Mechanisms of resistance to bispecific T cell engagers in multiple myeloma and their clinical implications

Bispecific T cell engagers (TCE) are revolutionizing patient care in multiple myeloma (MM). These monoclonal antibodies, that redirect T cells against cancer cells, are now approved for the treatment of triple-class exposed relapsed refractory multiple myeloma (RRMM). They are currently tested in earlier lines of the disease, including in first line. Yet, primary resistance occurs in about one third of RRMM patients, and most responders eventually develop acquired resistance. Understanding the mechanisms of resistance to bispecific TCE is thus essential to improve immunotherapies in MM. Here, we review recent studies investigating the clinical and molecular determinants of resistance to bispecific TCE. Resistance can arise from tumor-intrinsic or tumor-extrinsic mechanisms. Tumor-intrinsic resistance involves various alterations leading to the loss of the target antigen such as chromosome deletions, point mutations or epigenetic silencing. Loss of MHC class I, preventing MHC class I:TCR co-stimulatory signaling, was also reported. Tumor-extrinsic resistance involves abundant exhausted T cell clones and several factors generating an immunosuppressive microenvironment. Importantly, some resistance mechanisms impair response to one TCE while preserving the efficacy of others. We next discuss the clinical implications of these findings. Monitoring the status of target antigens in tumor cells and their immune environment will be key to select the most appropriate TCE for each patient, and to design combination and sequencing strategies for immunotherapy in multiple myeloma.

Characteristics and incidence of infections in patients with multiple myeloma treated by bispecific antibodies: a national retrospective study on the behalf of G2I and Intergroupe Francophone du Myélome

OBJECTIVES

Bispecific antibodies (BsAbs) are an effective treatment used in relapsed or refractory multiple myeloma. Despite a well-tolerated safety profile, infectious events appear to be frequent in clinical trials. Real-world data on epidemiology, characteristics, risk factors, and outcomes of infections in patients treated with BsAb are still needed.

METHODS

A retrospective, multicentre study in BsAb-treated patients with multiple myeloma was performed in 14 French centres from December 2020 to February 2023. The primary objective was to describe the incidence of infections that required hospitalization, specific treatment, or adaptation in BsAb administration.

RESULTS

Among 229 patients with multiple myeloma treated with BsAb, 153 (67%) received teclistamab, 47 (20%) received elranatamab, and 29 (13%) talquetamab. We reported a total of 234 infections, including 123 (53%) of grade of ≥3. Predominant infections affected the respiratory tract (n = 116, 50%) followed by bacteraemias (n = 36, 15%). The hospitalization rate was 56% (n = 131), and 20 (9%) infections resulted in death. Global cumulative incidence of the first infection was 70% in all patients, 73% in patients treated with B-cell maturation antigen-targeting, and 51% with GPRC5D-targeting BsAb. In univariate analyses, corticosteroids for cytokine release syndrome (CRS)/immune effector cell-associated neurotoxicity syndrome (ICANS) were associated with a higher risk of first infection (HR = 2.13; 95% CI, 1.38-3.28), whereas GPRC5D-targeting BsAb and anti-bacterial prophylaxis were associated with a lower risk (HR = 0.53; 95% CI, 0.3-0.94 and HR = 0.65; 95% CI, 0.46-0.9). Fine and Gray multivariate model found that only corticosteroids for CRS/ICANS were correlated with a higher risk of first infection (HR = 2.01; 95% CI, 1.27-3.19).

DISCUSSIONS

The implementation of preventive measures that aim to mitigate the risk of infection under BsAb is pivotal, notably in patients who received corticosteroids for CRS/ICANS.

Phase I study of zoledronic acid combined with escalated doses of interleukine-2 for early in vivo generation of Vγ9Vδ2 T-cells after haploidentical stem cell transplant with posttransplant cyclophosphamide

The presence of donor Vγ9Vδ2 T-cells after haploidentical hematopoietic stem cell transplant (h-HSCT) has been associated with improved disease-free survival. These cells kill tumor cells in a non-MHC restricted manner, do not induce graft-versus-host disease (GVHD), and can be generated by stimulation with zoledronic acid (ZA) in combination with interleukin-2 (IL-2). This monocentric phase I, open-label, dose-escalating study (ClinicalTrials.gov: NCT03862833) aimed at evaluating the safety and possibility to generate Vγ9Vδ2 T-cells early after h-HSCT. It applied a standard 3 + 3 protocol to determine the maximum tolerated dose (MTD) of increasing low-doses of IL-2 (5 days [d] per week, 4 weeks) in combination with a single dose of ZA, starting both the first Monday after d + 15 posttransplant. Vγ9Vδ2 T-cell monitoring was performed by multiparameter flow cytometry on blood samples and compared with a control cohort of h-HSCT recipients. Twenty-six patients were included between April 2019 and September 2022, 16 of whom being ultimately treated and seven being controls who received h-HSCT only. At the three dose levels tested, 1, 0, and 1 dose-limiting toxicities were observed. MTD was not reached. A significantly higher number of Vγ9Vδ2 T-cells was observed during IL-2 treatment compared with controls. In conclusion, early in vivo generation of Vγ9Vδ2 T-cells is feasible after h-HSCT by using a combination of ZA and repeated IL-2 infusions. This study paves the way to a future phase 2 study, with the hope to document lesser posttransplant relapse with this particular adaptive immunotherapy.

Daratumumab Carfilzomib Lenalidomide and Dexamethasone with tandem transplant in high-risk newly diagnosed myeloma

High-risk (HR) cytogenetics are associated with poor outcomes in newly diagnosed multiple myeloma (NDMM) and dedicated studies should address this difficult-to-treat population. The phase 2 study 2018-04 from the Intergroupe Francophone du Myelome evaluated feasibility of an intensive strategy with quadruplet induction and consolidation plus tandem transplant in HR transplant eligible (TE) NDMM (NCT03606577). HR cytogenetics were defined by the presence of del(17p), t(4;14) and/or t(14;16). Treatment consisted in daratumumab-carfilzomib-lenalidomide-dexamethasone (D-KRd) induction (6 cycles), autologous stem cell transplantation (ASCT), D-KRd consolidation (4 cycles), second ASCT, and daratumumab-lenalidomide maintenance for 2 years. The primary endpoint was feasibility. Fifty patients with previously untreated NDMM were included. Median age was 57. Del(17p), t(4;14) and t(14;16) were found in 40%, 52% and 20% of patients respectively. At data cut-off, the study met the primary endpoint with 36 (72%) patients completing second transplant. Twenty patients (40%) discontinued the study due to stem-cell collection failure (n=8), disease progression (n=7), adverse event (n=4), consent withdrawal (n=1). Grade 3-4 Dara-KRd induction/consolidation related adverse events (>5% of patients) were neutropenia (39%), anemia (12%), thrombocytopenia (7%) and infection (6%). The overall response rate was 100% for patients completing second transplant (n=36), including 81% complete response. Pre-maintenance Minimal Residual Disease (MRD) negativity rate (NGS, 10-6) was 94%. After a median follow up of 33 months, the 30-month progression-free (PFS) and overall survival were 80% and 91%, respectively. In conclusion, D-KRd with tandem transplant is feasible in high-risk TE NDMM patients and resulted in high rates of MRD negativity and PFS.

Real-life effectiveness of carfilzomib in patients with relapsed multiple myeloma receiving treatment in the context of early access: The CARMYN study

The real-life retrospective observational study CARMYN aimed at investigating the long-term efficacy and safety of carfilzomib in combination with dexamethasone and lenalidomide (KRd, 159 patients). These patients (62% in first and 38% in second relapse, median age 62 yo) were treated between 02/2014 and 02/2017. Most had been pre-exposed to bortezomib (98.2%) and to an IMID (75.4%). At the time of collection, 90% had permanently discontinued carfilzomib. Data collection was conducted from January to July 2021 in 27 participating sites, after a median of 39 months follow-up. For patients treated with KRd, an overall response rate of 78.4% translated in a median progression free survival (PFS) of 24.0 months (95% CI 18.8-27.6) and a median overall survival (OS) of 51.1 months (95% CI 41.3-not reached). Results were poorer but difficult to interpret in the small cohort of Kd recipients. The study is one of the longest real-life studies of carfilzomib treatment in patients in first or second relapse. CARMYN confirmed the real-life long-term efficacy of carfilzomib in combination with lenalidomide and dexamethasone with results similar to those of clinical trials. The KRd regimen is thus an option to consider for late relapses in the current context of MM management.

Venous thromboembolism prophylaxis and multiple myeloma patients in real-life: Results of a large survey and clinical guidance recommendations from the IFM group

Venous thromboembolism (VTE) remains a critical issue in the management of patients with multiple myeloma (MM), particularly when immunomodulatory drugs (IMiDs) combined with dexamethasone therapy are being prescribed as first-line and relapse therapy. One possible explanation for the persistent high rates of VTE, is the use of inappropriate thromboprophylaxis strategies for patients starting antimyeloma treatment. To tackle the issue, the Intergroupe francophone du myélome (IFM) offered convenient guidance for VTE thromboprophylaxis in MM patients initiating systemic therapy. This guidance is mainly supported by the results of a large survey on the clinical habits regarding VTE of physicians who are substantially involved in daily care of MM patients. VTE prophylaxis should be considered for all patients treated with IMiDs in combination with dexamethasone, in the absence of significant comorbidities, such as renal failure or bleeding risk. Anticoagulant should be preferred to antiplatelet agents for thromboprophylaxis. Despite the absence of large randomized controlled trials comparing those attitudes/options, available data on direct oral anticoagulants, which are already used in daily management of MM patients, are consistent with their potential usefulness for VTE prophylaxis in such patients. However, in order to implement a personalized continuous improvement strategy, clinicians must to be organized to collect all the data regarding this management. In other situations, thromboprophylaxis should be evaluated by using risk models and after careful evaluation of the risk/benefit ratio.

Quad-class exposed/refractory myeloma is associated with short survival

Very scarce data exist about outcomes of relapsed multiple myeloma patients who have failed proteasome inhibitor, immunomodulatory drug, anti-CD38 monoclonal antibody and therapies targeting B-cell maturation antigen (BCMA) (Quad-class exposed [QCE]). In this retrospective single-centre study, we determined progression-free survival (PFS) and overall survival (OS) from anti-BCMA failure in 45 QCE patients. Seven (16%) patients received antibody-drug conjugate, 20 (44%) bispecific antibodies and 18 (40%) CAR-T cell. Thirty patients (67%) received ≥1 subsequent line of treatment. PFS was 4.4 months (95% CI = 2.4-12.5) and OS 6.3 months (95% CI = 3.9-14.4). Having an adverse prognosis, QCE myeloma patients remain an unmet medical need.

Immune-related adverse events with bispecific T-cell engager therapy targeting B-cell maturation antigen

Not available.

A p53 score derived from TP53 CRISPR/Cas9 HMCLs predicts survival and reveals major role of BAX in BH3 mimetics response

To establish a strict p53-dependent gene expression profile, TP53-/- clones were derived from TP53+/+ and TP53-/mut t(4;14) human myeloma cell lines (HMCLs) using CRISPR/Cas9 technology. From the 17 dysregulated genes shared between the TP53-/- clones from TP53+/+ HMCLs, we established a functional p53 score, involving 13 genes specifically downregulated upon p53 silencing. This functional score segregated clones and myeloma cell lines, as well as other cancer cell lines according to their TP53 status. The score was efficient to identify myeloma patient samples with biallelic TP53 inactivation and was predictive of overall survival in MMRF-coMMpass and CASSIOPEA cohorts. At the functional level, we showed that among the 13 genes, p53-regulated BAX expression correlated to, and directly impacted, the MCL1 BH3 mimetic S63845 sensitivity of myeloma cells by decreasing MCL1-BAX complexes. However, resistance to S63845 was overcome by combining MCL1 and BCL2 BH3 mimetics which displayed synergistic efficacy. BH3 mimetics combination was efficient in 97% of patient samples with or without del17p. Nevertheless, scRNAseq analysis showed that myeloma cells surviving to the combination had lower p53 score, showing that myeloma cells with higher p53 score were more sensitive to BH3 mimetics. Taken together, we established a functional p53 score that identifies myeloma cells with biallelic TP53 invalidation, demonstrated that p53-regulated BAX is critical for optimal cell response to BH3 mimetics, and showed that MCL1 and BCL2 BH3 mimetics combination may be of interest for patients with biallelic TP53 invalidation, for whom there is still an unmet medical need.

Acquired resistance to a GPRC5D-directed T-cell engager in multiple myeloma is mediated by genetic or epigenetic target inactivation

Bispecific antibodies targeting GPRC5D demonstrated promising efficacy in multiple myeloma, but acquired resistance usually occurs within a few months. Using a single-nucleus multi-omic strategy in three patients from the MYRACLE cohort (ClinicalTrials.gov registration: NCT03807128 ), we identified two resistance mechanisms, by bi-allelic genetic inactivation of GPRC5D or by long-range epigenetic silencing of its promoter and enhancer regions. Molecular profiling of target genes may help to guide the choice of immunotherapy and early detection of resistance in multiple myeloma.

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.

Elranatamab in relapsed or refractory multiple myeloma: phase 2 MagnetisMM-3 trial results

Elranatamab is a humanized B-cell maturation antigen (BCMA)-CD3 bispecific antibody. In the ongoing phase 2 MagnetisMM-3 trial, patients with relapsed or refractory multiple myeloma received subcutaneous elranatamab once weekly after two step-up priming doses. After six cycles, persistent responders switched to biweekly dosing. Results from cohort A, which enrolled patients without prior BCMA-directed therapy (n = 123) are reported. The primary endpoint of confirmed objective response rate (ORR) by blinded independent central review was met with an ORR of 61.0% (75/123); 35.0% ≥complete response. Fifty responders switched to biweekly dosing, and 40 (80.0%) improved or maintained their response for ≥6 months. With a median follow-up of 14.7 months, median duration of response, progression-free survival and overall survival (secondary endpoints) have not been reached. Fifteen-month rates were 71.5%, 50.9% and 56.7%, respectively. Common adverse events (any grade; grade 3-4) included infections (69.9%, 39.8%), cytokine release syndrome (57.7%, 0%), anemia (48.8%, 37.4%), and neutropenia (48.8%, 48.8%). With biweekly dosing, grade 3-4 adverse events decreased from 58.6% to 46.6%. Elranatamab induced deep and durable responses with a manageable safety profile. Switching to biweekly dosing may improve long-term safety without compromising efficacy. ClinicalTrials.gov identifier: NCT04649359 .

Hybrid simultaneous whole-body 2-[18F]FDG-PET/MRI imaging in newly diagnosed multiple myeloma: first diagnostic performance and clinical added value results

OBJECTIVES

Mixing diagnostic and prognostic data provided by whole-body MRI (WB-MRI) and 2-18F-fluorodeoxyglucose (2-[18F]FDG) positron emission tomography (2-[18F]FDG-PET) from a single simultaneous imaging technique for newly diagnosed multiple myeloma (NDMM) initial workup seems attractive. However, to date, the published data are scarce and this possibility has not been fully explored. In this prospective study, we aimed to explore the diagnostic performance and added clinical value of WB-2-[18F]FDG-PET/MRI imaging in NDMM.

METHODS

All patients with confirmed NDMM at the Nantes University Hospital were prospectively enrolled in this study and underwent WB-2-[18F]FDG-PET/MRI imaging on a 3-T Biograph mMR before receiving treatment. Before imaging, they were considered either as symptomatic or as smoldering MM (SMM). Diagnostic performance of global WB-2-[18F]FDG-PET/MRI imaging, as well as PET and MRI separately for FL and diffuse BMI detection, was assessed and compared in each group. PET-based (maximal standardized uptake value, SUVmax) and MRI-based (mean apparent diffusion coefficient value, ADCmean) quantitative features were collected for FL/para-medullary disease (PMD)/bone marrow and were compared.

RESULTS

A total of 52 patients were included in this study. PET and MRI were equally effective at detecting patients with FL (69% vs. 75%) and with diffuse BMI (62% for both) in the symptomatic MM group. WB-2-[18F]FDG-PET/MRI imaging detected FL in 22% of patients with SMM (with a higher diagnostic performance for MRI), resulting in a significant impact on clinical management in this population. SUVmax and ADCmean quantitative features were weakly or not correlated.

CONCLUSIONS

WB-2-[18F]FDG-PET/MRI could represent the next-generation imaging modality for MM.

KEY POINTS

• Whole-body 2-[18F]FDG-PET/MRI imaging detected at least one focal bone lesion in 75% of patients with symptomatic multiple myeloma, and PET and MRI were equally effective at identifying patients with a focal bone lesion. • Whole-body 2-[18F]FDG-PET/MRI imaging detected a focal bone lesion in 22% of patients with smoldering multiple myeloma (with a higher diagnostic performance for MRI). • MRI had a significant impact on clinical management of smoldering multiple myeloma.

Inequality factors in access to early-phase clinical trials in oncology in France: results of the EGALICAN-2 study

BACKGROUND

Investigation of the disparities in the access to experimental treatment in early-phase clinical trials is lacking. The objective of the EGALICAN-2 study was to identify the factors underpinning such inequalities.

METHODS

A national prospective survey was conducted in 11 early-phase clinical trial centers (CLIP2) certified by the French National Cancer Institute. Sociodemographic, socioeconomic and medical data were collected. Univariate logistic regression models were carried out to estimate odds ratios and 90% confidence intervals associated with the effect of each study variable. A multivariate logistic regression model was built to explore the independent factors associated with the administration of the experimental treatment (C1D1). A post hoc analysis was carried out excluding female cancer patients.

RESULTS

Between 2015 and 2016, 1355 patients referred from 11 CLIP2 centers in France were included in the study. Eight hundred and forty-eight patients received C1D1 (73%) and 320 patients (27%) were screening failure. Median age was 58 years (range 17-97 years) and 667 patients (54%) were female. Most patients had a metastatic disease (n = 751, 87%). In the multivariate logistic regression analysis, the significant independent factors associated with C1D1 were male sex, initial care received in a hospital with an early-phase unit and living in wealthy metropolitan areas (P values <0.05). In the post hoc analysis, the sex factor was no longer significant [odds ratio = 1.21 (95% confidence interval 0.86-1.70), P value = 0.271].

CONCLUSIONS

This study investigated the factors producing social inequalities in the context of early-phase clinical trials in oncology. Our research highlights factors of sex, care pathway and geographic location. Gynecological cancer was found to impact C1D1 significantly, unlike breast cancer. The results of this study should contribute to improve patient access to early-phase clinical trials.

Clinical features and outcomes of patients admitted to the ICU for Cyclophosphamide-associated cardiac toxicity: a retrospective cohort

PURPOSE

To describe the management and outcome of critically-ill patients with Cyclophosphamide (CY)-associated cardiac toxicity.

METHODS

All patients admitted to the intensive care units (ICUs) of the Nantes and Rennes University Hospitals for a CY-associated cardiac toxicity between January 2015 and December 2020 were included.

RESULTS

Of the thirty-four patients included in the study, twenty-four (70%) underwent allogeneic hematopoietic stem cell transplantation (HSCT), four (12%) autologous HSCT, and six (18%) chemotherapy for hematological malignancies. Acute pulmonary edema (65%), cardiac arrest (9%), and cardiac arrhythmia (6%) were the most common reasons for ICU admission. Patients were admitted to the ICU 6.5 (4-12) days after the intravenous administration of a median dose of CY of 100 [60-101] mg/Kg. Echocardiographic findings showed moderate to severe left ventricular systolic dysfunction (69%) and pericardial effusion (52%). Eighteen (53%) patients ultimately developed cardiogenic shock and required vasopressors (47%) and/or inotropes (18%). Invasive mechanical ventilation and renal replacement therapy were required in twenty (59%) and five (14%) patients, respectively. Sixteen (47%) patients died of whom 12 (35.3%) died from refractory cardiogenic shock. The left ventricular ejection fraction improved over time in most survivors with a median time until full recovery of 33 (12-62) days. Two (11%) patients had a persistent left ventricular dysfunction at 6 months.

CONCLUSION

Refractory cardiogenic shock is the primary cause of death of patients with severe CY-related cardiotoxicity. Nonetheless, the cardiac function of most survivors recovered within a month.

BCLXL PROTAC degrader DT2216 targets secondary plasma cell leukemia addicted to BCLXL for survival

Secondary plasma cell leukemia (sPCL) is a rare form of aggressive plasma cell malignancy arising mostly at end-stage refractory multiple myeloma and consequently presenting limited therapeutic options. We analyzed 13 sPCL for their sensitivity to BH3 mimetics targeting either BCL2 (venetoclax) or BCLXL (A1155463) and showed that 3 sPCL were efficiently killed by venetoclax and 3 sPCL by A1155463. Accordingly, BH3 profiling of 2 sPCL sensitive to BCLXL inhibition confirmed their high BCLXL primed profile. While targeting BCLXL using BH3 mimetics induces platelets on-target drug toxicity, the recent development of DT2216, a clinical-stage BCLXL proteolysis targeting chimera PROTAC compound, provides an alternative strategy to target BCLXL. Indeed, DT2216 specifically degrades BCLXL via VHL E3 ligase, without inducing thrombocytopenia. We demonstrated in human myeloma cell lines and sPCL that sensitivity to DT2216 strongly correlated with the sensitivity to A1155463. Interestingly, we showed that low doses of DT2216 (nM range) were sufficient to specifically degrade BCLXL after 48 hours of treatment, consistent with VHL expression, in all cell lines but irrespectively to DT2216 sensitivity. In myeloma cells, DT2216 induced apoptotic cell death and triggered BAX and BAK activation. In conclusion, our study demonstrated that patients with sPCL addicted to BCLXL, a small but a very challenging group, could potentially receive therapeutic benefit from DT2216. Clinical trials of DT2216 in this subset of sPCL patients are warranted.

Cilta-cel or Standard Care in Lenalidomide-Refractory Multiple Myeloma

BACKGROUND

Ciltacabtagene autoleucel (cilta-cel), a B-cell maturation antigen (BCMA)-directed CAR-T cell therapy, is effective in heavily pretreated patients with relapsed or refractory multiple myeloma. We investigated cilta-cel in earlier treatment lines in patients with lenalidomide-refractory disease.

METHODS

In this phase 3, randomized, open-label trial, we assigned patients with lenalidomide-refractory multiple myeloma to receive cilta-cel or the physician's choice of effective standard care. All the patients had received one to three previous lines of treatment. The primary outcome was progression-free survival.

RESULTS

A total of 419 patients underwent randomization (208 to receive cilta-cel and 211 to receive standard care). At a median follow-up of 15.9 months (range, 0.1 to 27.3), the median progression-free survival was not reached in the cilta-cel group and was 11.8 months in the standard-care group (hazard ratio, 0.26; 95% confidence interval [CI], 0.18 to 0.38; P<0.001). Progression-free survival at 12 months was 75.9% (95% CI, 69.4 to 81.1) in the cilta-cel group and 48.6% (95% CI, 41.5 to 55.3) in the standard-care group. More patients in the cilta-cel group than in the standard-care group had an overall response (84.6% vs. 67.3%), a complete response or better (73.1% vs. 21.8%), and an absence of minimal residual disease (60.6% vs. 15.6%). Death from any cause was reported in 39 patients and 46 patients, respectively (hazard ratio, 0.78; 95% CI, 0.5 to 1.2). Most patients reported grade 3 or 4 adverse events during treatment. Among the 176 patients who received cilta-cel in the as-treated population, 134 (76.1%) had cytokine release syndrome (grade 3 or 4, 1.1%; no grade 5), 8 (4.5%) had immune effector cell-associated neurotoxicity syndrome (all grade 1 or 2), 1 had movement and neurocognitive symptoms (grade 1), 16 (9.1%) had cranial nerve palsy (grade 2, 8.0%; grade 3, 1.1%), and 5 (2.8%) had CAR-T-related peripheral neuropathy (grade 1 or 2, 2.3%; grade 3, 0.6%).

CONCLUSIONS

A single cilta-cel infusion resulted in a lower risk of disease progression or death than standard care in lenalidomide-refractory patients with multiple myeloma who had received one to three previous therapies. (Funded by Janssen and Legend Biotech; CARTITUDE-4 ClinicalTrials.gov number, NCT04181827.).

Prevention and management of adverse events during treatment with bispecific antibodies and CAR T cells in multiple myeloma: a consensus report of the European Myeloma Network

T-cell redirecting bispecific antibodies (BsAbs) and chimeric antigen receptor T cells (CAR T cells) have revolutionised multiple myeloma therapy, but adverse events such as cytokine release syndrome, immune effector cell-associated neurotoxicity syndrome (ICANS), cytopenias, hypogammaglobulinaemia, and infections are common. This Policy Review presents a consensus from the European Myeloma Network on the prevention and management of these adverse events. Recommended measures include premedication, frequent assessing for symptoms and severity of cytokine release syndrome, step-up dosing for several BsAbs and some CAR T-cell therapies; corticosteroids; and tocilizumab in the case of cytokine release syndrome. Other anti-IL-6 drugs, high-dose corticosteroids, and anakinra might be considered in refractory cases. ICANS often arises concomitantly with cytokine release syndrome. Glucocorticosteroids in increasing doses are recommended if needed, as well as anakinra if the response is inadequate, and anticonvulsants if convulsions occur. Preventive measures against infections include antiviral and antibacterial drugs and administration of immunoglobulins. Treatment of infections and other complications is also addressed.

2-[ 18 F]FDG PET/CT Flare-up Phenomena Following T-Cell Engager Bispecific Antibody in Multiple Myeloma

ABSTRACT

T-cell-redirecting bispecific antibodies represent a new standard of care for the treatment of triple-class refractory myeloma patients. Here, 2-[ 18 F]FDG PET/CT imaging was performed on a 61-year-old woman with relapsed myeloma to determine metabolic response to talquetamab, a GPRC5DxCD3-bispecific antibody. At day 28, monoclonal (M) component assessment confirmed very good partial response (97% monoclonal protein reduction), whereas 2-[ 18 F]FDG PET/CT imaging revealed early bone flare-up phenomena. At day 84, bone marrow aspirate, M-component assessment, and 2-[ 18 F]FDG PET/CT demonstrated complete response, confirming the early flare-up hypothesis.

Current Advances in Multiple Myeloma: A Post International Myeloma Society (IMS 2022) Round Table Debate by the International Academy for Clinical Hematology (IACH)

This round table discussion organized by the International Academy for Clinical Hematology (IACH) was dedicated to the 19th annual meeting of the International Myeloma Society (IMS), which was held in Los Angeles between the 25th and 27th August 2022. After some key meetings of the discipline of the field of clinical hematology, the IACH organizes regular round table discussion in order to summarize the flow of information and get the opinion of a panel of experts and the key take-home messages. As part of this discussion, the panellists debated 6 key topics: disease monitoring, management of high-risk multiple myeloma (MM), induction for newly-diagnosed MM, management of relapsed MM, immune reconstitution, and vaccination and cellular therapy in MM.

Phase 1 Study of the Combination of Escalated Total Marrow Irradiation Using Helical Tomotherapy and Fixed High-Dose Melphalan (140 mg/m²) Followed by Autologous Stem Cell Transplantation at First Relapse in Multiple Myeloma

PURPOSE

A second intensification is an option at first relapse in multiple myeloma (MM) after more than 36 months of initial remission. Many conditioning regimens have been tested, with or without total body irradiation (TBI). Recently, it was found that TBI could be replaced by total marrow irradiation (TMI) using helical tomotherapy, with promising results.

METHODS AND MATERIALS

This study was a prospective multicenter phase 1 trial that aimed to determine the maximum tolerated dose (MTD) of TMI administered in association with melphalan 140 mg/m², followed by autologous stem cell transplantation as consolidation at first relapse in MM. Four dose levels were explored: 8 Gy, 10 Gy, 12 Gy, and 14 Gy. The dose-limiting toxicity (DLT) was defined as grade 4 neutropenia >15 days, grade 4 thrombopenia >28 days, and all other grade 4 nonhematologic toxic effects except nausea, vomiting, alopecia, mucositis, and reaction to autologous stem cell infusion.

RESULTS

Thirteen patients were included; only 1 DLT at the third escalated dose level (12 Gy) was observed, whereas 1 patient was treated at 14 Gy with no adverse events. The MTD was not reached. The rate of acute toxicity was low: 38% of grade 3-4 diarrhea, mucositis, or unexplained fever. Regarding the lungs, the mean dose administered was systematically less than 8 Gy. After a median follow-up of 55 months, 70% of participants were alive. Of these 13 patients, 38.5% were in very good partial response and 30.8% were in complete response. Three of them were progression-free. Six patients were long survivors, still alive after 55 months of follow-up.

CONCLUSIONS

Total marrow irradiation provides good results with a good tolerance profile at first relapse in MM and makes it possible to increase the dose delivered to the planning target volume while sparing organs at risk. This technique could be discussed for all regimens before auto- or allo-stem cell rescue when TBI is required.

Molecular Signature of 18F-FDG PET Biomarkers in Newly Diagnosed Multiple Myeloma Patients: A Genome-Wide Transcriptome Analysis from the CASSIOPET Study

The International Myeloma Working Group recently fully incorporated ¹⁸F-FDG PET into multiple myeloma (MM) diagnosis and response evaluation. Moreover, a few studies demonstrated the prognostic value of several biomarkers extracted from this imaging at baseline. Before these ¹⁸F-FDG PET biomarkers could be fully endorsed as risk classifiers by the hematologist community, further characterization of underlying molecular aspects was necessary. Methods: Reported prognostic biomarkers (¹⁸F-FDG avidity, SUV_max, number of focal lesions, presence of paramedullary disease [PMD] or extramedullary disease) were extracted from ¹⁸F-FDG PET imaging at baseline in a group of 139 patients from CASSIOPET, a companion study of the CASSIOPEIA cohort (ClinicalTrials.gov identifier NCT02541383). Transcriptomic analyses using RNA sequencing were realized on sorted bone marrow plasma cells from the same patients. An association with a high-risk gene expression signature (IFM15), molecular classification, progression-free survival, a stringent clinical response, and minimal residual disease negativity were explored. Results:¹⁸F-FDG PET results were positive in 79.4% of patients; 14% and 11% of them had PMD and extramedullary disease, respectively. Negative ¹⁸F-FDG PET results were associated with lower levels of expression of hexokinase 2 (HK2) (fold change, 2.1; adjusted P = 0.04) and showed enrichment for a subgroup of patients with a low level of bone disease. Positive ¹⁸F-FDG PET results displayed 2 distinct signatures: either high levels of expression of proliferation genes or high levels of expression of GLUT5 and lymphocyte antigens. PMD and IFM15 were independently associated with a lower level of progression-free survival, and the presence of both biomarkers defined a group of "double-positive" patients at very high risk of progression. PMD and IFM15 were related neither to minimal residual disease assessment nor to a stringent clinical response. Conclusion: Our study confirmed and extended the association between imaging biomarkers and transcriptomic programs in MM. The combined prognostic value of PMD and a high-risk IFM15 signature may help define MM patients with a very high risk of progression.

Complications of Autologous Stem Cell Transplantation in Multiple Myeloma: Results from the CALM Study

Background: The main goal of this post hoc analysis of the Collaboration to Collect Autologous Transplant Outcomes in Lymphoma and Myeloma (CALM) study was to evaluate the rate of short- and long-term infectious and non-infectious complications occurring after ASCT in patients with multiple myeloma (MM). Methods: The analysis included all patients with MM from the CALM study who underwent ≥1 ASCT. The primary endpoint of the analysis was to determine the rate of infectious and non-infectious complications after ASCT and to compare them in three time periods: 0−100 days, 101 days−1 year, and >1 year after the first transplant. Results: The analysis included a total of 3552 patients followed up for a median of 56.7 months (range 0.4−108.1). Complication rates decreased with the time from ASCT with 24.85 cases per 100 patient-years from day 0 to 100 days after the transplant, and <2.31 cases per 100 patient-years from the 101st day. At 100 days after ASC T, 45.7% of patients had complications, with infectious events being twice as frequent as non-infectious complications. Bacterial infections (6.5 cases per 100 patient-years, 95% CI: 6.1−7.0) and gastrointestinal complications (4.7 cases per 100 patient-years, 95% CI: 4.3−5.1) were the most common early events. The pattern of complications changed with time from ASCT. The presence of complications after ASCT was not associated with overall survival. Conclusions: Our data provide a solid basis for comparing ASCT-related complications to those caused by emerging treatments in multiple myeloma, such as CAR T-cell therapy and other immunotherapies.

Melflufen for the treatment of multiple myeloma

INTRODUCTION

Melphalan flufenamide (melflufen) is a first-in-class peptide-drug conjugate that takes advantage of increased aminopeptidase activity inside tumor cells to rapidly release alkylating agents therein. Melflufen in combination with dexamethasone has been evaluated in multiple clinical trials in patients with relapsed/refractory multiple myeloma (MM).

AREAS COVERED

This profile covers the unique mechanism of action of melflufen, the preclinical results supporting its activity in cellular models of resistance to chemotherapy, its activity in animal models of MM, and the clinical pharmacokinetics of melflufen. Findings from clinical trials evaluating melflufen, including the pivotal phase II HORIZON study and the phase III OCEAN study, are discussed.

EXPERT OPINION

Although MM treatment has improved, patients with disease refractory to multiple standard-of-care drug classes face a dismal prognosis. Melflufen demonstrated efficacy and tolerability in select populations, with an initial approval in the United States in patients with ≥ four previous lines of therapy and triple-class-refractory MM. Results from the phase III OCEAN study - currently under discussion with regulatory agencies in the United States and Europe - are more complex and have been put into context herein. Lastly, melflufen provides a proof-of-concept for the utility of the peptide-drug conjugate platform in relapsed/refractory MM.

Daratumumab carfilzomib lenalidomide and dexamethasone as induction therapy in high-risk, transplant-eligible patients with newly diagnosed myeloma: Results of the phase 2 study IFM 2018-04

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Background: High-risk (HR) cytogenetic is associated with poor outcome in transplant eligible (TE) newly diagnosed myeloma multiple myeloma (NDMM). The triplet combination carfilzomib lenalidomide and dexamethasone (KRD) plus transplantation demonstrated high efficacy with favorable safety profile in TE-NDMM patients (FORTE). The addition of daratumumab (Dara) to frontline therapy also improved response rate and progression free-survival in TE-NDMM patients (CASSIOPEIA, GRIFFIN). Double transplant also improved outcome of HR TE NDMM patients (EMN02, STAMINA). The phase 2 trial 2018-04 from the Intergroupe Francophone du Myelome (IFM) is evaluating an intensive strategy with Dara-KRD induction and consolidation plus double transplant in HR TE NDMM (NCT03606577). Methods: HR MM was defined by the presence of del17p, t(4;14) and/or t(14;16). Stategy includes Dara-KRD induction (6 cycles), autologous stem cell transplantation (ASCT), Dara-KRD consolidation (4 cycles), second ASCT, Dara-lenalidomide maintenance. The primary endpoint was the feasibility of this intensive strategy. Here, we report efficacy and safety analysis of Dara-KRD induction. Results: Fifty patients with previously untreated NDMM were included from july 2019 to march 2021 in 11 IFM centers Median age was 57 (range 38 -65). ISS stage 3 was present in 12 (24%) patients. Based on inclusion criteria, all patients had HR cytogenetic, including 17p deletion (n = 20, 40%), t(4;14) (n = 26, 52%) or t(14;16) (n = 10,20%). Forty-six patients completed Dara-KRD induction. Two patients discontinued treatment due to severe adverse event (COVID-19 infection, n = 1 ; drug-induced hepatitis, n = 1) and 2 patients discontinued treatment due to disease progression. Grade 3-4 treatment related adverse event ( > 5% of patients) were neutropenia (38%), anemia (14%), thrombocytopenia (8%), infection (6%), renal insufficiency (6%) and deep-vein thrombosis (6%). Two patients (6%) experienced stem-cell collection failure. Overall response rate was 96%, including 92 % > very good partial response. Among 37 (/46) evaluable patients post induction, Minimal Residual Disease negativity rate (NGS, 10-5) was 62%. Conclusions: Dara-KRD as induction prior ASCT is safe and allows deep responses in TE NDMM patients with high-risk cytogenetic profile. IFM 2018-04 study is ongoing and longer follow-up is needed to evaluate safety and efficacy of the overall strategy with Dara-KRD induction and consolidation plus double transplant in this subset of HR patients. Clinical trial information: NCT03606577.

Efficacy and safety of teclistamab (tec), a B-cell maturation antigen (BCMA) x CD3 bispecific antibody, in patients (pts) with relapsed/refractory multiple myeloma (RRMM) after exposure to other BCMA-targeted agents

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Background: Tec (JNJ-64007957) is a BCMA x CD3 bispecific antibody (Ab) that redirects CD3+ T cells to mediate T-cell activation and subsequent lysis of BCMA-expressing myeloma cells. MajesTEC-1 is a multicohort, open-label phase 1/2 study of tec in pts with RRMM who previously received ≥3 prior lines of therapy (LOT). Results from a pooled analysis of phase 1 and phase 2 cohort A (median follow-up 7.8 mo) demonstrated an overall response rate (ORR) of 62.0% in pts with no prior anti-BCMA treatment (tx). We present initial results from cohort C, in which pts had prior exposure to an anti-BCMA tx. Methods: Eligible pts (age ≥18 y) had documented MM per IMWG criteria and had received ≥3 prior LOT including a PI, an IMiD, an anti-CD38 Ab, and an anti-BCMA tx (chimeric antigen receptor T [CAR-T] or Ab drug conjugate [ADC]). Pts were enrolled into a Simon’s stage design, receiving weekly subcutaneous tec 1.5 mg/kg preceded by step-up doses of 0.06 and 0.3 mg/kg. Primary endpoint was ORR (per IMWG 2016 criteria). AEs were graded per CTCAE v4.03; cytokine release syndrome (CRS) and immune effector cell–associated neurotoxicity syndrome (ICANS) were graded per ASTCT guidelines. Results: As of Sep 7, 2021, 38 pts in cohort C received tec (63% male; median age 63.5 y [range 32–82]; median prior LOT 6 [range 3–14]). 32 (84%) pts were refractory to last LOT; 25 (66%) were refractory to an anti-BCMA tx. Of 25 pts evaluated for efficacy, 16 (64%) had prior ADC, 11 (44%) prior CAR-T (2 pts received both). With median follow-up of 6.9 mo (range 0.7–8.7), ORR was 40% (95% CI 21–61). 5 pts (20%) achieved a complete response or better. The ORR (95% CI) was 38% (15–65) in ADC-exposed pts and 45% (17–77) in CAR-T–exposed pts. Most responses occurred rapidly; 7/25 pts had responses that deepened over time. Median time (range) to first and best response was 1.2 mo (0.2–4.9) and 2.1 mo (1.1–5.7), respectively. Median duration of response was not reached. The safety profile was comparable with that observed in BMCA tx-naive pts, with no new safety concerns. 16 pts (42%; grade 3/4 26%) had infections. Most common AEs (n = 38) were CRS (63%; all grade 1/2; median [range] time to CRS onset: 3 d [2–6], duration of CRS: 2 d [1–4]), neutropenia (55%; grade 3/4 50%), thrombocytopenia (42%; grade 3/4 29%), anemia (39%; grade 3/4 29%), and lymphopenia (40%; grade 3/4 37%). One pt had grade 3 ICANS that resolved with supportive care; pt remains on tx. No pts developed anti-tec Abs. Baseline BCMA expression was comparable with that observed in BCMA tx-naive pts. Updated efficacy and safety data will be presented for 40 pts. Conclusions: Initial results of serial targeting of BCMA with tec following ADC or CAR-T tx suggest a promising ORR with responses occurring early and deepening over time. A well-tolerated safety profile was observed in pts previously treated with anti-BCMA tx. Clinical trial information: NCT04557098.

Ixazomib and daratumumab without dexamethasone (I-Dara) in elderly frail RRMM patients: A multicenter phase 2 study (IFM 2018-02) of the Intergroupe Francophone du Myélome (IFM)

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Background: Frail patients with multiple myeloma have an inferior outcome, especially in the relapse setting. This adverse prognosis is mainly related to a high discontinuation rate due to treatment (Tx) related adverse events. The aim of this phase 2 study is to evaluate efficacy and tolerability of Ixazomib-Daratumumab (I-Dara) without Dexamethasone in elderly frail patients with relapsed myeloma (RRMM) (NCT03757221). Methods: Ixa-Dara naïve RRMM patients received oral Ixazomib (4 mg: days 1, 8, 15), IV Daratumumab (16 mg/kg; days 1, 8, 15, 22, cycles 1-2; days 1, 15, cycles 3-6; days 1, cycles 7+) and IV Methylprednisolone before Daratumumab (100 mg at day 1, 8, cycle 1 and then 60 mg). They were enrolled after 1 or 2 prior therapy if their frailty score was ≥ 2 by IMWG score. The primary endpoint was ≥ very good partial response rate (VGPR) at one year. Secondary endpoints included ORR, PFS, OS & toxicity according to NCI-CTCAE version 5. Results: Sixty-three patients were screened and 55 enrolled between 03/2018 and 09/2021. Patient were at first (n = 36) or second relapse (n = 19). Thirty-three patients (60%) were previously exposed to bortezomib, 37 (67%) were previously exposed to lenalidomide (Len) and 20 (36 %) were refractory to Len. Median age was 82 (72-93). All patients had a frailty score ≥2 and 13 (24 %) had a 3 or 4 frailty score. In 41 patients ISS at diagnosis was stage I (n = 11), II (n = 18) or III (n = 12). Seventeen (36%) patients harbored high-risk (HR) cytogenetic, including t(4;14) (n = 8) or del17p (n = 10). The median duration of Tx among 28 pts with ongoing Tx was 10 months [5-32] at data cutoff (February, 2)]. The median duration of Tx among 27 pts who stopped Tx was 6 months [0-18]: 18 had progressive disease. Nine patients died during the study: Daratumumab-related bronchospasm (D1C1); Ixazomib-related overdose (C2); sepsis (n = 4), progressive disease (n = 3). Regarding toxicity, 27 pts had a ≥grade 3 AE (49%). The most common grade 3-4 toxicities were thrombocytopenia (n = 9), other cytopenias (n = 4), infection (n = 8), hypertension (n = 3) and gastrointestinal disorders (n = 3). Fourteen out of 28 were SAE including 5 infections, 1 bronchospasm, 1 acute respiratory failure and 2 ixazomib overdoses. Overall response rate, including minimal response, was 86 % with a ≥VGPR rate of 32 % in the whole group. In Len refractory patients the ORR was 82 % and ≥VGPR 41%, in HR cytogenetic patients ORR was 85 % and ≥VGPR 46%. With a median follow-up of 11.6 months median PFS is 16 months and median OS NR (76% estimated at one year). Conclusions: In this elderly frail population Ixa-Dara is a feasible combination with favorable efficacy profile even in Len refractory and HR cytogenetic patients. Early toxicity remains a concern in this population eventhough more manageable with Dara SC. Clinical trial information: NCT03757221.

Bortezomib and high-dose melphalan conditioning regimen in frontline multiple myeloma: an IFM randomized phase 3 study

High-dose melphalan (HDM) and transplantation are recommended for eligible patients with multiple myeloma. No other conditioning regimen has proven to be more effective and/or safer. We previously reported in a phase 2 study that bortezomib can safely and effectively be combined with HDM (Bor-HDM), with a 32% complete response (CR) rate after transplantation. These data supported a randomized phase 3 trial. Randomization was stratified according to risk and response to induction: 300 patients were enrolled, and 154 were allocated to the experimental arm (ie, arm A) with bortezomib (1 mg/m2 intravenously [IV]) on days -6, -3, +1, and +4 and melphalan (200 mg/m2 IV) on day -2. The control arm (ie, arm B) consisted of HDM alone (200 mg/m2 IV). There were no differences in stringent CR + CR rates at day 60 posttransplant (primary end point): 22.1% in arm A vs 20.5% in arm B (P = .844). There were also no differences in undetectable minimum residual disease rates: 41.3% vs 39.4% (P = .864). Median progression-free survival was 34.0 months for arm A vs 29.6 months for arm B (adjusted HR, 0.82; 95% CI, 0.61-1.13; P = .244). The estimated 3-year overall survival was 89.5% in both arms (hazard ratio, 1.28; 95% CI, 0.62-2.64; P = .374). Sixty-nine serious adverse events occurred in 18.7% of Bor-HDM-treated patients (vs 13.1% in HDM-treated patients). The proportion of grade 3/4 AEs was similar within the 2 groups (72.0% vs 73.1%), mainly (as expected) blood and gastrointestinal disorders; 4% of patients reported grade 3/4 or painful peripheral neuropathy in arm A (vs 1.5% in arm B). In this randomized phase 3 study, a conditioning regimen with Bor-HDM did not improve efficacy end points or outcomes compared with HDM alone. The original trial was registered at www.clinicaltrials.gov as #NCT02197221.

Anti‐SARS‐CoV‐2 vaccines in recipient and/or donor before allotransplant

The impact of pre‐transplant anti‐severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2) vaccine in 20 recipients of allogeneic hematopoietic stem cell transplantation (Allo‐HSCT) and/or their donors is reported here, showing that the persistence of anti‐SARS‐CoV‐2 antibodies can be detected in almost all patients, whatever the type of vaccine used, and up to 9 months post transplant. Also, an anti‐SARS‐CoV‐2 spike glycoprotein CD3+ T‐cell response could be detected in six (35%) of 17 evaluable patients. This study provides a rationale to consider anti‐SARS‐CoV‐2 vaccination of both recipients and donors before Allo‐HSCT.

Extensive myelitis with eosinophilic meningitis after Chimeric antigen receptor T cells therapy

Immune effector cell‐associated neurotoxicity syndrome (ICANS) is a frequent adverse event after Chimeric antigen receptor T cells (CAR‐T cells). A patient treated with anti‐CD19 CAR‐T cells for a refractory mantle cell lymphoma presented at Day 8 post‐infusion with extensive myelitis. Unusual eosinophilia was disclosed in the patient's cerebrospinal fluid. After treatment with methylprednisolone and siltuximab, a decrease in clinical symptoms and magnetic resonance imaging lesions were obtained. This unprecedented presentation of eosinophilic meningitis after CAR‐T cells therapy highlights the need for a better understanding of the physiopathology of ICANS, especially to identify potentially targetable pathways.

B Cell Aplasia Is the Most Powerful Predictive Marker for Poor Humoral Response after BNT162b2 mRNA SARS-CoV-2 Vaccination in Recipients of Allogeneic Hematopoietic Stem Cell Transplantation

Little is known about the immune response to SARS-CoV-2 vaccination in recipients of allogeneic hematopoietic stem cell transplantation (allo-HSCT). However, several studies have reported that adequate protection could be provided to this population. The purpose of this study was to evaluate which factors can predict the efficacy of SARS-CoV-2 vaccination in these specifically immunosuppressed patients. Specific anti-Spike (S) antibody responses were assessed in a cohort of 117 allo-HSCT recipients after 2 injections of BNT162b2 mRNA SARS-CoV-2 vaccine (V1 and V2). Factors considered liable to influence the antibody response and analyzed in this series were the interval between allo-HSCT and V1, donor source, recipient and donor age, current immunosuppressive/chemotherapy (I/C) treatment, and levels of CD4⁺and CD8⁺ T cells, B cells, and natural killer cells at the time of V1. Overall, the S-antibody response rate, evaluated at a median of 35 days after V2, was 82.9% for the entire cohort, with 71 patients (61%) reaching the highest titer. In univariate analysis, a lower pre-V1 median total lymphocyte count, lower CD4⁺ T cell and B cell counts, ongoing I/C treatment, and a haploidentical donor were characteristic of nonhumoral responders. However, multiparameter analysis showed that B cell aplasia was the sole factor predicting the absence of a specific immune response (odds ratio, 0.01; 95% confidence interval, 0.00 to 0.10; P < 10^-3). Indeed, the rate of humoral response was 9.1% in patients with B cell aplasia versus 95.9% in patients with a B cell count >0 (P < 10^-9). These results advocate for the administration of anti-SARS-CoV-2 vaccination in allo-HSCT recipients as early as peripheral B cell levels can be detected, and also suggest the need for close monitoring of B-cell reconstitution after Allo-HSCT.

Trends in autologous stem cell transplantation for newly diagnosed multiple myeloma: Changing demographics and outcomes in European Society for Blood and Marrow Transplantation centres from 1995 to 2019

Multiple myeloma (MM) accounts for 10% of haematological malignancies. Overall survival (OS) has improved in recent years due to increased use of autologous stem cell transplantation (ASCT) in the treatment of newly diagnosed MM and the advent of novel agents, including proteasome inhibitors, immunomodulatory drugs and monoclonal antibodies. To assess trends in ASCT including patient selection, choice of induction regimen, depth of response and survival, we performed a retrospective analysis of all patients undergoing first ASCT for MM in European Society for Blood and Marrow Transplantation centres between 1995 and 2019. A total of 117 711 patients across 575 centres were included. The number of transplants performed increased sevenfold across the study period. The median age increased from 55 to 61 years, and the percentage of patients aged >65 years rose from 7% to 30%. Use of chemotherapy-based induction fell significantly, being largely replaced by bortezomib-based regimens. The two-year complete response rate increased from 22% to 42%. The five-year progression-free survival and OS rates increased from 28% to 31% and from 52% to 69%, respectively. Transplant mortality fell from 5.9% to 1.5%. Ongoing advances in MM treatment may challenge the future role of ASCT. However, at the current time, ASCT remains central to the MM treatment paradigm.

Daratumumab plus lenalidomide and dexamethasone in transplant-ineligible newly diagnosed multiple myeloma: frailty subgroup analysis of MAIA

In the phase 3 MAIA study of patients with transplant-ineligible newly diagnosed multiple myeloma (NDMM), daratumumab plus lenalidomide/dexamethasone (D-Rd) improved progression-free survival (PFS) versus lenalidomide/dexamethasone (Rd). We present a subgroup analysis of MAIA by frailty status. Frailty assessment was performed retrospectively using age, Charlson comorbidity index, and baseline Eastern Cooperative Oncology Group performance status score. Patients were classified as fit, intermediate, non-frail (fit + intermediate), or frail. Of the randomized patients (D-Rd, n = 368; Rd, n = 369), 396 patients were non-frail (D-Rd, 196 [53.3%]; Rd, 200 [54.2%]) and 341 patients were frail (172 [46.7%]; 169 [45.8%]). After a 36.4-month median follow-up, non-frail patients had longer PFS than frail patients, but the PFS benefit of D-Rd versus Rd was maintained across subgroups: non-frail (median, not reached [NR] vs 41.7 months; hazard ratio [HR], 0.48; P < 0.0001) and frail (NR vs 30.4 months; HR, 0.62; P = 0.003). Improved rates of complete response or better and minimal residual disease (10^-5) negativity were observed for D-Rd across subgroups. The most common grade 3/4 treatment-emergent adverse event in non-frail and frail patients was neutropenia (non-frail, 45.4% [D-Rd] and 37.2% [Rd]; frail, 57.7% and 33.1%). These findings support the clinical benefit of D-Rd in transplant-ineligible NDMM patients enrolled in MAIA, regardless of frailty status.

Cytokine release syndrome and tumor lysis syndrome in a multiple myeloma patient treated with palliative radiotherapy: A case report and review of the literature

We present the case of a 53-year-old woman treated with analgesic radiotherapy for a multiple myeloma bone lesion of the forearm. After a first fraction of 5 Gray (Gy), she presented with an acute respiratory syndrome with fever a few hours after the treatment. The same symptoms occurred after the second fraction 3 days later. The patient recovered quickly thanks to intravenous hydration and suspension of the radiotherapy. Biological tests revealed a tumor lysis syndrome. We concluded that the clinical symptoms could be defined as cytokine release syndrome. This is the second time in the literature that cytokine release syndrome has been described following radiotherapy. First, we synthesize TLS and radiotherapy to determine how radiotherapy could be a trigger associated with other well-known factors. Furthermore, we discuss radiotherapy and cytokine release syndrome.

Summary

We present the case of a woman treated with analgesic radiotherapy for a multiple myeloma bone lesion. Following the first and the second treatment fraction, the patient presented with an acute respiratory syndrome with fever and biological tests revealed a tumor lysis syndrome. We concluded that the clinical symptoms could be defined as cytokine release syndrome. Furthermore, we discuss how radiotherapy could be a trigger of cytokine release syndrome and tumor lysis syndrome in association with chemotherapy drugs.

Patient-reported outcomes in relapsed/refractory multiple myeloma treated with melflufen plus dexamethasone: analyses from the Phase II HORIZON study

Relapsed/refractory multiple myeloma (RRMM) is known to have a high burden of disease and complications associated with refractoriness to prior lines of therapy. Severe pain and fatigue symptoms and impairments in physical and emotional functioning have been strongly linked to reduced health‐related quality of life (HRQoL) in patients with RRMM. Assessment of patient reported‐outcome measures from the pivotal, Phase II HORIZON study (OP‐106; NCT02963493) in patients with RRMM (n = 64) demonstrated that melphalan flufenamide (melflufen) plus dexamethasone treatment preserved HRQoL. Patients had clinically meaningful improvements, even after eight treatment cycles, in relevant scales such as global health status/QoL, physical functioning, emotional functioning, pain, and fatigue. Patients with triple‐class–refractory disease (n = 50) displayed similar improvements. Patient‐reported outcome deterioration was delayed for a substantial amount of time in patients who experienced a response to melflufen plus dexamethasone treatment relative to patients who did not experience a response. These findings support the notion that treatment with melflufen plus dexamethasone may sustain or improve HRQoL over time in patients with RRMM, including in patients with triple‐class–refractory disease for whom outcomes are generally worse. The clinical benefits observed in patients from the HORIZON trial are encouraging and supportive of translation into real‐world practice.

Maintenance with daratumumab or observation following treatment with bortezomib, thalidomide, and dexamethasone with or without daratumumab and autologous stem-cell transplant in patients with newly diagnosed multiple myeloma (CASSIOPEIA): an open-label, randomised, phase 3 trial

BACKGROUND

CASSIOPEIA part 1 showed superior depth of response and significantly improved progression-free survival with daratumumab, bortezomib, thalidomide, and dexamethasone (D-VTd) versus bortezomib, thalidomide, and dexamethasone (VTd) as induction and consolidation in patients with autologous stem-cell transplant (ASCT)-eligible newly diagnosed multiple myeloma. In part 2, we compared daratumumab maintenance versus observation only.

METHODS

CASSIOPEIA is a two-part, open-label, randomised, phase 3 trial of patients aged 18-65 years with newly diagnosed multiple myeloma and Eastern Cooperative Oncology Group performance status 0-2, done in 111 European academic and community practice centres. In part 1, patients were randomly assigned (1:1) to induction and consolidation with D-VTd or VTd. Patients still on study who had a partial response or better were randomly assigned (1:1) by an interactive web-response system to daratumumab 16 mg/kg intravenously every 8 weeks (a reduced frequency compared with standard daratumumab long-term dosing) or observation only for up to 2 years. Stratification factors were induction treatment and depth of response in part 1. The part 2 primary endpoint was progression-free survival from second randomisation. This preplanned interim analysis of progression-free survival was done after 281 events and shall be considered the primary analysis of progression-free survival. Sponsor personnel and designees who were involved in the analysis were masked to treatment group until the independent data monitoring committee recommended that the preplanned interim analysis be considered the main analysis of progression-free survival in part 2. Otherwise, treatment assignments were unmasked. The interaction between induction and consolidation and maintenance was tested at a two-sided significance level of 0·05 by a stratified Cox regression model that included the interaction term between maintenance treatment and induction and consolidation treatment. Efficacy analyses were done in the maintenance-specific intention-to-treat population, which comprised all patients who underwent second randomisation. Safety was analysed in all patients in the daratumumab group who received at least one dose and all patients randomly assigned to observation only. This trial is registered with ClinicalTrials.gov, NCT02541383. Long-term follow-up is ongoing and the trial is closed to new participants.

FINDINGS

Between May 30, 2016, and June 18, 2018, 886 patients (458 [84%] of 543 in the D-VTd group and 428 [79%] of 542 in the VTd group) were randomly assigned to daratumumab maintenance (n=442) or observation only (n=444). At a median follow-up of 35·4 months (IQR 30·2-39·9) from second randomisation, median progression-free survival was not reached (95% CI not evaluable [NE]-NE) with daratumumab versus 46·7 months (40·0-NE) with observation only (hazard ratio 0·53, 95% CI 0·42-0·68, p<0·0001). A prespecified analysis of progression-free survival results showed a significant interaction between maintenance and induction and consolidation therapy (p<0·0001). The most common grade 3 or 4 adverse events were lymphopenia (16 [4%] of 440 patients in the daratumumab group vs eight [2%] of 444 patients in the observation-only group), hypertension (13 [3%] vs seven [2%]), and neutropenia (nine [2%] vs ten [2%]). Serious adverse events occurred in 100 (23%) patients in the daratumumab group and 84 (19%) patients in the observation-only group. In the daratumumab group, two adverse events led to death (septic shock and natural killer-cell lymphoblastic lymphoma); both were related to treatment.

INTERPRETATION

Daratumumab maintenance every 8 weeks for 2 years significantly reduced the risk of disease progression or death compared with observation only. Longer follow-up and other ongoing studies will shed further light on the optimal daratumumab-containing post-ASCT maintenance treatment strategy.

FUNDING

Janssen Research & Development, the Intergroupe Francophone du Myélome, and the Dutch-Belgian Cooperative Trial Group for Hematology Oncology.