KQB198 in Combination With Imatinib in Participants With Advanced/Metastatic GIST in 1st Line Setting

May 18, 2026 updated by: Kumquat Biosciences Inc.

A Phase 2, Multicenter, Study Evaluating the Efficacy, Safety, Tolerability, Pharmacokinetics of KQB198 in Combination With Imatinib in Participants With Advanced/Metastatic GI Stromal Tumor in 1st Line Setting

This study will test an experimental drug called KQB198 in combination with imatinib. The goal is to determine if this combination is safe and tolerable and assess how effective the combination is at treating GIST. Imatinib has been approved by the FDA for the treatment of different types of cancer including GIST.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

46

Phase

  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • United States
    • California
      • Los Angeles, California, United States, 90033
        • Recruiting
        • USC Norris Comprehensive Cancer Center
    • Florida
      • Jacksonville, Florida, United States, 32224
        • Recruiting
        • Mayo Clinic - Jacksonville
      • Tampa, Florida, United States, 33612
        • Recruiting
        • Moffitt Cancer Center
    • Michigan
      • Ann Arbor, Michigan, United States, 48109
        • Recruiting
        • University of Michigan Hospitals
    • Minnesota
      • Rochester, Minnesota, United States, 55905
        • Recruiting
        • Mayo Clinic - Rochester
    • Ohio
      • Cleveland, Ohio, United States, 44195
        • Recruiting
        • Cleveland Clinic
    • Texas
      • Houston, Texas, United States, 77030
        • Recruiting
        • UT MD Anderson Cancer Center
    • Washington
      • Seattle, Washington, United States, 98195
        • Recruiting
        • Fred Hutchinson Cancer Center

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria

All Participants:

  • Unresectable or metastatic disease
  • Tissue confirmation of GIST
  • Valid results from local testing of blood or tumor tissue documenting the presence of a KIT mutation (must not have exon 9 mutation) or PDGFRA mutation (must not have PDGFRA D842V).
  • Measurable disease per RECIST v1.1.
  • Patients must be in 1st line of treatment for advanced or metastatic disease. Prior imatinib is allowed in adjuvant or neoadjuvant setting, as long as imatinib was stopped over 1 year ago.
  • Adequate organ function and performance status

Exclusion Criteria

Participants are excluded from the study if any of the following criteria apply:

  • Unable to swallow or GI condition that prevents absorption.
  • Other active malignancies within the last 2 years.
  • History of hypersensitivity to any component of KQB198 or imatinib.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Sequential Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: KQB198 in Combination with Imatinib
Drug: KQB198
Oral KQB198
Drug: Imatinib (Gleevec)
Oral Imatinib

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Objective response rate (ORR)
Time Frame: 30 months
Evaluate efficacy of study treatment, as measured by Objective Response Rate (ORR) using Response Evaluation Criteria in Gastrointestinal Stromal Tumors (GIST). Objective response is the proportion of subjects that experience confirmed complete response (CR) or partial response (PR) based on RECIST v1.1 during the time period from 1st dose of study treatment until last dose.
30 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Duration of response (DOR)
Time Frame: 30 months
Duration of response defined as the time from date of the first documentation of objective tumor response (CR or PR) based on RECIST v1.1 to the first documentation of either PD or death due to any cause, whichever occurs first.
30 months
Disease control rate (DCR)
Time Frame: 30 months
Disease control rate is the proportion of subjects that experience confirmed complete response (CR), partial response (PR), or stable disease based on RECIST v1.1 during the time period from 1st dose of study treatment until last dose.
30 months
Time to response (TTR)
Time Frame: 30 months
Time to response is defined as time from 1st dose of study treatment to date of 1st documentation of objective tumor response (CR or PR) based on RECIST v1.1.
30 months
Progression-free survival (PFS)
Time Frame: Up to 30 months
Progression-free survival is defined as the time from enrollment to the date of Progressive Disease (PD) based on RECIST v1.1 or death due to any cause, whichever occurs first. PFS at 6 months will also be characterized which indicates the proportion of subjects that experience progression within 6 months from time of enrollment.
Up to 30 months
Overall survival (OS)
Time Frame: Up to 30 months
Evaluate efficacy of study treatment characterized by OS. Overall survival is defined as the time from start of treatment to death.
Up to 30 months
Number of patients who experience treatment-emergent adverse advents, serious adverse events, and dose-limiting toxicities (Part 1)
Time Frame: From enrollment to the end of treatment
Safety characterized by type, incidence, severity, timing, seriousness and relationship to study treatment of adverse events (AEs), serious adverse events (SAEs), and dose limiting toxicities (DLTs), from first dose of study treatment to 28 days after last dose of study treatment.
From enrollment to the end of treatment
Area under the curve (AUC)
Time Frame: Up to 30 months
Area under the concentration-time curve (AUC) of KQB198 in combination with imatinib.
Up to 30 months
Maximum plasma concentration (Cmax)
Time Frame: Up to 30 months
Maximum plasma concentration (Cmax) of KQB198 in combination with imatinib.
Up to 30 months
Time to maximum plasma concentration (Tmax)
Time Frame: Up to 30 months
Time to maximum plasma concentration (Tmax) of KQB198 in combination with imatinib.
Up to 30 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Kumquat Biosciences Inc.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

May 1, 2026

Primary Completion (Estimated)

October 1, 2027

Study Completion (Estimated)

October 1, 2028

Study Registration Dates

First Submitted

January 23, 2026

First Submitted That Met QC Criteria

February 9, 2026

First Posted (Actual)

February 12, 2026

Study Record Updates

Last Update Posted (Actual)

May 19, 2026

Last Update Submitted That Met QC Criteria

May 18, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • KQB198-103

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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