Evaluating the Treatment Patterns of Chlormethine/Mechlorethamine Gel in Patients With Stage I-IIA Mycosis Fungoides: By-time Reanalysis of a Randomized Controlled Phase 2 Study

Advances in the pharmacological management of cutaneous T-cell lymphoma

INTRODUCTION

Current treatment guidelines for cutaneous T cell lymphoma (CTCL) advocate a stage-driven approach, considering clinical presentation, symptom burden, and patient comorbidities. Therapy selection hinges on factors like disease subtype, severity, and treatment availability. The primary goal is to enhance the quality of life by mitigating symptoms, as achieving lasting complete remission is infrequent.

AREAS COVERED

Over the past decade (2013-2023), the therapeutic landscape of CTCL has experienced substantial transformation with the introduction of innovative therapies. This review explores the main pivotal developments in traditional treatment schedules and recently introduced drugs, aiming to offer clinicians and researchers a thorough perspective on the decade's progress in the field.

EXPERT OPINION

Despite the progress made in CTCL therapeutics, ranging from topical chemotherapeutics to immunomodulatory agents, several unmet needs persist. Firstly, there is a pressing need for the incorporation of readily available predictors for treatment response, encompassing clinical, pathological, and molecular features. Secondly, a more profound comprehension of the tumor microenvironment is imperative to optimize the landscape of targetable molecules. Lastly, the undertaking of studies on combination regimens should be encouraged as it enhances therapy efficacies by synergistically combining agents with diverse modes of action.

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.

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.

EORTC consensus recommendations for the treatment of mycosis fungoides/Sézary syndrome - Update 2023

On behalf of the EORTC Cutaneous Lymphoma Tumours Group (EORTC-CLTG) and following up on earlier versions published in 2006 and 2017 this document provides an updated standard for the treatment of mycosis fungoides and Sézary syndrome (MF/SS). It considers recent relevant publications and treatment options introduced into clinical practice after 2017. Consensus was established among the authors through a series of consecutive consultations in writing and a round of discussion. Treatment options are assigned to each disease stage and, whenever possible and clinically useful, separated into first- and second line options annotated with levels of evidence. Major changes to the previous version include the incorporation of chlormethine, brentuximab vedotin, and mogamulizumab, recommendations on the use of pegylated interferon α (after withdrawal of recombinant unpegylated interferons), and the addition of paragraphs on supportive therapy and on the care of older patients. Still, skin-directed therapies are the most appropriate option for early-stage MF and most patients have a normal life expectancy but may suffer morbidity and impaired quality of life. In advanced disease treatment options have expanded recently. Most patients receive multiple consecutive therapies with treatments often having a relatively short duration of response. For those patients prognosis is still poor and only for a highly selected subset long term remission can be achieved with allogeneic stem cell transplantation. Understanding of the disease, its epidemiology and clinical course, and its most appropriate management are gradually advancing, and there is well-founded hope that this will lead to further improvements in the care of patients with MF/SS.

Mechanism of action of chlormethine gel in mycosis fungoides

Mycosis fungoides (MF), the most common type of cutaneous T-cell lymphoma, is characterized by proliferation of malignant skin-tropic T cells. Progression from early-stage disease (skin patches and/or plaques) to more advanced stages (cutaneous tumours, erythroderma or extracutaneous involvement) occurs slowly and can be discontinuous. Prognosis is poor for the ~25% of patients who progress to advanced disease. Patients at any stage of MF may experience reduced health-related quality of life (QoL) via a spectrum of physically and psychologically debilitating symptoms that can impact many aspects of daily life. Allogeneic stem-cell transplantation is a curative treatment option for some patients with advanced disease, but otherwise there is currently no cure for MF; patients are often refractory to several treatments and require lifelong management. The goals of therapy are symptom control, prevention of disease progression, avoidance of treatment-related toxicity and maintenance/improvement of QoL. Although treatment regimens exist it can be difficult to know how to prioritize them, hence therapies are tailored according to patient needs and drug availabilities, following clinical recommendations. International consensus guidelines recommend skin-directed therapies (SDTs) as first-line treatment for early-stage disease, and SDTs combined with systemic therapy for advanced stages. Chlormethine (CL), also known as mechlorethamine, chlorethazine, mustine, HN2, caryolysine and embichin, is a synthetic deoxyribonucleic acid-alkylating agent that was used as a chemical weapon (mustard gas) during the First World War. Subsequent investigation revealed that survivors of mustard gas exposure had lymphocytopenia, and that CL could inhibit rapidly proliferating malignant T cells. CL has since been developed as a topical treatment for MF and prescribed as such for over 70 years. This review aims to summarize the current knowledge regarding the mechanism of action of CL in the cutaneous micro-environment, in the specific context of MF treatment.

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.

Response to Chlormethine/Mechlorethamine gel Maintenance Treatment Regimen in Patients With Mycosis Fungoides: A Single-center Retrospective Study

BACKGROUND

Mycosis fungoides (MF), the most common subtype of Cutaneous T-cell lymphomas, is caused by malignant T-cell proliferations in the skin that can invade blood, lymph nodes, or viscera. Currently, data on efficacy of maintenance therapies in MF are lacking. We developed a unique protocol to use chlormethine/mechlorethamine 0.016% gel formulation as maintenance regimen for MF patients in remission.

PURPOSE

To determine progression-free survival and efficacy of chlormethine/mechlorethamine as maintenance and active treatment regimens for MF.

MATERIALS AND METHODS

A retrospective review of MF patients seen at Thomas Jefferson University from 2012 to 2020 was conducted. Patients of all stages treated with chlormethine/mechlorethamine as maintenance or active treatment with 2 consecutive mSWATs (modified Severity Weighted Assessment Tool) documented were included. Treatment outcomes were assessed by change in mSWAT and progression-free survival. Dermatology Life Quality Index surveys before and after treatment were analyzed.

RESULTS

Of 186 MF patients, 44 met inclusion criteria. Patients on maintenance therapy had a 65.22% progression-free survival rate with median time to progression of 29.45 months. By-time analysis for responders on active and maintenance treatment showed an increased response over time. Peak responses were seen at last mSWAT recorded. Both cohorts experienced improved quality-of-life scores from initiation to discontinuation of chlormethine/mechlorethamine.

CONCLUSION

Patients on maintenance and active chlormethine/mechlorethamine treatment regimens demonstrated improvement in mSWAT and quality-of-life. Chlormethine/mechlorethamine treatment showed progression-free survival for a median of 29.45 months, indicating this therapy may be an effective maintenance regimen.

Chlormethin-Gel zur Behandlung der Mycosis fungoides: Ein Expertenkonsens aus Deutschland, Österreich und der Schweiz (DACH-Region) zum Therapiemanagement

HINTERGRUND

Chlormethin-Gel ist in Europa zur Therapie von Patienten mit Mycosis fungoides in allen Krankheitsstadien zugelassen. Die optimalen Behandlungsregime hinsichtlich Frequenz, Dosierung, Kombinations- oder Erhaltungstherapien sind noch nicht vollständig etabliert.

METHODIK

Zehn in der Erforschung und Behandlung kutaner T-Zell-Lymphome erfahrene Experten aus Deutschland, Österreich und der Schweiz (DACH-Region) wurden schriftlich zu Indikation, Anwendungsfrequenz, Beurteilung des Therapieerfolgs, Begleittherapie, Nebenwirkungen, Kombinationstherapien in späteren Krankheitsstadien, Erhaltungstherapie und Adhärenz im Rahmen der Therapie der Mycosis fungoides mit Chlormethin-Gel befragt. Die strukturiert aufbereiteten Ergebnisse der Umfrage wurden in einer Konsensuskonferenz diskutiert und Empfehlungen zum Management der Therapie mit Chlormethin-Gel entwickelt.

ERGEBNISSE

Wesentlich für die Therapie mit Chlormethin-Gel ist ein individuelles, symptomorientiertes Therapiemanagement. Systemische Nebenwirkungen des Wirkstoffs sind wegen der fehlenden systemischen Verfügbarkeit bei topischer Anwendung unwahrscheinlich. Die häufig auftretende allergische oder irritativ-toxische Kontaktdermatitis kann durch eine Anpassung des Therapieregimes, Therapiepausen sowie nebenwirkungsspezifische und unterstützende Maßnahmen häufig beherrscht werden. Ein einschleichender Therapiebeginn mit Anwendung von Chlormethin-Gel jeden zweiten Tag kann die Tolerabilität wesentlich verbessern, insbesondere wenn die Therapie alternierend mit topischen Kortikosteroiden erfolgt.

SCHLUSSFOLGERUNGEN

Die Anwendung von Chlormethin-Gel bei Mycosis fungoides wird durch die begleitende Kontaktdermatitis häufig eingeschränkt. Mit einem geeigneten Therapie- und Nebenwirkungsmanagement können vermeidbare Therapieabbrüche verhindert werden und mehr Patienten von der Therapie profitieren.

Chlormethine gel is effective for the treatment of skin lesions in patients with early- and late-stage mycosis fungoides in clinical practice

BACKGROUND

Chlormethine gel is a skin-directed therapy used for patients with mycosis fungoides (MF) that showed a favorable risk/benefit profile in a randomized clinical trial. Currently, data on chlormethine gel use in real-world settings are limited.

OBJECTIVES

To assess safety and efficacy of chlormethine gel treatment in patients treated during daily clinical practice, and investigate associations between response and disease stage, lesion type, mono- or combination therapy, and occurrence of dermatitis.

METHODS

Clinical data from patients using chlormethine gel from three sites in Greece were analyzed. Efficacy was assessed through modified Severity-Weighted Assessment Tool (mSWAT) scores. Safety assessments included analysis of the occurrence and severity of dermatitis. The Skindex-29 questionnaire was used for quality-of-life assessments.

RESULTS

Fifty-eight patients were included. The overall response rate (ORR) increased from 37.9% at month 1 to 80.8% at month 9. For 64.2% of patients, response was maintained for at least 4 months (ORR4). At month 3, a higher ORR was seen for patients with patches (69.7%) than patients with plaques/tumors (both 15.2%). A higher ORR4 was observed for patients with early- vs late-stage disease (71.4% vs 36.4%) and patients on mono- vs combination therapy (75% vs 47.6%). Dermatitis was observed in the majority of patients (72.4%), but the presence or severity of dermatitis was not directly correlated with treatment response. Both mSWAT and Skindex-29 scores decreased significantly during treatment, and changes in these scores from baseline to month 6 showed a positive correlation (r = 0.55, P = 0.026).

CONCLUSIONS

Chlormethine gel was effective for treatment of skin lesions in patients with early- and late-stage MF in clinical practice. Response rates increased over time, indicating that continued treatment with the gel is important. Dermatitis may be managed by reducing the treatment frequency; the occurrence of dermatitis did not affect the response to treatment.

Post hoc Analysis of a Randomized, Controlled, Phase 2 Study to Assess Response Rates with Chlormethine/Mechlorethamine Gel in Patients with Stage IA-IIA Mycosis Fungoides

BACKGROUND

Mycosis fungoides (MF) is the most common form of cutaneous T-cell lymphoma. Patients can be treated using chlormethine gel, a skin-directed therapy developed and approved for MF. In the randomized, controlled 201 trial, chlormethine gel was found to be noninferior to equal-strength chlormethine ointment. However, there remains a need to gain more insight into outcome measures after treatment.

OBJECTIVE

The aim of this study was to further investigate the potential of chlormethine gel treatment through a novel post hoc analysis of the 201 trial data (NCT00168064).

METHODS

Patients were randomized to chlormethine gel or ointment; response assessments included Composite Assessment of Index Lesion Severity (CAILS) and total body surface area (BSA). In this post hoc analysis, additional subgroup response analyses were performed for stage IA/IB-IIA MF. Very good partial response (75 to <100% improvement) was included as an additional response category. Time to response and overall response trends were determined. Finally, multivariate time-to-event analyses were performed to determine whether associations were observed between treatment frequency, response, and adverse events.

RESULTS

Response rates were significantly higher for patients with stage IA MF for CAILS (intent-to-treat [p = 0.0014] and efficacy-evaluable [EE; p = 0.0036] populations) and BSA (EE population [p = 0.0488]) treated with gel versus ointment. Time to first CAILS response and response trends were better for all-stage gel-treated patients overall. No association was seen between treatment frequency and response or occurrence of adverse events at the following visit. An association was observed between the occurrence of contact dermatitis and improved clinical response at the next visit (p = 0.0001).

CONCLUSION

This post hoc analysis shows that treatment with chlormethine gel may result in higher and faster response rates compared with chlormethine ointment, which confirms and expands results reported in the original analysis. The incidence of contact dermatitis may potentially be a prognostic indicator for clinical response; this needs to be confirmed in a larger population.