Role of daratumumab in the frontline management of multiple myeloma: a narrative review

CD38-specific immunoPET imaging for multiple myeloma diagnosis and therapeutic monitoring: preclinical and first-in-human studies

PURPOSE

CD38 is a glycoprotein highly specific to multiple myeloma (MM). Therapeutics using antibodies targeting CD38 have shown promising efficacy. However, the efficient stratification of patients who may benefit from daratumumab (Dara) therapy and timely monitoring of therapeutic responses remain significant clinical challenges. To address these issues, we developed a novel nanobody-based PET tracer, [68Ga]Ga-TOHP-CD3813, which exhibits rapid clearance from the blood and rapid accumulation in targeted tumor lesions, facilitating the detection of CD38 expression in murine models of MM and lymphoma. Furthermore, we conducted the world's first-in-human trials using CD38-targeted nanobodies to validate and assess the clinical imaging effectiveness of [68Ga]Ga-TOHP-CD3813 in guiding cancer immunotherapy.

MATERIALS AND METHODS

We prepared a new PET imaging probe based on a CD38-targeted nanobody CD3813, [68Ga]Ga-TOHP-CD3813, via the site-specific radiolabeling for noninvasive PET imaging of CD38 expression. [68Ga]Ga-TOHP-CD3813 was assessed for its affinity and specificity to CD38 and its ability to image CD38 expression in MM and lymphoma xenograft models. Biodistribution and the relationship between tumor uptake and CD38 expression were evaluated. Subsequently, we conducted a translational PET imaging of 2 MM patients using [68Ga]Ga-TOHP-CD3813, while compared with [18F]FDG PET/CT head-to-head. Dosimetry was also calculated based on the animal data.

RESULTS

TOHP-CD3813 retained a high affinity for CD38 with a KD of 0.0826 nmol/L. [68Ga]Ga-TOHP-CD3813 was successfully synthesized at room temperature within 10 min, exhibiting optimal radiochemical properties. Preclinical assessments revealed rapid blood clearance, high CD38 affinity, and significant uptake in CD38-positive xenograft mouse models (6.50 ± 2.69%ID/g). [68Ga]Ga-TOHP-CD3813 showed pronounced accumulation in the kidneys and bladder, with moderate liver uptake, indicating its potential as a viable clinical PET radiotracer for diagnosing MM. Additionally, in first-in-human trials, [68Ga]Ga-TOHP-CD3813 PET/CT provides a substantial improvement over [18F]FDG PET/CT for the visualization of MM.

CONCLUSIONS

[68Ga]Ga-TOHP-CD3813, with its high affinity, specificity, and robust imaging capabilities, rapidly and specifically accumulates in tumors with high CD38 expression, offering a significant advantage over [18F]FDG PET/CT for visualizing MM and enabling same-day PET imaging. Initial human trial results are promising, suggesting its potential as a companion diagnostic tool for optimizing CD38-targeted treatments in tumors. Ongoing larger trials aim to further confirm these findings.

Flow Cytometry for B-Cell Non-Hodgkin and Hodgkin Lymphomas

Multi-parametric flow cytometry is a powerful diagnostic tool that permits rapid assessment of cellular antigen expression to quickly provide immunophenotypic information suitable for disease classification. This chapter describes the classification of B-cell non-Hodgkin lymphoma (B-NHL) by flow cytometry suitable for the clinical and research environment. In addition to describing the immunophenotypic patterns of the most common B-NHL (including examples of common B-NHL), the effect of anti-CD19, -CD20, and -CD38 therapies on the evaluation of flow cytometric data is also discussed. Over the last 15 years, our laboratory has developed flow cytometry combinations that can immunophenotype classic Hodgkin lymphoma (CHL), nodular lymphocyte predominant Hodgkin lymphoma (NLPHL), and T-cell/histocyte-rich large B-cell lymphoma (THRLBCL) and the use of these assays will be presented. The CHL assay combination is also particularly well suited to immunophenotype primary mediastinal large B-cell lymphoma (PMLBCL) and our experience immunophenotyping PMLBCL by flow cytometry will be discussed. Finally, an approach to the evaluation of the reactive infiltrate of CHL, NLPHL, and THRLBCL that can provide diagnostic information will also be provided.

Is There a Role for Daratumumab Retreatment in Patients with Relapsed/Refractory Multiple Myeloma?

Multiple myeloma (MM) is a hematologic disease characterized by the clonal expansion of malignant plasma cells that accumulate in the bone marrow, leading to osteolytic bone disease, hypercalcemia, anemia, and renal dysfunction. Daratumumab was the first monoclonal anti-CD38 antibody approved for the treatment of MM, initially in relapse/refractory settings and, more recently, for newly diagnosed patients. Increased first-line usage of daratumumab will also substantially change treatment approaches for patients with relapsed/refractory disease. Due to the cost and availability of bispecific T cell redirecting antibodies (BsAbs) and chimeric antigen receptor T cell therapy (CAR-T) in real-life settings in many countries, retreatment with daratumumab in subsequent lines of therapy might be a reasonable choice. Data regarding efficacy and optimal combinations of daratumumab retreatment are lacking, and here we provide a short literature review of available data. We identified only a small number of articles based on retrospective analysis of medical records in real-life settings. A strong consistency in results regarding response rates and treatment duration was noticed among mainly heavily pre-treated MM patients, with approximately half of patients achieving at least partial remission (PR) after retreatment with daratumumab-based protocol. The duration of treatment and time to the next treatment for retreatment episodes were considerable and consistent with clinical expectations for later lines of therapy. The analysis of data in this literature review indicates that daratumumab retreatment may provide meaningful clinical benefit to some patients with relapsed/refractory MM despite having prior exposure. However, further research is needed to identify clinical and biological parameters that may predict favorable responses to daratumumab retreatment.

Efficacy of daratumumab on multiple myeloma patients with renal insufficiency: a systematic review and meta-analysis

BACKGROUND

Renal insufficiency (RI) is a key factor affecting the prognosis of multiple myeloma (MM) patients. Because the benefit of daratumumab for treating MM patients with RI remains unclear, our objective was to evaluate the efficacy of daratumumab on MM patients with RI.

METHODS

We conducted a systematic search of the PubMed, EMBASE, and Cochrane Library databases as of October 24, 2023. Two independent reviewers screened the article titles, abstracts, and full text to identify the randomized controlled trials (RCTs) meeting the inclusion and exclusion criteria. Meta-analyses were performed using RevMan version 5.4. Outcomes of interest were progression-free survival (PFS), overall survival (OS), complete response or better (≥CR), and minimal residual disease (MRD) negativity, all calculated as hazard ratios (HRs) or risk ratios (RRs) with 95% confidence intervals (CIs).

RESULTS

A total of 10 RCTs with 5003 patients were included. Add-on daratumumab improved PFS and OS among newly diagnosed MM (NDMM) patients with RI (HR 0.48 [95% CI: 0.36, 0.64, I2 = 65%] and HR 0.63 [95% CI: 0.48, 0.82, I2 = 0%]) as well as relapsed/refractory MM (RRMM)-RI patients, compared with the control group (HR 0.46 [95% CI: 0.37, 0.58, I2 = 0%] and HR 0.68 [95% CI: 0.51, 0.92, I2 = 0%]). In terms of the renal status, the efficacy of add-on daratumumab for MMRI patients was similar to that for MM patients with normal renal function. A prolonged PFS benefit for add-on daratumumab treatment versus the control was evident across all RRMM-RI subgroups, and the benefits tended to increase with the follow-up time.

CONCLUSIONS

Our results indicate that MM patients with RI could benefit from a daratumumab-added regimen regardless of MM status. Additional high-quality RCTs are still warranted to confirm our findings.

The role of antibody glycosylation in autoimmune and alloimmune kidney diseases

Immunoglobulin glycosylation is a pivotal mechanism that drives the diversification of antibody functions. The composition of the IgG glycome is influenced by environmental factors, genetic traits and inflammatory contexts. Differential IgG glycosylation has been shown to intricately modulate IgG effector functions and has a role in the initiation and progression of various diseases. Analysis of IgG glycosylation is therefore a promising tool for predicting disease severity. Several autoimmune and alloimmune disorders, including critical and potentially life-threatening conditions such as systemic lupus erythematosus, anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis and antibody-mediated kidney graft rejection, are driven by immunoglobulin. In certain IgG-driven kidney diseases, including primary membranous nephropathy, IgA nephropathy and lupus nephritis, particular glycome characteristics can enhance in situ complement activation and the recruitment of innate immune cells, resulting in more severe kidney damage. Hypofucosylation, hypogalactosylation and hyposialylation are the most common IgG glycosylation traits identified in these diseases. Modulating IgG glycosylation could therefore be a promising therapeutic strategy for regulating the immune mechanisms that underlie IgG-driven kidney diseases and potentially reduce the burden of immunosuppressive drugs in affected patients.

Longitudinal genetically detectable minimal residual disease by fluorescence in situ hybridization confers a poor prognosis in myeloma

Background

Deeper depth of response (DpR) after induction therapy, especially gain of negative minimal residual disease (MRD), has been linked to prolonged survival in multiple myeloma (MM). However, flow-MRD examination focuses on the numbers but not on the biological characteristics of residual plasma cells (PCs).

Objectives

To explore whether the genetic features of residual tumor cells affect the survival time of patients with MM.

Design

A retrospective cohort study.

Methods

We investigated the clonality of cytogenetic abnormalities (CAs) of the residual PCs using interphase fluorescence in situ hybridization (iFISH) in the National Longitudinal Cohort of Hematological Diseases in China (NCT04645199). Here, a longitudinal cohort of 269 patients with patient-paired diagnostic and post-induction iFISH results was analyzed.

Results

Persistent CAs after induction therapy were detected in about half of the patients (118/269, 43%), and patients with undetectable CAs showed significantly improved survival compared with those with genetically detectable MRD [median progression-free survival (mPFS): 59.7 versus 35.7 months, p < 0.001; median overall survival (mOS): 97.1 versus 68.8 months, p = 0.011]. In addition, different patterns of therapy-induced clonal evolution were observed by comparing the clonal structure of residual PCs with paired baseline samples. Patients who maintained at a high risk during follow-up had the worst survival (mPFS: 30.5 months; mOS: 54.4 months), while those who returned to lower risk or had iFISH- at both time points had the best survival (mPFS: 62.0 months, mOS: not reached).

Conclusion

These findings highlighted the prognostic value of genetic testing in residual tumor cells, which may provide a deep understanding of clonal evolution and guide clinical therapeutic strategies.