International Myeloma Working Group immunotherapy committee consensus guidelines and recommendations for optimal use of T-cell-engaging bispecific antibodies in multiple myeloma.

Multiple myeloma remains an incurable disease, despite the development of numerous drug classes and combinations that have contributed to improved overall survival. Immunotherapies directed against cancer cell-surface antigens, such as chimeric antigen receptor (CAR) T-cell therapy and T-cell-redirecting bispecific antibodies, have recently received regulatory approvals and shown unprecedented efficacy. However, these immunotherapies have unique mechanisms of action and toxicities that are different to previous treatments for myeloma, so experiences from clinical trials and early access programmes are essential for providing specific recommendations for management of patients, especially as these agents become available across many parts of the world. Here, we provide expert consensus clinical practice guidelines for the use of bispecific antibodies for the treatment of myeloma. The International Myeloma Working Group is also involved in the collection of prospective real-time data of patients treated with such immunotherapies, with the aim of learning continuously and adapting clinical practices to optimise the management of patients receiving immunotherapies.

Practical Aspects of Immunotherapy: A Report from the 20th International Myeloma Society (IMS) Annual Meeting.

Immunotherapeutic strategies, specifically T-cell-redirected therapies, have been transformative in the context of multiple myeloma (MM). With the approval of two chimeric antigen receptor T-cell (CAR-T) drug products and three bispecific antibodies/T-cell engagers (bsAbs/TCEs) in relapsed/refractory MM (RRMM), the 20th annual IMS meeting dedicated a session to the practical aspects of these therapies. Here, we highlight the discussion during this session, including the role of CAR-T and bsAb therapies in frontline MM treatment, management of acute toxicities, prevention and management of infections, and finally treatment sequencing of T-cell redirected therapies.

Elranatamab in relapsed or refractory multiple myeloma: the MagnetisMM-1 phase 1 trial.

Multiple myeloma (MM) is a plasma cell malignancy expressing B cell maturation antigen (BCMA). Elranatamab, a bispecific antibody, engages BCMA on MM and CD3 on T cells. The MagnetisMM-1 trial evaluated its safety, pharmacokinetics and efficacy. Primary endpoints, including the incidence of dose-limiting toxicities as well as objective response rate (ORR) and duration of response (DOR), were met. Secondary efficacy endpoints included progression-free survival (PFS) and overall survival (OS). Eighty-eight patients with relapsed or refractory MM received elranatamab monotherapy, and 55 patients received elranatamab at efficacious doses. Patients had received a median of five prior regimens; 90.9% were triple-class refractory, 29.1% had high cytogenetic risk and 23.6% received prior BCMA-directed therapy. No dose-limiting toxicities were observed during dose escalation. Adverse events included cytopenias and cytokine release syndrome. Exposure was dose proportional. With a median follow-up of 12.0 months, the ORR was 63.6% and 38.2% of patients achieving complete response or better. For responders, the median DOR was 17.1 months. All 13 patients evaluable for minimal residual disease achieved negativity. Even after prior BCMA-directed therapy, 53.8% achieved response. For all 55 patients, median PFS was 11.8 months, and median OS was 21.2 months. Elranatamab achieved durable responses, manageable safety and promising survival for patients with MM. ClinicalTrials.gov Identifier: NCT03269136 .

Radiation therapy as a bridging and salvage strategy in patients with relapsed or refractory multiple myeloma undergoing BCMA-targeted CAR T-cell therapy.

Radiation therapy (RT) may play an important role prior to and following BCMA-targeted CAR T-cell therapy in multiple myeloma (MM). We report a series of 13 patients: 5 patients received bridging RT pre-CAR T, 4 patients received salvage RT post-CAR T failure, and 4 patients received both. There was no worsening of CAR-T- or RT-related toxicities. The RT in-field local control rate was 100%, with a median follow-up after each RT course of 7.3 months. RT as a bridging and salvage strategy is safe, feasible, and offers excellent local control in MM patients treated with CAR T-cell therapy.

Idecabtagene vicleucel for relapsed and refractory multiple myeloma: post hoc 18-month follow-up of a phase 1 trial.

Idecabtagene vicleucel (ide-cel) is a B-cell-maturation antigen (BCMA)-directed chimeric antigen receptor T cell therapy. We performed a post hoc analysis of a single-arm phase 1 multicenter study in relapsed/refractory multiple myeloma (CRB-401) (n = 62; median follow-up, 18.1 months). The primary endpoint was safety outcomes, and secondary endpoints included overall response rate (ORR), complete response (CR) and very good partial response (VGPR). The study met its primary endpoint with low rates of grade 3/grade 4 cytokine release syndrome (6.5%) and neurotoxicity (1.6%). ORR was 75.8%; 64.5% achieved VGPR or better and 38.7% achieved CR or stringent CR. Among exploratory endpoints, median duration of response, progression-free survival (PFS) and overall survival were 10.3, 8.8 and 34.2 months, respectively, and ide-cel expansion in blood and bone marrow correlated with clinical efficacy and postinfusion reduction of soluble BCMA. Patients with PFS ≥ 18 months had more naive and less exhausted T cells in apheresis material and improved functional T cell phenotype in the drug product compared with those with less durable responses. These results confirm ide-cel safety, tolerability and efficacy and describe T cell qualities that correlate with durable response. Clinicaltrials.gov identifier : NCT02658929 .

Time-Dependent Prognostic Value of Serological and Measurable Residual Disease Assessments after Idecabtagene Vicleucel.

The role of measurable residual disease (MRD) in multiple myeloma patients treated with chimeric antigen receptor (CAR) T cells is uncertain. We analyzed MRD kinetics during the first year after idecabtagene vicleucel (ide-cel) infusion in 125 relapsed/refractory multiple myeloma patients enrolled in KarMMa. At month 1 after ide-cel, there were no differences in progression-free survival (PFS) between patients in less than complete response (CR) versus those in CR; only MRD status was predictive of significantly different PFS at this landmark. In patients with undetectable MRD at 3 months and beyond, PFS was longer in those achieving CR versus

Immune Reconstitution and Vaccinations in Multiple Myeloma: A Report From the 19th International Myeloma Society Annual Workshop.

Given the significance of the immune system and the important role of therapies within the context of the immune system in plasma cell disorders, the International Myeloma Society annual workshop convened a session dedicated to this topic. A panel of experts covered various aspects of immune reconstitution and vaccination. The top oral presentations were highlighted and discussed. This is a report of the proceedings.

Effect of granulocyte colony-stimulating factor on toxicities after CAR T cell therapy for lymphoma and myeloma.

Chimeric antigen receptor T cells (CAR T) are groundbreaking therapies but may cause significant toxicities including cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), and cytopenias. Granulocyte colony-stimulating factor (G-CSF) is often used to mitigate neutropenia after CAR T, but there is no consensus recommended strategy due to hypothesized, but largely unknown risks of exacerbating toxicities. To investigate the impact of G-CSF, we retrospectively analyzed 197 patients treated with anti-CD19 CAR T for lymphoma and 47 patients treated with anti-BCMA CAR T for multiple myeloma. In lymphoma, 140 patients (71%) received prophylactic G-CSF before CAR T (mostly pegylated G-CSF) and were compared with 57 patients (29%) treated with G-CSF after CAR T or not exposed. Prophylactic G-CSF was associated with faster neutrophil recovery (3 vs. 4 days, P < 0.01) but did not reduce recurrent neutropenia later. Prophylactic G-CSF was associated with increased grade ≥2 CRS (HR 2.15, 95% CI 1.11-4.18, P = 0.02), but not ICANS. In multiple myeloma, prophylactic G-CSF was not used; patients were stratified by early G-CSF exposure (≤2 days vs. ≥3 days after CAR T or no exposure), with no significant difference in toxicities. Future trials should clarify the optimal G-CSF strategy to improve outcomes after CAR T.

Quality of life, psychological distress, and prognostic perceptions in caregivers of patients with multiple myeloma.

Although caregivers of patients with multiple myeloma (MM) play a critical role in supporting their loved ones throughout the illness course, studies examining caregiver quality of life (QOL), psychological distress, and prognostic awareness are lacking. We conducted a cross-sectional, multisite study of patients undergoing treatment with MM and their caregivers. Eligible caregivers were enrolled to 1 of 3 cohorts based on lines of therapy. Caregivers completed validated questionnaires to assess their QOL, psychological distress, and perceptions of prognosis. We enrolled 127 caregivers of patients with MM (newly diagnosed [n = 43], 2-3 lines of therapy [n = 40], and ≥4 lines of therapy [n = 44]). Caregiver QOL and psychological distress did not differ by line of therapy. The rate of clinically significant anxiety, depression, and posttraumatic stress disorder symptoms were 44.1% (56/127), 15.8% (20/127), and 24.4% (31/127), respectively. When examined in dyads, caregivers reported higher rates of clinically significant anxiety (44.4% [55/124] vs 22.5% [28/124]) compared with patients with MM. Most caregivers (84.2%, 101/120) reported that the oncologist had informed them that the patient's cancer was incurable; however, only 50.9% (58/114) and 53.6% (59/110) of caregivers acknowledged the patient's cancer was terminal and incurable, respectively. Caregivers of patients undergoing treatment for MM experience substantial psychological distress across the disease continuum, particularly anxiety. The majority of caregivers of patients with MM report that knowing the patient's prognosis is extremely important and report that the oncologist told them that the patient was incurable. Nevertheless, a significant portion of caregivers believe that the patient's MM is curable.

Gaps and opportunities in the treatment of relapsed-refractory multiple myeloma: Consensus recommendations of the NCI Multiple Myeloma Steering Committee.

A wide variety of new therapeutic options for Multiple Myeloma (MM) have recently become available, extending progression-free and overall survival for patients in meaningful ways. However, these treatments are not curative, and patients eventually relapse, necessitating decisions on the appropriate choice of treatment(s) for the next phase of the disease. Additionally, an important subset of MM patients will prove to be refractory to the majority of the available treatments, requiring selection of effective therapies from the remaining options. Immunomodulatory agents (IMiDs), proteasome inhibitors, monoclonal antibodies, and alkylating agents are the major classes of MM therapies, with several options in each class. Patients who are refractory to one agent in a class may be responsive to a related compound or to a drug from a different class. However, rules for selection of alternative treatments in these situations are somewhat empirical and later phase clinical trials to inform those choices are ongoing. To address these issues the NCI Multiple Myeloma Steering Committee formed a relapsed/refractory working group to review optimal treatment choices, timing, and sequencing and provide recommendations. Additional issues considered include the role of salvage autologous stem cell transplantation, risk stratification, targeted approaches for genetic subsets of MM, appropriate clinical trial endpoints, and promising investigational agents. This report summarizes the deliberations of the working group and suggests potential avenues of research to improve the precision, timing, and durability of treatments for Myeloma.

Triplet Therapy, Transplantation, and Maintenance until Progression in Myeloma.

BACKGROUND: In patients with newly diagnosed multiple myeloma, the effect of adding autologous stem-cell transplantation (ASCT) to triplet therapy (lenalidomide, bortezomib, and dexamethasone [RVD]), followed by lenalidomide maintenance therapy until disease progression, is unknown. METHODS: In this phase 3 trial, adults (18 to 65 years of age) with symptomatic myeloma received one cycle of RVD. We randomly assigned these patients, in a 1:1 ratio, to receive two additional RVD cycles plus stem-cell mobilization, followed by either five additional RVD cycles (the RVD-alone group) or high-dose melphalan plus ASCT followed by two additional RVD cycles (the transplantation group). Both groups received lenalidomide until disease progression, unacceptable side effects, or both. The primary end point was progression-free survival. RESULTS: Among 357 patients in the RVD-alone group and 365 in the transplantation group, at a median follow-up of 76.0 months, 328 events of disease progression or death occurred; the risk was 53% higher in the RVD-alone group than in the transplantation group (hazard ratio, 1.53; 95% confidence interval [CI], 1.23 to 1.91; P<0.001); median progression-free survival was 46.2 months and 67.5 months. The percentage of patients with a partial response or better was 95.0% in the RVD-alone group and 97.5% in the transplantation group (P = 0.55); 42.0% and 46.8%, respectively, had a complete response or better (P = 0.99). Treatment-related adverse events of grade 3 or higher occurred in 78.2% and 94.2%, respectively; 5-year survival was 79.2% and 80.7% (hazard ratio for death, 1.10; 95% CI, 0.73 to 1.65). CONCLUSIONS: Among adults with multiple myeloma, RVD plus ASCT was associated with longer progression-free survival than RVD alone. No overall survival benefit was observed. (Funded by the National Heart, Lung, and Blood Institute and others; DETERMINATION ClinicalTrials.gov number, NCT01208662.).

Consensus guidelines and recommendations for infection prevention in multiple myeloma: a report from the International Myeloma Working Group.

Infection remains the leading cause of morbidity and mortality in patients with multiple myeloma because of the cumulative effect of disease, treatment, and host-related factors. Given that infectious risk is cumulative through the course of the disease, preventing infections is paramount. Optimal preventive strategies include vaccination against common pathogens, antimicrobial prophylaxis, infection control measures, and immunoglobulin replacement in a small subset of patients; however, there are no universally accepted guidelines for infection prevention. This Review provides a consensus statement from a panel of 36 experts with global representation, which was convened by The International Myeloma Society to review existing literature and current guidelines, address issues associated with the risk of infection and prevention of infectious complications in multiple myeloma in the context of emerging therapies, and offer recommendations for preventing these complications.

Quality of life, psychological distress, and prognostic perceptions in patients with multiple myeloma.

BACKGROUND: Multiple myeloma (MM) is an incurable hematologic malignancy requiring long-term, continuous therapy. Despite its chronic and unrelenting course, studies examining quality of life (QOL), psychological distress, and perceptions of prognosis by line of therapy are lacking. METHODS: The authors conducted a cross-sectional, multisite study of patients undergoing treatment for MM (excluding maintenance) between June 2020 and January 2021. The authors conducted purposeful sampling and recruited patients to 3 cohorts based on lines of therapy: 1) newly diagnosed receiving first-line therapy; 2) 2 to 3 lines; and 3) 4 or more lines. Patients completed validated questionnaires to assess their QOL, fatigue, psychological distress, and perceptions of prognosis. RESULTS: A total of 180 patients with MM were enrolled (newly diagnosed [n = 60], 2 to 3 lines [n = 60], and ≥4 lines of therapy [n = 60]). QOL, symptom burden, and fatigue scores did not differ by lines of therapy. There were no statistically significant differences in psychological distress by line of therapy. The rates of clinically significant depression, anxiety, and post-traumatic stress disorder symptoms were 23.9% (43 of 180), 23.9% (43 of 180), and 24.4% (44 of 180), respectively. Most patients (84.7%, 149 of 176) reported that their oncologist told them their cancer was incurable, but only 30.6% (53 of 173) acknowledged that they were terminally ill, and 42.0% (73 of 174) reported that they thought their cancer was incurable. CONCLUSIONS: Patients with MM undergoing treatment experience impaired QOL and elevated psychological distress across the disease continuum, regardless of line of therapy. A substantial proportion of patients with MM have significant misperceptions about their prognosis and the curability of their illness despite reporting being informed of the prognosis by their oncologist. LAY SUMMARY: This study discusses 180 patients with MM (newly diagnosed [n = 60], 2-3 lines [n = 60], and ≥4 lines of therapy [n = 60]). Quality of life, symptom burden, and fatigue scores do not differ by lines of therapy. There are also no statistically significant differences in psychological distress by line of therapy. The rates of clinically significant depression, anxiety, and post-traumatic stress disorder symptoms are 23.9%, 23.9%, and 24.4%, respectively. Most patients (84.7%) report that their oncologist told them their cancer was incurable, but only 30.6% acknowledge that they are terminally ill, and 42.0% report that they thought their cancer was incurable.

Cell-free DNA for the detection of emerging treatment failure in relapsed/ refractory multiple myeloma.

Interrogation of cell-free DNA (cfDNA) represents an emerging approach to non-invasively estimate disease burden in multiple myeloma (MM). Here, we examined low-pass whole genome sequencing (LPWGS) of cfDNA for its predictive value in relapsed/ refractory MM (RRMM). We observed that cfDNA positivity, defined as ≥10% tumor fraction by LPWGS, was associated with significantly shorter progression-free survival (PFS) in an exploratory test cohort of 16 patients who were actively treated on diverse regimens. We prospectively determined the predictive value of cfDNA in 86 samples from 45 RRMM patients treated with elotuzumab, pomalidomide, bortezomib, and dexamethasone in a phase II clinical trial (NCT02718833). PFS in patients with tumor-positive and -negative cfDNA after two cycles of treatment was 1.6 and 17.6 months, respectively (HR 7.6, P < 0.0001). Multivariate hazard modelling confirmed cfDNA as independent risk factor (HR 96.6, P = 6.92e-05). While correlating with serum-free light chains and bone marrow, cfDNA additionally discriminated patients with poor PFS among those with the same response by IMWG criteria. In summary, detectability of MM-derived cfDNA, as a measure of substantial tumor burden with therapy, independently predicts poor PFS and may provide refinement for standard-of-care response parameters to identify patients with poor response to treatment earlier than is currently feasible.

Low NCOR2 levels in multiple myeloma patients drive multidrug resistance via MYC upregulation.

MYC upregulation is associated with multidrug refractory disease in patients with multiple myeloma (MM). We, isolated patient-derived MM cells with high MYC expression and discovered that NCOR2 was down-regulated in these cells. NCOR2 is a transcriptional coregulatory protein and its role in MM remains unknown. To define the role of NCOR2 in MM, we created NCOR2 knockout human myeloma cell lines and demonstrated that NCOR2 knockout led to high MYC expression. Furthermore, NCOR2 knockout conferred resistance to pomalidomide, BET and HDAC inhibitors, independent of Cereblon (CRBN), indicating high MYC expression as a cause of multidrug resistance. Moreover, NCOR2 interacted with the nucleosome remodeling and deacetylase (NuRD) complex and repressed the expression of CD180 by directly binding to its promoter and inducing MYC expression. Next, we generated lenalidomide-resistant and pomalidomide-resistant human myeloma cell lines. Whole-exome sequencing revealed that these cell lines acquired the same exonic mutations of NCOR2. These cell lines showed NCOR2 downregulation and MYC upregulation independent of CRBN and demonstrated resistance to BET and HDAC inhibitors. Our findings reveal a novel CRBN independent molecular mechanism associated with drug resistance. Low NCOR2 expression can serve as a potential biomarker for drug resistance and needs further validation in larger prospective studies.

Dynamic transcriptional reprogramming leads to immunotherapeutic vulnerabilities in myeloma.

While there is extensive evidence for genetic variation as a basis for treatment resistance, other sources of variation result from cellular plasticity. Using multiple myeloma as an example of an incurable lymphoid malignancy, we show how cancer cells modulate lineage restriction, adapt their enhancer usage and employ cell-intrinsic diversity for survival and treatment escape. By using single-cell transcriptome and chromatin accessibility profiling, we show that distinct transcriptional states co-exist in individual cancer cells and that differential transcriptional regulon usage and enhancer rewiring underlie these alternative transcriptional states. We demonstrate that exposure to standard treatment further promotes transcriptional reprogramming and differential enhancer recruitment while simultaneously reducing developmental potential. Importantly, treatment generates a distinct complement of actionable immunotherapy targets, such as CXCR4, which can be exploited to overcome treatment resistance. Our studies therefore delineate how to transform the cellular plasticity that underlies drug resistance into immuno-oncologic therapeutic opportunities.

Lifestyle considerations in multiple myeloma.

As the prognosis for multiple myeloma (MM) has significantly improved and patients remain on therapy longer, there is a need for supportive care interventions to optimize patient quality of life (QOL) and functional status over the course of cancer treatment. MM is characterized by a significant symptom burden and a relatively lower QOL compared to other cancers. This review evaluates the role of healthy lifestyle behaviors in improving both the physical functioning and psychological well-being of the MM population. We (1) describe the current literature on physical activity, weight management, diet, sleep, and substance use in the context of MM, (2) present important considerations for incorporating lifestyle factors into clinical practice, and (3) identify directions for future research. Developing MM-specific guidelines for modifiable lifestyle changes that take into account both the length of treatment and the unique disease features (i.e. osteolytic lesions and anemia) may provide a promising path for improved patient QOL and functioning.

Single-Cell Profiling Reveals Metabolic Reprogramming as a Resistance Mechanism in BRAF-Mutated Multiple Myeloma.

PURPOSE: Although remarkably effective in some patients, precision medicine typically induces only transient responses despite initial absence of resistance-conferring mutations. Using BRAF-mutated myeloma as a model for resistance to precision medicine we investigated if BRAF-mutated cancer cells have the ability to ensure their survival by rapidly adapting to BRAF inhibitor treatment. EXPERIMENTAL DESIGN: Full-length single-cell RNA (scRNA) sequencing (scRNA-seq) was conducted on 3 patients with BRAF-mutated myeloma and 1 healthy donor. We sequenced 1,495 cells before, after 1 week, and at clinical relapse to BRAF/MEK inhibitor treatment. We developed an in vitro model of dabrafenib resistance using genetically homogeneous single-cell clones from two cell lines with established BRAF mutations (U266, DP6). Transcriptional and epigenetic adaptation in resistant cells were defined by RNA-seq and H3K27ac chromatin immunoprecipitation sequencing (ChIP-seq). Mitochondrial metabolism was characterized by metabolic flux analysis. RESULTS: Profiling by scRNA-seq revealed rapid cellular state changes in response to BRAF/MEK inhibition in patients with myeloma and cell lines. Transcriptional adaptation preceded detectable outgrowth of genetically discernible drug-resistant clones and was associated with widespread enhancer remodeling. As a dominant vulnerability, dependency on oxidative phosphorylation (OxPhos) was induced. In treated individuals, OxPhos was activated at the time of relapse and showed inverse correlation to MAPK activation. Metabolic flux analysis confirmed OxPhos as a preferential energetic resource of drug-persistent myeloma cells. CONCLUSIONS: This study demonstrates that cancer cells have the ability to rapidly adapt to precision treatments through transcriptional state changes, epigenetic adaptation, and metabolic rewiring, thus facilitating the development of refractory disease while simultaneously exposing novel vulnerabilities.

A phase 1, multicenter study evaluating the safety and efficacy of KITE-585, an autologous anti-BCMA CAR T-cell therapy, in patients with relapsed/refractory multiple myeloma.

Despite advances in treatment, most patients with multiple myeloma (MM) will relapse, and long-term survival remains poor. B-cell maturation antigen (BCMA) is an ideal therapeutic target as it is expressed throughout the disease course with normal tissue expression limited to plasma and some B-cell lineages. This phase 1, multicenter, first-in-human study evaluated the safety and efficacy of KITE-585, an autologous anti-BCMA chimeric antigen receptor (CAR) T-cell therapy, in patients with relapsed/refractory MM (RRMM). Key eligibility criteria included measurable MM and progression, defined by the International Myeloma Working Group Consensus Criteria within 60 days of the last treatment. Patients underwent leukapheresis and subsequently received a 3-day conditioning therapy regimen (cyclophosphamide [300 mg/m2/day] and fludarabine [30 mg/m2/day]). Patients then received a flat dose of 3 × 107 to 1 × 109 KITE-585 CAR T cells in a 3+3 dose-escalation design. The primary endpoint was incidence of adverse events (AEs) defined as dose-limiting toxicities (DLTs). Key secondary and exploratory endpoints included efficacy outcomes, incidence of AEs, levels of KITE-585 in blood, serum cytokines, and incidence of anti-BCMA CAR antibodies. Seventeen patients were enrolled, and 14 received KITE-585 with a median follow-up of 12.0 months. The median age of patients was 56 years, 41.2% had an Eastern Cooperative Oncology Group performance status of 1, 92.9% had baseline BCMA expression on plasma cells, and median number of prior therapies was 5.5. No patients experienced a DLT, all patients experienced ≥ 1 grade ≥ 3 treatment-emergent AE (TEAE), and no grade 5 TEAEs were observed. There were no grade ≥ 3 events of cytokine release syndrome, neurologic events, or infections; all were grade 1 or 2, and each occurred in 21.4% of patients. Among all patients infused with KITE-585, 1 patient who received 3 × 107 anti-BCMA CAR T cells experienced a partial response. Median peak CAR T-cell expansion was low (0.98 cells/µL), as were median peak serum levels of CAR-associated cytokines, including interferon-γ (61.45 pg/mL) and interleukin-2 (0.9 pg/mL). KITE-585 demonstrated a manageable safety profile; however, the limited CAR T-cell expansion and associated lack of anti-tumor response in patients with RRMM treated with KITE-585 is consistent with the minimal CAR T-cell activity observed.