A First-in-human (FIH) Study of IDRX-42 in Participants With Metastatic and/or Unresectable Gastrointestinal Stromal Tumors
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ClinicalTrials.gov Identifier: NCT05489237 |
Recruitment Status :
Recruiting
First Posted : August 5, 2022
Last Update Posted : May 26, 2023
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Condition or disease | Intervention/treatment | Phase |
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Gastrointestinal Stromal Tumor (GIST) Digestive System Disease Gastrointestinal Diseases Metastatic Cancer | Drug: IDRX-42 | Phase 1 |
Study Type : | Interventional (Clinical Trial) |
Estimated Enrollment : | 143 participants |
Allocation: | Non-Randomized |
Intervention Model: | Parallel Assignment |
Masking: | None (Open Label) |
Primary Purpose: | Treatment |
Official Title: | A First-in-human (FIH) Study of IDRX-42 in Participants With Metastatic and/or Unresectable Gastrointestinal Stromal Tumors (GIST) |
Actual Study Start Date : | August 1, 2022 |
Estimated Primary Completion Date : | April 24, 2026 |
Estimated Study Completion Date : | September 13, 2026 |

Arm | Intervention/treatment |
---|---|
Experimental: Dose Escalation (Phase I)
Participants should have advanced (metastatic and/or surgically unresectable) GIST, following failure of at least prior imatinib therapy due to progression of GIST.
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Drug: IDRX-42
IDRX-42 will be administered at assigned doses and schedules once daily in continuous cycles of 28 days each. |
Experimental: (Phase 1b) Cohort 1 - Participants with GIST progression after first-line imatinib therapy
Participants with advanced GIST who have had GIST progression only after first-line imatinib only (second line therapy setting).
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Drug: IDRX-42
IDRX-42 will be administered at RP2DS once daily in continuous cycles of 28 days each. |
Experimental: (Phase 1b): Cohort 2 - Participants with GIST progression after 2nd OR 3rd line TKI therapy
Participants with metastatic and/or surgically unresectable GIST following progression EITHER after sequential imatinib then sunitinib (third-line therapy setting) OR after imatinib, sunitinib, and then an additional TKI agent (i.e., regorafenib or ripretinib) (fourth-line therapy setting).
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Drug: IDRX-42
IDRX-42 will be administered at RP2DS once daily in continuous cycles of 28 days each. |
Experimental: (Phase 1b): Cohort 3 - Participants with GIST progression after 4th or greater lines of TKI therapy
Participants with advanced GIST who have had GIST progression after 4th line or greater lines of TKI therapy (failure due to progression of all available agents (imatinib, sunitinib, regorafenib, ripretinib, and possibly others (> 5th line therapy setting)
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Drug: IDRX-42
IDRX-42 will be administered at RP2DS once daily in continuous cycles of 28 days each. |
- Phase 1 (Dose Escalation) - Safety and Tolerability (Nature, incidence, and severity of any DLTs) [ Time Frame: When participant completes 1 cycle (28days) treatment with safety and tolerability assessment by investigators ]
- Phase 1 (Dose Escalation) - Safety and Tolerability (Nature, incidence, and severity of any DLTs) [ Time Frame: Approximately18 months from first participant enrolled ]
- Phase 1 (Dose Escalation) - Determination of the MTD and/or RP2DS of orally administered IDRX-42 [ Time Frame: Approximately18 months from first participant enrolled ]
- Phase 1b-Number of participants with TEAEs and with laboratory test results [ Time Frame: Approximately18 months ]
- Phase 1b - Objective Response Rate (ORR) mRESIST v1.1 [ Time Frame: Approximately 18 months ]
- Phase 1 (Dose Escalation)- Number of participants with non-DLT TEAEs and with laboratory test results [ Time Frame: 6 months ]
- Phase 1 (Dose Escalation) - ORR per mRECIST v1.1 [ Time Frame: 6 months ]
- Phase 1 (Dose Escalation) - Cmax; Maximum Observed Concentration of IDRX-42 [ Time Frame: At the end of Cycle 1 Day 1 and at the end of Cycle 2 Day 1 (each cycle is 28 days) ]
- Phase 1 (Dose Escalation) - Tmax; Time of First Occurrence of Maximum Plasma Concentration (Cmax) of IDRX-42 [ Time Frame: At the end of Cycle 1 Day 1 and at the end of Cycle 2 Day 1 (each cycle is 28 days) ]
- Phase 1 (Dose Escalation) - AUC 0-24; Area Under the Concentration-time Curve from Time Zero to 24 hours for IDRX-42 [ Time Frame: At the end of Cycle 1 Day 1 and at the end of Cycle 2 Day 1 (each cycle is 28 days) ]
- Phase 1 (Dose Escalation) - Duration of response (DOR) per mRECIST v1.1 [ Time Frame: 6 months ]
- Phase 1 (Dose Escalation) - Time to response (TTR) per mRECIST v1.1 [ Time Frame: 6 months ]
- Phase 1 (Dose Escalation) - Progression-free survival (PFS), per mRECIST v1.1 [ Time Frame: 6 months ]
- Phase 1b- Duration of response (DOR) per mRECIST v1.1 [ Time Frame: 18 months ]
- Phase 1b - PFS per mRECIST v1.1 [ Time Frame: 18 months ]
- Phase 1b - Clinical benefit rate (CBR) per mRECIST v1.1 [ Time Frame: 18 months ]
- Phase 1b - TTR per mRECIST v1.1 [ Time Frame: 18 months ]
- Phase 1b - Cmax; Maximum Observed Concentration of IDRX-42 [ Time Frame: At the end of Cycle 1 Day 1 and at the end of Cycle 2 Day 1 (each cycle is 28 days) ]
- Phase 1b - Tmax; Time of First Occurrence of Maximum Plasma Concentration (Cmax) of IDRX-42 [ Time Frame: At the end of Cycle 1 Day 1 and at the end of Cycle 2 Day 1 (each cycle is 28 days) ]
- Phase 1b - AUC 0-24; Area Under the Concentration-time Curve from Time Zero to 24 hours for IDRX-42 [ Time Frame: At the end of Cycle 1 Day 1 and at the end of Cycle 2 Day 1 (each cycle is 28 days) ]
- Phase 1b - Overall survival [ Time Frame: 18 months ]

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Ages Eligible for Study: | 18 Years and older (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Inclusion Criteria:
Phase 1
- Male or female participants ≥18 years of age
- Histologically or cytologically confirmed metastatic and/or surgically unresectable GIST
- Documented progression on imatinib (Phase 1)
- Documented pathogenic mutation in KIT OR any PDGFRA mutation other than exon 18 mutations, determined through local testing
- At least one measurable lesion by mRECIST v1.1 for participants with GIST
- Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1
- 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.
- 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
- For Cohort 1, progressed on imatinib only (second line therapy)
- 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)
- 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:
- Any prior exposure to the following investigational agents NB003 or THE-630 or bezuclastinib plus sunitinib combination.
- GIST with no documented mutation in both KIT and PDGFRA genes.
- Any prior primary CNS malignancy or known untreated or active central nervous system metastases.
- Has an active uncontrolled infection, including, but not limited to, the requirement for intravenous antibiotics.
- Has significant, uncontrolled, or active cardiovascular disease.

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT05489237
Contact: IDRX Clinical Operations | 339-234-7028 | clinicaltrials@idrx.com |
United States, Florida | |
University of Miami | Recruiting |
Miami, Florida, United States, 33136 | |
Contact: Jonathan Trent, Dr. 305-243-8175 nxr518@med.miami.edu | |
United States, Massachusetts | |
Dana-Farber Cancer Institute | Recruiting |
Boston, Massachusetts, United States, 02215 | |
Contact: Suzanne George, MD 617-632-5204 | |
United States, Oregon | |
Oregon Health & Science University (OHSU) | Recruiting |
Portland, Oregon, United States, 97239 | |
Contact: Michael Heinrich, MD 503-494-1080 trials@ohsu.edu | |
United States, Pennsylvania | |
Temple University Health System (Temple Health) - Fox Chase Cancer Center (FCCC) - Main Campus | Recruiting |
Philadelphia, Pennsylvania, United States, 19111-2497 | |
Contact: Margaret Von Mehren 215-728-2814 margaret.vonmehren@fccc.edu |
Responsible Party: | IDRx, Inc. |
ClinicalTrials.gov Identifier: | NCT05489237 |
Other Study ID Numbers: |
IDRX-42-001 |
First Posted: | August 5, 2022 Key Record Dates |
Last Update Posted: | May 26, 2023 |
Last Verified: | May 2023 |
Studies a U.S. FDA-regulated Drug Product: | Yes |
Studies a U.S. FDA-regulated Device Product: | No |
GIST IDRX IDRX-42 |
Gastrointestinal Stromal Tumors Gastrointestinal Diseases Digestive System Diseases Neoplasms Neoplasms, Connective Tissue |
Neoplasms, Connective and Soft Tissue Neoplasms by Histologic Type Gastrointestinal Neoplasms Digestive System Neoplasms |