First-in-human Study of IDRX-42 in Adults With Metastatic and/or Unresectable Gastrointestinal Stromal Tumors

What this Trial Is About

Researchers are evaluating IDRX-42, an oral small molecule tyrosine kinase inhibitor, in adults with advanced gastrointestinal stromal tumors (GIST) that are metastatic or cannot be removed surgically. This first-in-human Phase 1/1b study aims to assess the safety, tolerability, pharmacokinetics, and early antitumor activity of IDRX-42, especially in patients who have previously had imatinib and other therapies. The study includes a special substudy to understand the drug's effects on heart electrical activity in a subset of participants. The trial has two parts: Phase 1 involves gradually increasing doses to determine the best dose and safety profile of IDRX-42 after prior imatinib failure. Phase 1b will enroll different groups of participants based on their previous GIST treatments to explore the drug's preliminary antitumor effects and further safety. Participants will take IDRX-42 once or twice daily in continuous 28-day cycles. The study includes multiple cohorts covering a range of prior treatments, including those who are treatment-naive but ineligible for standard therapies. Participants will be monitored through regular visits involving safety assessments, laboratory tests, and scans to measure tumor response using established criteria. Heart monitoring with ECGs will be done in a subset. The study measures outcomes like dose-limiting toxicities, response rates, progression-free survival, and survival over approximately 18 months. Participants must comply with drug administration and study procedures throughout the trial period.

First-in-human Study of IDRX-42 in Participants With Metastatic and/or Unresectable Gastrointestinal Stromal Tumors