PRIMO Trial Design and Efficacy in Relapsed/Refractory PTCL

Zinzani details the design and outcomes of the PRIMO study, an international evaluation of duvelisib in relapsed or refractory peripheral T-cell lymphoma that enrolled a substantial cohort weighted toward the most common histologic subtypes. He explains the dose-optimization approach that informed an induction-and-maintenance strategy, with a higher dose used initially to maximize early response before reduction to limit cumulative toxicity. Zinzani reports overall and complete response rates that compared favorably with historical data from older agents, and both experts note how quickly responses often emerged, sometimes within a single cycle. They describe patients achieving durable remissions, with some bridged to allogeneic transplant and remaining in continuous response years later. Brammer underscores the particularly strong activity observed in the T-follicular helper and angioimmunoblastic subgroup, where response and complete response rates outpaced those seen in other subtypes, and notes that responses in this cohort proved durable even among patients who did not proceed to transplant.