The Mechanism of Action of Chlormethine (CL) Gel in the Treatment of MF-CTCL Adult Patients

Chlormethine is a topical alkylating agent whose role in MF-CTCL has been extensively studied over the last 40 years. While its efficacy is well established, many safety concerns have been raised due to high rates of delayed cutaneous hypersensitivity to aqueous solutions that limit the prolonged use of chlormethine in clinical practice. It has been shown that complete response to topical chlormethine is associated with lower risk of disease progression. Accordingly, clinical data from the investigators' clinic confirm that chlormethine gel is a safe and effective treatment, which be used in early and advanced stages of cutaneous lymphomas. Based investigators' clinical and biological results , the investigators like to further investigate the change in the percentage as well as the profile of malignant and inflammatory cells by CyTOF analysis and further investigate the pathways (eg OX40, PDL1) involved in this process.

Sex

All

Minimum age

18 Years

Inclusion Criteria:

* MF-CTCL early-stage diagnosed patients, or late-stage patients that relapse without current active tumoral disease who still have patches and/or plaques.
* Age ≥ 18 years
* Patients naïve from CL gel treatment
* Early-stage patients who will be using CL as monotherapy: at enrolment without any concomitant MF treatment
* Early-stage patients if treated with other topical or systemic (late or early-stage patients) at enrolment, then a 2 week for topical steroids (and/or other topical treatment) and 4 weeks for systemic treatments wash out period will be required
* Women of child bearing potential must have a negative serum pregnancy test within 3 days prior enrolment.
* Women of child bearing potential should use adequate birth control measures, during the study treatment period until 30 days after treatment
* Women who are breast feeding should discontinue nursing prior to the first application of study treatment and until 30 days after the last study treatment
* Before patient enrolment, written informed consent must be given according to ICH/GCP

Exclusion Criteria:

* \- Patients diagnosed with stage III and IV, unless they meet the inclusion criteria for late stage disease (see above)
* Patients with multiple active tumors - progressive disease
* Patients with concomitant and chronic use of topical or systemic corticosteroids for the treatment of any other disease
* Patients treated with concomitant topical (except chlormethine gel) and/or systemic MF treatments who have missed the wash-out period (2 weeks for topical treatment and 4 weeks for systemic treatment)
* Acute flare or atopic dermatitis or other dermatosis in the last 3 weeks
* Pregnant and breast-feeding women
* Patients unable to comply with study procedures (e.g. provide written consent, fill in the questionnaires, geographical condition potentially hampering compliance with the study protocol and follow-up schedule).
* Known hypersensitivity to any component of the CL gel formulation
* Concurrent or planned local or systemic anti-CTCL therapies

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