[Construction of CD138-targeted chimeric antigen receptor- modified T cells and their effect in multiple myeloma therapy].

Objective: To construct a novel chimeric antigen receptor T (CAR-T) cell targeting CD138 and to investigate its cytotoxicity against myeloma cells. Methods: The hybridoma strain that can stably secrete the CD138 monoclonal antibody (mAb) was prepared and obtained through monoclonal antibody screening technology. The hybridoma strain cells were intraperitoneally injected into mice to produce ascites containing monoclonal antibodies, which were then collected and purified to obtain pure CD138 mAb. Further examinations were performed to assess the biological characteristics of CD138 mAb. The variable region sequence of this antibody was amplified through reverse transcription polymerase chain reaction and was used as the antigen recognition domain of CD138 CAR, which was subsequently expressed on the surface of T cells by lentiviral infection. Flow cytometry was employed to assess the phenotype of CD138 CAR-T cells. In vitro cytotoxicity and degranulation assays were performed to evaluate their antitumor effects. Results: ① We successfully prepared anti-human CD138 antibody hybridoma cell lines and screened a hybridoma cell strain, 5G2, which could persistently and stably secrete the anti-CD138 antibody. ② The purified CD138 (5G2) mAb can especially recognize CD138(+) cells with a binding affinity constant (K(D)) of 6.011×10(-9) mol/L and showed no significant binding activity with CD138(-) cells. ③The variable region sequence of the CD138 (5G2) antibody was obtained using molecular cloning technology, and CD138 (5G2) CAR was successfully constructed and expressed on T cells through lentivirus infection and, concurrently, demonstrated effective binding to recombinant human CD138 protein.④ The proliferation of T cells transduced with the CD138 (5G2) CAR was highly efficient. The phenotype analysis revealed that CD138 (5G2) CAR-T cells exhibited a greater tendency to differentiate into central memory T cells and memory stem T cells, with a reduced proportion of terminally differentiated effector memory subsets. ⑤CD138 (5G2) CAR-T cells demonstrated specific cytotoxicity against CD138(+) myeloma cell line H929, whereas CD138(-) cell line K562 remained unaffected. The percentage of residual H929 cells was (12.92±8.02) % after co-culturing with CD138 (5G2) CAR-T cells, while (54.25±15.79) % was left in the Vector-T group (E∶T=1∶2; P<0.001). ⑥Results of degranulation assays demonstrated a significant activation of CD138 (5G2) CAR-T cells after co-culture with the H929 cell line, whereas no significant activation was observed in Vector-T cells [ (25.78±3.35) % vs (6.13±1.30) %, P<0.001]. ⑦After co-culturing with CD138(+) cells, CD138 (5G2) CAR-T cells exhibited a significant increase in cytokine secretion compared to the Vector-T group [interleukin-2: (1 697.52±599.05) pg/ml vs (5.07±1.17) pg/ml, P<0.001; interferon-γ: (3 312.20±486.38) pg/ml vs (9.28±1.46) pg/ml, P<0.001; and tumor necrosis factor-α: (1 837.43±640.49) pg/ml vs (8.75±1.65) pg/ml, P<0.001]. However, no significant difference was observed in cytokine secretion levels between the two groups after co-culturing with CD138(-) cells. Conclusion: This study successfully prepared a novel monoclonal antibody against CD138, and CAR-T cells constructed with the antigen recognition domain derived from this 5G2 mAb demonstrated effective antitumor activity against myeloma cells. This can be used as a new option for the detection of the CD138 antigen and proposes a novel strategy for multiple myeloma immunotherapy.

[Chinese expert consensus on diagnosis and treatment of high risk multiple myeloma (2024)].

High-risk multiple myeloma (HRMM) refers to patients with multiple myeloma whose overall survival time is less than 2-3 years under current standardized diagnosis and treatment. By combining various static and dynamic prognostic factors, risk stratification is performed to identify HRMM patients early and treat patients with personalized strategies, with the aim of significantly improving adverse survival outcomes in HRMM patients. Although the clinical value of HRMM has reached a consensus domestically in recent years, there still exist confusions and ambiguities in the definition, high-risk factors, risk stratification, and treatment of HRMM, necessitating standardization. In order to enhance the diagnostic and treatment capabilities of Chinese physicians in HRMM, the Professional Committee of Hematologic Malignancies of the Chinese Anti-Cancer Association (CACA) and the Multiple Myeloma Expert Committee of the Chinese Society of Clinical Oncology (CSCO) have organized relevant experts to develop this consensus. This consensus aims to clarify the definition of HRMM, high-risk factors, and risk stratification system, and provide treatment recommendations for HRMM, thereby improving the quality of life and prognosis of Chinese HRMM patients.

[Retrospective clinical study on cryopreservation-free integrated autologous hematopoietic stem cell transplantation model for newly diagnosed multiple myeloma].

Objective: To explore the efficacy and safety of cryopreservation-free integrated autologous hematopoietic stem cell transplantation (HSCT) model for patients with multiple myeloma. Methods: A total of 96 patients with newly diagnosed multiple myeloma (NDMM) between July 31, 2020, and December 31, 2022, were retrospectively analyzed, of which 41 patients in the observation group received integrated non-cryopreserved transplantation mode. After hematopoietic stem cells were mobilized and collected, melphalan was started immediately for pre-transplant conditioning, and non-cryopreserved grafts from the medical blood transfusion refrigerator were directly injected intravenously into the patient within 24-48 h after the melphalan conditioning. The control group consisted of 55 patients who received traditional transplantation mode. After hematopoietic stem cells were collected, stem cell cryopreservation was performed in liquid nitrogen, and then the transplant plans were started at the right time. All patients received mobilization of autologous hematopoietic stem cells using the G-CSF combined with the plerixafor. Results: ① A total of 34 patients (82.9% ) with VGPR plus CR in the observation group were significantly higher than 33 patients (60.0% ) in the control group (P=0.016). ②Compared with the control group, the incidence of grade 1 oral mucosal inflammation was higher in the observation group (P<0.001) ; however, the incidence of grades 2 and 3 oral mucosal inflammation was lower (P=0.004, P=0.048), and neither group experienced grade 4 or above oral mucosal inflammation. The incidence of grade 1 diarrhea was higher in the observation group (P=0.002), whereas the incidence of grade 3 diarrhea was lower (P=0.007). No statistically significant difference was observed in the incidence of grade 4 diarrhea (P=0.506), and neither group experienced grade 5 diarrhea. ③ The incidence of bacterial infection in the observation group was lower than that in the control group (34.1% vs 65.5%, P=0.002), whereas no statistically significant difference was observed in the incidence of fungal infection (29.3% vs 31.4%, P=0.863) and viral infection (4.88% vs 3.64%, P=0.831). ④No statistically significant difference was observed in the implantation time of granulocytes and platelets between the observation and control groups [10 (8-20) days vs 11 (8-17) days, P=0.501; 13 (10-21) days vs 15 (10-20) days, P=0.245]. ⑤ All patients did not receive lenalidomide treatment 100 days post-transplantation. At 30 days post-transplantation, the CTL, NK, and Th cell counts in the observation group were lower than those in the control group (P<0.001, P=0.002, P=0.049), and the NKT cell counts were higher than those in the control group (P=0.024). At 100 days post-transplantation, the CTL, NKT, and Th cell counts in the observation group were higher than those in the control group (P=0.025, P=0.011, P=0.007), and no statistically significant difference in NK cell counts was observed between the two groups (P=0.396). ⑥ The median follow-up was 18 (4-33) months. The overall 2-year survival rates of the observation and control groups post-transplantation were 91.5% and 78.2%, respectively (P=0.337). The recurrence-free survival rates were 85.3% and 77.6%, respectively (P=0.386), and the cumulative recurrence rates were 9.8% and 16.9%, respectively (P=0.373) . Conclusion: In NDMM, the cryopreservation-free integrated autologous HSCT model can achieve similar therapeutic effects as traditional transplantation models, with lower rates of severe mucosal inflammation and infection compared with traditional transplantation models.

[Novel therapies for multiple myeloma].

B-cell maturation antigen (BCMA)-targeting therapy is the most common approach to immunotherapy and cellular therapy for multiple myeloma (MM). Three major agents, CAR-T cells, bispecific antibodies, and ADC have been developed as novel therapeutic agents. CAR-T therapy showed favorable efficacy in the treatment of relapsed and refractory MM (RR MM) and was tried in early lines of therapy. Similarly, bispecific antibodies targeting BCMA or other targets have also shown promising effects in treatment of RR MM, and have been now tested in combination with other agents. Although issues such as poor fitness or exhaustion of T cells and increased susceptibility to viral infection remain to be fully resolved, novel immunotherapies and cellular therapies should further improve the prognosis of patients with RR MM.

[Comparison of etoposide combined with G-CSF and cyclophosphamide combined with G-CSF in the mobilization of autologous peripheral blood stem cells in patients with multiple myeloma].

Objective: The effect and safety of etoposide combined with G-CSF were compared with those of cyclophosphamide combined with G-CSF in autologous peripheral blood mobilization in patients with multiple myeloma (MM) . Methods: Patients with MM who received autologous peripheral blood stem cell mobilization and collection in the Department of Hematology, Beijing Chaoyang Hospital Affiliated to Capital Medical University from January 1, 2020 to July 31, 2023 were included. A total of 134 patients were screened by propensity score matching technology according to a 1∶1 ratio. A total of 67 cases were each treated with ETO combined with G-CSF mobilization scheme (ETO group) and CTX combined with G-CSF mobilization scheme (CTX group). Their clinical data were retrospectively analyzed. Results: ①Collection results: the ETO and CTX groups [2 (1-3) d vs 2 (1-5) d; P<0.001] and CD34(+) cells [7.62×10(6) (2.26×10(6)-37.20×10(6)) /kg vs 2.73×10(6) (0.53×10(6)-9.85×10(6)) /kg; P<0.001] were collected. The success rate of collection was 100.0% (67/67) versus 76.1% (51/67) (P<0.001). Excellent rate of collection was 82.1% (55/67) versus 20.9% (14/67; P<0.001). Two patients in the ETO group switched protocols after 1 day of collection, and 11 patients in the CTX group switched protocols after 1-2 days of collection. ②Adverse reactions: granular deficiency with fever (21.5%[14/65] vs. 10.7%[6/56]; P=0.110), requiring platelet transfusion [10.7% (7/65) vs 1.8% (1/56) ; P=0.047]. ③Until the end of follow-up, 63 cases in the ETO group and 54 cases in the CTX group have undergone autologous transplantation. The median number of CD34(+) cells infused in the two groups was 4.62×10(6) (2.14×10(6)-19.89×10(6)) /kg versus 2.62×10(6) (1.12×10(6)-5.31×10(6)) /kg (P<0.001), neutrophil implantation time was 11 (9-14) d versus 11 (10-14) d (P=0.049), and platelet implantation time was 11 (0-19) d vs. 12 (0-34) d (P=0.035). One case in the CTX group experienced delayed platelet implantation. Conclusion: The mobilization scheme of etoposide combined with G-CSF requires relatively platelet transfusion, but the collection days are shortened. The collection success rate, excellent rate, and the number of CD34(+) cells obtained are high, and the neutrophil and platelet engraftment is accelerated after transplantation.

The impact of continuous lenalidomide maintenance treatment on people living with multiple myeloma-a single-centre, qualitative service evaluation study.

PURPOSE: Continuous lenalidomide maintenance treatment after autologous stem cell transplantation delivers improvement in progression free and overall survival among newly diagnosed multiple myeloma patients and has been the standard of care in the UK since March 2021. However, there is scant information about its impact on patients' day-to-day lives. This service evaluation aimed to qualitatively assess patients receiving lenalidomide treatment at a cancer centre in London, in order that the service might better align with needs and expectations of patients. METHODS: We conducted 20 semi-structured interviews among myeloma patients who were on continuous lenalidomide maintenance treatment at a specialist cancer centre in London. Members of the clinical team identified potentially eligible participants to take part, and convenience sampling was used to select 10 male and 10 female patients, median age of 58 (range, 45-71). The median treatment duration was 11 months (range, 1-60 months). Participants were qualitatively interviewed following the same semi-structured interview guide, which was designed to explore patient experience and insights of lenalidomide. Reflexive thematic analysis was used for data analysis. RESULTS: Four overarching themes were as follows: (i) lenalidomide: understanding its role and rationale; (ii) reframing the loss of a treatment-free period to a return to normal life; (iii) the reality of being on lenalidomide: balancing hopes with hurdles; (iv) gratitude and grievances: exploring mixed perceptions of care and communication. Results will be used to enhance clinical services by tailoring communication to better meet patients' preferences when making treatment decisions. CONCLUSION: This study highlights that most patients feel gratitude for being offered continuous lenalidomide and perceive it as alleviating some fears concerning relapse. It reveals variations in side effects in different age groups; younger patients reported no/negligible side effects, whilst several older patients with comorbidities described significant symptom burden, occasionally leading to treatment discontinuation which caused distress at the perceived loss of prolonged remission. Future research should prioritise understanding the unique needs of younger patients living with multiple myeloma.

Skull base plasmacytoma in young patients aged below 40 years: Radiological perspectives and clinical outcomes.

BACKGROUND: Plasmacytoma of the skull base is a rare manifestation of plasma cell neoplasm with only a few cases documented in literature involving young adults. Plasmacytoma can be an isolated solitary lesion or a secondary manifestation of multiple myeloma (MM). In this study, we report the clinical and radiological characteristics, management, and outcomes of patients under the age of 40 who presented with skull base plasmacytoma and associated neurological manifestations. Additionally, we share our experience in treating a rare case of skull base plasmacytoma diagnosed during pregnancy, in which the patient exhibited a favorable response to myeloma treatment initiated after delivery. CASE SERIES: Four patients were identified, comprising one pregnant female and three male patients, with a median age of 36 years (range 33-37 years). The main presenting symptoms were headache, dizziness, and cranial nerve palsy. All patients received underwent systemic myeloma therapy and radiotherapy with three patients also underwent autologous stem cell transplantation (ASCT). Notably, all patients achieved complete remission. CONCLUSION: Skull base plasmacytoma represents a rare manifestation of plasma cell neoplasms, underscoring the importance of considering it in the differential diagnosis of skull base lesions to ensure early intervention and avoid potential serious complications. Throughout our series, the cornerstone of therapy involved radiotherapy, systemic myeloma therapy, and ASCT, all of which elicited a favorable response in every case.

Multiple myeloma: signaling pathways and targeted therapy.

Multiple myeloma (MM) is the second most common hematological malignancy of plasma cells, characterized by osteolytic bone lesions, anemia, hypercalcemia, renal failure, and the accumulation of malignant plasma cells. The pathogenesis of MM involves the interaction between MM cells and the bone marrow microenvironment through soluble cytokines and cell adhesion molecules, which activate various signaling pathways such as PI3K/AKT/mTOR, RAS/MAPK, JAK/STAT, Wnt/ß-catenin, and NF-κB pathways. Aberrant activation of these pathways contributes to the proliferation, survival, migration, and drug resistance of myeloma cells, making them attractive targets for therapeutic intervention. Currently, approved drugs targeting these signaling pathways in MM are limited, with many inhibitors and inducers still in preclinical or clinical research stages. Therapeutic options for MM include non-targeted drugs like alkylating agents, corticosteroids, immunomodulatory drugs, proteasome inhibitors, and histone deacetylase inhibitors. Additionally, targeted drugs such as monoclonal antibodies, chimeric antigen receptor T cells, bispecific T-cell engagers, and bispecific antibodies are being used in MM treatment. Despite significant advancements in MM treatment, the disease remains incurable, emphasizing the need for the development of novel or combined targeted therapies based on emerging theoretical knowledge, technologies, and platforms. In this review, we highlight the key role of signaling pathways in the malignant progression and treatment of MM, exploring advances in targeted therapy and potential treatments to offer further insights for improving MM management and outcomes.

Natural Language Processing Algorithm to Extract Multiple Myeloma Stage From Oncology Notes in the Veterans Affairs Healthcare System.

PURPOSE: Stage in multiple myeloma (MM) is an essential measure of disease risk, but its measurement in large databases is often lacking. We aimed to develop and validate a natural language processing (NLP) algorithm to extract oncologists' documentation of stage in the national Veterans Affairs (VA) Healthcare System. METHODS: Using nationwide electronic health record (EHR) and cancer registry data from the VA Corporate Data Warehouse, we developed and validated a rule-based NLP algorithm to extract oncologist-determined MM stage. To that end, a clinician annotated MM stage within over 5,000 short snippets of clinical notes, and annotated MM stage at MM treatment initiation for 200 patients. These were allocated into snippet- and patient-level development and validation sets. We developed MM stage extraction and roll-up algorithms within the development sets. After the algorithms were finalized, we validated them using standard measures in held-out validation sets. RESULTS: We developed algorithms for three different MM staging systems that have been in widespread use (Revised International Staging System [R-ISS], International Staging System [ISS], and Durie-Salmon [DS]) and for stage reported without a clearly defined system. Precision and recall were uniformly high for MM stage at the snippet level, ranging from 0.92 to 0.99 for the different MM staging systems. Performance in identifying for MM stage at treatment initiation at the patient level was also excellent, with precision of 0.92, 0.96, 0.90, and 0.86 and recall of 0.99, 0.98, 0.94, and 0.92 for R-ISS, ISS, DS, and unclear stage, respectively. CONCLUSION: Our MM stage extraction algorithm uses rule-based NLP and data aggregation to accurately measure MM stage documented in oncology notes and pathology reports in VA's national EHR system. It may be adapted to other systems where MM stage is recorded in clinical notes.

Engraftment Syndrome in Autologous Hematopoietic Stem Cell Transplant Patients: Incidence, Associated Risk Factors, Features, and Outcomes.

BACKGROUND Autologous stem cell transplantation (ASCT) is the standard treatment for multiple myeloma (MM) and refractory/relapsed (R/R) lymphoma patients. Engraftment syndrome (ES) is a non-infectious febrile syndrome during ASCT. This study focused on the incidence, risk factors, manifestations, and outcomes of patients with ES receiving ASCT. MATERIAL AND METHODS This retrospective cohort study included MM and R/R lymphoma patients who underwent ASCT at Chiang Mai University Hospital from January 2014 to September 2020. ES was diagnosed by the consensus of independent reviewers based on clinical manifestations, laboratory, and radiological findings. RESULTS We included 124 patients, of whom 67 (54.1%) had lymphoma. The mean age was 48.0±12.3 years. The incidence of ES was 36.3%. The ES group had a significantly higher proportion of patients with fever, elevated liver enzymes, elevated bilirubin, hypoalbuminemia, and weight gain compared to the non-ES group. TNC more than 10×108 cells/kg was an independent risk factor for ES (odds ratio 2.94 with a 95% confidence interval of 1.15-7.50, P=0.024). ES was associated with longer length of stay (22.5±8.2 vs 16.9±6.4 days, P<0.001) but was not associated with overall survival (OS). CONCLUSIONS The incidence of ES in this cohort was 36.3%. Features observed in ES patients were fever, elevated liver enzymes, elevated bilirubin, and hypoalbuminemia. TNC of more than 10×108 cells/kg was an independent risk factor. ES was associated with longer length of stay but not survival outcomes.

[Clinical analysis of the correlation between the expression of soluble B cell maturation antigen and the efficacy of chimeric antigen receptor T cell targeting B cell maturation antigen in patients with multiple myeloma].

Objective: The effect of bone marrow soluble B cell maturation antigen (sBCMA) expression on the efficacy and side effects of chimeric antigen receptor (CAR) -modified T-cell-targeting B cell maturation antigen (BCMA) in patients with multiple myeloma (MM) . Methods: This study involved 29 patients with relapsed or refractory MM (RRMM) who received humanized anti-BCMA CAR-T cell clinical trials from January 2018 to December 2021. The expression of sBCMA in bone marrow before and after anti-BCMA CAR-T cell treatment was detected by flow cytometry and compared. Results: ①Two months after BCMA CAR-T cell treatment, 20 patients (68.97%) achieved an overall response (OR), whereas nine patients had stable disease (SD) or miner emission (MR). ②The expression of sBCMA in the bone marrow of 20 patients with OR was higher before treatment than after [26 926 (18 215, 32 488) ng/L vs 9 968 (6 634, 11 459) ng/L; P<0.001]; no significant difference was observed in patients with MR and SD [41 187 (33 816, 47 046) ng/L vs. 33 954 (31 569, 36 256) ng/L; P=0.145]; sBCMA expression in patients with OR before CAR-T cell treatment was lower than in patients with MR and SD (P=0.005). ③No significant linear correlation was found between the peak value of CAR-T cells and sBCMA expression in the bone marrow of all 29 patients with RRMM (R(2)=0.035, P=0.330). ④No significant difference in sBCMA expression was found between grades 0-1 CRS group (13 patients) and grades 2-4 CRS group [16 patients; 32 045 (18 742, 40 801) ng/L vs 29 102 (24 679, 38 776) ng/L, P=0.879], nor between grade 0 ICANS group (22 patients) and grade 1-3 ICANS group [seven patients; 30 073 (19 375, 40 065) ng/L vs 33 816 (22 933, 43 459) ng/L, P=0.763]. Conclusion: sBCMA expression in the bone marrow is related to the efficacy of BCMA CAR-T cell therapy in patients with RRMM, but is not significantly correlated with the severity of adverse events. It may serve as a predictive biomarker for the efficacy of BCMA CAR-T cell therapy in these patients.

Acquired factor XIII deficiency and its unprecedented association with multiple myeloma: case report and literature review.

This case involves a 58-year-old patient, with no personal or family history of bleeding, diagnosed with stage III-A IgG Kappa multiple myeloma in 2016 and underwent autografting in 2017. In March 2022, he suffered a myeloma relapse. In October 2022, the patient presented with a large spontaneous compressive hematoma in the left shoulder and hemithorax, requiring two surgical procedures. The platelet count and hemostasis parameters were within normal range. Further diagnostic testing revealed acquired factor XIII deficiency and acquired thrombopathy. Diagnostic challenges arose from the absence of specific assays for the B subunit of Factor XIII. Treatment involved transfusions and corticosteroids, but efficacity was limited. The patient's response to chemotherapy raised questions about the involvement of the monoclonal component. Subsequent follow-ups showed factor XIII levels fluctuating, even without symptoms. The patient was deemed ineligible for autograft due to a significant risk of hemorrhage.

Quantitative Integrative Survival Prediction in Multiple Myeloma Patients Treated With Bortezomib-Based Induction, High-Dose Therapy and Autologous Stem Cell Transplantation.

PURPOSE: Given the high heterogeneity in survival for patients with multiple myeloma, it would be clinically useful to quantitatively predict the individual survival instead of attributing patients to two to four risk groups as in current models, for example, revised International Staging System (R-ISS), R2-ISS, or Mayo-2022-score. PATIENTS AND METHODS: Our aim was to develop a quantitative prediction tool for individual patient's 3-/5-year overall survival (OS) probability. We integrated established clinical and molecular risk factors into a comprehensive prognostic model and evaluated and validated its risk discrimination capabilities versus R-ISS, R2-ISS, and Mayo-2022-score. RESULTS: A nomogram for estimating OS probabilities was built on the basis of a Cox regression model. It allows one to translate the individual risk profile of a patient into 3-/5-year OS probabilities by attributing points to each prognostic factor and summing up all points. The nomogram was externally validated regarding discrimination and calibration. There was no obvious bias or overfitting of the prognostic index on the validation cohort. Resampling-based and external evaluation showed good calibration. The c-index of the model was similar on the training (0.76) and validation cohort (0.75) and significantly higher than for the R-ISS (P < .001) or R2-ISS (P < .01). CONCLUSION: In summary, we developed and validated individual quantitative nomogram-based OS prediction. Continuous risk assessment integrating molecular prognostic factors is superior to R-ISS, R2-ISS, or Mayo-2022-score alone.

Daratumumab in transplant-eligible patients with newly diagnosed multiple myeloma: final analysis of clinically relevant subgroups in GRIFFIN.

The randomized, phase 2 GRIFFIN study (NCT02874742) evaluated daratumumab plus lenalidomide/bortezomib/dexamethasone (D-RVd) in transplant-eligible newly diagnosed multiple myeloma (NDMM). We present final post hoc analyses (median follow-up, 49.6 months) of clinically relevant subgroups, including patients with high-risk cytogenetic abnormalities (HRCAs) per revised definition (del[17p], t[4;14], t[14;16], t[14;20], and/or gain/amp[1q21]). Patients received 4 induction cycles (D-RVd/RVd), high-dose therapy/transplant, 2 consolidation cycles (D-RVd/RVd), and lenalidomide±daratumumab maintenance (≤ 2 years). Minimal residual disease-negativity (10-5) rates were higher for D-RVd versus RVd in patients ≥ 65 years (67.9% vs 17.9%), with HRCAs (54.8% vs 32.4%), and with gain/amp(1q21) (61.8% vs 28.6%). D-RVd showed a trend toward improved progression-free survival versus RVd (hazard ratio [95% confidence interval]) in patients ≥ 65 years (0.29 [0.06-1.48]), with HRCAs (0.38 [0.14-1.01]), and with gain/amp(1q21) (0.42 [0.14-1.27]). In the functional high-risk subgroup (not MRD negative at the end of consolidation), the hazard ratio was 0.82 (0.35-1.89). Among patients ≥ 65 years, grade 3/4 treatment-emergent adverse event (TEAE) rates were higher for D-RVd versus RVd (88.9% vs 77.8%), as were TEAEs leading to discontinuation of ≥ 1 treatment component (37.0% vs 25.9%). One D-RVd patient died due to an unrelated TEAE. These results support the addition of daratumumab to RVd in transplant-eligible patients with high-risk NDMM. Video Abstract.

CXCR4 has a dual role in improving the efficacy of BCMA-redirected CAR-NK cells in multiple myeloma.

Multiple myeloma (MM) is a plasma cell disease with a preferential bone marrow (BM) tropism. Enforced expression of tissue-specific chemokine receptors has been shown to successfully guide adoptively-transferred CAR NK cells towards the malignant milieu in solid cancers, but also to BM-resident AML and MM. For redirection towards BM-associated chemokine CXCL12, we armored BCMA CAR-NK-92 as well as primary NK cells with ectopic expression of either wildtype CXCR4 or a gain-of-function mutant CXCR4R334X. Our data showed that BCMA CAR-NK-92 and -primary NK cells equipped with CXCR4 gained an improved ability to migrate towards CXCL12 in vitro. Beyond its classical role coordinating chemotaxis, CXCR4 has been shown to participate in T cell co-stimulation, which prompted us to examine the functionality of CXCR4-cotransduced BCMA-CAR NK cells. Ectopic CXCR4 expression enhanced the cytotoxic capacity of BCMA CAR-NK cells, as evidenced by the ability to eliminate BCMA-expressing target cell lines and primary MM cells in vitro and through accelerated cytolytic granule release. We show that CXCR4 co-modification prolonged BCMA CAR surface deposition, augmented ZAP-70 recruitment following CAR-engagement, and accelerated distal signal transduction kinetics. BCMA CAR sensitivity towards antigen was enhanced by virtue of an enhanced ZAP-70 recruitment to the immunological synapse, revealing an increased propensity of CARs to become triggered upon CXCR4 overexpression. Unexpectedly, co-stimulation via CXCR4 occurred in the absence of CXCL12 ligand-stimulation. Collectively, our findings imply that co-modification of CAR-NK cells with tissue-relevant chemokine receptors affect adoptive NK cell therapy beyond improved trafficking and retention within tumor sites.

Clinical features associated with poor response and early relapse following BCMA-directed therapies in multiple myeloma.

Three classes of BCMA-directed therapy (BDT) exist: antibody drug-conjugates (ADCs), CAR-T, and T-cell engagers (TCEs), each with distinct strengths and weaknesses. To aid clinicians in selecting between BDTs, we reviewed myeloma patients treated at Mayo Clinic with commercial or investigational BDT between 2018-2023. We identified 339 individuals (1-exposure = 297, 2-exposures = 38, 3-exposures = 4) who received 385 BDTs (ADC = 59, TCE = 134, CAR-T = 192), with median follow-up of 21-months. ADC recipients were older, with more lines of therapy (LOT), and penta-refractory disease. Compared to ADCs, CAR-T (aHR = 0.29, 95%CI = 0.20-0.43) and TCEs (aHR = 0.62, 95%CI = 0.43-0.91) had better progression-free survival (PFS) on analysis adjusted for age, the presence of extramedullary (EMD), penta-refractory disease, multi-hit high-risk cytogenetics, prior BDT, and the number of LOT in the preceding 1-year. Likewise, compared to ADCs, CAR-T (aHR = 0.28, 95%CI = 0.18-0.44) and TCEs (aHR = 0.60, 95%CI = 0.39-0.93) had superior overall survival. Prior BDT exposure negatively impacted all classes but was most striking in CAR-T, ORR 86% vs. 50% and median PFS 13-months vs. 3-months. Of relapses, 54% were extramedullary in nature, and a quarter of these cases had no history of EMD. CAR-T demonstrates superior efficacy and where feasible, should be the initial BDT. However, for patients with prior BDT or rapidly progressive disease, an alternative approach may be preferable.

Just scratching the surface: novel treatment approaches for multiple myeloma targeting cell membrane proteins.

A better understanding of the roles of the adaptive and innate immune systems in the oncogenesis of cancers including multiple myeloma (MM) has led to the development of novel immune-based therapies. B cell maturation antigen (BCMA), G protein-coupled receptor family C group 5 member D (GPRC5D) and Fc receptor-like protein 5 (FcRL5, also known as FcRH5) are cell-surface transmembrane proteins expressed by plasma cells, and have been identified as prominent immunotherapeutic targets in MM, with promising activity demonstrated in patients with heavily pretreated relapsed and/or refractory disease. Indeed, since 2020, antibody-drug conjugates, bispecific T cell engagers and autologous chimeric antigen receptor T cells targeting BCMA or GPRC5D have been approved for the treatment of relapsed and/or refractory MM. However, responses to these therapies are not universal, and acquired resistance invariably occurs. In this Review, we discuss the various immunotherapeutic approaches targeting BCMA, GPRC5D and FcRL5 that are currently either available or in clinical development for patients with MM. We also review the mechanisms underlying resistance to such therapies, and discuss potential strategies to overcome these mechanisms and improve patient outcomes.