Insights into treatment of patients with mycosis fungoides or Sézary syndrome using mogamulizumab

Mogamulizumab demonstrated improved outcomes <i>vs.</i> vorinostat across a range of disease and patient characteristics in patients with mycosis fungoides or Sézary syndrome in the MAVORIC trial. This <i>post-hoc</i> analysis further examined MAVORIC data to assess factors associated with long-term response (ORR &gt;12 months), time to next treatment (TTNT), and impact of concomitant steroid use, lymphopenia, and mogamulizumab-associated rash (MAR) on patient response. A higher proportion of patients achieved ORR lasting ≥4, 6, 8, or 12 months in the mogamulizumab <i>vs.</i> vorinostat arm. Long-term response was also observed in mogamulizumab-treated patients with more advanced disease (stage IVA1 [17/20], B2 blood involvement [18/20], and SS [14/20]). PFS was significantly longer (9.4 <i>vs.</i> 3.1 months; <i>p</i> &lt; 0.0001) in mogamulizumab <i>vs.</i> vorinostat-treated patients taking concomitant steroids. Mogamulizumab-treated patients experienced longer TTNT <i>vs.</i> vorinostat. Lymphopenia and MAR were associated with response to mogamulizumab. MAVORIC demonstrated greater efficacy with mogamulizumab <i>vs.</i> vorinostat in relapsed/refractory patients with CTCL, including those with more advanced disease. Concomitant steroid use improved ORR and PFS but did not impact vorinostat outcomes. Overall responses occurred more frequently in mogamulizumab-treated patients that developed lymphopenia than those that did not. A higher percentage of patients with MAR had an overall response than those without MAR.