Clinical Trial of High-Dose Pegylated-Interferon-Alfa-2b Combined With Phototherapy in Advanced Stage Mycosis Fungoides

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.

Transitioning to Pegylated Interferon for the Treatment of Cutaneous T-Cell Lymphoma: Meeting the Challenge of Therapy Discontinuation and a Proposed Algorithm

Cutaneous T-cell lymphoma (CTCL) is an uncommon non-Hodgkin lymphoma characterized by skin involvement, with the most recognized subtypes being mycosis fungoides (MF) and Sezary syndrome (SS). Interferon has been an established treatment for MF/SS since 1984 and is integrated into management guidelines internationally. In 2019, manufacturers abruptly discontinued interferon-α2b and interferon-α2a. Many alternative systemic therapies in MF/SS remain unfunded or unavailable in Canada, presenting a unique challenge. Although off-label use of pegylated interferon is a logical substitute, there are no established dosing guidelines and limited published experience. This case series provides a single-center experience on pegylated interferon-α2b for treatment of MF/SS, a suggested management algorithm, and a review of the literature. All patients identified in the Calgary Cutaneous Lymphoma Program with stage IIB–IVB MF/SS treated with interferon-α2b (4.5–9 MU/week) were switched to once weekly pegylated interferon (90 μg, 0.5 mL) between February and July 2021. Response was monitored using the mSWAT and SkinDex-29 tools. Eight patients were switched to pegylated interferon, with a median disease duration of 69 months (range: 8–275 months). Five out of eight patients remain on pegylated interferon, with the remainder having switched to preplanned therapies. Two patients required dose reduction due to side effects, including grade II anemia and mood changes. The remaining patients had normal laboratory investigations and no additional side effects. Uncommon lymphomas like MF/SS have limited treatment options, and the impact of abrupt product discontinuation is substantial. We propose a management algorithm for the transition of patients from interferon to pegylated interferon.

Mycosis fungoides and Sézary syndrome

Mycosis fungoides (MF) and Sézary syndrome (SS) are primary cutaneous T-cell lymphomas (CTCL) with not yet fully understood etiology and pathogenesis. Conceptually, MF and SS are classified as distinct entities arising from different T helper cell subsets. MF is the most common CTCL entity, while SS is very rare. MF presents clinically with patch, plaque and/or tumor stages, but can also evolve as erythroderma, which in turn is pathognomonic for SS. SS is characterized by a detectable tumor-cell burden (Sézary cells) in the peripheral blood consistent with advanced-stage disease and a poor prognosis. In early-stage disease of MF, which is the predominant form, the prognosis is generally favorable. However, in up to 30 % of patients, there is progression of skin lesions, which can ultimately lead to visceral involvement. The histological manifestation of MF can be subtle in early-stage disease and therefore a careful clinicopathological correlation is paramount. The treatment of MF/SS is dependent on the disease stage. Therapeutic options include both skin-directed and systemic regimens. Apart from allogeneic stem cell transplantation (alloSCT), there is as yet no curative therapy for MF/SS. Accordingly, the treatment approach is symptom oriented and aims to reduce the tumor burden and improve health-related quality of life. However, the therapeutic landscape for CTCL is constantly being expanded by the discovery of novel therapeutic targets.