Mycosis fungoides (MF), CD4(+) epidermotropic
cutaneous T-cell lymphoma (CTCL), often arises as indolent, inflammatory, chronic, persistent patches and plaques. Conservative and sequential topical
therapy patients have the same survival as patients treated with aggressive
chemotherapy. Hence, until curative
therapy is found,
therapies that keep MF in check and prevent progression to more advanced
lymphoma may be desirable alternatives and may preserve quality of life. Stage IA patients with stable disease have a very favorable prognosis and often initially receive
psoriasis-type
therapy.
Bexarotene gel, a new topical
retinoid X receptor retinoid will resolve MF lesions, reducing dermal T-cell infiltrates when used as a single agent. However, it may be even more effective when combined with topical
steroids, with
phototherapy (ultraviolet B and
psoralen-ultraviolet A), or even with oral
bexarotene. The gel may also provide a safe adjunctive
therapy for individual lesions that are refractory to other agents, including keratodermas. When more than 10% of the body is involved with CTCL or when
adenopathy is present (> stage IB), systemic
therapy is indicated.
Bexarotene capsules have the advantage of easy
oral administration and are extremely effective both for early-stage patients with long-standing extensive plaques and for late-stage patients with Sézary syndrome or large-cell transformation. Monitoring of white blood cell count,
lipids, and thyroid function is required.
Bexarotene should be tested in combination with
interferon-alfa or other
therapies such as
photopheresis,
psoralen-ultraviolet A, and
methotrexate and for maintenance after total body skin electron beam.
DAB(389)IL-2 is targeted to CD25(+), the
interleukin-2 receptor on activated T cells as measured by the expression of CD25.
DAB(389)IL-2 has given complete or partial remission in 30% of highly refractory patients with extensive plaques and disfiguring
tumors. Because it is effective in killing T cells that surround dermal vessels,
cytokine release may occur and result in
capillary leak syndrome. Hence, it will be reserved for more advanced and refractory patients and will require
intravenous administration and monitoring. The use of oral
bexarotene first to reduce dermal infiltrates prior to
DAB(389)IL-2 administration might reduce subsequent side effects imparted by this
therapy. With three new highly effective agents in the armamentarium for the treatment of CTCL, new combination treatment algorithms can be tested to achieve maximal benefit and quality of life for these patients.