Denileukin diftitox for the treatment of CD25 low-expression mycosis fungoides and Sézary syndrome.

In a placebo-controlled study, denileukin diftitox (DD) was effective against cutaneous T-cell lymphoma (CTCL) expressing CD25. An open-label companion study examined the efficacy and safety of DD in 36 patients with skin biopsies containing < 20% CD25 cells by immunohistochemistry staining (CD25 low expression). Patients received DD 18 µg/kg/day for 5 consecutive days every 3 weeks for up to eight courses. The primary endpoint, overall response rate, was 30.6% (95% confidence interval: 16.3, 48.1), 33.3% for stage IIA or lower disease, and 26.7% for stage IIB or greater disease. Median progression-free survival (PFS) was > 487 days, and median time to treatment failure was 68.5 days. No difference in PFS by disease stage was observed. The safety profile of DD in CD25 low-expression disease was similar to that in CD25+ disease. These findings suggest that CD25 low expression does not preclude a meaningful clinical response to DD in patients with CTCL.

Efficacy and safety of denileukin diftitox retreatment in patients with relapsed cutaneous T-cell lymphoma.

This open-label phase III trial, a companion to an earlier placebo-controlled trial, evaluated safety and efficacy of denileukin diftitox (DD) in patients with cutaneous T-cell lymphoma (CTCL) who relapsed after responding to DD primary treatment in the earlier trial. Twenty relapsed patients (stages IA-III) received DD 18 µg/kg/day intravenously on days 1-5 of a 21-day cycle, for ≤ 8 cycles. Efficacy was assessed monthly during the first year then every 3 months. The overall response rate was 40%, mostly partial responses. Nine patients (all baseline stages ≤ IIA) experienced progression. Intent-to-treat median progression-free survival was 205 days, and median duration of response was 274 days. The most common adverse events were nausea, upper respiratory tract infections, fatigue and rigors. Three patients withdrew because of toxicity. This study showed that DD may provide clinically meaningful benefit in patients with CTCL who relapsed after initial response to DD.

Topical bexarotene therapy for patients with refractory or persistent early-stage cutaneous T-cell lymphoma: results of the phase III clinical trial.

OBJECTIVES: We sought to determine the safety and efficacy of topical bexarotene (Targretin; Ligand Pharmaceuticals, La Jolla, Calif) gel 1% in patients with refractory or persistent early-stage cutaneous T-cell lymphoma. METHODS: We conducted a multinational, open-label, phase III study of 50 patients with stage IA to IIA cutaneous T-cell lymphoma. The primary end point classification was the overall complete and partial response rate by the higher of 2 measures: the Physician's Global Assessment of Clinical Condition or the Composite Assessment of Index Lesion Disease Severity. RESULTS: The overall response rates for the Physician's Global Assessment of Clinical Condition, Composite Assessment of Index Lesion Disease Severity, and primary end point classification were 44%, 46%, and 54%, respectively. The most common adverse events possibly related to study medication were mild to moderate irritant dermatitis, pruritus, pain (ie, primarily burning at application site), and skin disorder (eg, skin inflammation, excoriation, and new lesions). There were no serious treatment-related adverse events. CONCLUSIONS: Topical bexarotene gel was generally well tolerated and demonstrated substantial efficacy in patients with refractory or persistent early-stage cutaneous T-cell lymphoma.

Bexarotene gel: a new skin-directed treatment option for cutaneous T-cell lymphomas.

Cutaneous T-cell lymphomas (CTCLs) are a relatively uncommon group of lymphoproliferative disorders in which a malignant population of T cells is localized to the skin at presentation. Of the 4 classic CTCL phases (patches, infiltrated plaques, tumors, Sézary syndrome), the majority of patients present with early stage patch or plaque disease, which can usually be effectively managed using skin-directed therapies. Traditional skin-directed therapies include topical corticosteroids, topical chemotherapeutic agents (mechlorethamine, carmustine), electron beam therapy (local and total skin), and phototherapy (UV-A, UV-B). Each of these has demonstrated efficacy in early stage disease; however, with the exception of topical corticosteroids, all have some disadvantages and are associated with significant adverse events, particularly secondary skin malignancies and skin damage. Bexarotene is a synthetic retinoid analog that selectively activates retinoid X receptors. In clinical trials, bexarotene gel demonstrated efficacy for the topical treatment of cutaneous lesions in patients with stage IA or IB CTCL who have refractory or persistent disease following other therapies or who cannot tolerate other therapies. Initial evidence indicates that bexarotene gel may be active as first-line therapy in early stage disease. Its role in combination with other treatments remains to be determined. Topical bexarotene gel is generally well tolerated and offers patients greater convenience compared with traditional skin-directed therapies, with a flexible administration regimen. The availability of bexarotene gel provides patients and physicians with a new skin-directed treatment option for early stage CTCL.

Quality-of-life improvements in cutaneous T-cell lymphoma patients treated with denileukin diftitox (ONTAK).

Cutaneous T-cell lymphoma (CTCL) can be associated with painful, pruritic, disfiguring lesions. As part of a multicenter, randomized phase III trial in patients with heavily pretreated advanced and/or recurrent CTCL, the effects of an interleukin-2 receptor-targeted fusion protein, denileukin diftitox (DAB389IL-2, ONTAK), on patient-rated overall quality of life (QOL), skin appearance, and pruritus severity were evaluated. A total of 71 patients with stage IB-IVA CTCL received intravenous denileukin diftitox 9 microg/kg/day or 18 microg/kg/day over 15-60 minutes for 5 consecutive days on an outpatient basis; cycles were planned for every 21 days for a total of 8 cycles over 6 months. Prior to each treatment cycle, patients were evaluated for disease response and were asked to self-rate their overall QOL via the Functional Assessment of Cancer Therapy-General (FACT-G) questionnaire, skin appearance (7-point scale), and pruritus severity (10-cm visual analogue scale). Composite FACT-G and most individual subscale scores (physical, social/family, emotional, and functional well being) in documented responders (n = 21) gradually increased during the study period, generally reaching statistical significance (P < 0.05) by cycle 3, and were significantly (P < or = 0.041) higher than the scores of nonresponders at endpoint. Additionally for responders, assessments of skin severity and pruritus severity showed significant (P < or = 0.05) improvements at study endpoint compared with baseline. Adverse transfusion-related events (eg, hypersensitivity reactions, flu-like syndrome) were common during cycles 1 and 2, and vascular-leak syndrome occurred in 25% of patients. Denileukin diftitox was not associated with any clinically significant myelosuppression. Heavily pretreated patients with advanced and/or recurrent CTCL who responded to denileukin diftitox therapy showed significant improvements in self-rated overall QOL, skin appearance, and pruritus severity.