Pembrolizumab plus pomalidomide and dexamethasone for patients with relapsed or refractory multiple myeloma (KEYNOTE-183): a randomised, open-label, phase 3 trial

Multiple myeloma and the potential of new checkpoint inhibitors for immunotherapy

Multiple myeloma (MM), a cancer of the bone marrow, is categorized as the second most common hematological malignancy of adults in the Western world. Despite dramatic improvements in immunotherapies in the field of cancers, MM immunotherapy has not been promising until now. Recent clinical studies of immune checkpoint inhibitor therapy, either alone or in combination with anticancer drugs, showed excessive side effects or low efficacy, particularly in advanced MM patients. In this context, lymphocyte levels of exhaustion markers play a pivotal role in the MM tumor microenvironment (TME). Hence in the present review, the mechanisms relevant to MM of five inhibitory molecules including T-cell immunoreceptor with Ig and ITIM domains (TIGIT), T-cell immunoglobulin, and mucin domain 3 (Tim-3), lymphocyte activation gene-3 (LAG-3), V-domain Ig Suppressor of T-cell activation and killer immunoglobulin-like receptors along with bispecific T-cell antibodies (BsAbs) will be discussed. Further, we summarized the underlying biology of these checkpoints in cancer and their rapidly emerging role in pathways in MM along with presenting recent clinical trials in context.

The role of immune checkpoint inhibitors: Variable number of tandem repeat (VNTR) polymorphism in the second exon of the P-selectin glycoprotein ligand-1 (PSGL-1) gene polymorphism in multiple myeloma

Somatic mutations and polymorphisms may play a role in multiple myeloma (MM) susceptibility and survival. One of the immune checkpoint inhibitors is P-selectin glycoprotein ligand-1 (PSGL-1); the majority of tumor-infiltrating leukocytes express PSGL-1, causing T cell and immune inhibition via PSGL-1 mediator molecules. We aimed to investigate the effect of variable number of tandem repeat (VNTR) polymorphism in the second exon of the PSGL-1 gene on MM susceptibility, response to treatment and survival in our patient group. A total of 238 patients diagnosed with MM between January 2010 and January 2021 and 162 healthy individuals as a control group were included in this cross-sectional study. The genotypes of the VNTR polymorphism in the second exon of the PSGL-1 gene were statistically compared between patients and healthy controls; the statistically significant effects of the genotypes on response to first-line treatment and survival were examined. The AC genotype was significantly higher in healthy controls compared to patients diagnosed with MM (p < 0.001). The median PFS in patients with AA/AB/AC was 56 months, while it was 100 months in patients with BB/CC. The hazard ratio of 1.34 for PFS was found to be clinically significant and having the BB/CC genotype could provide a longer PFS compared to others, but it was not statistically significant due to the sample size. Our study results will shed light on new study plans in terms of immune checkpoint target therapies among conventional treatment preferences in MM.

Nivolumab, Pomalidomide, and Elotuzumab Combination Regimens for Treatment of Relapsed and Refractory Multiple Myeloma: Results from the Phase 3 CheckMate 602 Study

BACKGROUND

Preclinical studies suggest that combining nivolumab, a programmed death-1 (PD-1) immune checkpoint inhibitor, with pomalidomide/dexamethasone (Pd) with or without elotuzumab, an antisignaling lymphocytic activation molecule F7 monoclonal antibody, may improve multiple myeloma (MM) treatment efficacy.

PATIENTS AND METHODS

The phase 3 CheckMate 602 study (NCT02726581) assessed the efficacy and safety of nivolumab plus pomalidomide/dexamethasone (NPd) and NPd plus elotuzumab (NE-Pd). Eligible patients (aged ≥ 18 years) had measurable MM after ≥ 2 prior lines of therapy, that included an immunomodulatory drug (IMiD) and proteasome inhibitor (PI), each for ≥ 2 consecutive cycles, alone or combined, and were refractory to their last line of therapy. Patients were randomized 3:3:1 to receive NPd, Pd, or NE-Pd. The primary endpoint was progression-free survival (PFS); overall response rate (ORR) was a key secondary endpoint.

RESULTS

At a median follow-up of 16.8 months, PFS was similar between treatment arms (Pd, 7.3 months [95% CI, 6.5-8.4]; NPd, 8.4 months [95% CI, 5.8-12.1]; NE-Pd, 6.3 months [95% CI, 2.4-11.1]). ORR was similar in the Pd (55%), NPd (48%), and NE-Pd (42%) arms. Nivolumab-containing arms were associated with a less favorable safety profile versus Pd, including a higher rate of thrombocytopenia (NPd, 25.0%; NE-Pd, 16.7%; Pd, 15.7%), any-grade immune-mediated adverse events (NPd, 13.9%; NE-Pd, 16.7%; Pd, 2.9%), and adverse events leading to discontinuation (NPd, 25.0%; NE-Pd, 33.3%; Pd, 18.6%). No new safety signals were identified.

CONCLUSION

CheckMate 602 did not demonstrate clinical benefit of nivolumab (+/- elotuzumab) plus Pd versus Pd for patients with relapsed/refractory MM (RRMM).

Bispecific antibodies in the treatment of multiple myeloma

The treatment paradigm in myeloma is constantly changing. Upfront use of monoclonal antibodies like daratumumab along with proteasome inhibitors (PI)s, and immune modulators (IMiD)s have significantly improved survival and outcomes, but also cause unique challenges at the time of relapse. Engaging immune T cells for tumour cell kill with chimeric antigenic T-cell (CAR T-cell) therapy and bispecific antibodies have become important therapeutic options in relapsed multiple myeloma. Bispecific antibodies are dual antigen targeting constructs that engage the T cells to plasma cells through various target antigens like B-cell membrane antigen (BCMA), G-protein-coupled receptor family C group 5 member D (GPRC5D), and Fc receptor-homolog 5 (FcRH5). These agents have proven to induce deep and durable responses in heavily pre-treated myeloma patients with a predictable safety profile and the ease of off-the-shelf availability. Significant research is ongoing to overcome resistance mechanisms like T cell exhaustion, target antigen mutation or loss and high disease burden. Various trials are also studying these agents as first line options in the newly diagnosed setting. These agents play an important role in the relapsed setting, and efforts are underway to optimize their sequencing in the myeloma treatment algorithm.

A Pilot Study of the CD38 Antagonist Daratumumab in Patients with Metastatic Renal Cell Carcinoma or Muscle-Invasive Bladder Cancer

PURPOSE

We performed a pilot study of daratumumab (an mAb directed against CD38) in muscle-invasive bladder cancer (MIBC) and treatment-refractory metastatic renal cell carcinoma (mRCC).

EXPERIMENTAL DESIGN

Patients with MIBC underwent baseline transurethral resection of the bladder tumor followed by four weekly doses of daratumumab prior to cystectomy. Patients with mRCC underwent baseline and sequential biopsies after eight weekly doses. The primary endpoint was safety. The secondary endpoints were pathologic complete response rate for the MIBC cohort and objective response rate and progression-free survival for the mRCC cohort. Exploratory analyses included immune monitoring and overall survival. A Bayesian sequential monitoring design for toxicity was used for excessive toxicity.

RESULTS

In both the MIBC (n = 8) and mRCC (n = 8) cohorts, no toxicity events were encountered. In the MIBC cohort, one patient experienced pathologic complete response rate. In the mRCC cohort, no objective responses were reported, and the median progression-free survival was 1.5 months (95% confidence interval, 1.1-1.8 months). Immune monitoring found significant reductions in NK cells in circulation in both cohorts after treatment. In the tissue analysis, IHC found evidence of diminished CD38 presence in mRCC with treatment, whereas the baseline levels in MIBC were low.

CONCLUSION

Treatment with daratumumab was safe. No signal of efficacy was detected in mRCC, and conclusions on the activity in MIBC were limited. Evidence of daratumumab targeting CD38 was detected in circulating immune cells and within the tumor microenvironment of mRCC and MIBC.

SIGNIFICANCE

In this prospective clinical trial of daratumumab, treatment in patients with MIBC and mRCC was safe. Limited efficacy was observed. Treatment with daratumumab resulted in CD38-expressing immune cell subsets to be targeted both in circulation and within the tumor microenvironment.

Updates on Therapeutic Strategies in the Treatment of Relapsed/Refractory Multiple Myeloma

Multiple myeloma is a heterogeneous condition characterized by the proliferation of monoclonal B-cells, for which there is currently no curative treatment available. Relapses are, unfortunately, common after first-line treatment. While the prognosis for relapsed refractory multiple myeloma is generally poor, advances in the treatment of relapsed or refractory multiple myeloma offer hope. However, the expansion of effective options in targeted treatment offers renewed optimism and hope that patients who fail on older therapies may respond to newer modalities, which are often used in combination. We review currently approved and novel investigational agents classified by mechanisms of action, efficacy, approved setting, and adverse events. We delve into future directions of treatment for relapsed/refractory multiple myeloma, reviewing novel agents and therapeutic targets for the future.

The Evolving Role of Checkpoint Inhibitors in Multiple Myeloma

Multiple myeloma (MM) is a plasma cell dyscrasia characterized by production of abnormal levels of a monoclonal immunoglobulin or plasma cell deposition that leads to end organ destruction. The disease remains incurable despite advances in combination treatments with classes of medications that include proteosome inhibitors, immunomodulating agents, monoclonal antibodies, small molecule inhibitors, alkylating agents, T-cell-based immunotherapies, and others. Checkpoint inhibitors (CKP-I), though showing robust efficacy in solid tumor and lymphoma, have had limited success as single agents in the treatment of MM. Furthermore, early FDA holds on trials involving CKP-I in myeloma led to diminished enrollment and data on its potential use. Nevertheless, clearer understanding of the mechanisms of immune dysregulation and unique bone marrow biology in the pathophysiology of MM have opened the opportunity for future uses of CKP-I in multiple myeloma. Herein we provide a comprehensive review of the immunologic basis of multiple myeloma, preclinical and published data from trials utilizing CKP-I in MM patients, and future targets in CKP-I development that may provide promising opportunities in the treatment of MM.

Immunomodulatory drugs: a promising clinical ally for cancer immunotherapy

While immunomodulatory imide drugs (IMiDs) have been authorised for treatment of haematological cancers for over two decades, the appreciation of their ability to stimulate antitumour T cell and natural killer (NK) cell responses is relatively recent. Clinical trial data increasingly show that targeted immunotherapies, such as antibodies, T cells, and vaccines, improve outcomes when delivered in combination with the IMiD derivatives lenalidomide or pomalidomide. Here, we review these clinical data to highlight the relevance of IMiDs in combinatorial immunotherapy for both haematological and solid tumours. Further research into the molecular mechanisms of IMiDs and an increased understanding of their immunomodulatory effects may refine the specific applications of IMiDs and improve the design of future clinical trials, moving IMiDs to the forefront of combinatorial cancer immunotherapy.

CREB1 promotes expression of immune checkpoint HLA-E leading to immune escape in multiple myeloma

Multiple myeloma (MM) cells effectively escape anti-tumoral immunity to survive in the tumor microenvironment (TME). Herein, we identify non-classical major histocompatibility complex (MHC) class I molecule HLA-E as a major contributing factor in immune escape. Clinically, HLA-E expression correlates with aggressive disease features such as t(4;14) and CD56 expression and is induced by IFN-gamma (IFN-γ) in the TME. We discovered that HLA-E is regulated by cAMP responsive element binding protein 1 (CREB1) transcription factor by direct promoter binding; genomic and pharmacological inhibition of CREB1 reduced HLA-E levels even in the presence of IFN-γ or IFN-γ activating agents, such as immunomodulatory drugs and panobinostat. HLA-E binds to natural killer group 2A (NKG2A), delivering an inhibitor signal to natural killer (NK) cells. Treatment with a CREB1 inhibitor was able to restore NK cell-mediated cytotoxicity against MM cell lines and patient samples. In conclusion, our results strongly demonstrate that CREB1 inhibition promotes anti-tumoral immunity in MM by limiting HLA-E expression and enhancing the activity of NK cells.

Advances and clinical applications of immune checkpoint inhibitors in hematological malignancies

Immune checkpoints are differentially expressed on various immune cells to regulate immune responses in tumor microenvironment. Tumor cells can activate the immune checkpoint pathway to establish an immunosuppressive tumor microenvironment and inhibit the anti-tumor immune response, which may lead to tumor progression by evading immune surveillance. Interrupting co-inhibitory signaling pathways with immune checkpoint inhibitors (ICIs) could reinvigorate the anti-tumor immune response and promote immune-mediated eradication of tumor cells. As a milestone in tumor treatment, ICIs have been firstly used in solid tumors and subsequently expanded to hematological malignancies, which are in their infancy. Currently, immune checkpoints have been investigated as promising biomarkers and therapeutic targets in hematological malignancies, and novel immune checkpoints, such as signal regulatory protein α (SIRPα) and tumor necrosis factor-alpha-inducible protein 8-like 2 (TIPE2), are constantly being discovered. Numerous ICIs have received clinical approval for clinical application in the treatment of hematological malignancies, especially when used in combination with other strategies, including oncolytic viruses (OVs), neoantigen vaccines, bispecific antibodies (bsAb), bio-nanomaterials, tumor vaccines, and cytokine-induced killer (CIK) cells. Moreover, the proportion of individuals with hematological malignancies benefiting from ICIs remains lower than expected due to multiple mechanisms of drug resistance and immune-related adverse events (irAEs). Close monitoring and appropriate intervention are needed to mitigate irAEs while using ICIs. This review provided a comprehensive overview of immune checkpoints on different immune cells, the latest advances of ICIs and highlighted the clinical applications of immune checkpoints in hematological malignancies, including biomarkers, targets, combination of ICIs with other therapies, mechanisms of resistance to ICIs, and irAEs, which can provide novel insight into the future exploration of ICIs in tumor treatment.

Advancements in microenvironment-based therapies: transforming the landscape of multiple myeloma treatment

Multiple myeloma (MM) is the most prevalent malignant monoclonal disease of plasma cells. There is mounting evidence that interactions with the bone marrow (BM) niche are essential for the differentiation, proliferation, survival, migration, and treatment resistance of myeloma cells. For this reason, gaining a deeper comprehension of how BM microenvironment compartments interact with myeloma cells may inspire new therapeutic ideas that enhance patient outcomes. This review will concentrate on the most recent findings regarding the mechanisms of interaction between microenvironment and MM and highlight research on treatment targeting the BM niche.

Pembrolizumab and low-dose, single-fraction radiotherapy for patients with relapsed or refractory multiple myeloma: a prospective, single-centre, single-group, open-label, phase 2 pilot trial in the USA

BACKGROUND

Currently, the use of radiotherapy alone for people with multiple myeloma is limited to palliation of pain, pending fracture, and control of spinal-cord compression. Single immune-checkpoint inhibitors, such as anti-programmed death-1 (anti-PD1), have not been successful. We aimed to evaluate the activity and safety of the combination of pembrolizumab and low-dose, single-fraction, hypofractionated radiotherapy to treat patients with relapsed or refractory multiple myeloma.

METHODS

For this prospective, single-centre, single-group, open-label, phase 2 trial, we recruited patients with relapsed or refractory multiple myeloma from the Winship Cancer Institute (Emory University, Atlanta, GA, USA). Key inclusion criteria were aged 18 years or older, Eastern Cooperative Oncology Group (ECOG) performance score of 0 or 1, relapsed or refractory multiple myeloma as indicated by progression under International Myeloma Working Group (IMWG) criteria, and adequate candidacy for both pembrolizumab and radiotherapy. Baseline and post-treatment assessments were serial bone-marrow biopsy, peripheral blood collections, staging, serial serum and urine paraprotein analysis, serial PET-CT imaging, and a physical examination. On day 1, patients received hypofractionated 8 gray in 1 fraction (8 Gy/1 fx) radiotherapy to either symptomatic or progressing extra-osseous or osseous myeloma sites. Patients also received pembrolizumab (200 mg/kg intravenously) on day 2 or 3, then once every 3 weeks (±7 days) for 2 years or until progressive disease, unacceptable toxicity, withdrawal of consent, loss to follow-up, or death. Dose reduction and interruptions were not allowed. The primary outcome was acute toxicity defined as grade 3 or worse toxicity at 3 months within the radiated site when used in combination with pembrolizumab. All patients were analysed per protocol and included in safety analyses. This trial is registered on ClinicalTrials.gov (NCT03267888); it is completed and closed to accrual.

FINDINGS

32 patients were screened between June 1, 2018, and Sept 2, 2022, and 25 were enrolled in the trial and treated on protocol. Of the 25 treated patients, 11 (44%) were female and 14 (56%) were male. 19 (76%) patients were White and six (24%) were Black or African American. Toxicity, as the primary outcome, was deemed to be acceptable as no grade 4 or 5 adverse events were observed. At 3-month follow-up, eight (32%) of 25 patients had treatment benefit (one had stable disease, three had partial response, two had very good partial response, and two had complete response). There was no grade 3 or worse radiation-related toxicity within irradiated volumes. One (4%) patient of the 25 who received combination treatment had a grade 3 pembrolizumab-related adverse event. There were no treatment-related deaths.

INTERPRETATION

Combination treatment of low-dose, single-fraction radiotherapy with pembrolizumab was safe, with early promise of response activity. Our approach could be an option for patients with relapsed or refractory multiple myeloma who have not responded to previous treatment. Larger trials to substantiate our findings are needed.

FUNDING

Merck Sharp & Dohme.

T-cell exhaustion in multiple myeloma

INTRODUCTION

Chimeric Antigen Receptor (CAR) T-cells and Bispecific Antibodies (BsAb) are the leading platforms for redirecting the immune system against cells expressing the specific antigen, revolutionizing the treatment of hematological malignancies, including multiple myeloma (MM). In MM, drug-resistant relapses are the main therapy-limiting factor and the leading cause of why the disease is still considered incurable. T-cell-engaging therapies hold promise in improving the treatment of MM. However, the effectiveness of these treatments may be hindered by T-cell fitness. T-cell exhaustion is a condition of a gradual decline in effector function, reduced cytokine secretion, and increased expression of inhibitory receptors due to chronic antigen stimulation.

AREAS COVERED

This review examines findings about T-cell exhaustion in MM in the context of T-cell redirecting BsAbs and CAR-T treatment.

EXPERT OPINION

The fitness of T-cells has become an important factor in the development of T-cell redirecting therapies. The way T-cell exhaustion relates to these therapies could affect the further development of CAR and BsAbs technologies, as well as the strategies used for clinical use. Therefore, this review aims to explore the current understanding of T-cell exhaustion in MM and its relationship to these therapies.

Patient-Reported Outcomes in Phase 3 Clinical Trials for Blood Cancers: A Systematic Review

Importance

Published research suggests that patient-reported outcomes (PROs) are neither commonly collected nor reported in randomized clinical trials (RCTs) for solid tumors. Little is known about these practices in RCTs for hematological malignant neoplasms.

Objective

To evaluate the prevalence of PROs as prespecified end points in RCTs of hematological malignant neoplasms, and to assess reporting of PROs in associated trial publications.

Evidence Review

All issues of 8 journals known for publishing high-impact RCTs (NEJM, Lancet, Lancet Hematology, Lancet Oncology, Journal of Clinical Oncology, Blood, JAMA, and JAMA Oncology) between January 1, 2018, and December 13, 2022, were searched for primary publications of therapeutic phase 3 trials for adults with hematological malignant neoplasms. Studies that evaluated pretransplant conditioning regimens, graft-vs-host disease treatment, or radiotherapy as experimental treatment were excluded. Data regarding trial characteristics and PROs were extracted from manuscripts and trial protocols. Univariable analyses assessed associations between trial characteristics and PRO collection or reporting.

Findings

Ninety RCTs were eligible for analysis. PROs were an end point in 66 (73%) trials: in 1 trial (1%) as a primary end point, in 50 (56%) as a secondary end point, and in 15 (17%) as an exploratory end point. PRO data were reported in 26 of 66 primary publications (39%): outcomes were unchanged in 18 and improved in 8, with none reporting worse PROs with experimental treatment. Trials sponsored by for-profit entities were more likely to include PROs as an end point (49 of 55 [89%] vs 17 of 35 [49%]; P < .001) but were not significantly more likely to report PRO data (20 of 49 [41%] vs 6 of 17 [35%]; P = .69). Compared with trials involving lymphoma (18 of 29 [62%]) or leukemia or myelodysplastic syndrome (18 of 28 [64%]), those involving plasma cell disorders or multiple myeloma (27 of 30 [90%]) or myeloproliferative neoplasms (3 of 3 [100%]) were more likely to include PROs as an end point (P = .03). Similarly, compared with trials involving lymphoma (3 of 18 [17%]) or leukemia or myelodysplastic syndrome (5 of 18 [28%]), those involving plasma cell disorders or multiple myeloma (16 of 27 [59%]) or myeloproliferative neoplasms (2 of 3 [67%]) were more likely to report PROs in the primary publication (P = .01).

Conclusions and Relevance

In this systematic review, almost 3 of every 4 therapeutic RCTs for blood cancers collected PRO data; however, only 1 RCT included PROs as a primary end point. Moreover, most did not report resulting PRO data in the primary publication and when reported, PROs were either better or unchanged, raising concern for publication bias. This analysis suggests a critical gap in dissemination of data on the lived experiences of patients enrolled in RCTs for hematological malignant neoplasms.

Next-Generation Therapies for Multiple Myeloma

Recent therapeutic advances have significantly improved the outcome for patients with multiple myeloma (MM). The backbone of successful standard therapy is the combination of Ikaros degraders, glucocorticoids, and proteasome inhibitors that interfere with the integrity of myeloma-specific superenhancers by directly or indirectly targeting enhancer-bound transcription factors and coactivators that control expression of MM dependency genes. T cell engagers and chimeric antigen receptor T cells redirect patients' own T cells onto defined tumor antigens to kill MM cells. They have induced complete remissions even in end-stage patients. Unfortunately, responses to both conventional therapy and immunotherapy are not durable, and tumor heterogeneity, antigen loss, and lack of T cell fitness lead to therapy resistance and relapse. Novel approaches are under development to target myeloma-specific vulnerabilities, as is the design of multimodality immunological approaches, including and beyond T cells, that simultaneously recognize multiple epitopes to prevent antigen escape and tumor relapse.

Evaluation of time-to-onset and outcome of cardiac adverse events related to pembrolizumab using post-marketing surveillance in Japanese patients

BACKGROUND

Pembrolizumab has been widely used in patients since its release, but information on cardiac Adverse Events (AEs) related to pembrolizumab remains lacking, particularly in Japanese populations.

OBJECTIVES

This study aims to evaluate time to onset, incidence rates, and outcomes for pembrolizumab-induced cardiac AEs in patients with cancer using the Japanese Adverse Drug Event Report database.

METHODS

We analysed data for the period from April 2004 to March 2022. Data on cardiac AEs were extracted and relative risks of AEs were estimated using the reporting odds ratio.

RESULTS

We analysed 2,021,907 reports and identified 15,306 reports of AEs caused by pembrolizumab. Of these, 399 cardiac AEs were associated with pembrolizumab. Signals were detected for six cardiac AEs: myocarditis, immune-mediated myocarditis, pericardial effusion, cardiac tamponade, pericarditis, and pericarditis malignant. A histogram of median times to onset showed occurrence from 33 (21-97) days for immune-mediated myocarditis to 138 (67-168) days for pericarditis malignant, but some cases occurred even more than 1 year after the start of administration. Among these, myocarditis was the most frequently reported (27.1%), with fatal cases also reported.

CONCLUSION

This study focused on cardiac AEs caused by pembrolizumab as post-marketing AEs. Patients should be monitored not only at the time of administration, but also over time for signs of these AEs, especially myocarditis, as some patients may have serious outcomes.

Immune Checkpoint Inhibitors and Cardiotoxicity: A Comparative Meta-Analysis of Observational Studies and Randomized Controlled Trials

BACKGROUND

Immune checkpoint inhibitors (ICIs) have uncommon associations with cardiotoxicity, yet these cardiotoxic effects are associated with high mortality. An accurate assessment of risk for cardiotoxicity is essential for clinical decision-making, but data from randomized controlled trials often differ from real-world observational studies.

METHODS AND RESULTS

A systematic search of PubMed, Embase, Cochrane Library, and Scopus was performed, including phase II and III randomized controlled trials (RCTs) and observational studies (OSs) reporting myocarditis or pericardial disease, myocardial infarction, or stroke with an immunotherapy. Odds ratios (ORs) were used to pool results between ICIs and other cancer therapy in RCTs and OSs. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline was followed. In total, 54 RCTs (N=38 264) and 24 OSs (N=12 561 455) were included. In RCTs, ICI use resulted in higher risk of myocarditis (OR, 3.55 [95% CI, 2.10-5.98]), pericardial disease (OR, 2.73 [95% CI, 1.57-4.77]), and myocardial infarction (OR, 1.83 [95% CI, 1.03-3.25]), compared with non-ICI (placebo or chemotherapy). In OSs, ICI use was not associated with myocarditis, pericardial disease, or myocardial infarction compared with controls; however, combination ICIs demonstrated higher risk of myocarditis compared with single ICI use (OR, 3.07 [95% CI, 1.28-7.39]). Stroke risk was not increased with use of ICIs in RCTs.

CONCLUSIONS

We demonstrated increased risk of ICI myocarditis, pericardial disease, and myocardial infarction in RCTs but not OSs. Results of this study suggest there are differences between ICI cardiotoxicity risk, possibly suggesting differences in diagnoses and management, in clinical trials versus the OSs.

CD8 effector T cells enhance teclistamab response in BCMA-exposed and -naïve multiple myeloma

ABSTRACT

Teclistamab, a B-cell maturation antigen (BCMA)- and CD3-targeting bispecific antibody, is an effective novel treatment for relapsed/refractory multiple myeloma (R/RMM), but efficacy in patients exposed to BCMA-directed therapies and mechanisms of resistance have yet to be fully delineated. We conducted a real-world retrospective study of commercial teclistamab, capturing both clinical outcomes and immune correlates of treatment response in a cohort of patients (n = 52) with advanced R/RMM. Teclistamab was highly effective with an overall response rate (ORR) of 64%, including an ORR of 50% for patients with prior anti-BCMA therapy. Pretreatment plasma cell BCMA expression levels had no bearing on response. However, comprehensive pretreatment immune profiling identified that effector CD8+ T-cell populations were associated with response to therapy and a regulatory T-cell population associated with nonresponse, indicating a contribution of immune status in outcomes with potential utility as a biomarker signature to guide patient management.

Association between sex and efficacy of immune checkpoint inhibitors: a systematic review and meta-analysis

Aim: To explore the association between sex and immune checkpoint inhibitors (ICIs). Materials & methods: We assessed the difference in survival outcomes from ICIs between sexes using an interaction test. Results: 108 studies representing 70,243 patients were included. In the first-line setting, the pooled interaction HR was 0.97 (95% CI: 0.91-1.04). In the subsequent-line setting, the pooled interaction HR was 0.85 (95% CI: 0.77-0.95). When ICIs were given as perioperative therapy or as systemic therapy in patients with positive PD-L1 expression, both men and women obtained equal survival benefits. Conclusion: Both sex, line of therapy, cancer (sub)type and PD-L1 status should be taken into account in the assessment of risk versus benefit when deciding to offer ICIs to patients.

Role of Immune Cells and Immunotherapy in Multiple Myeloma

The clinical signs of multiple myeloma, a plasma cell (PC) dyscrasia, include bone loss, renal damage, and paraproteinemia. It can be defined as the uncontrolled growth of malignant PCs within the bone marrow. The distinctive bone marrow milieu that regulates the progression of myeloma disease involves interactions between plasma and stromal cells, and myeloid and lymphoid cells. These cells affect the immune system independently or because of a complicated web of interconnections, which promotes disease development and immune evasion. Due to the importance of these factors in the onset of disease, various therapeutic strategies have been created that either target or improve the immunological processes that influence disease progression. The immune system has a role in the mechanism of action of multiple myeloma treatments. The main contributions of immune cells to the bone marrow microenvironment, as well as how they interact and how immune regulation might lead to therapeutic effects, are covered in this study.

CD200 genotype is associated with clinical outcome of patients with multiple myeloma

Immune dysfunction in patients with MM affects both the innate and adaptive immune system. Molecules involved in the immune response pathways are essential to determine the ability of cancer cells to escape from the immune system surveillance. However, few data are available concerning the role of immune checkpoint molecules in predicting the myeloma control and immunological scape as mechanism of disease progression. We retrospectively analyzed the clinical impact of the CD200 genotype (rs1131199 and rs2272022) in 291 patients with newly diagnosed MM. Patients with a CD200 rs1131199 GG genotype showed a median overall survival (OS) significantly lower than those with CC+CG genotype (67.8 months versus 94.4 months respectively; p: 0.022) maintaining significance in the multivariate analysis. This effect was specially detected in patients not receiving an autologous stem cell transplant (auto-SCT) (p < 0.001). In these patients the rs1131199 GG genotype negatively influenced in the mortality not related with the progression of MM (p: 0.02) mainly due to infections events.

Rab37 mediates trafficking and membrane presentation of PD-1 to sustain T cell exhaustion in lung cancer

BACKGROUND

Programmed cell death protein 1 (PD-1) is an immune checkpoint receptor expressed on the surface of T cells. High expression of PD-1 leads to T-cell dysfunction in the tumor microenvironment (TME). However, the mechanism of intracellular trafficking and plasma membrane presentation of PD-1 remains unclear.

METHODS

Multiple databases of lung cancer patients were integratively analyzed to screen Rab proteins and potential immune-related signaling pathways. Imaging and various biochemical assays were performed in Jurkat T cells, splenocytes, and human peripheral blood mononuclear cells (PBMCs). Rab37 knockout mice and specimens of lung cancer patients were used to validate the concept.

RESULTS

Here, we identify novel mechanisms of intracellular trafficking and plasma membrane presentation of PD-1 mediated by Rab37 small GTPase to sustain T cell exhaustion, thereby leading to poor patient outcome. PD-1 colocalized with Rab37-specific vesicles of T cells in a GTP-dependent manner whereby Rab37 mediated dynamic trafficking and membrane presentation of PD-1. However, glycosylation mutant PD-1 delayed cargo recruitment to the Rab37 vesicles, thus stalling membrane presentation. Notably, T cell proliferation and activity were upregulated in tumor-infiltrating T cells from the tumor-bearing Rab37 knockout mice compared to those from wild type. Clinically, the multiplex immunofluorescence-immunohistochemical assay indicated that patients with high Rab37+/PD-1+/TIM3+/CD8+ tumor infiltrating T cell profile correlated with advanced tumor stages and poor overall survival. Moreover, human PBMCs from patients demonstrated high expression of Rab37, which positively correlated with elevated levels of PD-1+ and TIM3+ in CD8+ T cells exhibiting reduced tumoricidal activity.

CONCLUSIONS

Our results provide the first evidence that Rab37 small GTPase mediates trafficking and membrane presentation of PD-1 to sustain T cell exhaustion, and the tumor promoting function of Rab37/PD-1 axis in T cells of TME in lung cancer. The expression profile of Rab37high/PD-1high/TIM3high in tumor-infiltrating CD8+ T cells is a biomarker for poor prognosis in lung cancer patients.

Targeted immunotherapy: harnessing the immune system to battle multiple myeloma

Multiple myeloma (MM) remains an incurable hematological malignancy disease characterized by the progressive dysfunction of the patient's immune system. In this context, immunotherapy for MM has emerged as a prominent area of research in recent years. Various targeted immunotherapy strategies, such as monoclonal antibodies, antibody-drug conjugates, bispecific antibodies, chimeric antigen receptor T cells/natural killer (NK) cells, and checkpoint inhibitors have been developed for MM. This review aims to discuss promising experimental and clinical evidence as well as the mechanisms of action underlying these immunotherapies. Specifically, we will explore the design of exosome-based bispecific monoclonal antibodies that offer cell-free immunotherapy options. The treatment landscape for myeloma continues to evolve with the development of numerous emerging immunotherapies. Given their significant advantages in modulating the MM immune environment through immune-targeted therapy, these approaches provide novel perspectives in selecting cutting-edge treatments for MM.

Immune checkpoint blockade in hematological malignancies: current state and future potential

Malignant cells are known to evade immune surveillance by engaging immune checkpoints which are negative regulators of the immune system. By restoring the T-lymphocyte mediated anti-tumor effect, immune checkpoint inhibitors (ICI) have revolutionized the treatment of solid tumors but have met rather modest success in hematological malignancies. Currently, the only FDA approved indications for ICI therapy are in classic hodgkin lymphoma and primary mediastinal B cell lymphoma. Multiple clinical trials have assessed ICI therapy alone and in combination with standard of care treatments in other lymphomas, plasma cell neoplasms and myeloid neoplasms but were noted to have limited efficacy. These trials mostly focused on PD-1/PDL-1 and CTLA-4 inhibitors. Recently, there has been an effort to target other T-lymphocyte checkpoints like LAG-3, TIM-3, TIGIT along with improving strategies of PD-1/PDL-1 and CTLA-4 inhibition. Drugs targeting the macrophage checkpoint, CD47, are also being tested. Long term safety and efficacy data from these ongoing studies are eagerly awaited. In this comprehensive review, we discuss the mechanism of immune checkpoint inhibitors, the key takeaways from the reported results of completed and ongoing studies of these therapies in the context of hematological malignancies.

Efficacy and Safety of Immune Checkpoint Inhibitors in Hematologic Malignancies

The emergence of immune checkpoint inhibitors (ICIs) has led to a dramatic paradigm shift within the landscape of cancer treatment, igniting significant interest in their potential application in treating hematologic malignancies. This comprehensive review critically has examined the existing body of literature to shed light on the evolving understanding of the efficacy and safety of ICIs, both as a single agent and in combination regimens in hematologic malignancies. Across distinct lymphoma subtypes, the observed treatment responses exhibit diversity, and conflicts. Notably, Hodgkin lymphoma and certain non-Hodgkin lymphomas such as primary mediastinal B-cell lymphoma, emerge as remarkable cases, showing encouraging response rates and outcomes. However, the efficacy of ICIs reveals variations among subtypes such as chronic lymphocytic leukemia and multiple myeloma. Combination therapies consistently demonstrated superior outcomes compared to monotherapy in several malignancies. While the potential benefits of ICIs in hematologic malignancies are evident, the safety profile warrants careful consideration. Immune-related and other adverse events, though generally tolerable and manageable, highlight the necessity of meticulous monitoring and appropriate intervention. The discussions prompted by these findings underscore the need for tailored treatment approaches, driven by disease subtype, patient characteristics, and potential biomarkers. Moreover, the emerging realm of combination therapies involving immune checkpoint inhibitors holds promise for enhanced treatment outcomes, and ongoing research endeavors aim to unravel the optimal strategies.

The Involvement of LAG-3positive Plasma Cells in the Development of Multiple Myeloma

The Lymphocyte-Activation Protein 3 (LAG-3) inhibitory receptor is expressed on regulatory plasma cells (PCs). Micro-environmental cells that express LAG-3 were found to be increased during the progression of smoldering multiple myeloma (SMM). To assess the possible role of LAG-3 expression on regulatory PCs in patients with plasma cell dyscrasia. Purified Cluster of Differentiation 138 (CD138+) PCs from patients with premalignant conditions, active multiple myeloma (MM), and controls were analyzed for the expression of LAG-3 by flow cytometry. Autologous CD8+T cells were incubated with sorted LAG-3pos or LAG-3neg PCs for 24 h. The expression of granzyme (Grz) in CD8+T cells was assessed by flow cytometry. LAG-3 expression on PCs in active MM (newly diagnosed and relapse refractory MM) was significantly increased compared to monoclonal gammopathy of undetermined significance (MGUS)/ SMM. Grz expression was significantly decreased in CD8+T cells incubated with CD138+LAG-3pos PCs, compared to CD138+LAG-3neg PCs in patients with plasma cell dyscrasia, n = 31, p = 0.0041. LAG-3 expression on malignant PCs can be involved in the development of MM from MGUS by decreasing the expression of Grz in CD8+T cells.

Comprehensive Single-Cell Immune Profiling Defines the Patient Multiple Myeloma Microenvironment Following Oncolytic Virus Therapy in a Phase Ib Trial

PURPOSE

Our preclinical studies showed that the oncolytic reovirus formulation pelareorep (PELA) has significant immunomodulatory anti-myeloma activity. We conducted an investigator-initiated clinical trial to evaluate PELA in combination with dexamethasone (Dex) and bortezomib (BZ) and define the tumor immune microenvironment (TiME) in patients with multiple myeloma treated with this regimen.

PATIENTS AND METHODS

Patients with relapsed/refractory multiple myeloma (n = 14) were enrolled in a phase Ib clinical trial (ClinicalTrials.gov: NCT02514382) of three escalating PELA doses administered on Days 1, 2, 8, 9, 15, and 16. Patients received 40 mg Dex and 1.5 mg/m2 BZ on Days 1, 8, and 15. Cycles were repeated every 28 days. Pre- and posttreatment bone marrow specimens (IHC, n = 9; imaging mass cytometry, n = 6) and peripheral blood samples were collected for analysis (flow cytometry, n = 5; T-cell receptor clonality, n = 7; cytokine assay, n = 7).

RESULTS

PELA/BZ/Dex was well-tolerated in all patients. Treatment-emergent toxicities were transient, and no dose-limiting toxicities occurred. Six (55%) of 11 response-evaluable patients showed decreased paraprotein. Treatment increased T and natural killer cell activation, inflammatory cytokine release, and programmed death-ligand 1 expression in bone marrow. Compared with nonresponders, responders had higher reovirus protein levels, increased cytotoxic T-cell infiltration posttreatment, cytotoxic T cells in significantly closer proximity to multiple myeloma cells, and larger populations of a novel immune-primed multiple myeloma phenotype (CD138+ IDO1+HLA-ABCHigh), indicating immunomodulation.

CONCLUSIONS

PELA/BZ/Dex is well-tolerated and associated with anti-multiple myeloma activity in a subset of responding patients, characterized by immune reprogramming and TiME changes, warranting further investigation of PELA as an immunomodulator.

Immune checkpoint inhibitors for multiple myeloma immunotherapy

Multiple myeloma (MM) is related to immune disorders, recent studys have revealed that immunotherapy can greatly benefit MM patients. Immune checkpoints can negatively modulate the immune system and are closely associated with immune escape. Immune checkpoint-related therapy has attracted much attention and research in MM. However, the efficacy of those therapies need further improvements. There need more thoughts about the immune checkpoint to translate their use in clinical work. In our review, we aggregated the currently known immune checkpoints and their corresponding ligands, further more we propose various ways of potential translation applying treatment based on immune checkpoints for MM patients.

Immunotherapy of Multiple Myeloma: Current Status as Prologue to the Future

The landscape of therapeutic measures to treat multiple myeloma has undergone a seismic shift since the dawn of the current century. This has been driven largely by the introduction of new classes of small molecules, such as proteasome blockers (e.g., bortezomib) and immunomodulators (e.g., lenalidomide), as well as by immunotherapeutic agents starting with the anti-CD38 monoclonal antibody daratumumab in 2015. Recently, other immunotherapies have been added to the armamentarium of drugs available to fight this malignancy. These include the bispecifics teclistamab, talquetamab, and elranatamab, and the chimeric antigen receptor (CAR) T-cell products idecabtagene vicleucel (ide-cel) and ciltacabtagene autoleucel (cilta-cel). While the accumulated benefits of these newer agents have resulted in a more than doubling of the disease's five-year survival rate to nearly 60% and improved quality of life, the disease remains incurable, as patients become refractory to the drugs and experience relapse. This review covers the current scope of antimyeloma immunotherapeutic agents, both those in clinical use and in development. Included in the discussion are additional monoclonal antibodies (mAbs), antibody-drug conjugates (ADCs), bi- and multitargeted mAbs, and CAR T-cells and emerging natural killer (NK) cells, including products intended for "off-the-shelf" (allogeneic) applications. Emphasis is placed on the benefits of each along with the challenges that need to be surmounted if MM is to be cured.

Impacting T-cell fitness in multiple myeloma: potential roles for selinexor and XPO1 inhibitors

Competent T-cells with sufficient levels of fitness combat cancer formation and progression. In multiple myeloma (MM), T-cell exhaustion is caused by several factors including tumor burden, constant immune activation due to chronic disease, age, nutritional status, and certain MM treatments such as alkylating agents and proteasome inhibitors. Many currently used therapies, including bispecific T-cell engagers, anti-CD38 antibodies, proteasome inhibitors, and CART-cells, directly or indirectly depend on the anti-cancer activity of T-cells. Reduced T-cell fitness not only diminishes immune defenses, increasing patient susceptibility to opportunistic infections, but can impact effectiveness MM therapy effectiveness, bringing into focus sequencing strategies that could modulate T-cell fitness and potentially optimize overall benefit and clinical outcomes. Certain targeted agents used to treat MM, such as selective inhibitors of nuclear export (SINE) compounds, have the potential to mitigate T-cell exhaustion. Herein referred to as XPO1 inhibitors, SINE compounds inhibit the nuclear export protein exportin 1 (XPO1), which leads to nuclear retention and activation of tumor suppressor proteins and downregulation of oncoprotein expression. The XPO1 inhibitors selinexor and eltanexor reduced T-cell exhaustion in cell lines and animal models, suggesting their potential role in revitalizating these key effector cells. Additional clinical studies are needed to understand how T-cell fitness is impacted by diseases and therapeutic factors in MM, to potentially facilitate the optimal use of available treatments that depend on, and impact, T-cell function. This review summarizes the importance of T-cell fitness and the potential to optimize treatment using T-cell engaging therapies with a focus on XPO1 inhibitors.

Breaking barriers: NEK2 inhibition shines in multiple myeloma treatment

In their article, Cheng et al.1 reveal that NEK2 loss reshapes the tumor microenvironment, reducing tumor-associated macrophages and decreasing T cell exhaustion. They show that this ultimately favors the immune system's anti-cancer response in multiple myeloma.

Checkpoint inhibition in hematologic malignancies

Checkpoint inhibitor therapy has emerged as an effective therapeutic strategy for many types of malignancies, especially in solid tumors. Within the last two decades, numerous monoclonal antibody drugs targeting the CTLA-4 and PD-1/PD-L1 checkpoint pathways have seen FDA approval. Within hematologic malignancies, Hodgkin Lymphoma has seen the greatest clinical benefits thus far with more recent data showing efficacy in the front-line setting. As our understanding of checkpoint inhibition expands, using these pathways as a therapeutic target has shown some utility in the treatment of other hematologic malignancies as well, primarily in the relapsed/refractory settings. Checkpoint inhibition also appears to have a role as a synergistic agent to augment clinical responses to other forms of therapy such as hematopoietic stem cell transplant. Moreover, alternative checkpoint molecules that bypass the well-studied CTLA-4 and PD-1/PD-L1 pathways have emerged as exciting new therapeutic targets. Most excitingly is the use of anti-CD47 blockade in the treatment of high risk MDS and TP-53 mutated AML. Overall, there has been tremendous progress in understanding the benefits of checkpoint inhibition in hematologic malignancies, but further studies are needed in all areas to best utilize these agents. This is a review of the most recent developments and progress in Immune Checkpoint Inhibition in Hematologic Malignancies in the last decade.

High NEK2 expression in myeloid progenitors suppresses T cell immunity in multiple myeloma

Multiple myeloma (MM) growth is supported by an immune-tolerant bone marrow microenvironment. Here, we find that loss of Never in mitosis gene A (NIMA)-related kinase 2 (NEK2) in tumor microenvironmental cells is associated with MM growth suppression. The absence of NEK2 leads to both fewer tumor-associated macrophages (TAMs) and inhibitory T cells. NEK2 expression in myeloid progenitor cells promotes the generation of functional TAMs when stimulated with MM conditional medium. Clinically, high NEK2 expression in MM cells is associated with increased CD8+ T effector memory cells, while low NEK2 is associated with an IFN-γ gene signature and activated T cell response. Inhibition of NEK2 upregulates PD-L1 expression in MM cells and myeloid cells. In a mouse model, the combination of NEK2 inhibitor INH154 with PD-L1 blockade effectively eliminates MM cells and prolongs survival. Our results provide strong evidence that NEK2 inhibition may overcome tumor immune escape and support its further clinical development.

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.

Definers and drivers of functional high-risk multiple myeloma: insights from genomic, transcriptomic, and immune profiling

Traditional prognostic models for newly diagnosed patients with multiple myeloma (MM), including International Staging System criteria and number of high-risk chromosomal abnormalities, are based on disease characteristics at diagnosis. However, the identification of patients at risk of more rapidly progressive MM is inherently a dynamic assessment. In a subset of patients with MM, adverse disease biology only becomes evident after the failure of first-line therapy. We define this entity as functional high-risk MM (FHRMM), encompassing relapse within 18 months of treatment initiation and/or within 12 months of frontline autologous stem cell transplantation. FHRMM is not adequately captured by traditional prognostic models, and there is a need for better understanding of mechanisms or risk factors for early relapse or progression. In this review, we explore potential definitions of FHRMM before delving into its underlying drivers based on genetic, transcriptomic, and immune cell profiling studies. Emerging data suggest that specific features of both myeloma cells and immune cells can enable the FHRMM phenotype. We conclude our review by discussing ongoing and future studies that seek to identify and intervene upon patients with FHRMM preemptively.

Disparity in survival benefits of pembrolizumab between Asian and non-Asian patients with advanced cancers: A systematic review and meta-regression analysis

BACKGROUND

Immune checkpoint inhibitors have revolutionized the treatment of malignancies. However, disproportionate enrollment among races and ethnicities places the generalizability of global trial results in doubt.

METHODS

In this systematic review, phase 3 randomized controlled trials investigating pembrolizumab in advanced cancers and providing subgroup analyses of Asian and non-Asian participants were included. The primary and secondary effect measures were the mean differences (MDs) in the natural logarithms of the hazard ratios (HRs) for overall survival (OS) and progression-free survival (PFS) between these two subgroups, respectively. We used random-effects meta-analysis to calculate the pooled ratios of HRs (i.e., exp(MD)) and implemented a meta-regression analysis to identify significant covariates.

RESULTS

A total of 17 and 11 trials were included in the meta-analyses of OS and PFS, respectively. These trials included 2732 (25.49%) Asian and 7000 (65.32%) non-Asian participants in the OS analysis and 1438 (22.5%) Asian and 4129 (64.61%) non-Asian participants in the PFS analysis. The pooled ratio of HRs for OS was 0.87 (95% CI: 0.76-0.99; p = 0.0391), favoring Asian participants, but no significant difference was found in PFS (pooled ratio of HRs: 0.93; 95% CI: 0.82-1.07; p = 0.2391). Both linear meta-regression analyses revealed an open-label design as a crucial covariate, which indicated more benefits for non-Asian participants.

CONCLUSIONS

Compared with non-Asian patients, Asian patients with advanced cancers may derive superior OS benefits from pembrolizumab. Although the results warrant further exploration, this meta-analysis provides insight into clinical research design.

Immunomodulatory Effect of Proteasome Inhibitors via the Induction of Immunogenic Cell Death in Myeloma Cells

Several anti-cancer drugs are known to have immunomodulatory effects, including immunogenic cell death (ICD) of cancer cells. ICD is a form of apoptosis which is caused by the release of damage-associated molecular patterns (DAMPs), the uptake of cancer antigens by dendritic cells, and the activation of acquired immunity against cancer cells. ICD was originally reported in solid tumors, and there have been few reports on ICD in multiple myeloma (MM). Here, we showed that proteasome inhibitors, including carfilzomib, induce ICD in myeloma cells via an unfolded protein response pathway distinct from that in solid tumors. Additionally, we demonstrated the potential impact of ICD on the survival of patients with myeloma. ICD induced by proteasome inhibitors is expected to improve the prognosis of MM patients not only by its cytotoxic effects, but also by building strong immune memory response against MM cells in combination with other therapies, such as chimeric antigen receptor-T cell therapy.

Large T cell clones expressing immune checkpoints increase during multiple myeloma evolution and predict treatment resistance

Tumor recognition by T cells is essential for antitumor immunity. A comprehensive characterization of T cell diversity may be key to understanding the success of immunomodulatory drugs and failure of PD-1 blockade in tumors such as multiple myeloma (MM). Here, we use single-cell RNA and T cell receptor sequencing to characterize bone marrow T cells from healthy adults (n = 4) and patients with precursor (n = 8) and full-blown MM (n = 10). Large T cell clones from patients with MM expressed multiple immune checkpoints, suggesting a potentially dysfunctional phenotype. Dual targeting of PD-1 + LAG3 or PD-1 + TIGIT partially restored their function in mice with MM. We identify phenotypic hallmarks of large intratumoral T cell clones, and demonstrate that the CD27- and CD27+ T cell ratio, measured by flow cytometry, may serve as a surrogate of clonal T cell expansions and an independent prognostic factor in 543 patients with MM treated with lenalidomide-based treatment combinations.

Immune checkpoint inhibition improves antimyeloma activity of bortezomib and STING agonist combination in Vk*MYC preclinical model

Multiple myeloma (MM), a hematological malignancy of plasma cells, has remained incurable despite the development of novel therapies that improve patients' outcome. Recent evidence indicates that the stimulator of interferon genes (STING) pathway may represent a novel target for induction of antitumor immune response in multiple myeloma. Here, we investigated antitumor effects of STING agonist with bortezomib with or without checkpoint inhibitor in the treatment of MM.

METHODS

STING expression in bone marrow plasma cells of 58 MM patients was examined by immunohistochemical staining. The effectiveness of the proposed therapy was evaluated in vivo in a syngeneic transplantable mouse model of MM (Vĸ*MYC) in immunocompetent mice. Flow cytometry was used to assess tumor burden and investigate activation of immune response against MM. ELISA was performed to measure serum inflammatory cytokines concentrations upon treatment.

RESULTS

Combining a STING agonist [2'3'-cGAM(PS)2] with bortezomib significantly decreased tumor burden and improved the survival of treated mice compared to either of the compounds used alone. The combination treatment led to secretion of pro-inflammatory cytokines and increased the percentage of neutrophils, activated dendritic cells and T cells in the tumor microenvironment. However, it resulted also in increased expression of PD-L1 on the surface of the immune cells. Addition of anti-PD1 antibody further potentiated the therapeutic effects.

CONCLUSIONS

Our findings indicate high antimyeloma efficacy of the three-drug regimen comprising bortezomib, STING agonist, and a checkpoint inhibitor.

Effect modification in network meta-analyses for relapsed/refractory multiple myeloma: systematic review and meta-analysis

OBJECTIVES

To systematically review and meta-analyse the evidence for effect modification by refractory status and number of treatment lines in relapsed/refractory multiple myeloma (RRMM); and to assess whether effect modification is likely to invalidate network meta-analyses (NMA) that assume negligible modification.

DESIGN

Systematic review, meta-analysis and simulation.

DATA SOURCES

We systematically searched the literature (e.g., OVID Medline) to identify eligible publications in February 2020 and regularly updated the search until January 2022. We also contacted project stakeholders (including industry) ELIGIBILITY CRITERIA: Phase 2 and 3 randomised controlled trials reporting stratified estimates for comparisons with at least one of a prespecified set of treatments relevant for use in Norwegian RRMM patients.

OUTCOMES

We used meta-analysis to estimate relative HRs (RHRs) for overall survival (OS) and progression-free survival (PFS) with respect to refractory status and number of treatment lines. We used the estimated RHRs in simulations to estimate the percentage of NMA results expected to differ significantly in the presence versus absence of effect modification.

RESULTS

Among the 42 included publications, stratified estimates were published by and extracted from up to 18 (43%) publications and on as many as 8364 patients. Within-study evidence for effect modification is very weak (p>0.05 for 47 of 49 sets of stratified estimates). The largest RHR estimated was 1.32 (95% CI 1.18 to 1.49) for the modifying effect of refractory status on HR for PFS. Simulations suggest that, in the worst case, this would result in only 4.48% (95% CI 4.42% to 4.54%) of NMA estimates differing statistically significantly in the presence versus absence of effect modification.

CONCLUSIONS

Based on the available evidence, effect modification appears to be sufficiently small that it can be neglected in adequately performed NMAs. NMAs can probably be relied on to provide estimates of HRs for OS and PFS in RRMM, subject to caveats discussed herein.

Multi-omic analysis of the tumor microenvironment shows clinical correlations in Ph1 study of atezolizumab +/- SoC in MM

Multiple myeloma (MM) remains incurable, and treatment of relapsed/refractory (R/R) disease is challenging. There is an unmet need for more targeted therapies in this setting; deep cellular and molecular phenotyping of the tumor and microenvironment in MM could help guide such therapies. This phase 1b study (NCT02431208) evaluated the safety and efficacy of the anti-programmed death-ligand 1 monoclonal antibody atezolizumab (Atezo) alone or in combination with the standard of care (SoC) treatments lenalidomide (Len) or pomalidomide (Pom) and/or daratumumab (Dara) in patients with R/R MM. Study endpoints included incidence of adverse events (AEs) and overall response rate (ORR). A novel unsupervised integrative multi-omic analysis was performed using RNA sequencing, mass cytometry immunophenotyping, and proteomic profiling of baseline and on-treatment bone marrow samples from patients receiving Atezo monotherapy or Atezo+Dara. A similarity network fusion (SNF) algorithm was applied to preprocessed data. Eighty-five patients were enrolled. Treatment-emergent deaths occurred in 2 patients; both deaths were considered unrelated to study treatment. ORRs ranged from 11.1% (Atezo+Len cohorts, n=18) to 83.3% (Atezo+Dara+Pom cohort, n=6). High-dimensional multi-omic profiling of the tumor microenvironment and integrative SNF analysis revealed novel correlations between cellular and molecular features of the tumor and immune microenvironment, patient selection criteria, and clinical outcome. Atezo monotherapy and SoC combinations were safe in this patient population and demonstrated some evidence of clinical efficacy. Integrative analysis of high dimensional genomics and immune data identified novel clinical correlations that may inform patient selection criteria and outcome assessment in future immunotherapy studies for myeloma.

Detection of mutant antigen-specific T cell receptors against multiple myeloma for T cell engineering

Multiple myeloma (MM) remains an incurable hematological neoplasm. Neoantigen-specific T cell receptor (TCR)-engineered T (TCR-T) cell therapy is a potential alternative treatment. Particularly, TCRs derived from a third-party donor may cover broad ranges of neoantigens, whereas TCRs in patients suffering from immune disorders are limited. However, the efficacy and feasibility of treating MM have not been evaluated thoroughly. In this study, we established a system for identifying immunogenic mutant antigens on MM cells and their corresponding TCRs using healthy donor-derived peripheral blood mononuclear cells (PBMCs). Initially, the immune responses to 35 candidate peptides predicted by the immunogenomic analysis were investigated. Peptide-reactive T lymphocytes were enriched, and subsequently, TCR repertoires were determined by single-cell TCR sequencing. Eleven reconstituted TCRs showed mutation-specific responses against 4 peptides. Particularly, we verified the HLA-A∗24:02-binding QYSPVQATF peptide derived from COASY S55Y as the naturally processed epitope across MM cells, making it a promising immune target. Corresponding TCRs specifically recognized COASY S55Y⁺HLA-A∗24:02⁺ MM cells and augmented tumoricidal activity. Finally, adoptive cell transfer of TCR-T cells showed objective responses in the xenograft model. We initiatively proposed the utility of tumor mutated antigen-specific TCR genes to suppress MM. Our unique strategy will facilitate further identification of neoantigen-specific TCRs.

Cardiac toxicities in multiple myeloma: an updated and a deeper look into the effect of different medications and novel therapies

With the continuous improvement in survival of cancer patients, including those with multiple myeloma, related to the novel treatment agents and therapeutic approaches, the probability for patients to develop cardiovascular disease has significantly increased, especially in elderly patients and those with additional risk factors. Multiple myeloma is indeed a disease of the elderly population and so these patients are, solely by age, at an increased risk of cardiovascular disease. Risk factors for these events can be patient-, disease- and/or therapy-related, and they have been shown to adversely impact survival. Cardiovascular events affect around 7.5% of patients with multiple myeloma and the risk for different toxicities has considerably varied across trials depending on patients' characteristics and treatment utilized. High grade cardiac toxicity has been reported with immunomodulatory drugs (odds ratio [OR] around 2), proteasome inhibitors (OR 1.67-2.68 depending on the specific agent, and generally higher with carfilzomib), as well as other agents. Cardiac arrhythmias have also been reported with various therapies and drug interaction plays a significant role in that setting. Comprehensive cardiac evaluation before, during and after various anti-myeloma therapy is recommended and the incorporation of surveillance strategies allows early detection and management resulting in improved outcomes of these patients. Multidisciplinary interaction including hematologists and cardio-oncologists is critical for optimal patient care.

Therapeutic strategies to enhance immune response induced by multiple myeloma cells

Multiple myeloma (MM)as a haematological malignancy is still incurable. In addition to the presence of somatic genetic mutations in myeloma patients, the presence of immunosuppressive microenvironment greatly affects the outcome of treatment. Although the discovery of immunotherapy makes it possible to break the risk of high toxicity and side effects of traditional chemotherapeutic drugs, there are still obstacles of ineffective treatment or disease recurrence. In this review, we discuss therapeutic strategies to further enhance the specific anti-tumor immune response by activating the immunogenicity of MM cells themselves. New ideas for future myeloma therapeutic approaches are provided.

Isatuximab in combination with cemiplimab in patients with relapsed/refractory multiple myeloma: A phase 1/2 study

BACKGROUND

Given the incurable nature of multiple myeloma (MM), efforts are made to improve the efficacy of anti-CD38 monoclonal antibodies via combinations with other potentially synergistic therapies. This Phase 1/2 trial (NCT03194867) was designed to determine whether cemiplimab (anti-PD-1) enhances the anti-myeloma activity of isatuximab (anti-CD38) in patients with relapsed and refractory multiple myeloma (RRMM), to confirm the feasibility of the combination, determine its efficacy, and further evaluate its safety.

METHODS

Patients received isatuximab 10 mg/kg once weekly for 4 weeks followed by every 2 weeks (Isa), or isatuximab 10 mg/kg plus cemiplimab 250 mg every 2 (Isa + CemiQ2W) or every 4 weeks (Isa + CemiQ4W).

RESULTS

Overall, 106 patients with RRMM treated with a median of 4 prior lines were included; 25.5% had high-risk cytogenetics, 63.2% were refractory to proteasome inhibitors and immunomodulatory agents, 26.4% were previously exposed to daratumumab, and 84.0% were refractory to their last treatment line. There were no major changes in the safety or pharmacokinetic profile of isatuximab with the addition of cemiplimab. As assessed by investigators, four patients (11.8%) in the Isa arm, nine patients (25.0%) in the Isa + CemiQ2W arm, and eight patients (22.2%) in the Isa + CemiQ4W arm were responders. Though response rates were numerically higher in cemiplimab-containing arms, differences were not statistically significant and did not translate to improved progression-free or overall survival after a median follow-up of 9.99 months.

CONCLUSION

Our results suggest a marginal benefit by adding cemiplimab to isatuximab, despite demonstration of target engagement, without additional observed safety issues.

Treatment Strategy for Ultra-High-Risk Multiple Myelomas with Chromosomal Aberrations Considering Minimal Residual Disease Status and Bone Marrow Microenvironment

Despite the development of anti-myeloma therapeutics, such as proteasome inhibitors, immunomodulatory drugs, anti-CD38 monoclonal antibodies, and autologous stem cell transplantation (ASCT), multiple myeloma remains incurable. A trial treatment combining four drugs-daratumumab, carfilzomib, lenalidomide, and dexamethasone-followed by ASCT frequently results in minimal residual disease (MRD) negativity and prevents progressive disease in patients with standard- and high-risk cytogenetics; however, it is insufficient to overcome the poor outcomes in patients with ultra-high-risk chromosomal aberration (UHRCA). In fact, MRD status in autografts can predict clinical outcomes after ASCT. Therefore, the current treatment strategy might be insufficient to overcome the negative impact of UHRCA in patients with MRD positivity after the four-drug induction therapy. High-risk myeloma cells lead to poor clinical outcomes not only by aggressive myeloma behavior but also via the generation of a poor bone marrow microenvironment. Meanwhile, the immune microenvironment effectively suppresses myeloma cells with a low frequency of high-risk cytogenetic abnormalities in early-stage myeloma compared to late-stage myeloma. Therefore, early intervention might be key to improving clinical outcomes in myeloma patients. The purpose of this review is to improve clinical outcomes in patients with UHRCA by considering MRD assessment results and improvement of the microenvironment.