A Study to Investigate the Safety and Efficacy of KQB365 as Monotherapy and in Combination in Participants With Advanced Solid Malignancies

April 20, 2026 updated by: Kumquat Biosciences Inc.

A Phase 1/1b, Open-label, Multicenter, Dose Escalation and Dose Optimization Study Evaluating the Safety, Tolerability, Pharmacokinetics and Efficacy of KQB365 as Monotherapy and in Combination With Anti-cancer Agents in Participants With Advanced Solid Malignancies With KRAS G12S or G12C Mutations

The goal of this clinical trial is to learn if KQB365 works to treat advanced solid tumor cancer in adults. It will also learn about the safety of KQB365. The main questions it aims to answer are:

  • What is the safe dose of KQB365 by itself, in combination with cetuximab, or in combination with KQB198?
  • Does KQB365 alone, in combination with cetuximab, or in combination with KQB198 decrease the size of the tumor?
  • What happens to KQB365 in the body?

Participants will:

  • Receive KQB365 infusion weekly alone, in combination with cetuximab, or in combination with oral KQB198.
  • Visit the clinic about 9 times in the first 6 weeks, and then once every week after that.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

140

Phase

  • Phase 1

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
    • Arizona
      • Phoenix, Arizona, United States, 85054
        • Recruiting
        • Mayo Clinic, Phoenix
        • Contact:
          • Phone Number: 855-776-0015
    • Colorado
    • Florida
      • Jacksonville, Florida, United States, 32224
        • Recruiting
        • Mayo Clinic, Jacksonville
        • Contact:
          • Phone Number: 855-776-0015
    • Massachusetts
      • Boston, Massachusetts, United States, 02215
    • Michigan
    • Minnesota
      • Rochester, Minnesota, United States, 55905
        • Recruiting
        • Mayo Clinic, Rochester
        • Contact:
          • Phone Number: 855-776-0015
    • Ohio
      • Cleveland, Ohio, United States, 44195
        • Recruiting
        • Cleveland Clinic, Taussig Cancer Institute
        • Contact:
    • Oklahoma
      • Oklahoma City, Oklahoma, United States, 73104
        • Recruiting
        • OU Health Stephenson Cancer Center
        • Contact:
          • Shamika Wright
    • Pennsylvania
      • Philadelphia, Pennsylvania, United States, 19107
    • Texas
      • San Antonio, Texas, United States, 78229
    • Virginia
      • Fairfax, Virginia, United States, 22031

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:

  • PART 1 (monotherapy and combo therapy with KQB198): Histologically confirmed diagnosis of a solid tumor malignancy with either a KRAS G12C or KRAS G12S mutation.
  • PART 1 (combo therapy with Cetuximab) & PART 2: Histologically confirmed diagnosis of adenocarcinoma of the colon or rectum with either a KRAS G12C or KRAS G12S mutation.
  • Unresectable or metastatic disease
  • No available treatment with curative intent
  • Adequate organ function
  • Measurable disease per RECIST v1.1

Exclusion Criteria:

  • Active primary central nervous system tumors
  • Cardiac abnormalities
  • Active interstitial lung disease
  • Unable to swallow or GI condition that prevents absorption for patients in KQB198 combination cohorts

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: Non-Randomized
  • Interventional Model: Sequential Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Monotherapy Dose Escalation (Part 1)

Drug: KQB365

- Intravenous KQB365
Drug: KQB365
Intravenous KQB365
Experimental: Combo Therapy with Cetuximab Dose Escalation (Part 1)

Drug: KQB365 - Intravenous KQB365

Drug:

- Intravenous cetuximab
Drug: KQB365
Intravenous KQB365
Drug: Cetuximab
Intravenous cetuximab
Experimental: Monotherapy Dose Expansion - RP2D (Part 2)

Drug: KQB365

- Intravenous KQB365
Drug: KQB365
Intravenous KQB365
Experimental: Monotherapy Dose Expansion - RP2D-1 (Part 2)

Drug: KQB365

- Intravenous KQB365
Drug: KQB365
Intravenous KQB365
Experimental: Combo Therapy with Cetuximab Dose Expansion - RP2D (Part 2)

Drug: KQB365 - Intravenous KQB365

Drug:

- Intravenous cetuximab
Drug: KQB365
Intravenous KQB365
Drug: Cetuximab
Intravenous cetuximab
Experimental: Combo Therapy with Cetuximab Dose Expansion - RP2D-1 (Part 2)

Drug: KQB365 - Intravenous KQB365

Drug:

- Intravenous cetuximab
Drug: KQB365
Intravenous KQB365
Drug: Cetuximab
Intravenous cetuximab
Experimental: Combo Therapy with KQB198 Dose Escalation (Part 1)

Drug: KQB365 - Intravenous KQB365

Drug:

- Oral KQB198
Drug: KQB198
Oral KQB198
Drug: KQB365
Intravenous KQB365

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Number of patients who experience treatment-emergent adverse events, 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 AEs, SAEs, and DLTs, from first dose of study treatment to 30 days after last dose of study treatment.
From enrollment to the end of treatment
Recommended Phase 2 Dose (RP2D) (Part 1)
Time Frame: up to 35 months
Evaluate safety and assess number of patients with dose-limiting toxicity to determine the RP2D.
up to 35 months
Efficacy and Optimal Biologic Dose of study treatment, as measured by Objective Response Rate (ORR) (Part 2)
Time Frame: up to 35 months
ORR 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.
up to 35 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Concentration-time curve (AUC)
Time Frame: up to 35 months
up to 35 months
Maximum plasma concentration (Cmax)
Time Frame: up to 35 months
up to 35 months
Time to maximum plasma concentration (tmax)
Time Frame: up to 35 months
up to 35 months
Overall survival (OS)
Time Frame: up to 35 months
up to 35 months
Progression-free survival (PFS)
Time Frame: up to 35 months
using RECIST v1.1
up to 35 months
Overall response rate (ORR)
Time Frame: up to 35 months
using RECIST v1.1
up to 35 months
Duration of response (DOR)
Time Frame: up to 35 months
using RECIST v1.1
up to 35 months
Time to response (TTR)
Time Frame: up to 35 months
using RECIST v1.1
up to 35 months
Disease control rate (DCR)
Time Frame: up to 35 months
using RECIST v1.1
up to 35 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 (Actual)

February 4, 2025

Primary Completion (Estimated)

June 30, 2029

Study Completion (Estimated)

June 30, 2030

Study Registration Dates

First Submitted

December 3, 2024

First Submitted That Met QC Criteria

December 3, 2024

First Posted (Actual)

December 6, 2024

Study Record Updates

Last Update Posted (Actual)

April 23, 2026

Last Update Submitted That Met QC Criteria

April 20, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • KQB365-101

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

product manufactured in and exported from the U.S.

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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