Soquelitinib for R/R T-cell lymphomas: Phase I results

During the 67th American Society of Hematology (ASH) Annual Meeting and Exposition, December 6–9, 2025, Orlando, US, Richard Miller presented the final results from the phase I dose-escalation trial (NCT03952078) evaluating the safety and efficacy of soquelitinib, a selective interleukin-2-inducible T-cell kinase (ITK) inhibitor, in 75 patients with relapsed/refractory (R/R) T-cell lymphomas (TCL). In the dose-escalation cohort (n = 27), patients received 100 mg twice a day (BID), 200 mg BID, 400 mg BID, and 600 mg BID. The dose-expansion cohort (n = 48) received 200 mg BID. Primary endpoints included pharmacokinetics, dose-limiting toxicities (DLTs), and tumor responses.

Key data: Soquelitinib 200 mg demonstrated durable target occupancy. In patients with 1–3 prior therapies, median progression-free survival (PFS) was 6.2 months (18-month PFS, 30%), and median overall survival (OS) was 28.1 months (24-month OS: 67%). Durable responses were observed in patients with adequate baseline immunocompetence across peripheral T-cell lymphoma not otherwise specified (PTCL-NOS), T-follicular helper lymphoma (TFHL), natural killer T-cell lymphoma (NKTCL), anaplastic large cell lymphoma (ALCL), and cutaneous T-cell lymphoma (CTCL) histology. No DLTs were observed, and Grade ≥3 adverse events (AEs) occurred in 29.3% of all patients.

Key learning: Soquelitinib demonstrated durable objective responses with manageable toxicity in heavily pretreated patients with R/R TCL, particularly in patients with adequate baseline immunocompetence.