Background The treatment of mycosis fungoides (MF), the most common form of primary cutaneous lymphoma T cells, depends on clinical staging. In the presence of lesions in patch/plaque the use of phototherapy, retinoids, immunomodulators and radiotherapy is common in the early stages and in the presence of disseminated nodular lesions the use of systemic chemotherapy.

Purpose The possibility to have a preparation of topical chemotherapy available, which can be used alone or in combination with other treatments, could be an important therapeutic option. Thus topical formulations of mechlorethamine with characterisation and evaluation stability were developed. The authors then proceeded to the evaluation of the clinical activity and the tolerability of the topical preparation based mechlorethamine 0.02% in the treatment of plaque and nodular lesions of MF. Materials and Methods Various lipophilic and hydrophilic formulations were prepared and characterised. Mechlorethamine 0.02% in Aquaphor ointment base was identified and characterised for chemical and microbiological stability for clinical investigation. After informed consent, 6 patients, median age 67 years (48 -88), whose disease had relapsed after chemotherapy were treated. The galenic preparation was applied daily for the treatment of 11 lesions, 5 days / week for up to 3 weeks. The response was evaluated after treatment using the RECIST criteria.

Results The use of mechlorethamine has been improved in order to obtain a new preparation technique in consideration of instrumental resources available in a hospital pharmacy and the difficulty of handling cytostatic drugs for topical formulations. 11 lesions were treated, a partial clinical response was obtained in 5 and a complete response in 2. In all the cases, the treatment was well tolerated, 2 patients developed short-lived erythema / oedema peri-lesional. There was no evidence of systemic toxicity.

Conclusions Based on these preliminary results, topical application of mechlorethamine has been well tolerated and associated with good clinical activity. The encouraging results obtained in this preliminary phase encouraged us to continue the study on a larger number of patients.