Pembrolizumab and Mogamulizumab in Advanced-stage, Relapsed/Refractory Cutaneous T-cell Lymphomas

This is an open-label, single-arm, multicenter, phase II study combining pembrolizumab and mogamulizumab in patients with advanced-stage, relapsed or refractory CTCL Each cycle will equal 6 weeks. Pembrolizumab will be administered on Day 1 of each cycle. Mogamulizumab will be administered on Day 1, 8, 15, and 22 of Cycle 1. For Cycle 2 and subsequent cycles, mogamulizumab will be administered on Day 1, 15 and 29 of each cycle. Subjects will undergo a response assessment prior to Cycle 3 and every 2 cycles thereafter. Subjects will continue study treatment until documented progression, unacceptable toxicity, or any other condition for discontinuation is met in protocol. A maximum of 2 years of study treatment may be administered. If a subject achieves a complete response (CR) per mSWAT criteria after 3 months of study treatment (2 cycles), they will continue study therapy for an additional 6 months (4 cycles). If a confirmed and persistent CR is met, they may discontinue study treatment and enter an observation period in protocol. Repeat disease evaluation is required prior to study therapy discontinuation. Subjects who progress during the observation period may be eligible for up to an additional 9 cycles (1 year) of pembrolizumab and mogamulizumab.