In patients with leukemic cutaneous T-cell lymphoma, diffuse cutaneous erythema without plaques or tumors predicted complete remission with low-dose alemtuzumab therapy, investigators reported online April 23 in a JAMA Dermatology research letter.
"Initial clinical presentation was more predictive of response than was complex cellular phenotyping of T cells from blood and skin," wrote Dr. Rei Watanabe at Brigham and Women’s Hospital in Boston and associates. "In other words, the eyes of a well-trained dermatologist were more powerful than a comprehensive translational research program in identifying complete responders to LDA [low-dose alemtuzumab] therapy."
The researchers treated 23 patients with leukemic cutaneous T-cell lymphoma with 10 mg subcutaneous LDA three times weekly. Seventeen patients presented with diffuse erythema without superimposed plaques or tumors, of whom 13 experienced complete remission after LDA treatment and 4 had residual or emergent disease that could be controlled with skin-directed therapy (JAMA Dermatol. 2014 [doi:10.1001/jamadermatol.2013.10099]).
However, none of the six patients who presented with discrete patches, plaques, or tumors experienced full remission with LDA, the researchers reported. One patient later remitted with electron beam therapy, while five had their disease recur or progress, including two who developed large cell transformation.
Patients also were more likely to respond to LDA if more than 80% of their malignant T cells had TCM markers (CCR7+/L-selectin+), but clinical presentation better predicted response, the investigators reported.
"On a scientific level, diffuse erythema is likely caused by migrating T cells, and only T cells that migrate into blood are cleared by LDA," noted Dr. Watanabe and her associates. "Fixed skin lesions are more likely to be caused by TRM [nonmigratory skin resident memory T cells], cells that escape LDA clearance by remaining long-term in skin."
Based on the findings, the investigators recommended using LDA with or without adjuvant skin-directed treatments in patients who present with diffuse cutaneous erythema. But "we caution against its use in patients with preexisting plaques and/or tumors," the researchers said.
The Leukemia & Lymphoma Society, the National Institutes of Health, the Damon Runyon Cancer Research Foundation, and a private contribution from Edward P. Lawrence, Esq., funded the study. Coauthor Dr. Clark reported receiving honoraria from Novartis and Stiefel Laboratories. The authors disclosed no other conflicts of interest.