Expert Panel Consensus Statement for Proper Evaluation of First Relapse in Multiple Myeloma

Daratumumab-based regimens for patients with multiple myeloma plus extramedullary plasmacytomas or paraskeletal plasmacytomas: initial follow-up of an Italian multicenter observational clinical experience

Myeloma with extramedullary plasmacytomas not adjacent to bone (EMP) is associated with an extremely poor outcome compared with paraosseous plasmacytomas (PP) as current therapeutic approaches are unsatisfactory. The role of new molecules and in particular of monoclonal antibodies is under investigation. To determine whether daratumumab-based regimens are effective for myeloma with EMP, we report herein an initial multicenter observational analysis of 102 myeloma patients with EMP (n = 10) and PP (n = 25) at diagnosis and EMP (n = 28) and PP (n = 39) at relapse, treated with daratumumab-based regimens at 11 Haematological Centers in Italy.EMP and PP at diagnosis were associated with higher biochemical (90% vs. 96%, respectively) and instrumental ORR (86% vs. 83.3%, respectively), while at relapse, biochemical (74% vs. 73%) and instrumental (53% vs. 59%) ORR were lower. Median OS was inferior in EMP patients compared with patients with PP both at diagnosis (21.0 months vs. NR) (p = 0.005) and at relapse (32.0 vs. 40.0 months) (p = 0.428), although, during relapse, there was no statistically significant difference between the two groups. Surprisingly, at diagnosis, median TTP and median TTNT were not reached either in EMP patients or PP patients and during relapse there were no statistically significant differences in terms of median TTP (20 months for two groups), and median TTNT (24 months for PP patients vs. 22 months for EMP patients) between the two groups. Median TTR was 1 month in all populations.These promising results were documented even in the absence of local radiotherapy and in transplant-ineligible patients.

Daratumumab plus bortezomib or daratumumab plus lenalidomide as salvage therapy for patients with myeloma: initial follow-up of an Italian multicentre retrospective clinical experience by 'Rete Ematologica Pugliese'

We report herein a multicentre retrospective analysis of 192 consecutive patients with symptomatic refractory/relapsed multiple myeloma (RRMM) treated with daratumumab in combination with bortezomib or lenalidomide as salvage therapy at 9 haematological centres in Puglia. Choice of both regimens was based on previous treatment and/or physicians' preference. Considering the under-representation of older patients (very old patient ≥ 80 years) in clinical trials and the prognostic and predictive importance and value of frailty status, here, we further characterised the patient cohort by age. The overall response rate (ORR) was generally lower than what was previously reported in the CASTOR (ORR 72.6% vs 85%) and POLLUX (ORR 86.5% vs 93%) trials. The lower ORR in our analysis compared to the CASTOR and POLLUX trials could be related to a less selected population. Similarly, amongst very old patients, the ORR was encouraging: ORR to treatment with DVd (daratumumab + bortezomib + dexamethasone) was 66.7%, and ORR to treatment with DRd (daratumumab + lenalidomide + dexamethasone) was 92.3%. Median TTP (time to progression) was 10.8 months (1-year TTP: 44.7%; 2-year TTP: 25.3%) in the DVd group; median TTP was not reached in the DRd group (1-year TTP: 82.7%; 2-year TTP: 71.4%). Median OS (overall survival) was not reached either in the DRd group (1-year OS: 85.9%; 2-year OS: 73.7%) or the DVd group (1-year OS: 70.2%; 2-year OS: 58.9%).

Correlations between apparent diffusion coefficient values of WB-DWI and clinical parameters in multiple myeloma

Background

Whole-body diffusion-weighted imaging (WB-DWI) is a method for evaluating bone marrow infiltration in multiple myeloma (MM). This study seeks to elucidate the correlation between the apparent diffusion coefficient (ADC) value and some selected clinical parameters.

Methods

A total of 101 Chinese patients with MM who had undergone WB-DWI from May 2017 to May 2019 were enrolled in this study. The ADC values of the MM lesions and the clinical parameters were quantified at the first (baseline) visit and after four-course induction chemotherapy. Multiple linear regression and logistic analyses were carried out to find the implicit inherent relationships within the patients’ data.

Results

The paired Wilcoxon test showed that the ADC values at the baseline visit (ADC₀) were significantly lower than the values after four-course induction chemotherapy (ADC_{4 c}) (p < 0.001), including different therapeutic responses. The Revised International Staging System (RISS) stage, type of MM, and β2-microglobulin (β2-MG) were predictors of clinically significant increases or decreases in the ADC values (p < 0.05). Multiple linear regression showed that the ADC₀ was negatively associated with β2-MG (p < 0.001) and immunoglobulin heavy chain gene rearrangement (p = 0.012), while the RISS Stage III (p = 0.001), type IgG λ (p = 0.005), and albumin were negatively associated with ADC_{4 c} (p = 0.010). The impacts of the therapeutic response were associated with ADC₀ and immunoglobulin heavy chain gene rearrangement (p < 0.001).

Conclusion

The ADC values of WB-DWI may be associated with clinical parameters of MM including the fluorescence in situ hybridization result, and may be useful in the prognosis of patients with MM.

Trial Registration: ChiCTR2000029587

Daratumumab as Single Agent in Relapsed/Refractory Myeloma Patients: A Retrospective Real-Life Survey

Background

The anti-CD38 monoclonal antibody daratumumab is approved as a single agent for the treatment of patients with relapsed/refractory multiple myeloma (RRMM) who received at least three prior lines of therapy, including proteasome inhibitor and immunomodulatory agent. A retrospective multicentric study was designed to evaluate feasibility, tolerability, and efficacy of daratumumab in monotherapy in RRMM.

Methods

This study included 44 consecutive RRMM patients that underwent daratumumab monotherapy after a median number of four prior therapies (range 2–9). Patients were treated in seven Sicilian centers, as part of Sicilian Myeloma Network and three Calabrian centers outside of controlled clinical trials from August 2016 through July 2020.

Results

The regimen was well tolerated with few grade 3–4 haematological and rare non-haematological adverse events, such as pneumonia. Definitive discontinuation was due to disease progression in 25 (57%) patients. Since three patients did not complete at least one full cycle, a total of 41 patients was evaluated for response. Overall response rate was 37%, and the disease control rate (stable disease or better) was high (73%). The best achieved responses within 6 months were very good partial remission or better (27%), partial remission (10%), minimal response (14%) and stable disease (22%). After a median follow up of 7.8 months, median progression free survival (PFS) was 7.2 months and overall survival (OS) 7.8 months. Univariate analysis showed that patients with PR or better after 6 months of therapy had longer median PFS and OS (respectively 29.5 vs 3.6 months, p=0.0001 and 30.6 vs 3.9 months p=0.0001), confirmed by multivariate analysis. Furthermore, standard cytogenetic risk and biochemical relapse type had prolonged median PFS, but not OS (respectively unreached vs 2.6, p=0.03 and 23.9 vs 6.2, p=0.05) in both univariate and multivariate analysis. Additionally, univariate analysis showed that patients treated with carfilzomib-lenalidomide-dexamethasone prior to daratumumab had significantly shorter PFS compared to pomalidomide-dexamethasone (3.4 months vs 9.3 months, p=0.03), that multivariate analysis failed to confirm.

Conclusions

Our findings indicate that daratumumab as single agent is safe and well-tolerated regimen in real-life, associated to prolonged PFS and OS in responding patients. No new safety signals were identified.

Monoclonal Antibodies: Leading Actors in the Relapsed/Refractory Multiple Myeloma Treatment

Multiple myeloma is a complex hematologic malignancy, and despite a survival improvement related to the growing number of available therapeutic options since 2000s, it remains an incurable disease with most patients experiencing relapse. However, therapeutic options for this disease are constantly evolving and immunotherapy is becoming the mainstay of the therapeutic armamentarium of Multiple Myeloma (MM), starting with monoclonal antibodies (MoAbs) as elotuzumab, daratumumab and isatuximab. Elotuzumab, the first in class targeting SLAMF7, in combination with lenalidomide and dexamethasone and daratumumab, directed against CD38, in combination with Rd and with bortezomib and dexamethasone (Vd), have been approved for the treatment of relapsed/refractory MM (RRMM) after they demonstrated excellent efficacy. More recently, another anti-CD38 MoAb named isatuximab was approved by FDA in combination with pomalidomide-dexamethasone (Pd) in the same setting. Many phase II and III trials with regimens containing these MoAbs are ongoing, and when available, preliminary data are very encouraging. In this review we will describe the results of major clinical studies that have been conducted with elotuzumab, daratumumab and isatuximab in RRMM, focusing on phase III trials. Moreover, we will summarized the emerging MoAbs-based combinations in the RRMM landscape.

Treatment of relapsed and refractory multiple myeloma

The therapeutic strategy for relapsed and refractory multiple myeloma (RRMM) integrates a holistic approach regarding patient, disease, and drug-related factors. Patient-related factors include age, frailty status, and underlying comorbidities, especially cardiovascular and renal diseases and peripheral neuropathies that affect tolerability to multiple drug combinations or transplantations. Disease-related factors encompass these multiple patient-related factors, particularly the aggressiveness of the disease and cytogenetics. Regarding drug-related factors, the approval of novel proteasome inhibitors (such as carfilzomib and ixazomib), immunomodulatory agents (such as pomalidomide), monoclonal antibodies (such as daratumumab and elotuzumab), and new classes of drugs increasingly makes the choice treatment more complex and necessitates a comprehensive summary and an update of the efficacy and toxicities of each antimyeloma drug and its combinations. Further, careful monitoring of the side effects and supportive care throughout the course of treatment are important to achieve better outcomes for patients with RRMM.