Evaluating Response Trends of Chlormethine/Mechlorethamine Gel in Patients With Stage I-IIA Mycosis Fungoides: Analysis of Individual Patient Data From a Randomized Controlled Phase II Study to Facilitate Optimal Treatment Experiences.

INTRODUCTION: Chlormethine (CL) gel was approved for treatment of mycosis fungoides based on the pivotal 201 trial (NCT00168064). Data visualization from individual patients is a powerful tool for discovery of hidden treatment trends. Here, we present a post hoc analysis of individual patient data from the pivotal trial to provide a more granular depiction of treatment and response changes over time, with an emphasis on end of treatment status. MATERIALS AND METHODS: Individual patient response data were plotted over a 12-month treatment period to visualize patient experiences while using CL gel. Responder status was assigned according to end-of-treatment Composite Assessment of Index Lesion Severity (CAILS) score, and patients were classified as early (≤4 months) or late responders based on timing of response. Baseline and active treatment characteristics were compared between early and late responders, and baseline body surface area (BSA) was compared between responders and patients with stable or progressive disease. RESULTS: Data from 123 patients with baseline and postbaseline results were included. At the end of treatment, 64.2%/55.3% were responders, 30.9%/34.1% had stable disease, and 4.9%/10.6% had progressive disease by CAILS and mSWAT, respectively. Among patients who responded to treatment, 64.6% and 35.4% were early and late responders, respectively. Response pattern analysis also identified patients with an intermittent response or initial progressive disease. Baseline BSA was not associated with responder status. Late responders had longer treatment duration and higher postbaseline plaque elevation, while early responders had a higher frequency of dermatitis. CONCLUSIONS: Results presented here can facilitate optimal treatment experiences for patients starting CL gel.

Reprogramming of PD-1+ M2-like tumor-associated macrophages with anti-PD-L1 and lenalidomide in cutaneous T cell lymphoma.

Cutaneous T cell lymphoma (CTCL) is a disfiguring and incurable disease characterized by skin-homing malignant T cells surrounded by immune cells that promote CTCL growth through an immunosuppressive tumor microenvironment (TME). Preliminary data from our phase I clinical trial of anti-programmed cell death ligand 1 (anti-PD-L1) combined with lenalidomide in patients with relapsed/refractory CTCL demonstrated promising clinical efficacy. In the current study, we analyzed the CTCL TME, which revealed a predominant PD-1+ M2-like tumor-associated macrophage (TAM) subtype with upregulated NF-κB and JAK/STAT signaling pathways and an aberrant cytokine and chemokine profile. Our in vitro studies investigated the effects of anti-PD-L1 and lenalidomide on PD-1+ M2-like TAMs. The combinatorial treatment synergistically induced functional transformation of PD-1+ M2-like TAMs toward a proinflammatory M1-like phenotype that gained phagocytic activity upon NF-κB and JAK/STAT inhibition, altered their migration through chemokine receptor alterations, and stimulated effector T cell proliferation. Lenalidomide was more effective than anti-PD-L1 in downregulation of the immunosuppressive IL-10, leading to decreased expression of both PD-1 and PD-L1. Overall, PD-1+ M2-like TAMs play an immunosuppressive role in CTCL. Anti-PD-L1 combined with lenalidomide provides a therapeutic strategy to enhance antitumor immunity by targeting PD-1+ M2-like TAMs in the CTCL TME.

Profiling endogenous, environmental, and infectious disease mutational signatures in blastic plasmacytoid dendritic cell neoplasms.

BACKGROUND: Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare hematopoietic disease derived from plasmacytoid dendritic lineage cells. The disease typically shows skin as well as frequent bone marrow and peripheral blood involvement. However, the pathogenesis of this disease is still not well understood. While somatic point mutations and genetic rearrangements have been described in BPDCN, the types and origins of these mutations and relationships to other cancer types is not well understood. MATERIALS AND METHODS: To probe the origins of BPDCN, we analyzed the exome sequence data of 9 tumor-normal pair cases of BPDCN. We utilized SignatureAnalyzer, SigProfiler and a custom microbial analysis pipeline to understand the relevance of endogenous and environmental mutagenic processes. RESULTS: Our results identified a significant tobacco exposure and aging genetic signature as well as signatures related to nucleotide excision repair deficiency, ultra violet (UV) exposure, and endogenous deamination in BPDCN. We also assessed the samples for microbial infectious disease organisms but did not find a link to a microbial etiology. CONCLUSION: The identification of a tobacco exposure and aging genetic signature in patients with BPDCN suggests that environmental and endogenous genetic changes may be central to the oncogenesis of BPDCN.

Effective treatment with the selective cytokine inhibitor BNZ-1 reveals the cytokine dependency of T-LGL leukemia.

T-cell large granular lymphocytic leukemia (T-LGLL) is a clonal proliferation of cytotoxic T lymphocytes that can result in severe neutropenia, anemia, and bone marrow failure. Strong evidence from patients and mouse models demonstrate the critical role of interleukin-15 (IL-15) in T-LGLL pathogenesis. BNZ-1 is a pegylated peptide that selectively inhibits the binding of IL-15 and other γc cytokines to their cellular receptor complex, which has demonstrated efficacy in ex vivo T-LGLL cells and transgenic mice in preclinical studies. We conducted a phase 1/2 trial of BNZ-1 in patients with T-LGLL who had hematocytopenias (anemia or neutropenia) and required therapy. Clinical responses were assessed using hematologic parameters (improvement in hematocytopenias) based on response criteria from the Eastern Cooperative Oncology Group 5998 T-LGLL trial. BNZ-1 demonstrated clinical partial responses in 20% of patients with T-LGLL with minimal toxicity and the maximum tolerated dose was not reached. Furthermore, T-LGL leukemic cells showed significantly increased apoptosis in response to BNZ-1 treatment as early as day 2, including in clinical nonresponders, with changes that remained statistically different from baseline throughout treatment (P < .005). We report first-in-human proof that T-LGL leukemic cells are dependent on IL-15 and that intervention with IL-15 inhibition with BNZ-1 in patients with T-LGLL shows therapeutic effects, which carries important implications for the understanding of the pathogenesis of this disease. This trial was registered at www.clinicaltrials.gov as #NCT03239392.

Blockade of the Immune Checkpoint CD47 by TTI-621 Potentiates the Response to Anti-PD-L1 in Cutaneous T-Cell Lymphoma.

Cutaneous T-cell lymphoma (CTCL) is an incurable and cosmetically disfiguring disease associated with microenvironmental signals. We investigated the effects of CD47 and PD-L1 immune checkpoint blockades, as a strategy for targeting both innate and adaptive immunity. CIBERSORT analysis identified the immune-cell composition in the CTCL tumor microenvironment and the immune checkpoint expression profile for each immune-cell gene cluster from CTCL lesions. We investigated the relationship between MYC and CD47 and PD-L1 expression and found that MYC short hairpin RNA knockdown and MYC functional suppression by TTI-621 (SIRPαFc) and anti-PD-L1 (durvalumab) in CTCL cell lines reduced the expression of CD47 and PDL1 mRNA and protein as measured by qPCR and flow cytometry, respectively. In vitro, blockade of the CD47-SIRPα interaction with TTI-621 increased the phagocytic activity of macrophages against CTCL cells and enhanced CD8+ T-cell-mediated killing in a mixed leucocyte reaction. Moreover, TTI-621 synergized with anti-PD-L1 in macrophages reprogram to M1-like phenotypes and inhibited CTCL cell growth. These effects were mediated by cell death-related pathways, including apoptosis, autophagy, and necroptosis. Collectively, our findings show that CD47 and PD-L1 are critical regulators of immune surveillance in CTCL and that dual targeting of CD47 and PD-L1 will provide insight into tumor immunotherapy for CTCL.

Primary Cutaneous Multifocal Indolent CD8+ T-Cell Lymphoma: A Novel Primary Cutaneous CD8+ T-Cell Lymphoma.

We report the case of a patient who was referred to our institution with a diagnosis of CD4+ small/medium-sized pleomorphic lymphoma. At the time, the patient showed a plethora of lesions mainly localizing to the legs; thus, we undertook studies to investigate the lineage and immunophenotype of the neoplastic clone. Immunohistochemistry (IHC) showed marked CD4 and CD8 positivity. Flow cytometry (FCM) showed two distinct T-cell populations, CD4+ and CD8+ (+/- PD1), with no CD4/CD8 co-expression and no loss of panT-cell markers in either T-cell subset. FCM, accompanied by cell-sorting (CS), permitted the physical separation of four populations, as follows: CD4+/PD1-, CD4+/PD1+, CD8+/PD1- and CD8+/PD1+. TCR gene rearrangement studies on each of the four populations (by next generation sequencing, NGS) showed that the neoplastic population was of T-cytotoxic cell lineage. IHC showed the CD8+ population to be TIA-1+, but perforin- and granzyme-negative. Moreover, histiocytic markers did not render the peculiar staining pattern, which is characteristic of acral CD8+ T-cell lymphoma (PCACD8). Compared to the entities described in the 2018 update of the WHO-EORTC classification for primary cutaneous lymphomas, we found that the indolent lymphoma described herein differed from all of them. We submit that this case represents a hitherto-undescribed type of CTCL.

Identifying unmet needs and challenges in the definition of a plaque in mycosis fungoides: An EORTC-CLTG/ISCL survey.

BACKGROUND: Consensus about the definition and classification of 'plaque' in mycosis fungoides is lacking. OBJECTIVES: To delineate a comprehensive view on how the 'plaque' entity is defined and managed in clinical practice; to evaluate whether the current positioning of plaques in the TNMB classification is adequate. METHODS: A 12-item survey was circulated within a selected panel of 22 experts (pathologists, dermatologists, haematologists and oncologists), members of the EORTC and International Society for Cutaneous Lymphoma. The questionnaire discussed clinical and histopathological definitions of plaques and its relationship with staging and treatment. RESULTS: Total consensus and very high agreement rates were reached in 33.3% of questions, as all panellists regularly check for the presence of plaques, agree to evaluate the presence of plaques as a potential separate T class, and concur on the important distinction between plaque and patch for the management of early-stage MF. High agreement was reached in 41.7% of questions, since more than 50% of the responders use Olsen's definition of plaque, recommend the distinction between thin/thick plaques, and agree on performing a biopsy on the most infiltrated/indurated lesion. High divergence rates (25%) were reported regarding the possibility of a clinically based distinction between thin and thick plaques and the role of histopathology to plaque definition. CONCLUSIONS: The definition of 'plaque' is commonly perceived as a clinical entity and its integration with histopathological features is generally reserved to specific cases. To date, no consensus is achieved as for the exact definition of thin and thick plaques and current positioning of plaques within the TNMB system is considered clinically inadequate. Prospective studies evaluating the role of histopathological parameters and other biomarkers, as well as promising diagnostic tools, such as US/RM imaging and high-throughput blood sequencing, are much needed to fully integrate current clinical definitions with more objective parameters.

Characteristics and Outcomes for Hospitalized Patients With Cutaneous T-Cell Lymphoma.

Importance: Cutaneous T-cell lymphoma (CTCL) is a group of rare, complex cutaneous malignant neoplasms associated with significant disease burden on patients and the health care system. Currently, the population of patients with CTCL admitted to the hospital remains largely uncharacterized and poorly understood. Objective: To characterize the clinical characteristics, course of hospitalization, and mortality outcomes of an inpatient CTCL cohort. Design, Setting, and Participants: This multicenter retrospective cohort study reviewed medical records for adult patients (age ≥18 years) with a CTCL diagnosis per National Comprehensive Cancer Network guidelines admitted for inpatient hospitalization at 5 US academic medical centers with inpatient dermatology consult services and CTCL clinics between August 2016 and August 2020. Main Outcomes and Measures: Patient demographics, clinical history and findings, hospitalization courses, and mortality outcomes. Results: A total of 79 hospitalized patients with CTCL were identified, including 52 (70.3%) men and 22 (29.7%) women, with a median (IQR) age at hospitalization of 62.9 (27-92) years. The majority of admitted patients with CTCL were White (65 patients [82.3%]), had disease classified as mycosis fungoides (48 patients [61.5%]), and had advanced-stage disease (≥IIB, 70 patients [89.7%]). Most hospitalizations were complicated by infection (45 patients [57.0%]) and required intravenous antibiotic therapy (45 patients [57.0%]). In-hospital mortality occurred in 6 patients (7.6%) and was associated with higher body mass index (36.5 vs 25.3), history of thromboembolic disease (50.0% vs 12.3%), and diagnosis of sepsis on admission (66.7% vs 20.5%). At 1-year postdischarge, 36 patients (49.3%) patients had died, and mortality was associated with history of solid organ cancers (27.8% vs 10.8%), wound care as the reason for dermatology consultation (58.3% vs 24.3%), and presence of large cell transformation (58.3% vs 22.9%). Conclusions and Relevance: The findings of this cohort study improve the understanding of hospitalized patients with CTCL and lend valuable insight into identifying factors associated with both in-hospital and long-term mortality outcomes. This refined understanding of the inpatient CTCL population provides a foundation for larger, more robust studies to identify causal risk factors associated with mortality, development of prognostic scoring systems to estimate the probability of hospital mortality. Overall, the findings may prompt physicians caring for patients with CTCL to implement preventive strategies to diminish hospitalization and improve clinical management across this unique disease spectrum.

Real-Life Barriers to Diagnosis of Early Mycosis Fungoides: An International Expert Panel Discussion.

Mycosis fungoides (MF) is a rare, primary cutaneous T-cell lymphoma that is challenging to diagnose due to its heterogeneous clinical presentation and complex histology. The subtlety of the initial clinical appearance of MF can result in diagnostic delays and hesitancy to refer suspected cases to specialist clinics. An unmet need remains for greater awareness and education. Therefore, an international expert panel of dermatologists, oncologists, hematologists, and dermatopathologists convened to discuss and identify barriers to early and accurate MF diagnosis that could guide clinicians toward making a correct diagnosis. Confirmation of MF requires accurate assessment of symptoms and clinical signs, and subsequent correlation with dermatopathological findings. This review summarizes the expert panel's guidance, based on the literature and real-life experience, for dermatologists to help include MF in their list of differential diagnoses, along with simple clinical and histopathologic checklists that may help clinicians to suspect and identify potential MF lesions and reduce diagnostic delays.

An Analysis of the Pathologic Features of Blastic Plasmacytoid Dendritic Cell Neoplasm Based on a Comprehensive Literature Database of Cases.

CONTEXT.­: Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare hematologic malignancy with poor outcome. BPDCN diagnostically overlaps with entities such as acute myeloid leukemia, histiocytic/dendritic cell neoplasms, and natural killer/T-cell lymphomas. Unfortunately, large, patient-centered studies that comprehensively analyze clinical, pathologic, and other diagnostic features are lacking. As such, there is an incomplete understanding of this disease. OBJECTIVE.­: To better characterize BPDCN, a multicenter working group consisting of hematopathologists and dermatopathologists gathered in person and remotely to review the current understanding of BPDCN, discuss specific issues regarding the diagnosis and differential diagnosis, and perform a retrospective analysis of the literature. DATA SOURCES.­: The working group curated a database of published BPDCN patient cases (BPDCN Network literature database), and following careful discussion and review, 361 articles were identified, comprising a total of 1513 individually annotated patients. CONCLUSIONS.­: By conducting an in-depth analysis, not only did we confirm known findings such as frequent skin involvement (84% of patients; 861 of 1028) and a male predominance among older patients (>60 years old; male to female ratio of 3.5:1; 617:177), but we also identified a number of underrecognized features, such as significant central nervous system involvement (38% of cases; 24 of 64), and a more equal male to female prevalence among patients younger than 40 years (male to female ratio of 1.25:1; 167:134). Furthermore, we were able to accurately summarize the immunophenotypic, cytogenetic, and molecular features of this disease. BPDCN is a complex disease with distinct morphologic, immunophenotypic, and molecular findings. Continual updates of the literature database generated here and further analysis can allow for prospective refinement of our understanding of this orphan disease.

Chlormethine gel in combination with other therapies for treatment of mycosis fungoides: a review with patient cases.

Topical chlormethine gel has been approved as monotherapy for treatment of adult patients with mycosis fungoides (MF), the most common form of cutaneous T-cell lymphoma. In clinical practice, chlormethine gel is often combined with other skin-directed or systemic therapies to optimize response and target recalcitrant lesions. Positive outcomes with combination regimens using chlormethine gel and topical corticosteroids, phototherapy, retinoids, methotrexate, or interferon-α have been reported in literature. However, there are no treatment guidelines on the use of combination regimens with chlormethine gel. To provide real-world evidence and guidance on the use of chlormethine gel combination regimens, several cases of patients treated with chlormethine gel combined with phototherapy (n = 5), retinoids (n = 16), or mogamulizumab (n = 3) are presented. These different combination regimens showed promising results. Most patients had a complete or partial response following treatment and the combinations were well-tolerated over extended treatment periods. Patients receiving chlormethine gel with retinoids had long-term periods of remission, even after treatment discontinuation. Durations of response of up to 3 years were observed in these patients. This long-term disease control may be the result of disease-modifying effects of chlormethine. Previous studies have shown targeted reductions in malignant T-cell clones in patients treated with chlormethine gel as well as improved post-treatment responses. Further research is needed to determine the effectiveness and safety of combination treatment regimens with chlormethine gel and to assess the impact chlormethine gel has on disease control.

Expert opinions and clinical experiences with chlormethine gel as maintenance treatment for patients with mycosis fungoides.

Maintenance treatment can be recommended for patients with mycosis fungoides (MF) whose disease responds to primary treatment. While positive outcomes have been observed in small studies with maintenance therapy, there is a lack of practical guidelines and agreement on when and how maintenance therapy for MF should be approached. In this article, we discuss expert opinions and clinical experiences on the topic of maintenance therapy for patients with MF, with a focus on chlormethine gel. Ideally, patients should have a durable response before initiating maintenance therapy. The definition of and required duration of durable response are topics that are open to debate and currently have no consensus. Chlormethine gel has several attributes that make it suitable for maintenance therapy; it can be easily applied at home, can be combined with other treatment options for maintenance, and has a manageable safety profile. Chlormethine gel as maintenance therapy can be applied at decreasing frequencies after active treatment with chlormethine gel or other therapies until the minimally effective dose is reached. Patients generally tend to adhere well to chlormethine gel maintenance regimens and may remain on treatment for several years. The experiences described here may be useful for clinicians when deciding on maintenance treatment regimens for their patients. Development of guidelines based on clinical trial outcomes will be important to ensure the most effective maintenance treatment strategies are used for patients with MF.

Maintenance and Concomitant Therapy Use with Chlormethine Gel Among Patients with Stage IA/IB Mycosis Fungoides-Type Cutaneous T-Cell Lymphoma (MF-CTCL): A Real-World Evidence Study.

INTRODUCTION: Chlormethine (CL) gel is a skin-directed therapy approved for treatment of stage IA/IB mycosis fungoides-type cutaneous T-cell lymphoma (MF-CTCL) in the USA. MF-CTCL has a chronic clinical course, requiring long-term maintenance therapy with one or more therapies. This analysis describes real-world patterns of maintenance therapy and use of concomitant therapy with CL gel among patients with stage IA/IB MF-CTCL. METHODS: In a US-based registry, MF-CTCL patients treated with CL gel were enrolled between 3/2015 and 10/2018 across 46 centers and followed for up to 2 years. Patient demographics, clinical characteristics, CL gel treatment patterns, concomitant treatments, clinical response, and adverse events (AEs) were collected from medical records. Descriptive statistics are reported. RESULTS: Of the 206 patients with stage IA/IB MF-CTCL, 58.7% were male, and average age was 60.7 years with 4.6 years since diagnosis. Topical steroids, phototherapy, and topical retinoids were used concomitantly with CL gel in 62.6%, 26.2%, and 6.3% of patients, respectively. Most concomitant therapies (up to 85%) were started before CL gel initiation and, in about half of the cases (up to 57%), were used concurrently for ≥ 12 months. Overall, 158 (76.7%) patients experienced partial response (PR) and 144 continued with maintenance therapy. After achieving PR, most patients (74.3%) kept the same maintenance therapy schedule, most commonly once daily. Of patients who had any skin-related AE (31.6%) or skin-related AEs associated with CL gel (28.2%), nearly half experienced CL gel treatment interruption and ~40% had a dosing reduction. The observed real-world treatment patterns were concordant with National Comprehensive Cancer Network (NCCN) guidelines. CONCLUSION: The study results suggest that continuing CL gel maintenance therapy and combining treatments with CL gel are common practice in the real-world setting, with most maintained on a stable dosing schedule. Careful management of AEs may help patients maintain long-term optimal dosing with less treatment interruptions and dosing reductions.

Chlormethine Gel for Patients with Mycosis Fungoides Cutaneous T Cell Lymphoma: A Review of Efficacy and Safety in Clinical Trial and Real-World Settings.

Mycosis fungoides (MF) is a rare disease and is the most common form of cutaneous T cell lymphoma. Topical chlormethine (CL) gel is the first cytotoxic chemotherapy gel that was specifically developed for treatment of MF. In this review, we provide an overview of all available data on the use of CL gel for treatment of patients with MF. On the basis of the current data collected, CL gel is highly effective, with good response rates observed both in clinical trial and real-world settings. While the gel is approved for monotherapy, it is also used in combination with concomitant skin-directed or systemic therapies in clinical practice. Responses to CL gel treatment can be rapid, but they also frequently occur with a delayed onset of up to 6 months. This indicates that continued treatment with CL gel is important. CL gel has a manageable safety profile, with most adverse events being mild and skin related. Contact dermatitis is one of the more common skin-related adverse events to occur with CL gel treatment that can potentially lead to treatment discontinuation. The data from the literature indicate that patients being treated with CL gel should be monitored carefully, and that dermatitis must be managed effectively to allow patients to continue treatment and achieve the best possible response to treatment.

Efficacy and Safety of Topical Hypericin Photodynamic Therapy for Early-Stage Cutaneous T-Cell Lymphoma (Mycosis Fungoides): The FLASH Phase 3 Randomized Clinical Trial.

Importance: Given that mycosis fungoides-cutaneous T-cell lymphoma (MF/CTCL) is chronic, there is a need for additional therapies with minimal short- and long-term adverse effects. Topical synthetic hypericin ointment, 0.25%, activated with visible light is a novel, nonmutagenic photodynamic therapy (PDT). Objectives: To determine the efficacy and safety of topical synthetic hypericin ointment, 0.25%, activated with visible light as a nonmutagenic PDT in early-stage MF/CTCL. Design, Settings, and Participants: This was a multicenter, placebo-controlled, double-blinded, phase 3 randomized clinical trial (FLASH study) conducted from December 2015 to November 2020 at 39 academic and community-based US medical centers. Participants were adults (≥18 years) with early-stage (IA-IIA) MF/CTCL. Interventions: In cycle 1, patients were randomized 2:1 to receive hypericin or placebo to 3 index lesions twice weekly for 6 weeks. In cycle 2, all patients received the active drug for 6 weeks to index lesions. In cycle 3 (optional), both index and additional lesions received active drug for 6 weeks. Main Outcomes and Measures: The primary end point was index lesion response rate (ILRR), defined as 50% or greater improvement in modified Composite Assessment of Index Lesion Severity (mCAILS) score from baseline after 6 weeks of therapy for cycle 1. For cycles 2 and 3, open label response rates were secondary end points. Adverse events (AEs) were assessed at each treatment visit, after each cycle, and then monthly for 6 months. Data analyses were performed on December 21, 2020. Results: The study population comprised 169 patients (mean [SD] age, 58.4 [16.0] years; 96 [57.8%] men; 120 [72.3%] White individuals) with early-stage MF/CTCL. After 6 weeks of treatment, hypericin PDT was more effective than placebo (cycle 1 ILRR, 16% vs 4%; P = .04). The ILRR increased to 40% in patients who received 2 cycles of hypericin PDT (P < .001 vs cycle 1 hypericin) and to 49% after 3 cycles (P < .001 vs cycle 1 hypericin). Significant clinical responses were observed in both patch and plaque type lesions and were similar regardless of age, sex, race, stage IA vs IB, time since diagnosis, and number of prior therapies. The most common treatment-related AEs were mild local skin (13.5%-17.3% across cycles 1-3 vs 10.5% for placebo in cycle 1) and application-site reactions (3.2%-6.9% across cycles 1-3 vs 4% for placebo in cycle 1). No drug-related serious AEs occurred. Conclusion and Relevance: The findings of this randomized clinical trial indicate that synthetic hypericin PDT is effective in early-stage patch and plaque MF/CTCL and has a favorable safety profile. Trial Registration: ClinicalTrials.gov Identifier: NCT02448381.