Vieyra-Garcia P, et al. - In this randomized clinical trial of 27 patients with mycosis fungoides, the most common type of cutaneous T-cell lymphoma, researchers assessed low-dose, low-frequency psoralen—UV-A (PUVA) and if maintenance treatment in patients with mycosis fungoides prolongs disease-free remission. According to this proof-of-concept study, potential biomarkers in mycosis fungoides for therapeutic response to PUVA have been identified. In addition, it showed that low-dose, low-frequency PUVA seems to be highly efficacious, and maintenance treatment can prolong disease-free remission. During the induction or maintenance phase of PUVA, no severe adverse effects were seen.

Methods

• Prospective randomized clinical trial in five centers (Graz, Vienna, Hietzing, Innsbruck, and Salzburg) across Austria with defined PUVA dosing regimen.
• Subjects with stage IA to IIA mycosis fungoides (n = 27) were recruited in the study starting on March 13, 2013 with the last patient enrolled on March 21, 2016.
• These patients received oral 8-methoxypsoralen followed by UV-A exposure 2 times per week for 12 to 24 weeks until CR; for 9 months (14 total exposures), patients with CR were randomized to no maintenance or PUVA maintenance.
• From April 27, 2012 to July 27, 2018, the study was conducted.
• Main outcomes and measures included effectiveness of the PUVA regimen determined by the rate of CR defined by a modified severity-weighted assessment tool (mSWAT) score reduction to 0.
• To evaluate clinical response, levels of proinflammatory molecules in serum and histologic features and percentage of clonal T cells in skin were assessed.

Results

• In 27 mycosis fungoides patients, 19 (70%) were male with mean (range) age 61 (30-80) years.
• Patients with CR had a mean (range) mSWAT score of 18.6 (1-47) vs 16.8 (3-46) in patients with partial response at baseline.
• In all patients, induction of PUVA treatment reduced the mSWAT score.
• In 19 (70%) of 27 patients, the 12- to 24-week PUVA induction regimen resulted in CR and a low mean cumulative UV-A dose of 78.5 J/cm².
• The ensuing standardized 9-month maintenance phase of PUVA extended median (range) disease-free remission from 4 (1-20) months to 15 (1-54) months (P=.02).
• High histological infiltrate density and high percentage of clonal TCR sequences in skin biopsy specimens at baseline were inversely linked to therapeutic response.
• During the PUVA induction or maintenance phase, no severe adverse effects were observed.