Larkspur opens dosing in first-in-human trial of oral LRK-4189 for advanced tumors
The Phase 1/2 study moved to recruiting with enrollment unchanged at 120, starting a safety and dose-finding trial with a primary completion date of June 2029.
Executive Summary
- Larkspur Biosciences' first clinical trial of its oral compound LRK-4189 moved from not-yet-recruiting to actively enrolling patients with advanced tumors.
- The study is designed to characterize safety and tolerability across doses and regimens before any efficacy claim can be assessed, the standard sequence for a first-in-human oncology program.
- The trial's primary completion date sits years out, meaning the status change advances the program's start without yet producing a data readout to evaluate.
- The compound's target and mechanism are not established in available records, so its position relative to other advanced-tumor programs cannot yet be benchmarked on mechanism, only on stage and design.
The status change
The trial, registered as NCT07498725, updated its ClinicalTrials.gov status from Not yet recruiting to Recruiting, with dosing now underway at sites in France and the United Kingdom. The study carries a title describing its purpose plainly: to evaluate the safety, tolerability and preliminary efficacy of LRK-4189 alone and in combination in patients with advanced tumors. The actual start date landed at July 7, 2026, close to the initially anticipated May 2026 window. NCT07498725A Study to Evaluate the Safety, Tolerability and Preliminary Efficacy of LRK-4189 Alone and in Combination in Patients With Solid TumorsNCT07498725
Probability of SuccessBased on the AppliedXL Probability of Success model. For more information about the methodology, read the research here.
The design
The Phase 1/2 study targets 120 adult patients with locally advanced or metastatic cancer that has progressed despite prior treatment, an ECOG performance status of 0 to 1, and measurable disease. Patients enter in the second line or later. The primary endpoint is the evaluation of treatment-related adverse events and toxicity, presented by dose, regimen and tumor type, measured from enrollment through the end of the first 21-day treatment cycle. That endpoint structure identifies this as a dose-escalation and tolerability study, not a trial built to demonstrate efficacy on its own; regulatory records list it as non-registrational. NCT07498725A Study to Evaluate the Safety, Tolerability and Preliminary Efficacy of LRK-4189 Alone and in Combination in Patients With Solid TumorsNCT07498725
Enrollment and operations
The enrollment target held at 120 patients before and after the status change, a flat figure that the operational model flags as within its routine band for this type of update. The trial's protocol history since its March 2026 registration shows one status transition and no amendments to endpoints, eligibility, or the primary completion date, which remains set for June 1, 2029. That combination, an on-schedule start with an unchanged target and a stable protocol, is the profile of a trial proceeding as designed rather than one under operational strain. NCT07498725A Study to Evaluate the Safety, Tolerability and Preliminary Efficacy of LRK-4189 Alone and in Combination in Patients With Solid TumorsNCT07498725
The competitive field
LRK-4189's target and mechanism are not established in available records, so its position cannot be benchmarked against other advanced-tumor programs on that basis. The broader advanced-tumor field carries dozens of Phase 3 programs from sponsors including Merck, GlaxoSmithKline, AbbVie, and Pfizer, but none of the identified programs share LRK-4189's mechanism, and no direct comparator exists in the current competitive set. Larkspur has one other active trial of any kind on record, this one, giving it a single program on which to build a clinical track record.
This analysis was produced using AI-assisted reporting systems, AppliedXL data, and official public records. These systems undergo editorial review, quality checks, and regular audits by human experts. Errors may still occur, as with any automated system. Always consult the linked primary sources. Read our AI Editorial Policy.