT-2 to the phospholipase Cg enzymes SH2 domain leads to enhanced Ca²⁺ influx and MAPK/Erk pathway activation, resulting in granule polarization and enhanced exocytosis in NK cells. Elotuzumab does not stimulate the proliferation of MM cells due to a lack of EAT-2. The inhibitory effects of elotuzumab on MM cell growth are not induced by the lack of CD45, even though SHP-2, SHP-1, SHIP-1, and Csk may be recruited to phosphorylated ITSM of SLAMF7. ELd improves PFS in patients with high-risk cytogenetics, i.e. t(4;14), del(17p), and 1q21 gain/amplification. Since the immune state is paralytic in advanced MM, the efficacy of ELd with minimal toxicity may bring forward for consideration of its use in the early stages of the disease.

The role of elotuzumab in the treatment of relapsed or refractory multiple myeloma

PURPOSE

The pharmacology, pharmacokinetics, clinical efficacy and safety, cost, and place in therapy of elotuzumab for treatment of relapsed or refractory multiple myeloma (MM) are reviewed.

SUMMARY

Elotuzumab is a humanized monoclonal antibody that targets the signaling lymphocytic activation molecule (SLAM) protein SLAMF7 and facilitates an antibody-dependent cellular cytotoxicity interaction between myeloma cells and natural killer cells. Elotuzumab has U.S. marketing approval for use in combination with lenalidomide and dexamethasone in patients with relapsed or refractory MM who have received 1-3 previous therapies; this regimen is among the preferred regimens for relapsed or refractory MM recommended by the National Comprehensive Cancer Network (NCCN). A Phase III trial involving 321 patients demonstrated a median progression-free survival duration of 19.4 months with elotuzumab plus lenalidomide and dexamethasone versus 14.9 months with lenalidomide and dexamethasone alone (hazard ratio for progression or death, 0.70; 95% confidence interval, 0.57-0.85; p < 0.001). Common adverse effects of elotuzumab-lenalidomide-dexamethasone therapy include hematologic toxicities, fatigue, pyrexia, diarrhea, constipation, muscle spasms, and cough. Elotuzumab plus bortezomib and dexamethasone is an NCCN-recommended alternative option for relapsed or refractory MM.

CONCLUSION

While elotuzumab plus lenalidomide and dexamethasone is a promising regimen for patients with MM, it is only one of several regimens recommended by NCCN for relapsed or refractory MM. Key factors in patient selection for elotuzumab therapy include adverse effects, prior treatments received, and cost considerations.

Triplet vs. doublet drug regimens for managing multiple myeloma

INTRODUCTION

Multiple Myeloma (MM) is a complex and heterogeneous plasma cell disorder. Sub-clones present before therapy and clonal evolution during therapy make this disease more resistant and finally refractory. These findings make us aware of the difficulty to target MM with few agents. Multi-drugs therapies allow us to target more pathways and more sub-clones both at diagnosis and in advanced disease.

AREAS COVERED

In this review, the authors focus on the effectiveness and tolerability of three drug regimens (triplet) in comparison with two drug regimens (doublet) and discuss their implications in the present and future of MM therapy.

EXPERT OPINION

It has been demonstrated that triplet regimens are better than doublet in terms of response rate and PFS in newly diagnosed, relapsed-refractory MM and in most patient subgroups. Whether this translates into OS improvement needs further demonstration. However, achievement of MRD negativity in most newly diagnosed and, firstly, in a consistent proportion of relapsed-refractory MM patients is very encouraging in this respect. However, not all patients are able to tolerate all triplet combinations; therefore, the choice should be based on patient characteristics, besides disease features. Finally, cost of triplets may be an important limitation in some countries.

Functional Imaging with 18F-FDG PET/CT and Diffusion Weighted Imaging (DWI) in Early Response Evaluation of Combination Therapy of Elotuzumab, Lenalidomide, and Dexamethasone in a Relapsed Multiple Myeloma Patient

Elotuzumab is the first monoclonal antibody approved for the treatment of relapsed-refractory multiple myeloma (MM) in combination with lenalidomide, an immunodulatory drug, and dexamethasone. We report on a multiply pre-treated MM patient with disease progression due to appearance of new focal lesions on imaging modalities, who was started on a combination treatment of elotuzumab, lenalidomide, and dexamethasone. After completion of three cycles of the new therapy the patient responded very well with a major decline of serological myeloma activity parameters serum monoclonal protein, kappa light chains, free light chains (FLC) ratio. The patient was also monitored with the functional imaging modalities ¹⁸F-FDG PET/CT and diffusion weighted imaging (DWI), which exhibited a mismatch of almost complete metabolic remission on positron emission tomography/computed tomography (PET/CT) with ¹⁸F-fluoro-2-deoxy-d-glucose (¹⁸F-FDG) (consistent with the serological response), and signal elevation persistence on DWI. This case demonstrates the potentially superior performance of ¹⁸F-FDG PET/CT over DWI in early response evaluation of combined treatment with a monoclonal antibody, an immunomodulatory drug, and dexamethasone in MM.

A review discussing elotuzumab and its use in the second-line plus treatment of multiple myeloma

Monoclonal antibodies (mAb) represent a new frontier to treat newly diagnosed and relapsed-refractory multiple myeloma (MM). Elotuzumab, an mAb targeted SLAM7 in the plasma cells and natural killer cells surface, is the first mAb approved for the treatment of relapsed-refractory MM in combination with lenalidomide and dexamethasone. This approval was the final result of several preclinical and Phase I-II clinical studies leading to ELOQUENT-2 Phase III trial that demonstrated that elotuzumab adds a significant and durable value to standard therapy, paved the way of this new treatment strategy for MM. In this review we will describe elotuzumab mechanisms of action, clinical pharmacology and clinical studies that have led to these developments.

CS1 (SLAMF7, CD319) is an effective immunotherapeutic target for multiple myeloma

CS1 (also known as CD319, CRACC and SLAMF7) was identified as an NK cell receptor regulating immune functions. It is also expressed on B cells, T cells, Dendritic cells, NK-T cells, and monocytes. CS1 is overexpressed in multiple myeloma and makes it a target for immunotherapy. A humanized anti-CS1 antibody, Elotuzumab or Empliciti has shown promising results in clinical studies. This review focuses on the biology of CS1 in NK and other hematopoietic cells and multiple myeloma. Anti-CS1 mAb can activate natural cytotoxicity of NK cells as well as enhance ADCC (antibody-dependent cell-mediated cytotoxicity) and thus makes an effective target for immunotherapy of MM.