A phase III, randomized, double-blind, placebo-controlled study of peldesine (BCX-34) cream as topical therapy for cutaneous T-cell lymphoma

Background: The purine nucleoside phosphorylase inhibitor peldesine is a new agent being evaluated as a T-cell inhibitor. Objective: We attempted to determine the efficacy of peldesine (BCX-34) in a 1% dermal cream formulation as a treatment for cutaneous T-cell lymphoma (CTCL). Methods: Ninety patients with patch and plaque phase CTCL, histologically confirmed by a referee dermatopathologist, were enrolled in a randomized, double-blind, placebo-controlled study BCX-34 dermal cream 1% or the vehicle cream las a placebo control was applied twice daily to the entire skin surface for up to 24 weeks. Efficacy of the topical therapy was assessed in terms of complete or partial (greater than or equal to 50%) clearing of patches and plaques. Results: Of the 89 patients able to be examined, 43 received BCX-34 and 46 received the placebo vehicle cream. One patient withdrew early and was not analyzed. The two groups were well balanced for potential prognostic factors. A total of 28% (12/43) of the patients treated with BCX-34 showed a response, but 24% (11/46) of patients who received vehicle also responded (P = .677). Conclusion: Although BCX-34 dermal cream 1% was not significantly better than the control as therapy fur patch and plaque-phase CTCL, this appears to be the first published placebo-controlled trial evaluating treatment for CTCL. Whether the vehicle cream has more than a placebo therapeutic effect is unclear. The relatively high (24%) placebo response rate should be kept in mind in assessing other treatments for early-stage CTCL.