Jak-STAT Inhibition Mediates Romidepsin and Mechlorethamine Synergism in Cutaneous T-Cell Lymphoma.

Sézary syndrome is an aggressive and disseminated form of cutaneous T-cell lymphoma associated with dismal prognosis in which the histone deacetylase inhibitor romidepsin has shown remarkable activity as a single agent. However, clinical responses to romidepsin are typically transient, highlighting the need for more effective therapies. In this study, we show synergistic antilymphoma effects of romidepsin in combination with mechlorethamine, an alkylating agent, in cutaneous T-cell lymphoma cell lines and primary samples with strong antitumor effects in an in vivo model of Sézary syndrome. Mechanistically, gene expression profiling points to abrogation of Jak/signal transducer and activator of transcription (STAT) signaling as an important mediator of this interaction. Consistently, the combination of mechlorethamine plus romidepsin resulted in downregulation of STAT5 phosphorylation in romidepsin-sensitive cell lines and primary Sézary syndrome samples, but not in romidepsin-resistant tumors. Moreover, in further support of Jak/STAT signaling as a modulator of romidepsin activity in cutaneous T-cell lymphoma, treatment with romidepsin in combination with Jak inhibitors resulted in markedly increased therapeutic responses. Overall, these results support a role for romidepsin plus mechlorethamine in combination in the treatment of cutaneous T-cell lymphoma and uncover a previously unrecognized role for Jak/STAT signaling in the response to romidepsin and romidepsin-based combination therapies in Sézary syndrome.

Three antigen-loading methods in dendritic cell vaccines for metastatic melanoma.

In the current era of checkpoint inhibitors, some patients with metastatic melanoma have shown a significant improvement in survival. However, optimization of immunotherapy is an ongoing effort. Monocyte-derived dendritic cell (MODC) vaccines have been shown in clinical trials to be safe and capable of inducing tumor-specific immunity as well as occasional objective clinical responses. Here, we conducted a three-arm pilot clinical study in 15 patients with metastatic melanoma to evaluate three types of MODC vaccines, differing only by strategies of tumor antigen delivery. MODCs were isolated from each patient and loaded with patients' own melanoma cells as sources of antigens. Antigen loading was achieved ex vivo by fusing melanoma cells with MODCs, co-culturing melanoma cells with MODCs, or by pulsing MODCs with melanoma cell lysates. The vaccines were then injected into superficial lymph nodes using high-resolution ultrasound guidance. Primary end points included delayed-type hypersensitivity responses and positive ELISpot result, which measures interferon-γ production. Five of 15 patients achieved delayed-type hypersensitivity responses and six of 15 patients had positive ELISpot results. We demonstrated that the vaccines were safe and well-tolerated by all patients and produced immunological responses in all arms. Although MODC vaccine monotherapy has limited efficacy, combining this vaccine with other immunotherapies, such as checkpoint inhibitors, to engage multiple components of the immune system may be an effective and viable future approach.

Clinical Insights and Emerging Strategies in Managing Cutaneous T-Cell Lymphoma.

Mycosis Fungoides and Sézary Syndrome, the two most common types of Cutaneous T-Cell Lymphoma (CTCL), present many management challenges for dermatologists. Here, we provide a comprehensive review of up-to-date literature, guidelines, and expert clinical insights. We highlight the updates in the World Health Organization Classification of Cutaneous Lymphomas; we summarize the epidemiology, including a recently observed stabilization of increasing incidence of CTCL in the past decade and increased incidence in males, blacks, and veterans; we also provide the most recent updates on prognostic factors for CTCL. Utilization of Next-Generation Sequencing and other novel technologies has shed light on pathogenic mechanisms of CTCL, including immune dysregulation, antigen stimulation, and genomic alterations. CTCL management still remains a significant challenge due to lack of standardization of therapies for every stage of the disease. We provide a straightforward approach to clinical evaluation, diagnostic workup via immunophenotyping and molecular studies, staging guidelines, and select treatment strategies in Mycosis Fungoides and Sézary Syndrome. CTCL patients require individualized, holistic, and multidisciplinary care, for whom addressing management in different skin types and prioritizing quality of life issues are essential.

J Drugs Dermatol. 2017;16(5):405-412.