RNA-sequencing based first choice of treatment and determination of risk in multiple myeloma

Plasma Cell Enrichment and New Genomic Approaches in Multiple Myeloma: A Scoping Review

BACKGROUND

Multiple myeloma (MM) is a genetically heterogeneous disease where specific genetic abnormalities have a significant impact on a patient's prognosis. Diagnostic and prognostic tools like fluorescence in situ hybridization (FISH), PCR, microarrays, and next-generation sequencing (NGS) have transformed MM management. However, the effectiveness of these techniques is often limited by the low concentration of plasma cells in bone marrow samples, which makes enrichment methods necessary. This review aims to clarify how these techniques enhance the detection of genetic abnormalities, reduce false-negative results, and facilitate more precise risk stratification for MM patients.

CONTENT

Following Preferred Reporting Items for Systematic reviews and Meta-Analyses Extension for Scoping Review (PRISMA-ScR) guidelines, the literature on plasma cell separation methods used in genetic studies of MM was systematically identified and mapped. Searches were conducted in the Medline and Embase databases using a structured strategy, supplemented by manual searches on Google Scholar. Of 399 publications evaluated, 69 met the inclusion criteria; 37% utilized FISH and 19% demonstrated an increasing use of NGS. Plasma cell enrichment significantly improved diagnostic accuracy, increasing the detection rates of genetic abnormalities from 61% in non-enriched samples to 95.5% in enriched samples. While FISH remains the gold standard, emerging technologies such as NGS offer superior sensitivity and the ability to identify critical genetic alterations to refine molecular subtypes.

SUMMARY

Clinically significant genetic alterations are detected more frequently with plasma cell enrichment techniques, contributing to improved prognosis and treatment strategies for MM patients.

Bortezomib-releasing silica-collagen xerogels for local treatment of osteolytic bone- and minimal residual disease in multiple myeloma

BACKGROUND

Accumulation of malignant plasma cells in the bone marrow causes lytic bone lesions in 80% of multiple myeloma patients. Frequently fracturing, they are challenging to treat surgically. Myeloma cells surviving treatment in the presumably protective environment of bone lesions impede their healing by continued impact on bone turnover and can explain regular progression of patients without detectable minimal residual disease (MRD). Locally applicable biomaterials could stabilize and foster healing of bone defects, simultaneously delivering anti-cancer compounds at systemically intolerable concentrations, overcoming drug resistance.

METHODS

We developed silica-collagen xerogels (sicXer) and bortezomib-releasing silica-collagen xerogels (boXer) for local treatment of osteolytic bone disease and MRD. In vitro and in vivo (tissue sections) release of bortezomib was assessed by ultrahigh-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). Material impact on bone formation was assessed in vitro regarding osteoclast/osteoblast numbers and activity. In vivo, drilling defects in a rat- and the 5T33-myeloma mouse model were treated by both materials and assessed by immunohistochemistry, UPLC-MS/MS, µCT, and ToF-SIMS. The material's anti-myeloma activity was assessed using ten human myeloma cell lines (HMCLs) and eight primary myeloma cell samples including four patients refractory to systemic bortezomib treatment.

RESULTS

sicXer and boXer show primary stability comparable to trabecular bone. Granule size and preparation method tailor degradation as indicated by release of the xerogel components (silica and collagen) and bortezomib into culture medium. In vitro, both materials reduce osteoclast activity and do not negatively interfere with osteoblast differentiation and function. The presumed resulting net bone formation with maintained basic remodeling properties was validated in vivo in a rat bone defect model, showing significantly enhanced bone formation for boXer compared to non-treated defects. Both materials induce myeloma cell apoptosis in all HMCLs and primary myeloma cell samples. In the 5T33-myeloma mouse model, both materials stabilized drilling defects and locally controlled malignant plasma cell growth.

CONCLUSIONS

The combination of stabilization of fracture-prone lesions, stimulation of bone healing, and anti-tumor effect suggest clinical testing of sicXer and boXer as part of a combined systemic/local treatment strategy in multiple myeloma and non-malignant diseases.

Advancements in the design and function of bispecific CAR-T cells targeting B Cell-Associated tumor antigens

Single-targeted CAR-T has exhibited notable success in treating B-cell tumors, effectively improving patient outcomes. However, the recurrence rate among patients remains above fifty percent, primarily attributed to antigen escape and the diminished immune persistence of CAR-T cells. Over recent years, there has been a surge of interest in bispecific CAR-T cell therapies, marked by an increasing number of research articles and clinical applications annually. This paper undertakes a comprehensive review of influential studies on the design of bispecific CAR-T in recent years, examining their impact on bispecific CAR-T efficacy concerning disease classification, targeted antigens, and CAR design. Notable distinctions in antigen targeting within B-ALL, NHL, and MM are explored, along with an analysis of how CAR scFv, transmembrane region, hinge region, and co-stimulatory region design influence Bi-CAR-T efficacy across different tumors. The summary provided aims to serve as a reference for designing novel and improved CAR-Ts, facilitating more efficient treatment for B-cell malignant tumors.

Cell surface marker heterogeneity in human myeloma cell lines for modeling of disease and therapy

Multiple myeloma (MM) is a hematological malignancy originating from plasma cells. Genetically, MM is categorized into two subtypes: hyperdiploid and non-hyperdiploid tumors, with distinct chromosomal characteristics. Human myeloma cell lines (HMCLs) are instrumental in understanding MM and identifying therapeutic targets. However, their utility depends on their resemblance to patient-derived cells. We analyzed protein expression of cell surface markers, including myeloma drug targets and immunotherapy-relevant markers, in nine HMCLs using flow cytometry. RNAseq analysis was performed to correlate protein expression with transcriptomic data. While five cell surface markers (CD47, CD49d, CD138, CD269 (BCMA), and GPRC5D) were highly expressed and three (CD19, CD20, and CD117) were low or negative across cell lines, heterogenous expression was observed for the 16 remaining markers. A comparative study with patient-derived transcriptomic data indicated that four of our six in-house HMCLs closely resembled patient disease. Furthermore, our hyperdiploid HMCLs correlated better with hyperdiploid than non-hyperdiploid patient samples. Here, we also describe three previously uncharacterized HMCLs; IH-1, URVIN and FOLE. Our findings underscore the importance of evaluating surface protein expression in HMCLs when modeling MM. The observed variations in expression levels emphasize the need for a strategic selection of cell lines based on the study's objectives.

Clinical bioinformatics desiderata for molecular tumor boards

Clinical Bioinformatics is a knowledge framework required to interpret data of medical interest via computational methods. This area became of dramatic importance in precision oncology, fueled by cancer genomic profiling: most definitions of Molecular Tumor Boards require the presence of bioinformaticians. However, all available literature remained rather vague on what are the specific needs in terms of digital tools and expertise to tackle and interpret genomics data to assign novel targeted or biomarker-driven targeted therapies to cancer patients. To fill this gap, in this article, we present a catalog of software families and human skills required for the tumor board bioinformatician, with specific examples of real-world applications associated with each element presented.

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

PURPOSE

Given the high heterogeneity in survival for patients with multiple myeloma, it would be clinically useful to quantitatively predict the individual survival instead of attributing patients to two to four risk groups as in current models, for example, revised International Staging System (R-ISS), R2-ISS, or Mayo-2022-score.

PATIENTS AND METHODS

Our aim was to develop a quantitative prediction tool for individual patient's 3-/5-year overall survival (OS) probability. We integrated established clinical and molecular risk factors into a comprehensive prognostic model and evaluated and validated its risk discrimination capabilities versus R-ISS, R2-ISS, and Mayo-2022-score.

RESULTS

A nomogram for estimating OS probabilities was built on the basis of a Cox regression model. It allows one to translate the individual risk profile of a patient into 3-/5-year OS probabilities by attributing points to each prognostic factor and summing up all points. The nomogram was externally validated regarding discrimination and calibration. There was no obvious bias or overfitting of the prognostic index on the validation cohort. Resampling-based and external evaluation showed good calibration. The c-index of the model was similar on the training (0.76) and validation cohort (0.75) and significantly higher than for the R-ISS (P < .001) or R2-ISS (P < .01).

CONCLUSION

In summary, we developed and validated individual quantitative nomogram-based OS prediction. Continuous risk assessment integrating molecular prognostic factors is superior to R-ISS, R2-ISS, or Mayo-2022-score alone.

Transcriptome of bone marrow-Derived stem cells reveals new inflammatory mediators related to increased survival in patients with multiple myeloma

Although multiple myeloma (MM) is a neoplasm that leads affected individuals to death, little is known about why some patients survive much longer than others. In this context, we investigated the transcriptomic profile of bone marrow hematopoietic stem cells obtained from MM patients and compared the clinical outcomes of death and survival six months after bone marrow transplantation. The leukapheresis products of 39 patients with MM eligible for autologous transplantation were collected and analyzed. After extraction, the RNA was analyzed using the GeneChip Human Exon 1.0 Array method. The transcriptome profile was analyzed in silico, and the differentially expressed signaling pathways of interest were validated. The results showed a difference in the expression of inflammation-related genes, immune response processes, and the oxidative stress pathway. The in silico study also pointed out the involvement of the NFκB transcription factor in the possible modulation of these genes. We chose to validate molecules participating in these processes, including the cytokines TNF-α, IFN-γ, and TGF-β1; in addition, we measured the levels of oxidative stress mediators (pro-oxidant profile and the total antioxidant capacity). TNF-α levels were significantly reduced in patients who died and were over 50 years old at diagnosis, as well as in patients with plasmacytoma. Increased TNF-α was detected in patients with very high levels of β2-microglobulin. IFN-γ reduction was observed in patients with a complete response to treatment compared to those with a very good response. Patients with plasmacytoma who died also had an increased pro-oxidant profile. These data show the profile of inflammatory response markers that are altered in patients with MM who die quickly and serve as a basis for the development of future studies of markers to predict better survival in this disease.

Molecular Long-Term Analysis of the GMMG-HD4 Trial in Multiple Myeloma-Patterns of Association of Chromosomal Aberrations with Response and Proliferation Determining Survival in Selecting Treatments in View of Limited Resources in Low- and Middle-Income Countries

Based on the lack of differences in progression-free and overall survival after a median follow-up of 93 months in our HOVON-65/GMMG-HD4 trial (German part; n = 395) randomizing VAD induction (vincristin/adriamycin/dexamthasone)/tandem-transplantation/thalidomide-maintenance vs. PAD induction (bortezomib/adriamycin/dexamethasone)/tandem transplantation/bortezomib maintenance, we discern how chromosomal aberrations determine long-term prognosis by different patterns of association with proliferation and treatment-dependent response, whether responses achieved by different regimens are equal regarding prognosis, and whether subpopulations of patients could be defined as treatable without upfront "novel agents" in cases of limited resources, e.g., in low- or middle-income countries. Serum parameters and risk factors were assessed in 395 patients. CD138-purified plasma cells were subjected to fluorescence in situ hybridization (n = 354) and gene expression profiling (n = 204). We found chromosomal aberrations to be associated in four patterns with survival, proliferation, and response: deletion (del) del17p13, del8p21, del13q14, (gain) 1q21+, and translocation t(4;14) (all adverse) associate with higher proliferation. Of these, del17p is associated with an adverse response (pattern 1), and 1q21+, t(4;14), and del13q14 with a treatment-dependent better response (pattern 2). Hyperdiploidy associates with lower proliferation without impacting response or survival (pattern 3). Translocation t(11;14) has no association with survival but a treatment-dependent adverse response (pattern 4). Significantly fewer patients reach a near-complete response or better with "conventional" (VAD) vs. bortezomib-based treatment after induction or high-dose melphalan. These patients, however, show significantly better median progression-free and overall survival. Molecularly, patients responding to the two regimens differ in gene expression, indicating distinct biological properties of the responding myeloma cells. Patients with normal renal function (89.4%), low cytogenetic risk (72.5%), or low proliferation rate (37.9%) neither benefit in progression-free nor overall survival from bortezomib-based upfront treatment. We conclude that response level, the treatment by which it is achieved, and molecular background determine long-term prognosis. Chromosomal aberrations are associated in four patterns with proliferation and treatment-dependent responses. Associations with faster and deeper responses can be deceptive in the case of prognostically adverse aberrations 1q21+ and t(4;14). Far from advocating a return to "outdated" treatments, if resources do not permit state-of-the-art-treatment, normal renal function and/or molecular profiling identifies patient subpopulations doing well without upfront "novel agents".