Clinical Trial

A Study of Lonitoclax (ZE50-0134) in Relapsed or Refractory B-cell Malignancies

Recruiting Phase 1

Summary

This Phase 1, open-label, multicenter study is evaluating the safety, tolerability, pharmacokinetics, pharmacodynamics, and preliminary antitumor activity of lonitoclax (ZE50-0134) in adults with relapsed or refractory chronic lymphocytic leukemia (CLL), small lymphocytic lymphoma (SLL), and select low-grade B-cell lymphomas. The study has two sequential parts. Part 1 uses dose escalation to determine the biologically effective dose and/or maximum tolerated dose of lonitoclax. Participants receive a 3-day step-up regimen followed by continuous once-daily or twice-daily oral dosing in 28-day cycles. Part 2 is a randomized dose-expansion comparison of two selected lonitoclax dose levels in venetoclax-naive participants with relapsed or refractory CLL/SLL. Treatment may continue for up to 12 cycles and, for participants deriving clinical benefit, for up to 24 cycles with approval from the Medical Monitor.

Protocol Amendment History 5 changes

critical Primary endpoint(s) modified 2026-08-01

notable Enrollment increased: 66 -> 84 participants 2026-08-01

minor Trial arms changed: 8 -> 12 2026-08-01

notable Primary completion pushed: 2026-03 -> 2028-01 2026-08-01

minor Completion pushed: 2028-04 -> 2028-07 2026-08-01

Trial Details

NCT Number	NCT06708897
Lead Sponsor	Lomond Therapeutics Holdings, Inc.
Conditions	CLL / SLL, CLL (Chronic Lymphocytic Leukemia), SLL (Small Lymphocytic Lymphoma), Marginal Zone Lymphoma(MZL), Lymphoplasmacytic Lymphoma/Waldenström Macroglobulinemia
Enrollment	84 participants
Start Date	2025-04-08
Primary Completion	2028-01 (estimated)
Study Completion	2028-07 (estimated)
Updated on ClinicalTrials.gov	2026-07-31