Impressive Continuous Complete Response after Mogamulizumab in a Heavily Pretreated Sézary Syndrome Patient

Background

Sézary syndrome (SS) is a rare lymphoproliferative neoplasm, almost incurable outside the setting of allogeneic transplantable patients. The prognosis for relapsed/refractory patients remains poor, as the available drugs confer short-lasting remission. In this setting, the anti-chemokine receptor type 4 (CCR4) monoclonal antibody mogamulizumab demonstrated efficacy in an international, open-label, randomized controlled phase 3 trial (MAVORIC) versus vorinostat.

Case description

A heavily pretreated 57-year-old SS woman (stage IVA) was randomized in the mogamulizumab arm of MAVORIC at our Institution. She quickly achieved a response, but after 30 cycles, she was discontinued from therapy due to cutaneous toxicity. Nevertheless, she is still in complete response (CR).

Conclusions

mogamulizumab is an anti-CCR4 monoclonal antibody that can induce long-lasting response also in very heavily pretreated patients not responding to any previous treatment. The extraordinary characteristic of our patient is that she is still in CR after 2.5 years since treatment discontinuation.

Tumor-infiltrating and circulating granulocytic myeloid-derived suppressor cells correlate with disease activity and adverse clinical outcomes in mycosis fungoides

PURPOSE

Cutaneous T cell lymphomas (CTCL) are rare and histologically diverse lymphoproliferative neoplasms, with mycosis fungoides (MF) representing the most common disease subset. Given the emerging role of myeloid-derived suppressor cells (MDSC) as a clinically applicable biomarker in solid tumors, we sought to investigate the presence of tumor-infiltrating and circulating MDSC in early- and advanced-stage MF patients and evaluate their prognostic significance in patient overall survival.

METHODS

Tumor-infiltrating MDSC were assessed immunohistochemically with Arginase-1 in 31 MF and 14 non-MF skin punch biopsies. Circulating MDSC were assessed with flow cytometry in freshly isolated PBMC from 29 MF patients. Granulocytic MDSC (G-MDSC) were defined as CD11b+CD14-CD15+ and monocytic MDSC (M-MDSC) were defined as CD11b+CD14+HLA-DRlow/-.

RESULTS

MDSC infiltration occurred in approximately one-third (35.5%) of CTCL lesions, with a predilection for non-MF lesions (p < 0.05). The predominant morphology of MDSC was granulocytic. Although in MF lesions the presence of MDSC infiltrates did not correlate with clinical stage, it conferred significantly worse overall survival outcomes (p < 0.05). Circulating G-MDSC were significantly higher in MF patients compared to healthy donor controls (p < 0.0001), while M-MDSC did not show any statistically significant difference. G-MDSC were significantly higher in patients with active disease compared to patients who were in partial remission (p < 0.01). As with tumor-infiltrating MDSC, clinical stage did not correlate with circulating G-MDSC levels, while prospective overall survival analysis showed that patients with high levels of circulating G-MDSC have significantly inferior outcomes (p < 0.01).

CONCLUSIONS

This study shows that G-MDSC could represent a novel and easily assessable biomarker in MF, which mirrors disease activity and can predict patient subgroups with aggressive clinical features.