First-in-Human Study of PLX-61639 in Locally Advanced or Metastatic Solid Tumors

A multicenter, single-arm, first-in-human study to investigate the safety, pharmacokinetics, and preliminary antitumor activity of PLX-61639 in participants with locally advanced or metastatic, relapsed/refractory, SMARCA4-deficient solid tumors who are intolerant of or have failed available, approved therapies. The study will be conducted in 3 parts: dose escalation (Part 1), dose optimization (Part 2), and cohort expansion (Part 3). Each part of the study will consist of a Screening Phase lasting up to 28 days during which participants will be assessed for eligibility, a Treatment Phase beginning on Cycle 1 Day 1 and consisting of consecutive 28-day cycles, an End of Treatment Visit, and a Post-Treatment Follow-Up Phase. Participants will receive their assigned dose of PLX-61639 administered orally, once daily until progression/relapse, intolerance, death, or withdrawal from study treatment by the Investigator or participant.

NCT Number	NCT07284186
Lead Sponsor	Plexium, Inc.
Conditions	Esophageal Squamous Cell Carcinoma, Gastric Adenocarcinoma, Gastric Squamous Cell Carcinoma, Gastroesophageal Junction (GEJ) Adenocarcinoma, Metastatic Solid Tumor, Non-Small Cell Lung Carcinoma, Esophageal Adenocarcinoma, SMARCA4 Mutation +2 more
Enrollment	155 participants
Start Date	2025-12-01
Primary Completion	2029-12 (estimated)
Study Completion	2030-09 (estimated)
Updated on ClinicalTrials.gov	2026-06-12