A Study to Investigate the Safety and Efficacy of KQB368 as Monotherapy in Participants With Advanced Solid Malignancies

A Phase 1/1b, Open-label, Multicenter, Dose Escalation and Dose Expansion Study Evaluating the Safety, Tolerability, Pharmacokinetics and Efficacy of KQB368 in Participants With Advanced Solid Malignancies With KRAS G12S or G12C Mutations

The goal of this study is to learn if KQB368 works to treat advanced solid malignancies in adults. The study will also learn about the safety of KQB368. The main questions the study aims to answer are:

• What is the safe dose of KQB368 as a monotherapy?
• Does KQB368 decrease the size of the tumor?
• What happens to KQB368 in the body?

Participants will:

• Take KQB368 orally daily in 21-day cycles
• Return to the study site about 7 times in the first 5 weeks, and then once at the beginning of every 21-day cycle after that

Study Overview

• Status: Not yet recruiting
• Conditions: Non-Small Cell Lung Cancer; Advanced Solid Tumors; Uterine Cancer; Colorectal Cancer (CRC); KRAS G12C Mutations; KRAS G12S Mutations
• Intervention / Treatment: Drug: KQB368

• Study Type: Interventional
• Enrollment (Estimated): 48
• Phase: Phase 1

Contacts and Locations

• Study Contact: Name: Kumquat Clinical Development Telephone; Phone Number: 858.214.2700; Email: kumquatstudies@kumquatbio.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

• Histologically confirmed diagnosis of a solid tumor
• Malignancy 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
• Must be able to swallow with no GI condition that prevents absorption

Study Plan

How is the study designed?

Design Details

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

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Monotherapy Dose Escalation	Drug: KQB368; Oral KQB368

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Primary Objective	Number of patients who experience treatment-emergent adverse events, serious adverse events, and dose-limiting toxicities. 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.	Up to 44 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Objective response rate (ORR)	Evaluate efficacy of study treatment, as measured by Objective Response Rate (ORR) using Response Evaluation Criteria (RECISTv1.1). 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 first dose of study treatment until last dose.	Up to 44 months
Overall survival (OS)	Evaluate efficacy of study treatment characterized by OS. Overall survival is defined as the time from start of treatment to death.	Up to 44 months
Duration of response (DOR)	Duration of response is 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.	Up to 44 months
Time to response (TTR)	Time to response is defined as time from first dose of study treatment to date of first documentation of objective tumor response (CR or PR) based on RECIST v1.1.	Up to 44 months
Disease control rate (DCR)	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 first dose of study treatment until last dose.	Up to 44 months
Progression-free survival (PFS)	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.	Up to 44 months
Area under the concentration-time curve (AUC)		Up to 44 months
Maximum plasma concentration (Cmax)		Up to 44 months
Time to maximum plasma concentration (tmax)		Up to 44 months

Collaborators and Investigators

• Sponsor: Kumquat Biosciences Inc.
• Collaborators: Worldwide Clinical Trials

Study record dates

Study Major Dates

• Study Start (Estimated): May 1, 2026
• Primary Completion (Estimated): December 1, 2029
• Study Completion (Estimated): December 1, 2029

Study Registration Dates

• First Submitted: April 13, 2026
• First Submitted That Met QC Criteria: April 17, 2026
• First Posted (Actual): April 21, 2026

Study Record Updates

• Last Update Posted (Actual): April 21, 2026
• Last Update Submitted That Met QC Criteria: April 17, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: KQB368
• Additional Relevant MeSH Terms: Urogenital Diseases; Genital Diseases; Urogenital Neoplasms; Neoplasms by Site; Neoplasms; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Intestinal Diseases; Respiratory Tract Diseases; Gastrointestinal Neoplasms; Digestive System Neoplasms; Digestive System Diseases; Gastrointestinal Diseases; Intestinal Neoplasms; Rectal Diseases; Uterine Diseases; Genital Diseases, Female; Lung Diseases; Respiratory Tract Neoplasms; Thoracic Neoplasms; Colonic Diseases; Lung Neoplasms; Genital Neoplasms, Female; Carcinoma, Bronchogenic; Bronchial Neoplasms; Colorectal Neoplasms; Carcinoma, Non-Small-Cell Lung; Uterine Neoplasms
• Other Study ID Numbers: KQB368-101

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