Impact of blood involvement on efficacy and time to response with mogamulizumab in mycosis fungoides and Sézary syndrome

A Narrative Review of the State of the Art of CCR4-Based Therapies in Cutaneous T-Cell Lymphomas: Focus on Mogamulizumab and Future Treatments

The CCR4 receptor is a pivotal target in cutaneous T-cell lymphoma (CTCL) therapy due to its role in impairing immune responses against malignant T-cells and expression profiles. Monoclonal antibodies like mogamulizumab effectively bind to CCR4, reducing tumour burden and enhancing patient outcomes by inhibiting the receptor's interaction with ligands, thereby hindering malignant T-cell migration and survival. Combining CCR4 antibodies with chemotherapy, radiation, and other drugs is being explored for synergistic effects. Additionally, small-molecular inhibitors, old pharmacological agents interacting with CCR4, and CAR-T therapies are under investigation. Challenges include drug resistance, off-target effects, and patient selection, addressed through ongoing trials refining protocols and identifying biomarkers. Despite advancements, real-life data for most of the emerging treatments are needed to temper expectations. In conclusion, CCR4-targeted therapies show promise for CTCL management, but challenges persist. Continued research aims to optimise treatments, enhance outcomes, and transform CTCL management. This review aims to elucidate the biological rationale and the several agents under various stages of development and clinical evaluation with the actual known data.

MHC-I upregulation safeguards neoplastic T cells in the skin against NK cell-mediated eradication in mycosis fungoides

Cancer-associated immune dysfunction is a major challenge for effective therapies. The emergence of antibodies targeting tumor cell-surface antigens led to advancements in the treatment of hematopoietic malignancies, particularly blood cancers. Yet their impact is constrained against tumors of hematopoietic origin manifesting in the skin. In this study, we employ a clonality-supervised deep learning methodology to dissect key pathological features implicated in mycosis fungoides, the most common cutaneous T-cell lymphoma. Our investigations unveil the prominence of the IL-32β-major histocompatibility complex (MHC)-I axis as a critical determinant in tumor T-cell immune evasion within the skin microenvironment. In patients' skin, we find MHC-I to detrimentally impact the functionality of natural killer (NK) cells, diminishing antibody-dependent cellular cytotoxicity and promoting resistance of tumor skin T-cells to cell-surface targeting therapies. Through murine experiments in female mice, we demonstrate that disruption of the MHC-I interaction with NK cell inhibitory Ly49 receptors restores NK cell anti-tumor activity and targeted T-cell lymphoma elimination in vivo. These findings underscore the significance of attenuating the MHC-I-dependent immunosuppressive networks within skin tumors. Overall, our study introduces a strategy to reinvigorate NK cell-mediated anti-tumor responses to overcome treatment resistance to existing cell-surface targeted therapies for skin lymphoma.

Die Wirkung von Mogamulizumab auf die aberrante T-Zell-Population im peripheren Blut - eine monozentrische retrospektive Analyse

Hintergrund

Die Wirkung von Mogamulizumab bei kutanen T‐Zell‐Lymphomen (CTCL) auf die T‐Zellen (TZ) im peripheren Blut und deren potenzielle Rolle bei der Steuerung von Behandlungsintervallen wird noch erforscht.

Methodik

Wir untersuchten in einer retrospektiven monozentrischen Analyse die Wirkung von Mogamulizumab auf die CD3+ TZ und die aberrante T‐Zellpopulation (TZP), CD4+/CD7– und die CD4+/CD26– TZ, die mittels Durchflusszytometrie analysiert wurden.

Ergebnisse

Dreizehn Patienten mit CTCL wurden eingeschlossen. Nach vier Zyklen kam es zu einer durchschnittlichen Reduktion der CD3+ TZ um 57%, der CD4+/CD7− um 72% und der CD4+/CD26− TZ um 75% im Vergleich zum individuellen Ausgangswert eines jeden Patienten. Die Reduktionen der CD4+/CD7+ und CD4+/CD26+ TZ fielen mit durchschnittlich 54% und 41% geringer aus. Ein signifikanter Rückgang der aberranten TZP war bereits nach der ersten Infusion zu beobachten. Ein medianes Plateau der TZP trat bereits während der Induktionsphase ein. Bei 5/13 Patienten kam es zu einem Progress der Erkrankung, ohne dass eine eindeutige Korrelation mit der aberranten TZP bestand.

Schlussfolgerungen

Bereits nach einer Gabe Mogamulizumab reduzierte sich die aberrante TZP und – in geringerem Maße – die normale TZP. Wir konnten keine eindeutige Korrelation der TZP mit der Wirksamkeit von Mogamulizumab beobachten. Es werden weitere Untersuchungen mit einer größeren Anzahl von Patienten benötigt.

The effect of mogamulizumab on the aberrant T cell population in the peripheral blood - A monocentric retrospective analysis

BACKGROUND AND OBJECTIVES

The effect of mogamulizumab in cutaneous T-cell lymphoma (CTCL) on T cells (TC) in the peripheral blood and its potential role to navigate treatment intervals are explored.

METHODS

We investigated within a retrospective monocentric analysis the effect of mogamulizumab on the CD3+ TC and the aberrant T cell population (TCP), i.e., the CD4+ /CD7- and the CD4+ /CD26- TC, analyzed by flow cytometry.

RESULTS

Thirteen patients with CTCL were included. After four cycles there was a mean reduction of 57% in CD3+ TC, 72% in the CD4+ /CD7- and 75% in the CD4+ /CD26- TCP compared to the individual baseline of each patient. The reduction in CD4+ /CD7+ and CD4+ /CD26+ TC was lower, averaging 54% and 41%. A significant decrease in aberrant TCP was already evident after the first administration. A median plateau of TCP already occurred during the IP. Progressive disease occurred in 5/13 patients without a clear correlation to aberrant TCP.

CONCLUSIONS

Already after one dose of mogamulizumab, aberrant TCP and, to a lesser extent, normal TC decrease. We did not observe a clear correlation between TCP and the efficacy of mogamulizumab, but further studies with larger numbers of patients are needed.

Phenotypic plasticity of malignant T cells in blood and skin of a Sézary syndrome patient revealed by single cell transcriptomics

Background

Sézary Syndrome (SS) is an aggressive leukemic variant of cutaneous T-cell lymphomas (CTCL). In SS patients, malignant T cells are circulating through the blood and cause erythroderma.

Objective

To compare the transcriptome of single cells in blood and skin samples from a patient with advanced SS.

Methods

We utilized combined single cell RNA and T-cell receptor (TCR) sequencing (scRNA-seq).

Results

We scrutinized the malignant T cells in blood and skin in an unbiased manner without pre-sorting of cells. We observed different phenotypes of the same monoclonal malignant T-cell population, confirmed by TCR sequencing and inferred copy number variation analysis. Malignant T cells present in the circulating blood expressed genes resembling central memory T cells such as CCR7, IL7R and CD27. In the skin, we detected two major malignant T-cell populations: One subpopulation was closely related to the malignant T cells from the blood, while the other subpopulation expressed genes reminiscent of skin resident effector memory T cells including GZMB and NKG7. Pseudotime analysis indicated crucial transcriptomic changes in the transition of malignant T cells between blood and skin. These changes included the differential regulation of TXNIP, a putative tumor suppressor in CTCL, and the adaptation to the hypoxic conditions in the skin. Tumor cell proliferation in the skin was supported by stimulating interactions between myeloid cells and malignant T cells.

Conclusions

Using scRNA-seq we detected a high degree of functional heterogeneity within the malignant T-cell population in SS and highlighted crucial differences between SS cells in blood and skin.