Alemtuzumab is an effective third-line treatment versus single-agent gemcitabine or pralatrexate for refractory Sezary syndrome: a systematic review

The efficacy of alemtuzumab for the treatment of refractory Sezary syndrome (SS) versus other third-line agents such as pralatrexate and gemcitabine is poorly characterized. To elucidate the effectiveness of alemtuzumab versus other third-line options for the treatment of refractory SS, we conducted a meta-analysis of existing data. A systematic review was performed in March 2017 based on a search using Ovid-MEDLINE (R) and OVID-EMBASE (R) for articles evaluating single-agent alemtuzumab, gemcitabine, or pralatrexate for the treatment of SS and mycosis fungoides (MF). Twenty-two publications were identified that fulfilled all search criteria (total n = 323 patients), with six publications of lower quality being excluded from our analysis in order to decrease the risk of bias (final: n = 308 patients; 93 with SS and 147 with MF). Across all studies, alemtuzumab was significantly more effective in patients with SS (overall response rate [ORR]: 81%; complete response rate [CRR]: 38%) than patients with MF (ORR: 29%; CRR: 8%). However, gemcitabine was more effective than alemtuzumab or pralatrexate in treating MF. Alemtuzumab-treated patients had more frequent side effects, which were influenced by route of administration and dose. There was a lower incidence of lymphopenia and other serious adverse events in patients treated with subcutaneous (38%) compared to intravenous regimens (68%), and lower-dose (5%) compared to high-dose alemtuzumab regimens (54%). No significant differences were found in the effectiveness of different routes of administration or dosing regimens. Our review supports the use of low-dose subcutaneous alemtuzumab as a third-line treatment for SS.