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.

Leukocyte immunoglobulin-like receptor B1 (LILRB1) protects human multiple myeloma cells from ferroptosis by maintaining cholesterol homeostasis.

Multiple myeloma (MM) is a hematologic malignancy characterized by uncontrolled proliferation of plasma cells in the bone marrow. MM patients with aggressive progression have poor survival, emphasizing the urgent need for identifying new therapeutic targets. Here, we show that the leukocyte immunoglobulin-like receptor B1 (LILRB1), a transmembrane receptor conducting negative immune response, is a top-ranked gene associated with poor prognosis in MM patients. LILRB1 deficiency inhibits MM progression in vivo by enhancing the ferroptosis of MM cells. Mechanistic studies reveal that LILRB1 forms a complex with the low-density lipoprotein receptor (LDLR) and LDLR adapter protein 1 (LDLRAP1) to facilitate LDL/cholesterol uptake. Loss of LILRB1 impairs cholesterol uptake but activates the de novo cholesterol synthesis pathway to maintain cellular cholesterol homeostasis, leading to the decrease of anti-ferroptotic metabolite squalene. Our study uncovers the function of LILRB1 in regulating cholesterol metabolism and protecting MM cells from ferroptosis, implicating LILRB1 as a promising therapeutic target for MM patients.

Clonal evolution of hematopoietic stem cells after cancer chemotherapy.

Normal hematopoietic stem and progenitor cells (HSPCs) inherently accumulate somatic mutations and lose clonal diversity with age, processes implicated in the development of myeloid malignancies 1 . The impact of exogenous stressors, such as cancer chemotherapies, on the genomic integrity and clonal dynamics of normal HSPCs is not well defined. We conducted whole-genome sequencing on 1,032 single-cell-derived HSPC colonies from 10 patients with multiple myeloma (MM), who had undergone various chemotherapy regimens. Our findings reveal that melphalan treatment distinctly increases mutational burden with a unique mutation signature, whereas other MM chemotherapies do not significantly affect the normal mutation rate of HSPCs. Among these therapy-induced mutations were several oncogenic drivers such as TET2 and PPM1D . Phylogenetic analysis showed a clonal architecture in post-treatment HSPCs characterized by extensive convergent evolution of mutations in genes such as TP53 and PPM1D . Consequently, the clonal diversity and structure of post-treatment HSPCs mirror those observed in normal elderly individuals, suggesting an accelerated clonal aging due to chemotherapy. Furthermore, analysis of matched therapy-related myeloid neoplasm (t-MN) samples, which occurred 1-8 years later, enabled us to trace the clonal origin of t-MNs to a single HSPC clone among a group of clones with competing malignant potential, indicating the critical role of secondary mutations in dictating clonal dominance and malignant transformation. Our findings suggest that cancer chemotherapy promotes an oligoclonal architecture with multiple HSPC clones possessing competing leukemic potentials, setting the stage for the selective emergence of a singular clone that evolves into t-MNs after acquiring secondary mutations. These results underscore the importance of further systematic research to elucidate the long-term hematological consequences of cancer chemotherapy.

Isatuximab, Bortezomib, Lenalidomide, and Dexamethasone for Multiple Myeloma.

BACKGROUND: Bortezomib, lenalidomide, and dexamethasone (VRd) is a preferred first-line treatment option for patients with newly diagnosed multiple myeloma. Whether the addition of the anti-CD38 monoclonal antibody isatuximab to the VRd regimen would reduce the risk of disease progression or death among patients ineligible to undergo transplantation is unclear. METHODS: In an international, open-label, phase 3 trial, we randomly assigned, in a 3:2 ratio, patients 18 to 80 years of age with newly diagnosed multiple myeloma who were ineligible to undergo transplantation to receive either isatuximab plus VRd or VRd alone. The primary efficacy end point was progression-free survival. Key secondary end points included a complete response or better and minimal residual disease (MRD)-negative status in patients with a complete response. RESULTS: A total of 446 patients underwent randomization. At a median follow-up of 59.7 months, the estimated progression-free survival at 60 months was 63.2% in the isatuximab-VRd group, as compared with 45.2% in the VRd group (hazard ratio for disease progression or death, 0.60; 98.5% confidence interval, 0.41 to 0.88; P<0.001). The percentage of patients with a complete response or better was significantly higher in the isatuximab-VRd group than in the VRd group (74.7% vs. 64.1%, P = 0.01), as was the percentage of patients with MRD-negative status and a complete response (55.5% vs. 40.9%, P = 0.003). No new safety signals were observed with the isatuximab-VRd regimen. The incidence of serious adverse events during treatment and the incidence of adverse events leading to discontinuation were similar in the two groups. CONCLUSIONS: Isatuximab-VRd was more effective than VRd as initial therapy in patients 18 to 80 years of age with newly diagnosed multiple myeloma who were ineligible to undergo transplantation. (Funded by Sanofi and a Cancer Center Support Grant; IMROZ ClinicalTrials.gov number, NCT03319667.).

Trends in Outcomes After Upfront Autologous Transplant for Multiple Myeloma Over Three Decades.

Upfront autologous stem cell transplantation (auto-SCT) remains standard of care for eligible patients with newly diagnosed multiple myeloma (NDMM), although recently its role has been questioned. The aim of the study was to evaluate trends in patient characteristics, treatment, and outcomes of NDMM who underwent upfront auto-SCT over three decades. We conducted a single-center retrospective analysis of patients with NDMM who underwent upfront auto-SCT at MD Anderson Cancer Center between 1988 to 2021. Primary end points were progression-free survival (PFS) and overall survival (OS). Patients were grouped by the year of auto-SCT: 1988-2000 (n = 249), 2001-2005 (n = 373), 2006-2010 (n = 568), 2011-2015 (n = 815) and 2016-2021 (n = 1036). High-risk cytogenetic abnormalities were defined as del (17p), t (4;14), t (14;16), and 1q21 gain or amplification by fluorescence in situ hybridization. We included 3041 MM patients in the analysis. Median age at auto-SCT increased from 52 years (1988-2000) to 62 years (2016-2021), as did the incidence of high-risk cytogenetics from 15% to 40% (P < .001). Comorbidity burden, as measured by a Hematopoietic Cell Transplantation-Specific Comorbidity Index (HCT-CI) of >3, increased from 17% (1988-2000) to 28% (2016-2021) (P < .001). Induction regimens evolved from predominantly chemotherapy to immunomodulatory drug (IMiD) and proteasome inhibitor (PI) based regimens, with 74% of patients receiving IMiD-PI triplets in 2016-2021 (39% bortezomib, lenalidomide and dexamethasone (VRD) and 35% carfilzomib, lenalidomide and dexamethasone [KRD]). Response rates prior to auto-SCT steadily increased, with 4% and 10% achieving a ≥CR and ≥VGPR compared to 19% and 65% between 1988-2000 and 2016-2021, respectively. Day 100 response rates post auto-SCT improved from 24% and 49% achieving ≥CR and ≥VGPR between 1988-2000 to 41% and 81% between 2016-2021, respectively. Median PFS improved from 22.3 months between 1988-2000 to 58.6 months between 2016-2021 (HR 0.42, P < .001). Among patients with high-risk cytogenetics, median PFS increased from 13.7 months to 36.8 months (HR 0.32, P < .001). Patients aged ≥65 years also had an improvement in median PFS from 33.6 months between 2001 and 2005 to 52.8 months between 2016-2021 (HR 0.56, P = .001). Median OS improved from 55.1 months between 1988-2000 to not reached (HR 0.41, P < .001). Patients with high-risk cytogenetics had an improvement in median OS from 32.9 months to 66.5 months between 2016-2021 (HR 0.39, P < .001). Day 100 non-relapse mortality from 2001 onwards was ≤1%. Age-adjust rates of second primary malignancies were similar in patients transplanted in different time periods. Despite increasing patient age and comorbidity burden, this large real-world study demonstrated significant improvements in the depth of response and survival outcomes in patients with NDMM undergoing upfront auto-SCT over the past three decades, including those with high-risk disease.

Ixazomib plus daratumumab and dexamethasone: Final analysis of a phase 2 study among patients with relapsed/refractory multiple myeloma.

Novel therapies have improved outcomes for multiple myeloma (MM) patients, but most ultimately relapse, making treatment decisions for relapsed/refractory MM (RRMM) patients increasingly challenging. We report the final analysis of a single-arm, phase 2 study evaluating the oral proteasome inhibitor (PI) ixazomib combined with daratumumab and dexamethasone (IDd; NCT03439293). Sixty-one RRMM patients (ixazomib/daratumumab-naïve; 1-3 prior therapies) were enrolled to receive IDd (28-day cycles) until disease progression/unacceptable toxicity. Median age was 69 years; 14.8% of patients had International Staging System stage III disease; 14.8% had received three prior therapies. Patients received a median of 16 cycles of IDd. In 59 response-evaluable patients, the overall response rate was 64.4%; the confirmed ≥very good partial response (VGPR) rate (primary endpoint) was 30.5%. Rates of ≥VGPR in patient subgroups were: high-risk cytogenetics (n = 15, 26.7%), expanded high-risk cytogenetics (n = 24, 29.2%), aged ≥75 years (n = 12, 16.7%), lenalidomide-refractory (n = 21, 28.6%), and prior PI/IMiD therapy (n = 58, 31.0%). With a median follow-up of 31.6 months, median progression-free survival was 16.8 months (95% confidence interval: 10.1-23.7). Grade ≥3 treatment-emergent adverse events (TEAEs) occurred in 54.1% of patients; 44.3% had serious TEAEs; TEAEs led to dose modifications/reductions/discontinuations in 62.3%/36.1%/16.4%. There were five on-study deaths. Any-grade and grade ≥3 peripheral neuropathy occurred in 18.0% and 1.6% of patients. Quality of life was generally maintained throughout treatment. IDd showed a positive risk-benefit profile in RRMM patients and was active in clinically relevant subgroups with no new safety signals.

Multiple myeloma patients with a long remission after autologous hematopoietic stem cell transplantation.

Autologous stem cell transplantation (autoHCT) is considered standard of care for newly diagnosed multiple myeloma (MM). Although most patients eventually progress after autoHCT, a small proportion achieve a durable response. In this retrospective study we included 1576 patients, 244 (15%) of whom were long-term responders (LTR), defined as having a progression-free survival (PFS) of ≥8 years after transplant. Patients in the LTR group were younger than the non-LTR group (median age 58.4 vs. 59.5 years; p = 0.012), less likely to have high-risk cytogenetics (4% vs. 14%; p < 0.001), more often had <50% bone marrow plasma cells (67% vs. 58%; p = 0.018) and R-ISS stage I disease (43% vs. 34%). More patients in the LTR group received post-transplant maintenance (63% vs. 52%; p = 0.002). Patients in the LTR group had higher rates of complete response (CR) at day100 (41% vs. 27%; p < 0.001) and at best post-transplant response (70% vs. 37%; p < 0.001), compared to the non-LTR group. Patients in the LTR groups had a median PFS of 169.3 months and the median overall survival (OS) had not been reached. The leading cause of death in the LTR was disease progression. In conclusion, 15% of patients in the cohort were LTR after upfront autoHCT, with distinct characteristics and a median PFS of more than 14 years.

Daratumumab-based quadruplet therapy for transplant-eligible newly diagnosed multiple myeloma with high cytogenetic risk.

In the MASTER study (NCT03224507), daratumumab+carfilzomib/lenalidomide/dexamethasone (D-KRd) demonstrated promising efficacy in transplant-eligible newly diagnosed multiple myeloma (NDMM). In GRIFFIN (NCT02874742), daratumumab+lenalidomide/bortezomib/dexamethasone (D-RVd) improved outcomes for transplant-eligible NDMM. Here, we present a post hoc analysis of patients with high-risk cytogenetic abnormalities (HRCAs; del[17p], t[4;14], t[14;16], t[14;20], or gain/amp[1q21]). Among 123 D-KRd patients, 43.1%, 37.4%, and 19.5% had 0, 1, or ≥2 HRCAs. Among 120 D-RVd patients, 55.8%, 28.3%, and 10.8% had 0, 1, or ≥2 HRCAs. Rates of complete response or better (best on study) for 0, 1, or ≥2 HRCAs were 90.6%, 89.1%, and 70.8% for D-KRd, and 90.9%, 78.8%, and 61.5% for D-RVd. At median follow-up (MASTER, 31.1 months; GRIFFIN, 49.6 months for randomized patients/59.5 months for safety run-in patients), MRD-negativity rates as assessed by next-generation sequencing (10-5) were 80.0%, 86.4%, and 83.3% for 0, 1, or ≥2 HRCAs for D-KRd, and 76.1%, 55.9%, and 61.5% for D-RVd. PFS was similar between studies and superior for 0 or 1 versus ≥2 HRCAs: 36-month PFS rates for D-KRd were 89.9%, 86.2%, and 52.4%, and 96.7%, 90.5%, and 53.5% for D-RVd. These data support the use of daratumumab-containing regimens for transplant-eligible NDMM with HCRAs; however, additional strategies are needed for ultra-high-risk disease (≥2 HRCAs). Video Abstract.

Health-related quality of life in transplant-eligible patients with newly diagnosed multiple myeloma treated with daratumumab, lenalidomide, bortezomib, and dexamethasone: Patient-reported outcomes from GRIFFIN.

In the phase 2 GRIFFIN trial (ClinicalTrials.gov identifier: NCT02874742), daratumumab added to lenalidomide, bortezomib, and dexamethasone (D-RVd) improved depth of response and progression-free survival (PFS) versus lenalidomide, bortezomib, and dexamethasone (RVd) alone in transplant-eligible (TE) patients with newly diagnosed multiple myeloma (NDMM). Here, we present patient-reported outcomes (PROs) collected using the European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core 30-item (QLQ-C30), EORTC Quality of Life Questionnaire Multiple Myeloma Module 20-item (QLQ-MY20), and EuroQol 5-Dimension 5-Level (EQ-5D-5L) tools on day 1 of cycles 1, 2, and 3; on day 21 of cycle 4 (end of induction therapy); on day 1 of cycle 5; on day 21 of cycle 6 (end of posttransplant consolidation therapy); and at months 6, 12, 18, and 24 of maintenance therapy. Meaningful improvements from baseline were seen in most of the PRO scales with both treatments after consolidation and were sustained for at least 2 years of maintenance treatment. Large reductions from baseline (~20 points) were especially observed in pain symptoms for both treatment groups, although these were numerically higher for patients receiving D-RVd during the majority of the time points. In addition, improvements in key scales, such as global health status, fatigue symptoms, and physical functioning, were also seen with both D-RVd and RVd. These improvements in health-related quality of life contribute to the totality of evidence supporting the improvement in clinical outcomes such as response rates and PFS with D-RVd in induction, consolidation, and maintenance therapy in TE patients with NDMM.

Impact of revised International Staging System 2 risk stratification on outcomes of patients with multiple myeloma receiving autologous haematopoietic stem cell transplantation.

The second revision of the International Staging System (R2-ISS) is a simple tool to risk-stratify newly diagnosed multiple myeloma (NDMM) patients. Here, we completed a retrospective analysis to evaluate the utility of R2-ISS in NDMM patients who underwent up-front autologous haematopoietic stem cell transplantation (auto-HCT). A total of 1291 patients were included, with a median age of 62 years (range 29-83). The distribution of R2-ISS stages was: 123 (10%) stage I, 471 (36%) stage II, 566 (44%) stage III and 131 (10%) stage IV. With a median follow-up of 42.2 months (range 0.3-181.0), the median PFS was 73.0, 65.2, 44.0 and 24.8 months, (p < 0.001) and the median OS was 130.8, 128.5, 94.2 and 61.4 months (p < 0.001) for patients with R2-ISS stages I, II, III and IV respectively. On multivariable analysis (MVA) for PFS, using R2-ISS stage I as reference, R2-ISS stages III (hazard ratio [95% confidence interval], 1.55 [1.05-2.29]; p = 0.028) and IV (2.04 [1.24-3.36]; p = 0.005) were associated with significantly inferior PFS. In the MVA of OS, using R2-ISS stage I as reference, only R2-ISS stage IV was associated with significantly inferior OS (2.43 [1.18-5.01]; p = 0.017). Overall, we found that R2-ISS is a reliable prognostic tool for NDMM patients undergoing up-front auto-HCT.

MUC20 regulated by extrachromosomal circular DNA attenuates proteasome inhibitor resistance of multiple myeloma by modulating cuproptosis.

BACKGROUND: Proteasome inhibitors (PIs) are one of the most important classes of drugs for the treatment of multiple myeloma (MM). However, almost all patients with MM develop PI resistance, resulting in therapeutic failure. Therefore, the mechanisms underlying PI resistance in MM require further investigation. METHODS: We used several MM cell lines to establish PI-resistant MM cell lines. We performed RNA microarray and EccDNA-seq in MM cell lines and collected human primary MM samples to explore gene profiles. We evaluated the effect of MUC20 on cuproptosis of PI-resistant MM cells using Co-immunoprecipitation (Co-IP), Seahorse bioenergetic profiling and in vivo assay. RESULTS: This study revealed that the downregulation of Mucin 20 (MUC20) could predict PI sensitivity and outcomes in MM patients. Besides, MUC20 attenuated PI resistance in MM cells by inducing cuproptosis via the inhibition of cyclin-dependent kinase inhibitor 2 A expression (CDKN2A), which was achieved by hindering MET proto-oncogene, receptor tyrosine kinase (MET) activation. Moreover, MUC20 suppressed MET activation by repressing insulin-like growth factor receptor-1 (IGF-1R) lactylation in PI-resistant MM cells. This study is the first to perform extrachromosomal circular DNA (eccDNA) sequencing for MM, and it revealed that eccDNA induced PI resistance by amplifying kinesin family member 3 C (KIF3C) to reduce MUC20 expression in MM. CONCLUSION: Our findings indicated that MUC20 regulated by eccDNA alleviates PI resistance of MM by modulating cuproptosis, which would provide novel strategies for the treatment of PI-resistant MM.

Cost effectiveness of pembrolizumab plus lenvatinib compared with chemotherapy for treating previously treated advanced endometrial cancer in Sweden.

OBJECTIVE: Pembrolizumab plus lenvatinib was recently approved for the treatment of advanced or recurrent endometrial carcinoma in women with disease progression on or following prior treatment with a platinum­containing therapy in any setting, and who are not candidates for curative surgery or radiation (KEYNOTE-775/Study-309; NCT03517449). The objective was to assess the cost effectiveness of pembrolizumab plus lenvatinib compared with chemotherapy from a Swedish healthcare perspective. MATERIALS AND METHODS: A lifetime partitioned-survival model with three health states (progression free, progressed disease, death) was constructed. Chemotherapy was represented by paclitaxel or doxorubicin. Overall survival, progression-free survival, time on treatment, and utility data were obtained from KEYNOTE-775 (database lock: March 1, 2022). Costs (in 2020 Swedish Krona [SEK]) included drug acquisition and administration, health state, end of life, adverse event management, subsequent treatment, and societal (scenario analysis). Outcomes were calculated as quality-adjusted life-years (QALY) and life-years. Model results were presented as incremental cost-effectiveness ratios for all-comers, patients with proficient mismatch repair tumors, and deficient mismatch repair tumors. Deterministic and probabilistic sensitivity analyses were conducted. RESULTS: Pembrolizumab plus lenvatinib is a cost-effective treatment when compared with chemotherapy, with estimated deterministic and probabilistic incremental cost-effectiveness ratios of SEK 795,712 and 819,757 per QALY gained. Pembrolizumab plus lenvatinib was associated with a large incremental QALY and life-year gain per person versus chemotherapy over the model time horizon (1.49 and 1.76). LIMITATIONS: Time-to-event data were incomplete and semiparametric and parametric curves were utilized for lifetime extrapolation. Willingness-to-pay thresholds, costs, and utility weights vary by country, which would vary the treatment's cost effectiveness in different countries. CONCLUSIONS: This partitioned survival analysis suggests that pembrolizumab plus lenvatinib is cost effective compared with chemotherapy in Sweden for women with advanced or recurrent endometrial carcinoma following previous systemic therapy. Results were robust to mismatch repair status and to changes in parameters/assumptions.

Analysis of East Asia subgroup in Study 309/KEYNOTE-775: lenvatinib plus pembrolizumab versus treatment of physician's choice chemotherapy in patients with previously treated advanced or recurrent endometrial cancer.

OBJECTIVE: In the global phase 3 Study 309/KEYNOTE-775 (NCT03517449) at the first interim analysis, lenvatinib+pembrolizumab significantly improved progression-free survival (PFS), overall survival (OS), and objective response rate (ORR) versus treatment of physician's choice chemotherapy (TPC) in patients with previously treated advanced/recurrent endometrial cancer (EC). This exploratory analysis evaluated outcomes in patients enrolled in East Asia at the time of prespecified final analysis. METHODS: Women ≥18 years with histologically confirmed advanced, recurrent, or metastatic EC with progressive disease after 1 platinum-based chemotherapy (2 if 1 given in neoadjuvant/adjuvant setting) were enrolled. Patients were randomized 1:1 to lenvatinib 20 mg orally once daily plus pembrolizumab 200 mg intravenously every 3 weeks (≤35 cycles) or TPC (doxorubicin or paclitaxel). Primary endpoints were PFS per RECIST v1.1 by blinded independent central review and OS. No alpha was assigned for this subgroup analysis. RESULTS: Among 155 East Asian patients (lenvatinib+pembrolizumab, n=77; TPC, n=78), median follow-up time (data cutoff: March 1, 2022) was 34.3 (range, 25.1-43.0) months. Hazard ratios (HRs) with 95% confidence intervals (CIs) for PFS (lenvatinib+pembrolizumab vs. TPC) were 0.74 (0.49-1.10) and 0.64 (0.44-0.94) in the mismatch repair proficient (pMMR) and all-comer populations, respectively. HRs (95% CI) for OS were 0.68 (0.45-1.02) and 0.61 (0.41-0.90), respectively. ORRs were 36% with lenvatinib+pembrolizumab and 22% with TPC (pMMR) and 39% and 21%, respectively (all-comers). Treatment-related adverse events occurred in 97% and 96% (grade 3-5, 74% and 72%), respectively. CONCLUSION: Lenvatinib+pembrolizumab provided clinically meaningful benefit with manageable safety compared with TPC, supporting its use in East Asian patients with previously treated advanced/recurrent EC. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03517449.

Bispecific BCMA/CD24 CAR-T cells control multiple myeloma growth.

Anti-multiple myeloma B cell maturation antigen (BCMA)-specific chimeric antigen receptor (CAR) T-cell therapies represent a promising treatment strategy with high response rates in myeloma. However, durable cures following anti-BCMA CAR-T cell treatment of myeloma are rare. One potential reason is that a small subset of minimal residual myeloma cells seeds relapse. Residual myeloma cells following BCMA-CAR-T-mediated treatment show less-differentiated features and express stem-like genes, including CD24. CD24-positive myeloma cells represent a large fraction of residual myeloma cells after BCMA-CAR-T therapy. In this work, we develop CD24-CAR-T cells and test their ability to eliminate myeloma cells. We find that CD24-CAR-T cells block the CD24-Siglec-10 pathway, thereby enhancing macrophage phagocytic clearance of myeloma cells. Additionally, CD24-CAR-T cells polarize macrophages to a M1-like phenotype. A dual-targeted BCMA-CD24-CAR-T exhibits improved efficacy compared to monospecific BCMA-CAR-T-cell therapy. This work presents an immunotherapeutic approach that targets myeloma cells and promotes tumor cell clearance by macrophages.

Outcomes of patients with multiple myeloma and 1q gain/amplification receiving autologous hematopoietic stem cell transplant: the MD Anderson cancer center experience.

The prognostic impact of additional copies of chromosome 1q (1q + ) on outcomes of newly-diagnosed multiple myeloma (NDMM) patients undergoing autologous transplantation (autoSCT) is unclear. We conducted a retrospective single-center analysis of NDMM patients with 1q21 gain/amplification (3 or ≥4 copies of 1q, respectively) that received autoSCT between 2008-2018. 213 patients were included (79% 1q gain; 21% 1q amplification). The most commonly used induction regimen was bortezomib, lenalidomide, and dexamethasone (41%). At day100 post-autoSCT and at best post-transplant response, 78% and 87% of patients achieved ≥VGPR, and 38% and 50% achieved MRD-negative ≥VGPR, respectively. Median PFS and OS for the entire cohort were 35.5 months and 81.4 months, respectively. On multivariable assessment for PFS, MRD negative ≥VGPR before autoSCT (HR 0.52, p = 0.013) was associated with superior PFS, whereas 1q amplification was associated with inferior PFS (2.03, p = 0.003). On multivariate analysis for OS, achieving MRD negative ≥VGPR at best post-transplant response was associated with superior survival (0.29, p < 0.001), whereas R-ISS III and concomitant del17p or t(4:14) were associated with inferior survival (6.95, p = 0.030, 2.33, p = 0.023 and 3.00, p = 0.047, respectively). In conclusion, patients with 1q+ NDMM, especially 1q amplification, have inferior survival outcomes compared to standard-risk disease after upfront autoSCT, though outcomes are better than other high-risk cytogenetic abnormalities.

Novel Anti-B-cell Maturation Antigen Alpha-Amanitin Antibody-drug Conjugate HDP-101 Shows Superior Activity to Belantamab Mafodotin and Enhanced Efficacy in Deletion 17p Myeloma Models.

B-cell maturation antigen (BCMA) plays a pathobiologic role in myeloma and is a validated target with five BCMA-specific therapeutics having been approved for relapsed/refractory disease. However, these drugs are not curative, and responses are inferior in patients with molecularly-defined high-risk disease, including those with deletion 17p (del17p) involving the tumor suppressor TP53, supporting the need for further drug development. Del17p has been associated with reduced copy number and gene expression of RNA polymerase II subunit alpha (POLR2A) in other tumor types. We therefore studied the possibility that HDP-101, an anti-BCMA antibody drug conjugate (ADC) with the POLR2A poison α-amanitin could be an attractive agent in myeloma, especially with del17p. HDP-101 reduced viability in myeloma cell lines representing different molecular disease subtypes, and overcame adhesion-mediated and both conventional and novel drug resistance. After confirming that del17p is associated with reduced POLR2A levels in publicly available myeloma patient databases, we engineered TP53 wild-type cells with a TP53 knockout (KO), POLR2A knockdown (KD), or both, the latter to mimic del17p. HDP-101 showed potent anti-myeloma activity against all tested cell lines, and exerted enhanced efficacy against POLR2A KD and dual TP53 KO/POLR2A KD cells. Mechanistic studies showed HDP-101 up-regulated the unfolded protein response, activated apoptosis, and induced immunogenic cell death. Notably, HDP-101 impacted CD138-positive but not-negative primary cells, showed potent efficacy against aldehyde dehydrogenase-positive clonogenic cells, and eradicated myeloma in an in vivo cell line-derived xenograft (CDX). Interestingly, in the CDX model, prior treatment with HDP-101 precluded subsequent engraftment on tumor cell line rechallenge in a manner that appeared to be dependent in part on natural killer cells and macrophages. Finally, HDP-101 was superior to the BCMA-targeted ADC belantamab mafodotin against cell lines and primary myeloma cells in vitro, and in an in vivo CDX. Together, the data support the rationale for translation of HDP-101 to the clinic, where it is now undergoing Phase I trials, and suggest that it could emerge as a more potent ADC for myeloma with especially interesting activity against the high-risk del17p myeloma subtype.

Evaluation of potential biomarkers for lenvatinib plus pembrolizumab among patients with advanced endometrial cancer: results from Study 111/KEYNOTE-146.

BACKGROUND: Lenvatinib plus pembrolizumab demonstrated clinically meaningful benefit in patients with previously treated advanced endometrial carcinoma in Study 111/KEYNOTE-146 (NCT02501096). In these exploratory analyses from this study, we evaluated the associations between clinical outcomes and gene expression signature scores and descriptively summarized response in biomarker subpopulations defined by tumor mutational burden (TMB) and DNA variants for individual genes of interest. METHODS: Patients with histologically confirmed metastatic endometrial carcinoma received oral lenvatinib 20 mg once daily plus intravenous pembrolizumab 200 mg every 3 weeks for 35 cycles. Archived formalin-fixed paraffin-embedded tissue was obtained from all patients. T-cell-inflamed gene expression profile (TcellinfGEP) and 11 other gene signatures were evaluated by RNA sequencing. TMB, hotspot mutations in PIK3CA (oncogene), and deleterious mutations in PTEN and TP53 (tumor suppressor genes) were evaluated by whole-exome sequencing (WES). RESULTS: 93 and 79 patients were included in the RNA-sequencing-evaluable and WES-evaluable populations, respectively. No statistically significant associations were observed between any of the RNA-sequencing signature scores and objective response rate or progression-free survival. Area under the receiver operating characteristic curve values for response ranged from 0.39 to 0.54; all 95% CIs included 0.50. Responses were seen regardless of TMB (≥175 or <175 mutations/exome) and mutation status. There were no correlations between TcellinfGEP and TMB, TcellinfGEP and microvessel density (MVD), or MVD and TMB. CONCLUSIONS: This analysis demonstrated efficacy for lenvatinib plus pembrolizumab regardless of biomarker status. Results from this study do not support clinical utility of the evaluated biomarkers. Further investigation of biomarkers for this regimen is warranted. TRIAL REGISTRATION NUMBER: NCT02501096.

Daratumumab for patients with myeloma with early or late relapse after initial therapy: subgroup analysis of CASTOR and POLLUX.

ABSTRACT: High-risk multiple myeloma (MM) is often defined based on cytogenetic abnormalities, but patients who relapse early after initial therapy are considered a functional high-risk group. In the phase 3 CASTOR and POLLUX studies, daratumumab plus bortezomib/dexamethasone (D-Vd) or lenalidomide/dexamethasone (D-Rd) improved progression-free survival (PFS) and overall survival (OS), regardless of cytogenetic risk, and achieved higher rates of complete response or better (≥CR) and minimal residual disease (MRD) negativity vs that with Vd/Rd alone in relapsed/refractory MM. Post hoc analyses of CASTOR and POLLUX evaluated patient subgroups with 1 prior line of therapy based on timing of progression/relapse (early or late) after initiation of first line of therapy. PFS consistently favored the daratumumab-containing regimens across subgroups using both a 24- and 18-month early-relapse cutoff. In the CASTOR/POLLUX pooled data set, daratumumab reduced the risk of disease progression or death by 65% (hazard ratio [HR], 0.35; 95% confidence interval [CI], 0.26-0.48; P < .0001) in the early-relapse (<24 months) subgroup and by 65% (HR, 0.35; 95% CI, 0.26-0.47; P < .0001) in the late-relapse (≥24 months) subgroup. OS also favored the daratumumab-containing regimens in both the early-relapse (HR, 0.62; 95% CI, 0.45-0.86; P = .0036) and late-relapse (HR, 0.67; 95% CI, 0.48-0.93; P = .0183) subgroups in the pooled population using a 24-month cutoff. Rates of ≥CR and MRD negativity (10-5) were higher with daratumumab vs control, regardless of progression/relapse timing. Although daratumumab is unable to fully overcome the adverse prognosis of early relapse, our results support the use of daratumumab for patients with 1 prior line of therapy, including for those who progress/relapse early after initial therapy and are considered to have functional high-risk MM. These trials were registered at www.clinicaltrials.gov as #NCT02136134 (CASTOR) and #NCT02076009 (POLLUX).

Management and Outcomes of Patients with Refractory Solitary Plasmacytoma after Treatment with Definitive Radiation Therapy.

PURPOSE: Radiation therapy (RT) is the standard treatment for solitary plasmacytoma (SP); however, the optimal management of RT-refractory SPs is unknown. We examined outcomes after early systemic therapy, surgical resection, or observation for patients with RT-refractory disease and assessed the potential impact of treatment selection on disease outcomes. METHODS AND MATERIALS: We retrospectively reviewed patients with SP treated with definitive radiation and evaluated at a single institution with persistent disease on imaging or biopsy. Descriptive statistics were used to characterize patient and disease characteristics and treatment outcomes. RESULTS: Of 102 total SP patients, 17 (17%) were RT-refractory. The median RT dose was 45 Gy, and median follow-up was 71 months from end of RT. Fifteen patients had additional treatment for refractory disease at a median time of 9.5 months after RT, with the following subsequent interventions: surgical resection (n = 4), additional RT (n = 2), systemic therapy without evidence of multiple myeloma (MM; n = 4), systemic therapy for progression to MM (n = 5), and observation (n = 2). Of 4 patients treated with surgical resection, 3 progressed to MM 22 to 43 months after diagnosis. Of 2 patients treated with additional RT, neither responded, and both had pathologic confirmation of residual disease after the second course. Four patients treated with systemic therapy without MM all had complete responses on positron emission tomography and no subsequent MM progression. Eight patients were initially observed after RT for ≥12 months (n = 8) or ≥24 months (n = 6). Of the 2 patients in continued observation, both had stable/unchanged avidity after radiation treatment for 12 and 22 months and ultimately had a slow decrease of disease avidity over multiple years. CONCLUSIONS: Patients with RT-refractory SPs can achieve good local control with alternative therapies, such as surgery or systemic therapy, if needed. Additional RT does not seem to be effective. Given the known high rates of progression from SP to MM, close observation of asymptomatic persistent disease until disease progression is likely sufficient in most cases.