Mogamulizumab monotherapy achieves 41.2% overall response rate in patients with cutaneous T-cell lymphomasMogamulizumab Shows Meaningful Response in Cutaneous T-cell Lymphoma

Cutaneous T-cell lymphomas (CTCL) are heterogeneous skin malignancies. Mycosis fungoides (MF), followed by Sézary syndrome (SS), are the most prevalent. Mogamulizumab demonstrated a superior overall response rate (ORR) compared to vorinostat in the MAVORIC phase III trial, leading to regulatory approval for relapsed/refractory MF/SS; real-world efficacy remains poorly characterized. No systematic review has integrated the trial evidence with real-world data to estimate efficacy and safety. Systematic search on PubMed, Embase, and Cochrane CENTRAL from inception to February 16, 2026, for clinical trials and cohort studies reporting mogamulizumab monotherapy in CTCLs. This systematic review was prospectively registered in PROSPERO (CRD420251171992). Seven studies were included, comprising 453 CTCL patients with a median of two to three prior systemic therapies. Pooled ORR for CTCL was 41.2% (95% confidence intervals [CI] 30.2%-53.2%, I² = 81.4%). Pooled ORR for SS was 52.5% (95% CI 34.7%-69.7.% I² = 78.6.%), whereas the pooled ORR for MF was 31.1% (95% CI 21.1%-43.3% I² = 60.0%). A statistically significant subgroup difference was observed between SS and MF. The pooled blood compartment response rate was 82.6% (95% CI 67.4%-91.6%; I² = 72.7%), superior to the pooled skin compartment response rate of 43.7% (95% CI 38.8%-48.7%; I² = 0%). The pooled incidence of serious adverse events was 18.8% (95% CI 15.0%-23.3%; I² = 0.0%). Mogamulizumab demonstrates meaningful response in CTCL with greater activity in SS and those with blood involvement, suggesting preferential use in these populations.