Soquelitinib Monotherapy Yields Durable Responses in Peripheral T-Cell Lymphoma

Final data from the phase 1/1b clinical trial of soquelitinib in T-cell lymphoma demonstrated durable responses including complete responses (CRs) maintained for more than 2 years in some patients alongside a favorable safety profile across all dose cohorts, according to a news release from the developer, Corvus Pharmaceuticals.¹ Findings published in Blood and presented at the 2025 American Society of Hematology (ASH) Annual Meeting supports the ongoing registration phase 3 trial of soquelitinib in patients with relapsed/refractory peripheral T-cell lymphoma (PTCL), a disease for which no FDA-approved agents exist based on randomized clinical trials.²

What efficacy did soquelitinib demonstrate in the phase 1/1b trial?

In the 200 mg twice-daily dose cohort (n = 36), 6 patients achieved a CR. The clearest efficacy signal emerged in the prespecified subgroup of patients with 1 to 3 prior lines of therapy (n = 24), in whom the objective response rate (ORR) was 37.5% (n = 9/24), comprising 6 CRs and 3 partial responses. The median progression-free survival (PFS) in this group was 6.2 months, with 30% of patients remaining progression-free at 18 months. Moreover, the median overall survival (OS) was 28.1 months, and 67% of patients were alive at 24 months.

No dose-limiting toxicities were observed across any cohort, patients were given up to 600 mg twice daily, and no myelosuppression or immunosuppression was reported. A total of 29.3% of patients experienced grade 3 or higher AEs, including 37.5% of those treated in the 600 mg cohort (n = 16).

Historically, patients with relapsed/refractory PTCL treated with currently available salvage chemotherapy have a median PFS of approximately 3 to 4 months and a median OS of 6 to 12 months.

What was the soquelitinib phase 1/1b trial design?

The trial enrolled 75 patients who were heavily pretreated with T-cell lymphoma subtypes, including PTCL, T follicular helper cell lymphoma, natural killer/T-cell lymphoma, cutaneous T-cell lymphoma, anaplastic large cell lymphoma, and adult T-cell lymphoma/leukemia. The median number of prior therapies was 3 (range, 1-18), and only 31% of patients had responded to their most recent prior therapy.

In the dose escalation portion (n = 27), patients received soquelitinib at 100 mg, 200 mg, 400 mg, or 600 mg twice daily. Biomarker analyses demonstrating complete ITK target occupancy at doses of 200 mg or greater led to selection of 200 mg twice daily as the recommended phase 2 dose for the 48-patient expansion cohort. The median age on the study was 62 years (range, 21-84) and 57.3% of patients were male. Most patients had a baseline absolute lymphocyte count (ALC) of 900 or greater (80%).

What immunologic and mechanistic data were reported in Blood?

Soquelitinib (formerly CPI-818) is an investigational oral small molecule designed to selectively inhibit ITK (interleukin-2-inducible T-cell kinase), an enzyme predominantly expressed in T cells and natural killer cells. Selective ITK inhibition promotes Th1 T-cell differentiation while simultaneously blocking Th2 and Th17 differentiation, a mechanism relevant to both T-cell malignancies, in which tumor cells frequently express a Th2 phenotype, and immune-inflammatory conditions.

What is soquelitinib's regulatory and development status in R/R PTCL?

The FDA has granted soquelitinib orphan drug designation for T-cell lymphoma and fast track designation for adult patients with relapsed/refractory PTCL who have received at least 2 prior lines of systemic therapy.

The developers are currently enrolling patients in a registration phase 3 trial (NCT06561048) evaluating soquelitinib 200 mg twice daily vs physicians' choice of either belinostat (Beleodaq) or pralatrexate (Folotyn).³ The randomized trial is expected to enroll approximately 150 patients with relapsed/refractory PTCL who have progressed after 1 to 3 prior lines of therapy. The primary end point is PFS; secondary end points include OS, ORR, and duration of response.

“In patients with advanced, aggressive and difficult-to-treat T cell lymphomas, soquelitinib demonstrated durable responses, including [complete responses] maintained for more than 2 years in some patients and a median [OS] exceeding two years," stated Richard A. Miller, MD, co-founder, president and chief executive officer of Corvus Pharmaceuticals, in the press release.¹ "This compares favorably to currently available therapies, providing the rationale for our ongoing registration phase 3 trial in relapsed/refractory PTCL."

References

1. Corvus Pharmaceuticals announces publication in Blood of Final phase 1 data from the soquelitinib phase 1/1b T cell lymphoma trial. News release. Corvus Pharmaceuticals, Inc. August 27, 2026. Accessed August 27, 2026. https://tinyurl.com/t44utbf8
2. Miller, R, Wilcox R, Reneau J, et al. Final results of a phase 1 trial with soquelitinib (SQL), a selective interleukin-2-inducible T cell kinase (ITK) inhibitor for treatment of relapsed/refractory (R/R) T cell lymphomas (TCL). Presented at: 2025 American Society of Hematology Annual Meeting. December 12-15, 2026. New Orleans, LA
3. Soquelitinib vs standard of care in participants with relapsed/​refractory peripheral T-cell lymphoma not otherwise specified, follicular helper T-cell lymphomas, or systemic anaplastic large-cell lymphoma. ClinicalTrials.gov. Updated April 8, 2026. Accessed August 27, 2026. https://tinyurl.com/fkw3xy43