Treatment Of Multiple Myeloma Patients Research Articles

COVID-19 in multiple myeloma patients: frequencies and risk factors for hospitalization, ventilatory support, intensive care admission and mortality –cooperative registry from the Grupo Brasileiro de Mieloma Multiplo (GBRAM)

IntroductionThis study evaluated outcomes and risk factors for COVID-19 in 91 Brazilian multiple myeloma (MM) patients between April 2020 and January 2022. ResultsOf the 91 MM patients diagnosed with COVID-19, 64% had comorbidities and 66% required hospitalization due to COVID-19, with 44% needing ventilatory support and 37% intensive care. Age (OR 2.02; 95%CI 1.02 – 7.7) and hypertension OR 4.5; 95%CI 1.3 – 15.5) were independently associated with hospitalization and certain MM therapies (corticosteroids and monoclonal drugs) were associated with ventilatory support (OR 4.3; 95%CI 1.3 – 14 and OR 5.7; 95%CI 1.8 – 18, respectively), while corticosteroids and immunomodulatory drugs were linked to ICU admission (OR 5.1; 95% CI 1.4 – 18 and OR 3.4; 95%CI 1.1 – 10, respectively). The overall mortality rate was 30%, with the highest rate observed in the ICU (73%). Additionally, the ECOG performance status was linked to increased mortality (OR 11.5; 95%CI 1.9 – 69). The MM treatment was delayed in 63% of patients who recovered from COVID-19. ConclusionsThe findings highlight the need for preventing COVID-19 and prioritizing vaccination among MM patients, as they have high rates of severe outcomes in the event of COVID-19. It is also essential to monitor the potential clinical impacts of COVID-19 on MM patients in the long-term. Given the limited resources available in treating MM patients in Brazil during the COVID-19 pandemic, outcomes might be worse in this population.

GRP78 inhibitor HA15 increases the effect of Bortezomib on eradicating multiple myeloma cells through triggering endoplasmic reticulum stress

Bortezomib (BTZ), a selective proteasome inhibitor, exhibits a significant efficacy in the therapy of multiple myeloma (MM) partly through triggering endoplasmic reticulum (ER) stress-dependent apoptosis. However, sensitivity to BTZ varies greatly among patients. ER stress functions as a double-edged sword in regulating cell survival depending on cell context and ER stress extent. The major aim of this study was to investigate whether GRP78 inhibitor, HA15, increased the therapeutic effect of BTZ on MM to through further increasing ER stress and shifting the balance towards cell apoptosis. The biological role of BTZ and HA15 was assessed using Cell counting kit- (CCK-) 8, colony formation, and Terminal deoxynucleotidyl transferase (TdT) dUTP nick-end labelling (TUNEL) assay. We found that BTZ combined with HA15 remarkably decreased MM cell viability more effective than BTZ monotherapy, though low dose of HA15 did not exhibit a significant cytotoxicity to MM cells. BTZ combined with HA15 also repressed colony formation ability of MM cell and accelerated MM cell apoptosis compared with BTZ monotherapy. Mechanistically, HA15 synergized with BTZ to trigger ER stress, as evidence by significantly increased expression of ER stress markers (GRP78, ATF4, CHOP, and XBP1). Importantly, unfolded protein response (UPR) inhibitor significantly damaged the effect of BTZ combined with HA15 on accelerating MM cell death. In vivo, combination treatment with BTZ and HA15 inhibited tumor growth more effective than BTZ alone, whereas these effects were blocked by UPR inhibitor. Taken together, these results demonstrate that ER stress is a critical pathway in regulating MM cell survival, and that combination treatment with BTZ and HA15 may be an effective strategy to treat MM patients that fail to respond to BTZ monotherapy.

#5831 LIGHT CHAIN REMOVAL IN MULTIPLE MYELOMA PATIENTS WITH HFR-SUPRA HEMODIALYSIS: OUR EXPERIENCE

Abstract Background and Aims Kidney injury is a common complication in multiple myeloma (MM) and it has a negative prognostic implication. Most common cause of Acute Kidney Injury (AKI) in these patients is Light chain Cast Nephropathy, where free light chains precipitate in the tubules and bind with uromodulin, turning into intratubular casts that obstruct the tubules and also promote local giant cell reaction and interstitial inflammation and fibrosis. Free light chains (FLCs) can also damage the kidneys due to direct tubular toxicity when excessive amounts are reabsorbed by the proximal tubules. Targeted therapy to reduce FLC load can help recover renal function. Both total reduction and reduction speed are relevant for prognosis. FLC removal through extracorporeal techniques can be used as an adjuvant therapy, having an important part on the evolution of the disease. We gathered data from our experience treating MM patients with AKI with HFR-supra hemodialysis (HD) and analized the evolution and possible influence of this technique on renal recovery. Method This is an observational retrospective study. We included all patients with a diagnosis of multiple myeloma and acute kidney injury who received HFR-Supra hemodialysis in between years 2016-2022 in Hospital Virgen Macarena (Seville). We initially performed 6-10 daily HFR-Supra HD sessions and then modulated the frequency based on renal response (if renal replacement therapy had to be continued they underwent a usual hemodialysis regime 3 days a week). We continued these sessions until renal recovery was achieved or free light chain levels were reduced in agreement with the Hematology team. Measurement of pre and post dialysis FLCs was made always at first and last session and at least once in between, depending on the total number of sessions. Results 12 patients, with mean age at diagnosis 63.6 (43-86) years, presented with AKI stage KDIGO 3. 1 of them was oliguric. Median serum creatinine at diagnosis was 4.4 mg/dL [2,2-17], mean proteinuria was 4,1g/24 h [0,7-8,7] and 66,7% had positive Bence Jones proteinuria (mean 2,3g/24 h). 2 of the patients had previous chronic kidney disease stage 3a. All of them were diagnosed with Light Chain Multiple Myeloma (75% kappa, mean 10346 mg/L; 25% lambda, mean 5990 mg/L). Mean clonal bone marrow plasma cell was 20,7% [2-55]. According to the Revised International Staging System (R-ISS), 25% were stage 2 and 75% were stage 3. Renal biopsy was performed in 4 patients, all showed evidence of Cast Nephropathy. The indication for starting HFR-Supra HD was FLC removal in 9 patients, need of renal replacement therapy in 1 and both in 2 patients. We have experience in our center with using this therapy as an adyuvant treatment and often we start the technique in patients who present with AKI but would not necessarily have immediate need for renal replacement therapy. The goal is to remove FLCs and avoid further damage to the kidney tissue. Out of the 12 patients, 9 were able so stop dialysis (75%). They received a mean number of 12,4 [3-41] sessions in 3,7 [0,2-25] months). Free light chain removal per session was 24% on average [5-43%]. All of them were started on bortezomib-dexamethasone regime as initial chemotherapy for MM. As per renal recovery, at 3 months 33,3% achieved complete response, 11,1% partial response and 55,6% minimal response. At 1 year, 42,9% achieved complete response, 14,3% partial response and 42,9% minimal response. One-year survival rate was 91,7% (1 patient died from respiratory sepsis less than 1 month after diagnosis). Conclusion HFR-Supra hemodialyisis achieved a 24% free light chain removal per session on average. After presenting severe AKI (KDIGO 3), almost 43% of patients who received this adyuvant therapy obtained full renal recovery at 1 year and in 75% of patients withdrawal from hemodialysis was possible. 1 year survival was 91,7%.

Cellular immunity in the era of modern multiple myeloma therapy.

Multiple myeloma (MM) is a relapsing clonal plasma cell malignancy and incurable thus far. With the increasing understanding of myeloma, highlighting the critical importance of the immune system in the pathogenesis of MM is essential. The immune changes in MM patients after treatment are associated with prognosis. In this review, we summarize currently available MM therapies and discuss how they affect cellular immunity. We find that the modern anti-MM treatments enhance antitumour immune responses. A deeper understanding of the therapeutic activity of individual drugs offers more effective treatment approaches that enhance the beneficial immunomodulatory effects. Furthermore, we show that the immune changes after treatment in MM patients can provide useful prognostic marker. Analysing cellular immune responses offers new perspectives for evaluating clinical data and making comprehensive predictions for applying novel therapies in MM patients.

High Hospital-related Costs at the End-of-life in Patients With Multiple Myeloma: A Single-center Study.

High Hospital-related Costs at the End-of-life in Patients With Multiple Myeloma: A Single-center Study.

Targeting Exportin 1 as treatment for cutaneous squamous cell carcinoma.

e21564 Background: Cutaneous squamous cell carcinomas (cSCC) are among the most frequent solid cancers in humans and in the U.S., cSCC cases are increasing. Molecular mechanisms transitioning premalignant lesions to cancer are not well characterized. As a result, targeted therapies need to be identified to treat these lesions. Preliminary data shows that Exportin 1 (XPO1) is one of the major proteins regulating nuclear export of proteins, helping to maintain cellular homeostasis. Previous work showed that Exportin 1 modulates the nuclear:cytoplasmic ratio of signaling proteins in skin cancer; resulting in an anti-apoptotic effect by adjusting the nuclear-cytoplasmic balance of pro-survival proteins such as CDC25A and Survivin. XPO1 expression is upregulated in many cancers, thereby affecting the nuclear:cytoplasmic ratio of many pro-survival proteins and enhancing tumorigenesis. This research project was designed to investigate the effects of XPO1 inhibition on cSCC survival. Selinexor is FDA cleared for treatment of multiple myeloma patients. Selinexor is a selective inhibitor of XPO1 regulated nuclear transport causing target molecules to remain within the cell leading to decreased cancer cell growth and decreased cancer cell survival. We hypothesize that inhibiting XPO1 with Selinexor or by CRISPRi genetic knockdown of XPO1 in cSCC cells will reduce proliferation and increase apoptosis in cSCC cells. Methods: Human cSCC cell lines SCC13 and SRB12 were seeded in 96-well plates at 8,000 cells/well density and 3,000 cells/well, respectively. Cells were treated with varying concentrations of Selinexor (0.005mM – 5mM) or DMSO as vehicle control. At 24-hour intervals, cell imaging and Neutral red staining assays were conducted to determine the IC50 concentration for Selinexor in cSCC cell lines. SCC13 cells stably expressing dCas9-KRAB and a doxycycline-inducible XPO1 guide RNA were used for CRISPRi experiments. Cells were treated with doxycycline daily and apoptosis was assayed by Caspase Glo 3/7 daily for four days. CRIPSRi enabled a doxycycline inducible XPO1 knock down on SCC13 cells allowing us to disrupt the cellular transporter protein XPO1. Results: Selinexor treatment of SRB12 cells resulted in an IC50 of 1.174 μM and 0.071 μM for SCC13. In contrast, normal human keratinocyte cell lines had higher IC50 values of 2.18 μM for HaCaT and 5.29 μM for KerCT cells. Apoptosis significantly increased after 72 and 96 hours of XPO1 knock down in SCC13 cells measured by Caspase Glo. Conclusions: These results document how XPO1 inhibition reduces proliferation and is toxic to both normal keratinocytes and cSCC cells. Additionally, cSCC cells had lower IC50 values for Selinexor, suggesting cSCC may be more sensitive to XPO1 inhibition compared to normal keratinocytes. Further, targeting XPO1 also increases apoptosis in these cells. This data supports the hypothesis that targeting XPO1 may be effective in treating cSCC.

Study on the Effect of EZH2 Inhibitor Combined with TIGIT Monoclonal Antibody against Multiple Myeloma Cells.

EZH2, a member of the polycomb repressive complex 2, induces trimethylation of the downstream gene at the histone three lysine 27 (H3K27me3) position to inhibit tumor cell proliferation. Here, we showed that the apoptosis rate and apoptotic protein expression increased after EZH2 inhibition, whereas key molecules of the NF-κB signaling pathway and the downstream target genes were inhibited. Additionally, the expression of CD155, a TIGIT high-affinity ligand in multiple myeloma (MM) cells, was decreased by the mTOR signaling pathway. Furthermore, the combination of EZH2 inhibitor and TIGIT monoclonal antibody blockade enhanced the anti-tumor effect of natural killer cells. In summary, the EZH2 inhibitor not only plays an anti-tumor role as an epigenetic drug, but also enhances the anti-tumor effect of the TIGIT monoclonal antibody by affecting the TIGIT-CD155 axis between NK cells and MM cells, thus providing new ideas and theoretical basis for the treatment of MM patients.

Excessive serine from the bone marrow microenvironment impairs megakaryopoiesis and thrombopoiesis in Multiple Myeloma

Thrombocytopenia is a major complication in a subset of patients with multiple myeloma (MM). However, little is known about its development and significance during MM. Here, we show thrombocytopenia is linked to poor prognosis in MM. In addition, we identify serine, which is released from MM cells into the bone marrow microenvironment, as a key metabolic factor that suppresses megakaryopoiesis and thrombopoiesis. The impact of excessive serine on thrombocytopenia is mainly mediated through the suppression of megakaryocyte (MK) differentiation. Extrinsic serine is transported into MKs through SLC38A1 and downregulates SVIL via SAM-mediated tri-methylation of H3K9, ultimately leading to the impairment of megakaryopoiesis. Inhibition of serine utilization or treatment with TPO enhances megakaryopoiesis and thrombopoiesis and suppresses MM progression. Together, we identify serine as a key metabolic regulator of thrombocytopenia, unveil molecular mechanisms governing MM progression, and provide potential therapeutic strategies for treating MM patients by targeting thrombocytopenia.

Abstract 1883: A novel T cell engager targeting BCMA and GPRC5D showed promising preclinical activity with low toxic risk for multiple myeloma treatment

Abstract Background: Multiple myeloma (MM) has become the second most hematological malignance. The patients are rarely cured and experience the recurrence or resistance. There is still an urgent need to develop potential therapeutic agents with better response. BCMA (B cell maturation antigen) and GPRC5D (G-protein-coupled receptor class 5 member D) are independently expressed in MM cells. The percentage of MM patients with single or co-expression of BCMA and GPRC5D is close to 90%, which means both are the ideal therapeutical targets. Methods/Results: Anti-GPRC5D and anti-BCMA antibodies with high binding affinity were respectively screened from hybridoma or alpaca phage library. Two antibodies were assembled to anti-CD3 antibody with low binding activity. Candidate molecule SCR-8572 was selected from dozens of triple-specific antibodies. The affinity of SCR-8572 to recombinant BCMA protein is 41.3pM. Binding EC50 to GPRC5D over-expressed cell is 2.4nM. SCR-8572 also showed very good binding activity with several MM cell lines, such as H929, RPMI-8226 and Molp-8, etc. The weak binding to CD3 can decrease the sink effect in peripheral blood. In vitro cytotoxicity of SCR-8572 against three MM cell lines with different expression levels was evaluated. It showed strong tumor-induced T cell activation but not non-specific activation, which resulted in the excellent tumor cytotoxicity. And the cytotoxicity was much stronger than that of BCMA-CD3 (Teclistamab analogue) and/or GPRC5D-CD3 (Talquetamab analogue) treatments. In the meanwhile, the cytokine release levels of IL-6 and TNFa are acceptable and similar with two TCE benchmarks. This predicted the low risk of CRS. We also conducted in vivo efficacy test in two MM Cell-derived-Xenograft mice models with PBMC reconstitution. SCR-8572 can eliminate the tumors and maintained tumor regression after drug withdrawal, while the tumor relapse occurred in Teclistamab and/or Talquetamb groups. The preliminary toxic effect of SCR-8572 was explored in cynomolgus by 10mpk followed by 30mpk intravenous injection with 21 days interval. The cynomolgus tolerated very well. Lymphocyte reduction was observed which indicated the lymphocyte redistribution. C Reaction Protein (CRP) level increased to 19-33mg/L and recovered to baseline in 7 days. IL-6 level increased to 116.3pg/ml in 24 hours after 10mpk injection and 52.5pg/ml in 2 hours after followed 30mpk injection. IFNγ, IL-2 and IL-10 levels were detected to be very low or below the limit of quantitation. Conclusion: We have developed a novel dual-targeted T cell engager for MM treatment, which showed strong tumor killing effect in in vitro and in vivo models with low CRS risk. The toleration of high dosage in cynomolgus suggested the good safety performance. Above all, the preclinical study illustrated SCR-8572 can be a promising therapeutic candidate in treatment of MM patients. Citation Format: Yayuan Fu, Shumei You, Menghao Wei, Bowei Yin, Qi Deng, Xiaokang Qin, Yun Zhang, Yanqiu Wang, Renhong Tang. A novel T cell engager targeting BCMA and GPRC5D showed promising preclinical activity with low toxic risk for multiple myeloma treatment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1883.

Abstract 782: Circulating tumour DNA-based molecular response predicts treatment outcome in multiple myeloma

Abstract Background: Multiple myeloma (MM) is an incurable and multi-focal plasma cell malignancy manifesting predominantly within the bone marrow (BM). BM-based minimal residual disease (MRD) assessment utilising next generation flow (NGF - EuroFlowTM) has become an important measure of treatment response and a validated predictor of patient outcome. However, MRD is a single-site BM-derived assay and is conceptually limited due to the spatially heterogenous nature of MM and response to treatment. Objective: We investigated if the evaluation of circulating tumour DNA (ctDNA) can be utilised as an adjunct to MRD analysis in predicting patient outcome. Methods: Peripheral blood plasma was obtained at baseline (B), cycle 3 day 1 (C3D1) and end of study (EOS)/relapse from a phase II, multicentre single arm study of carfilzomib-thalidomide-dexamethasone (KTd) in 50 transplant-eligible newly diagnosed MM patients who were refractory to or had demonstrated a suboptimal response to first-line therapy. Extracted ctDNA was assessed utilising high-sensitivity targeted amplicon sequencing (TAS) of 22 MM-relevant genes. The variant allele frequency (VAF) of mutations at B was utilised to calculate a fold change in VAF at C3D1 and/or EOS. A negative fold change was defined as a decrease in VAF (ctDNA-) and a positive fold change an increase in VAF (ctDNA+) with the average fold change across all mutations calculated for each patient. EuroflowTM was performed on BM obtained pre and post-autologous stem cell transplant (ASCT) and at EOS and the ‘best MRD response’ achieved (MRD+ or MRD-) was recorded. The ctDNA and MRD responses were combined and correlated with progression-free survival (PFS) calculated using Kaplan-Meier estimates. Results: A total of 45 patients had one or more mutations identified at B that could be tracked at C3D1 and/or EOS and 40 patients had one or more mutations that emerged at C3D1, EOS and/or relapse. Of these, 33 patients were evaluable for both MRD and ctDNA response. Patients that were MRD- and ctDNA- as best response for B mutations had a significantly longer PFS compared to those who were MRD+/ctDNA- or MRD-/ctDNA+ (p<0.0001, Log-rank tests; 23.9 months vs not reached for MRD-ctDNA-, Log rank-tests). Patients that were MRD- and ctDNA- at C3D1 (as early response for B mutations) had a significantly longer PFS compared to those that were MRD+/ctDNA- or MRD-/ctDNA+ (p=0.0011, 26.4 months vs not reached in MRD-ctDNA-, Log-rank tests). Conclusions: Our results demonstrate that treated MM patients manifesting a molecular response, as defined by a reduction in ctDNA mutational burden, and who are also MRD- have a superior outcome to those patients who are MRD- but without a molecular response. These results for the first time confirm the utility of ctDNA-based early molecular response as a predictor of patient outcome in MM. Citation Format: Sridurga Mithraprabhu, Tiffany Khong, Flora Yuen, John Reynolds, Brian Durie, Andrew Spencer. Circulating tumour DNA-based molecular response predicts treatment outcome in multiple myeloma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 782.

GTN057, a komaroviquinone derivative, induced myeloma cells' death in vivo and inhibited c-MET tyrosine kinase.

Despite the development of newly developed drugs, most multiple myeloma (MM) patients with high-risk cytogenetic abnormalities such as t(4;14) or del17p relapse at anin early stage of their clinical course. We previously reported that a natural product,komaroviquinone (KQN), isolated from the perennial semi-shrub Dracocephalum komarovi, i.e., komaroviquinone (KQN) and its derivative GTN024 induced the apoptosis of MM cells by producing reactive oxygen species (ROS), but both exhibited significant hematological toxicity. Aim of this study is to clarify anti-tumor activity, safety and pharmacokinetics of GTN057, an optimization compound of KQN in vivo. ICR/SCID xenograft model of KMS11, a t(4;14) translocation-positive MM cell line, was used for in vivo study. Mice pharmacokinetics of GTN057 and the degradation products were analyzed by LC-MS/MS. Herein, our in vitro experiments revealed that GTN057 is much less toxic to normal hematopoietic cells, induced the apoptosis of both MM cell lines andpatient samples, including those with high-risk cytogenetic changes. A xenograft model of a high-risk MM cell line demonstrated that GTN057 significantly delayed the tumor growth with no apparent hematological or systemic toxicities in vivo. The pathological examination of GTN057-treated tumors in vivoshowed revealed apoptosis of MM cells and anti-angiogenesis. In addition to the production of ROS, GTN057 inhibited the downstream signaling of c-MET, a receptor tyrosine kinase a receptor forand hepatocyte growth factor (HGF) receptor. Thus, GTN057 is less toxic and is able tomay be a candidate drug for treating MM patients, via multifunctional mechanisms. We have also extensively studied the pharmacologyical analysis of GTN057. The metabolites of GTN057, (e.g.,such as GTN054), may also have anti-tumorantitumor activity. Natural products or and their derivatives can could be good sources of antineoplastic drugs even for high-risk cancer.

The Efficacy and Safety of Daratumumab-Based Regimen in Treatment of Multiple Myeloma Patients with Renal Impairment

To investigate the efficacy and safety of daratumumab in treatment of multiple myeloma (MM) patients with renal impairment (RI). The clinical data of 15 MM patients with RI who received daratumumab-based regimen from January 2021 to March 2022 in three centers were retrospectively analyzed. Patients were treated with daratumumab or daratumumab combined with dexamethasone or daratumumab combined with bortezomib and dexamethasone and the curative effect and survival were analyzed. The median age of 15 patients was 64 (ranged 54-82) years old. Six patients were IgG-MM, 2 were IgA-MM,1 was IgD-MM and 6 were light chain MM. Median estinated glomerular filtration rate (eGFR) was 22.48 ml/(min·1.73 M2). Overall response rate of 11 patients with MM was 91% (≥MR), including 1 case of stringent complete response (sCR), 2 cases of very good partial response (VGPR), 3 cases of partial response (PR) and 4 cases of minor response (MR). The rate of renal response was 60%(9/15), including 4 cases of complete response (CR), 1 case of PR and 4 cases of MR. A median time of optimal renal response was 21 (ranged 7-56) days. With a median follow-up of 3 months, the median progression-free survival and overall survival of all patients were not reached. After treatment with daratumumab-based regimen, grade 1-2 neutropenia was the most common hematological adverse reaction. Non-hematological adverse reactions were mainly infusion-related adverse reactions and infections. Daratumumab-based regimens have good short-term efficacy and safety in the treatment of multiple myeloma patients with renal impairment.

Treatment Profile of CAR-T Cell Therapy Induced Cytokine Release Syndrome and Neurotoxicity: Insights from Real-World Evidence

Background: Cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) are well-recognized complications of chimeric antigen receptor (CAR)-T cell therapies. Tocilizumab with or without corticosteroid (e.g., dexamethasone) is the current standard management for moderate to severe CRS (Brudno JN & Kochenderfer JN, 2020 Blood Rev.). However, little is known about the treatment in tocilizumab non-responding CRS patients or in patients with co-occurring ICANS. Using electronic health records (EHRs), we aim to investigate characteristics of CRS induced by CAR-T cell therapies and treatment patterns for CRS in real-world settings. Methods: We extracted all patients who received CAR-T cell therapies from 5437 multiple myeloma (MM), 1120 diffused large b-cell lymphoma (DLBCL), and 1036 acute lymphoid leukemia (ALL) patients in Sema4 EHRs. We followed the trajectories of CRS and/or ICANS treatments from the initial CRS/ICANS onset after CAR-T cell therapies, through the progression with grade evaluation, until they were resolved. The data was curated automatically, annotated manually and further analyzed descriptively by two domain experts. Results: We curated 74 BCMA CAR-T cell treated MM patients and 31 CD19 CAR-T cell treated DLBCL/ALL patients. Among those, 58 (78.4%) BCMA CAR-T treated MM patients, and 22 (71%) CD19 CAR-T treated DLBCL/ALL patients developed CRS. The median initial CRS onset day was Day +3 (min day 0, max day +10) after CAR-T cell infusion (day 0) in CD19 CAR-T cell treated cohorts and Day +4 (min day 0, max day +21) in BCMA CAR-T cell treated cohorts. At Day +5, 86.3% of CD19 CAR-T treated patients and 65% of BCMA CAR-T treated patients developed CRS (Table 1). In CD19 CAR-T cell treated cohorts, 72.7% and 27.3% of patients developed grade 1 and 2 CRS, respectively. Ten patients (32.3%) had co-occurred ICANS. In BCMA CAR-T cell treated cohorts, 69.1%, 16.1%, and 12.5% of patients developed grade 1, 2, and 3 CRS, respectively. Five patients (6.8%) had co-occurring ICANS, and one patient was dead caused by CRS complication (Table 1). The CRS treatment pattern was summarized in Table 2. As expected, tocilizumab (IL6 receptor antagonist)-based treatment was predominant in both BCMA CAR-T treated (77.6%) and CD19 CAR-T treated (86.4%) groups. Only 17.2% and 9.1% of patients received supportive managements with antibiotics or analgesics. Tocilizumab 1x dose was the most common treatment (37.8% in BCMA CAR-T treated cohorts vs 31.6% in CD19 CAR-T treated cohorts). In CRS grade 2/3 cohorts or ICANS co-occurred cohorts, either the tocilizumab dose was increased (2.2% vs 5.3%), or dexamethasone (corticosteroid) was added (11.1% vs 31.6%) in both BCMA CAR-T treated and CD19 CAR-T treated, respectively. Among the patients who had additional antagonists after tocilizumab, anakinra (IL1 receptor antagonist) was the only antagonist used in CD19 CAR-T cell treated cohorts. Total 6 patients (31.6%) had anakinra after tocilizumab. Patients receiving anakinra had higher rates of ICNAS co-occurrence than patients who did not receive anakinra (67% vs. 38%). In BCMA CAR-T treated cohorts, anakinra was used in 21 (46.6%) patients. The usage of siltuximab (anti-IL6 antibody) was observed in one patient with high CRS grade alone (2.2%, wo anakinra) and one patient with co-occurring ICANS (2.2% w anakinra). Out of 21 anakinra treated patients, 4 (20%) patients had the co-occurrence of ICANS, and 16 (80%) patients had no co-occurrence of ICANS (Table 2). Interestingly, 15 patients complicated with grade 1 CRS only had anakinra in BCMA CAR-T treated cohorts with the description of persistent febrile and increased ferritin level under tocilizumab. Etanercept (TNF antagonist) was also used after tocilizumab, methylprednisolone, and anakinra in one patient with severe CRS complication and co-occurring ICANS. Conclusions: In this study, we provided a real-world clinical pattern for patients with tocilizumab non-responding CRS or patients with co-occurring ICANS. Gaining a better understanding of toxicity management in those groups can help guiding the treatment of CAR-T cell therapy toxicity and improving quality of life for patients with cancer. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Liposome Formulation of Carfilzomib with Improved Activity As a Monotherapy and in Combination with Vinblastine

Introduction: Carfilzomib (CFZ) is an epoxyketone-based irreversible proteasome inhibitor that is one of the leading treatments for multiple myeloma (MM). Cardiotoxicity is the primary limitation for the clinical use of CFZ. We developed a novel liposome nanoparticle formulation of CFZ, a compound with low water solubility (<5 µg/mL) and low pKa (5.14) (LS-CFZ) that dramatically reduces the toxicity, increases the plasma half-life, and improves the antitumor efficacy compared to the commercial formulation. In addition, CFZ was combined in the same liposome, with vinblastine (VBL) an autophagy inhibitor. The combination exhibited synergistic anti-tumor cell activity in vitro and in vivo using a colon cancer (C26) mouse tumor model. Methods: CFZ was screened for cytotoxicity in combination with various cell lines including MM and C26 with a focus on autophagy inhibitors. VBL was co-loaded into the same liposomes with CFZ, and also loaded into separate particles. Formulations with various lipids, trapping agents and drug to lipid ratios were screened for drug loading efficiency. The lead formulation was selected based on mouse plasma half-life after IV injection in male CD1 mice. The plasma concentration of CFZ, VBL and a fluorescent lipid (liposome) label (DiIC18(5)) were measured by HPLC. The dose ratio of the CFZ and VBL was by determined by the MTD in tumor-free mice and the optimum dose and ratio was used for the efficacy study. The lead formulations were evaluated for anti-tumor efficacy in the C26 colon cancer using a single treatment (day 1) when the tumor volume was 200 mm3 for all liposome formulations and two treatments (day 1 and day 2) (optimum for CFZ) for the unencapsulated CFZ and VBL. Results: Cytotoxicty studies in C26 cells indicated the optimum ratio of CFX/VBL was between 5:1 and 20:1. All liposomes used had a diameter of 110-130 nm. Ammonium sucrose octasulfate yielded the longest retention of CFZ and VBL in the liposome after IV injection in mice. The best lipid composition was sphingomyelin/Cholesterol/PEG-2000-PE (55/45/2.8, mol/mol/mol) with a particle size of 110-130 nm in diameter. Cryo TEM images of the LS-CFZ show a dense amorphous mass of drug precipitate in the center of the liposomes. The drug to lipid ratio chosen for use in the efficacy study was 101 g/mol lipid for CFZ and 103 g/mol lipid for VBL with a loading efficiency >90%. Using the optimized trapping agent and lipid composition the %ID of CFZ is nearly identical to that of the liposome carrier up to 6 h; an average of 98.4±5.4% of the drug is retained up to 6 h. The %ID of CFZ decreases below that of the liposome between 6 and 24 h and most (>98%) of the CFZ has been released from the liposomes by the 24 h point. The AUC for LS-CFZ (2 mg/kg) is 1584 fold higher than CFZ administered as SBCD-CFZ (sulfobutyl cyclodextrin formulated, Kyprolis®) (5 mg/kg). CFZ administered as SBCD-CFZ has a t1/2 of 0.2 h compared to 3.0 h for LS-CFZ. VBL had slightly better stability than CFZ with a plasma half-life of 4.9 h. LS-CFZ had single dose MTD of 30 mg/kg for L-CFZ, while SBCD-CFZ given QDx2 had an MTD 6 mg/kg. The dramatic decrease in toxicity is likely due to lower Cmax of the bioavailable CFZ and reduced cardiotoxicity. The increased tolerability of LS-CFZ allowed for a CFZ/VBL ratio of 20:1 (18/0.9 mg/kg, CFZ/VBL) for the liposome formulation; the unencapsulated CFZ and VBL were administered at a ratio of 5:1 (5/1 mg/kg, CFZ/VBL). The anti-tumor efficacy of LS-CFZ/VBL combination was far superior to all other treatments. LS-CFZ was nearly identical to LS-VBL, and both single agents had more activity than any unencapsulated drug. As a monotherapy, LS-CFZ was far more efficacious than SBCD-CFZ, which is commonly used for treatment of multiple myeloma patients. Conclusion: Liposome formulation of CFZ increased the tolerability by 5-fold compared to the commercial CFZ formulation. The described liposome technology enables significant improvement in anti-tumor efficacy for CFZ as a monotherapy or in combination against a C26 mouse model. The improved activity in solid tumors warrants investigation of LS-CFZ for MM treatment. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Real-World Treatment Patterns and Outcomes of Patients with Newly Diagnosed Multiple Myeloma: An Analysis Using National Health Insurance Service Database

Introduction: Available treatments for multiple myeloma (MM) have improved rapidly in recent years. However, due to huge disparities in economy, healthcare infrastructure, and accessibility to new drugs, there are big barriers to provide optimal treatment for MM patients in Asian countries. Until now, there are few data on treatment patterns for MM in real practice setting of Asian countries. In terms of continuous improvement of MM management, it is necessary to ascertain the treatment patterns for achieving optimal treatment. Therefore, we investigated the actual treatment patterns and outcomes of MM patients in Korea using the National Health Insurance Service (NHIS) database. Methods: Newly diagnosed MM patients were identified from the Korean NHIS database between 1st January 2010 to 31st December 2018. Patients had diagnosis with MM (ICD-10 codes C90.0) confirmed with rare and intractable disease registration program. Patients that received at least one stem cell transplantation (SCT) were classified into SCT patients and those without SCT to non-SCT patients. SCT patients and non SCT patients were divided into before and after 1st October 2015 (reimbursement date of bortezomib/dexamethasone [Vd], bortezomib/thalidomide/dexamethasone [VTd] regimens), and 1st December 2017 (reimbursement date of lenalidomide/dexamethasone [Rd] regimen) respectively. MM treatment was defined to start from the first prescription claim including MM treatment following the diagnosis index date, and the therapies within 14-days period from the first date of each line of therapy (LOT) were considered to constitute the treatment regimen of the respective LOT. When a new MM therapy that was not part of the prior LOT appeared in the prescription claim, LOT was considered to advance to the next LOT. Treatment duration, and treatment-free interval times between LOTs were estimated up to 5th LOT. Median overall survival (OS) was assessed by Kaplan Meier. Comparison between groups was evaluated by Log rank and Wilcoxon test. Results: The study population included total of 9,986 newly diagnosed MM patients, 7,501 non-SCT and 2,485 SCT for baseline analyses. Incidence of MM gradually increased by 5.7% of an average annual percent change, from 841 in 2010 to 1,309 in 2018. The mean age of the non-SCT group was older than the SCT group (71.6±9.4 vs 56.7±6.7). The proportion of patients aged <65 was 36.9% and ≥65 was 63.1%. Regardless of SCT eligibility (<65 years), 24.9% of MM patients received SCT. Of the patient eligible for SCT, 62.0% received SCT. Those 8,367 patients (non-SCT:5,925 / SCT:2,442) with at least ≥1 prescription claims with MM treatment after index date were included for treatment pattern analyses. The proportion of patients advancing to each subsequent LOT was higher across all LOT for SCT patients (range, 44%-58%) than non-SCT patients (range, 35%-44%) and decreased with each line. Higher proportion of patients remained to receive 5th LOT in SCT patients than non-SCT (8% vs 3%). Treatment duration and treatment-free interval between LOTs decreased as the LOTs advanced in both SCT and non-SCT patients. Treatment-free interval was the longest after the 1st LOT in SCT patients which was 17.7 months (Fig. 1). The most common 1st LOT treatment regimen for the non-SCT patients was bortezomib/melphalan/prednisolone and for the SCT patients, thalidomide/dexamethasone was mostly used for induction therapy in the 1st LOT. This trend changed as new regimens were available by reimbursement in the 1st LOT: for SCT patients, to VTd; and for non-SCT patients, to Rd. The median OS of all patients was 3.36 years (95% CI: 3.22-3.50). The median OS of the SCT patients was significantly longer with median OS of 7.04 years (95% CI: 6.49-8.11) compared to 2.32 years (95% CI: 2.22-2.44) for the non-SCT patients (p<0.0001). When stratified by age and SCT, SCT patients of younger age (< 65 years) had the longest median OS of 7.10 years (95% CI: 6.56-8.20) (Fig. 2). OS was significantly improved for the SCT group after the reimbursement of Vd and VTd in the 1st LOT (p=0.0019). Conclusions: This real-world data suggests that MM treatment evolves rapidly following the reimbursement of new novel drugs, to treat patients with the most optimal treatment available. And these results show that the OS improves as new novel drugs are incorporated to the treatment. Also, SCT remains an essential treatment providing OS benefit. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Identification of the Proteasome Subunits PSMB4 and PSMD4 As Novel Targets in Multiple Myeloma Patients Carrying 1q21 Amplification

Gain and/or amplification of the 1q21 (1q21+) region is one of the most frequent secondary cytogenetic abnormalities present in multiple myeloma (MM) patients. Interestingly, it has been reported that the incidence of the amplification of chromosome 1q (Amp1q) in patients with pre-malignant smoldering myeloma (SMM) is about 40%. Several data indicate that the presence of Amp1q is associated with a worse clinical outcome and a poor response to therapies including proteasome inhibitors (PIs). Recently, a study showed that newly diagnosed MM (NDMM) carrying Amp1q receiving carfilzomib-based treatment have an early disease progression and shorter overall survival, compared to those with 1q21 gain. The genes driving amplification of the 1q21 region have not been fully elucidated. This study aims to identify novel targets in the 1q21 region possibly correlated to PIs treatment. We purified CD138+ plasma cells (PCs) by immunomagnetic beads from bone marrow (BM) aspirates. We used a total cohort of 29 MM patients: 11 SMM and 18 NDMM. Fluorescent in situ hybridization analysis was performed on all the patients. 48% (14/29) patients carried 1q21+. A score indicating the number of 1q21 copies was calculated based on the FISH hybridization pattern of each patient. The expression profile of all 29 samples was generated using GeneChip ClariomD Arrays (Affymetrix Inc., Santa Clara, CA, USA). The smar package was used to identify differentially expressed genes between 1q21+ and control samples. The expression profile of our cohort showed that the expression of both proteasome subunits, PSMB4 and PSMD4 was significantly upregulated in MM patients Amp1q compared to control patients (PSMB4 p=0.0006; PSMD4p=<0.0001 respectively). Additionally, we found a strong positive correlation between gene expression levels and 1q21 copy number for the proteasome subunits PSMB4 (p=<0.0001, r=0.5631) and PSMD4 (p=<0.0001, r=0.6391). Interestingly, the PSMB4 and PSMD4 expression levels were independent of the disease stage (SMM vs MM) and the expression was driven exclusively by the 1q21 copy number. We evaluated PSMB4 and PSMD4 mRNA and protein expression levels in a 1q21 wild-type MM cell line (OCI-MY5) and a panel of MM cell lines carrying 1q21+. Our results showed that PSMB4 and PSMD4 expression levels were higher in cell lines with Amp1q, following a 1q21 copy number fashion. Subsequently, we assessed the role of PSMB4 and PSMD4 to the sensibility of PI bortezomib in two myeloma cell lines carrying 1q21+. Our results showed that bortezomib treatment downregulates the protein expression of PSMD4 while PSMB4 was unaffected. Moreover, the MTT viability test correlated with the anti-myeloma effect of bortezomib. Furthermore, we generated a JJN3 PSMB4 and PSMD4-knockdown MM cell line using short hairpin RNA (shRNA) lentivectors. An empty vector was used as a control plasmid. Cell viability and apoptosis assays were performed using MTT assay and Apo 2.7 staining. Our functional studies showed that shPSMB4 and shPSMD4 decreased MM cell viability when treated with PI. Moreover, both shPSMB4 and shPSMD4 knockdown cells showed elevated levels of polyubiquitylated proteins, indicating blockade of proteasome-mediated protein degradation. In conclusion, our study identified proteasome subunits PSMB4 and PSMD4 to be significantly upregulated in MM patients carrying 1q21+, correlated with 1q21 copy number but not with disease stage. Therefore, targeting PSMB4 and PSMD4 could be a strategy to treat MM patients with 1q21+.

Evaluation of Daratumumab for the Treatment of Multiple Myeloma in Patients with Renal Insufficiency: A Systematic Review and Meta-Analysis

Introduction: Renal insufficiency (RI) is a common feature of multiple myeloma (MM). The relative risk (RR) of disease progression or death in patients with RI was higher than those without. RI increases risk of early death and affects disease management in multiple ways in MM, as it may complicate treatment options and dosing, and render patients more susceptible to infections and prolonged hospitalizations. Therefore, there is an urgent need to figure out the most effective regimen to treat MM patients with RI. But according to our knowledge, no head-to-head trial or meta-analysis has been conducted to determine which regimen would be the best choice for those patients. Daratumumab, an IgG1κ human monoclonal antibody that targets CD38, has shown durable responses and a favorable safety profile in both heavily pretreated patients with relapsed/refractory MM (RRMM) as monotherapy or combined with other agents and patients with newly diagnosed MM (NDMM). Pharmacokinetic analyses suggest that no clinically significant differences were found in patients with normal or impaired renal function following exposure to daratumumab, but the available data on efficacy of MM patients with RI are limited. Thus, to generate the efficacy evidence in MM patients with RI of Daratumumab among currently available agents, we conduct this meta-analysis regarding comparative efficacy of treatments for multiple myeloma patients with renal insufficiency, and compare those of MM with RI with those of MM without RI. Methods and methodology: A comprehensive literature search on 3 databases (PubMed, EMBASE and Cochrane Library) was performed from inception of each database to March 30, 2022. In addition, we performed a search of the gray literature through manual hand search of conference abstracts and proceedings of the American Society of Hematology, American Society of Clinical Oncology, European Hematology Association, European Myeloma Network and European Society for Medical Oncology from 2018 to 2022. A total of 8 studies including 4576 patients were included in this study. 2388 were in the Dara group and 2188 were in the control group. HR of OS, PFS and MRD negativity rate were computed by using a fixed-effect model by RevMan v.5.4. Results: Among the included studies which conducted in the NDMM patients, MAIA and ALCYONE studies reported mature median OS data. The meta-analysis of these two studies showed the addition of Daratumumab to backbone regimens in transplant-ineligible NDMM with RI significantly improved the OS (pooled HR, 0.63; 95%CI, 0.48-0.82; P = .0007). Similarly, Daratumumab addition to backbone regimens in RRMM patients with RI decreased the risk of death (Pooled HR, 0.68; 95% CI, 0.51-0.92; P = .01). In the meta-analysis, the addition of daratumumab to backbone regimens in NDMM among patients with RI was associated with improved PFS (pooled HR, 0.46; 95%CI, 0.36-0.57; P < .00001). Similar results were seen for RRMM patients with RI (pooled HR, 0.46; 95% CI, 0.37-0.58; P < .00001). 2 studies (Alcyone, Cassiopeia) conducted in NDMM patients had subgroup analysis of MRD- rate in MM with RI, the meta-analysis showed that the addition of Daratumumab to backbone regimens could lead to higher MRD- rate (Risk ratio, 1.72; 95% CI, 1.45-2.06; P＜.00001). Meta-analysis conducted among patients with non-RI showed that addition of Daratumumab to standard of care treatment significantly improved the OS (NDMM: pooled HR, 0.64; 95% CI, 0.50-0.82; P =.0005; RRMM: pooled HR, 0.73; 95% CI, 0.60-0.89; P = .001) and PFS (NDMM: pooled HR, 0.57, 95% CI, 0.47-0.69; P＜.00001; RRMM: pooled HR, 0.43; 95% CI, 0.37-0.49; P＜.00001) in both NDMM and RRMM. And MRD- rate was improved as well (NDMM: Risk ratio, 1.58; 95% CI, 1.36-1.83; P＜.00001). Through the test for outcomes of MM patients with RI and non-RI, the result showed that the addition of Daratumumab to the backbone regimens can improve the OS (NDMM: p=0.93; RRMM: p=0.70), PFS (NDMM: p=0.28; RRMM: p=0.55) and MRD- rate (NDMM: p=0.45) of MM patients with RI and non-RI in both NDMM and RRMM to the same extend. Discussion: This study suggests that the addition of Daratumumab to the backbone regimens can lead to longer OS, PFS and achieve higher MRD- rate among patients with RI and non-RI in the context of newly diagnosed and relapsed or refractory disease. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Pre-Clinical Efficacy of AB-101, an Allogeneic Cord-Blood Derived Natural Killer (NK) Cell Therapeutic Candidate, in Combination with Anti-CD38 Antibodies in Models of Multiple Myeloma

Introduction: AB-101 is a non-engineered, allogeneic, off-the-shelf, cryopreserved cord blood-derived natural killer (NK)-cell therapy in development as a cancer therapeutic. A highly scaled manufacturing process enables production of 1000s of doses of AB-101 from a single donor cord blood unit (CBU). AB-101 is derived from CBUs selected for KIR-B haplotype and natural high-affinity variant of CD16 (158V/V), which are associated with improved anti-tumor activity and ADCC enhancement, resulting in a highly active NK cell product without the requirement for additional engineering. We are developing AB-101 for combination with monoclonal antibodies (mAbs) to enhance antibody dependent cellular cytotoxicity (ADCC) in patients, initially in an ongoing Phase I clinical trial for NHL. To further develop AB-101 as an ADCC enhancer, we assessed anti-tumor activity in combination with CD38 mAb, against multiple myeloma (MM) cell lines. CD38 is a transmembrane glycoprotein that is uniformly and highly upregulated on MM cells. Anti-CD38 mAbs exert anti-tumor activity against MM through ADCC and other mechanisms. NK cells play a key role in ADCC responses through CD16 receptor signaling. However, the majority of NK cells express CD38 and are depleted by therapeutic CD38 mAbs which could limit their therapeutic efficacy. Combining NK cell therapies with anti-CD38 mAbs, thus necessitates CD38 knockout to prevent fratricide. AB-101 has a naturally low percent and intensity of CD38 expression. Here we present data demonstrating that AB-101 are resistant to anti-CD38 mAb-induced fratricide and can elicit significant ADCC against MM cell lines both in vitro and in vivo. Since anti-CD38 mAbs are combined with glucocorticoids in the clinic, we assessed the impact of dexamethasone and methylprednisolone on ADCC by AB-101. Here we report robust ADCC following treatment of AB-101 with glucocorticoids. Methods: AB-101 was screened for CD38 expression and incubated with anti-CD38 mAb - daratumumab or hIgG1 control (300 - 0.41 µg/ml) for 4 hours to assess fratricide. In vitro ADCC assays were performed at various effector to target ratios against control (Daudi and K562) and MM cell lines (NCI-H929, RPMI 8226, MM.1S and MM.1R) using 2 µg/ml of daratumumab or hIgG1. To study the effect of glucocorticoids, AB-101 was cultured in various concentrations of dexamethasone and methylprednisolone for 48 hours in the presence of 50 or 500 IU/ml of IL-2, prior to ADCC assay. In vivo efficacy of AB-101 in combination with daratumumab was assessed in the intraperitoneal (IP) MM.1S-Luc xenograft model in NSG mice (Figure 1A). Daratumumab and AB-101 were administered by IP injection. Tumor burden was assessed by bioluminescent imaging (BLI). Results: AB-101 was over 98% CD56+/CD3- with 87% CD56+/CD16+ population. Only 22% of GMP drug product were CD38+ with low intensity of expression compared to peripheral blood NK cells (~88%). In the presence of daratumumab AB-101 viability was unaltered compared to hIgG1 control demonstrating resistance to fratricide. Daratumumab enhanced ADCC potential of AB-101 against MM cell lines and Daudi in in vitro. ADCC against MM lines and Daudi did not decrease on exposure to glucocorticoids compared to no treatment group. In vivo anti-tumor efficacy, as evidenced by reduction in BLI signal, was observed in the MM.1S model in AB-101 + daratumumab groups compared to daratumumab and AB-101 alone (Figure 1B). AB-101 + daratumumab (1 and 3mpk) led to 98 and 99% tumor growth inhibition (TGI), respectively, relative to no treatment. Daratumumab monotherapy at 1 and 3mpk showed 21% and 87% TGI respectively, and AB-101 showed 16% TGI relative to no treatment. Conclusions: AB-101 has high and consistent expression of CD16 and low CD38 expression and is resistant to daratumumab induced fratricide and hence can be combined with daratumumab without additional engineering such as CD38 knockout. Daratumumab is combined in the clinic with glucocorticoids, immunomodulatory drugs (IMiDs) and proteosome inhibitors (PI). While IMiDs and PIs are reported to enhance NK cell function, glucocorticoids have been shown to diminish NK cell cytotoxicity. Data presented here suggests that ADCC potential of AB-101 is not negatively impacted by glucocorticoids. Taken together, the in vitro and in vivo data supports further clinical development of AB-101 in combination with daratumumab to treat MM patients. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Evaluation of Repotrectinib's Anti-MM Effects in Combination with Bortezomib, Carfilzomib, Cyclophosphamide, and Dexamethasone in Vitro and Ex Vivo

Introduction: The proteasome inhibitors bortezomib and carfilzomib are anticancer drugs which are indicated for the treatment of multiple myeloma (MM). The alkylating agent cyclophosphamide is also an effective drug against MM. Glucocorticoids including dexamethasone induce MM cell apoptosis and are effective in MM. However, the disease remains incurable with currently available therapies. Repotrectinib (Turning Point Therapeutics, San Diego, CA) is a novel next-generation ROS1/TRK/ALK-tyrosine kinase inhibitor (TKI). Repotrectinib also inhibits the Janus kinase (JAK) 2 and indirectly down-regulates STAT5 phosphorylation in the SET2 cancer cell line harboring a JAK2 V617F tyrosine kinase mutation (Drilon et al 2018). We have previously shown the preclinical anti-MM effects of JAK1/2 inhibitors in combination with corticosteroids and other anti-MM drugs in vitro and in vivo. Although activation of JAK2 and PI3K signaling is often detected in hematological malignancies, there is no data regarding the potential anti-MM effects of repotrectinib alone or in combination with other anti-MM drugs. Thus, we evaluated the anti-myeloma effects of repotrectinib alone and in combination with bortezomib, carfilzomib, cyclophosphamide, and dexamethasone in vitro using MM cell lines and ex vivo using the human MM xenograft model LAG- λ1. Methods: The human MM cell lines U266, RPMI8226 and MM1S were obtained from ATCC. MCs were isolated from MM patients' BM aspirates. Cell viability was quantified using the MTS assay. For the ex vivo studies, cells were isolated from the MM xenograft LAG-λ1 after it was established in SCID mice. We determined the IC curves using the MM cell lines and fresh BMMCs from 6 MM patients. Next, we combined repotrectinib with other active anti-MM drugs (carfilzomib, bortezomib, cyclophosphamide, and dexamethasone) using these same three MM cell lines and BMMCs from 6 MM patients to evaluate the anti-proliferative effects of these combinations. Results: We first evaluated the anti-MM effects of repotrectinib in combination with bortezomib or carfilzomib by using the MM1S, RPMI-8226, and U266 MM cell lines. Specifically, the results with repotrectinib in combination with carfilzomib showed enhanced anti-MM effects when compared to repotrectinib alone or carfilzomib alone. We also determined the anti-MM effects of repotrectinib alone and in combination with carfilzomib by using isolated LAG- λ1 MM xenograft cells. Repotrectinib alone inhibited tumor cell proliferation in a concentration dependent manner (IC50 4.5 µM) and in combination with carfilzomib synergistically inhibited LAG- λ1 MM tumor cell proliferation. These results were not seen when it was combined with bortezomib. We studied BMMCs from 3 PD and 3 CR patients using a cell proliferation assay. The results showed that repotrectinib alone minimally inhibited MM tumor cell proliferation among patients with PD. Repotrectinib combined with carfilzomib showed enhanced anti-proliferative effects compared with either drug alone among BMMCs from PD patients but not those in CR. In contrast, bortezomib did not show this enhanced anti-proliferative effect. We also determined the anti-MM effects of repotrectinib in combination with cyclophosphamide using ex vivo and in vivo studies. The results showed that repotrectinib in combination with cyclophosphamide enhanced the inhibition of LAG- λ1 MM tumor cell and fresh MM BMMC proliferation compared with repotrectinib or cyclophosphamide alone. We further determined the anti-MM effects of repotrectinib in combination with dexamethasone. The results showed that repotrectinib in combination with dexamethasone reduced LAG- λ1 MM cell proliferation in a concentration dependent manner and enhanced inhibition in 2 PD patients' samples but not the other PD patient or 3 CR patients' samples. Summary Single agent repotrectinib decreased MM tumor cell proliferation in all 3 MM cell lines and reduced LAG- λ1 tumor cell proliferation ex vivo. Repotrectinib also reduced proliferation of BMMCs from MM patients with PD but not those in CR. Repotrectinib in combination with carfilzomib, cyclophosphamide or dexamethasone showed enhanced anti-proliferative effects compared with the drugs alone. The results suggest that this kinase inhibitor may have activity in treating MM patients in combination with other active anti-MM agents. Further evaluation is warranted.

High hospital-related burden of treatment for multiple myeloma patients: outcomes of a feasibility study using reimbursement data from electronic health records

ObjectiveMultiple Myeloma (MM) is an incurable plasma cell malignancy with intensive and prolonged treatment, presumably causing a considerable burden of treatment on patients. The concept of treatment burden is defined as the work of being a patient and its impact on well-being. However, there is no consistent definition and method to measure treatment burden in patients with MM. Therefore, the aim of this study was to determine the burden of treatment in MM patients and to compare it to Chronic Lymphoid Leukaemia (CLL). MethodsWe conducted a retrospective analysis using reimbursement data from electronic health records (EHR) to calculate treatment burden. Treatment burden was defined as the number of hospital visits on unique days. After data clearance, data were analysed using descriptive statistics comparing treatment burden between different types of visits, age groups, years since diagnosis, and between MM and CLL patients. ResultsReimbursement data of 176 MM and 173 CLL patients were included in the analysis, which showed i) highest treatment burden in the first year immediately after diagnosis, ii) small differences between age groups (total visits year 0: 68.2 ≤ 65/63.8>65 years in MM and 21.7 ≤ 65/25.6>65 years in CLL), iii) higher treatment rates with more treatment burden in MM patients compared to CLL. Conclusion: EHR reimbursement data provided useful information to measure treatment burden and showed higher burden in MM patients compared to CLL patients. With improving survival, measuring burden of treatment in clinical practice in patients with MM contributes to decreasing treatment burden and more patient-centred care. ConclusionEHR reimbursement data provided useful information to measure treatment burden and showed higher burden in MM patients compared to CLL patients. With improving survival, measuring burden of treatment in clinical practice in patients with MM contributes to decreasing treatment burden and more patient-centred care. Public interest summaryAs in other malignant diseases, new treatment options dramatically improved survival in patients with multiple myeloma (MM). As a consequence, MM patients undergo intensive and intermittent periods of treatment, which causes a considerable burden of treatment. In this study we used data retrieved from Electronic Health Records (EHR) from 176 patients with MM and 173 patients with chronic lymphoid leukaemia (CLL) (both haematological diseases), to measure and analyse patients’ burden of undergoing treatment. The results showed that EHR-data provided useful information to determine treatment burden in patients and that treatment burden is considerably higher in patients with MM compared to CLL patients. Further development of this method makes it possible to frequently monitor and evaluate treatment burden. Eventually, this may help health care professionals to provide more patient-centred care and improve quality of life by reducing treatment burden.