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

• Status: Not yet recruiting
• Trial end date: 2026-09-13
• Target enrollment: 0
• Participant gender: All

Summary

This is the first clinical trial of IDRX-42. The study is designed to evaluate the safety, tolerability, PK, and preliminary antitumor activity of IDRX-42 in adult participants with advanced (metastatic and/or surgically unresectable) GIST.

• Phase: Phase 1
• Accepts Healthy Volunteers?: No

Details

• Lead Sponsor: IDRx, Inc.

Criteria

Inclusion Criteria:

Phase 1

1. Male or female participants ≥18 years of age

2. Histologically or cytologically confirmed metastatic and/or surgically unresectable GIST

3. Documented progression on imatinib (Phase 1)

4. Documented pathogenic mutation in KIT OR any PDGFRA mutation other than exon 18 mutations, determined through local testing

5. At least one measurable lesion by mRECIST v1.1 for participants with GIST

6. Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1

7. Resolution of any toxicities from prior treatment(s) to ≤ Grade 1 by NCI CTCAE v5.0 criteria, or have resolved to baseline, at the time of first dose of study drug.

8. Willing and able to comply with scheduled visits, drug administration plan, laboratory tests, or other study procedures and study restrictions.

Additional for Phase 1b Exploratory Cohorts

1. For Cohort 1, progressed on imatinib only (second line therapy)

2. For Cohort 2, progressed on both imatinib and sunitinib (third line therapy) or progressed on imatinib, sunitinib, and an additional agent (i.e., regorafenib or ripretinib) (fourth line therapy)

3. For Cohort 3, progressed on at all U.S. -approved TKI therapies for KIT-mutant GIST [imatinib, sunitinib, regorafenib, and ripretinib] (fifth line or greater therapy)

Exclusion Criteria:

1. Any prior exposure to the following investigational agents NB003 or THE-630 or bezuclastinib plus sunitinib combination.

2. GIST with no documented mutation in both KIT and PDGFRA genes.

3. Any prior primary CNS malignancy or known untreated or active central nervous system metastases.

4. Has an active uncontrolled infection, including, but not limited to, the requirement for intravenous antibiotics.

5. Has significant, uncontrolled, or active cardiovascular disease.