Advanced/Metastatic Solid TumorPhase 1NCT05047536

KZR-261 in Subjects With Advanced Solid Malignancies

A Phase 1 study testing KZR-261 in people with Advanced/Metastatic Solid Tumor, run by Kezar Life Sciences, Inc. at 12 sites in United States.

Terminated

Stopped early. The study ended before it was planned to and will not resume.

Official record

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Trial summary

Who is it for?: Ages 18 years and older
Conditions the study is for: Advanced/Metastatic Solid Tumor
What is being tested?: KZR-261
Type of treatment: Injection or infusion
Could I receive a placebo?: No, everyone receives an active treatment
How many people: 61 participants
Where: 12 sitesUnited States
Study dates: 30 Sep 2021to 17 Jan 2025
Phase: Phase 1
Are there results?: Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

Ages 18 years and older
All sexes
No healthy volunteers
Adult, Older adult

Who may be able to join

Histologic or cytologic evidence of malignant solid tumor with advanced disease (except primary central nervous system [CNS] neoplasms), defined as cancer that is either metastatic or locally advanced and unresectable (and for which additional radiation therapy or other locoregional therapies are not considered to result in reasonable clinical benefit).
Disease that is resistant to or relapsed following available standard systemic therapy, or for which there is no standard systemic therapy or reasonable therapy in the Investigator's judgement likely to result in clinical benefit, or if such therapy has been refused by the subject. Documentation of the reason must be provided for subjects who have not received a standard therapy likely to result in clinical benefit.
Eastern Cooperative Oncology Group Performance Status score of 0 or 1.
Adequate baseline hematologic and organ function.
Willing to use contraception.
Additional Inclusion for Part 2: Histologic or cytologic evidence of malignancy (melanoma/uveal melanoma, colorectal cancer, castration-resistant prostate cancer, mesothelioma).

Who cannot join

Subjects who have participated in Part 1 dose escalation are not eligible to enroll in Part 2 dose expansion.
Persistent clinically significant toxicities from previous anticancer therapy (excluding alopecia).
Treatment with cytotoxic, biologic, or targeted therapies for advanced cancer within 14 days before administration of the subject's first dose of KZR-261.
Treatment with an investigational drug within 28 days before administration of the subject's first dose of KZR-261.
Radiation therapy within 14 days of before administration of the subject's first dose of KZR-261.
Major surgical procedure within 28 days before administration of the subject's first dose of KZR-261.

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History of risk factors for Torsades de pointes.
Active, symptomatic CNS metastases or primary CNS malignancy.
Any female who is breastfeeding or who plans to become pregnant during the study, or who are actively trying to conceive at the time of signing of the informed consent form (ICF).
Uncontrolled, clinically significant pulmonary disease.

Trial locations and contacts

12 sites in 1 country.

City, postcode or hospital

12 sites in 1 country

United States12 sites

Winship Cancer Institute of Emory University
Atlanta, Georgia, 30322
University Hospitals - Cleveland Medical Center
Cleveland, Ohio, 44106
Cleveland Clinic
Cleveland, Ohio, 44195
Henry Ford Health System
Detroit, Michigan, 48202
Virginia Cancer Specialists (VCS)
Fairfax, Virginia, 22031
Cedars Sinai Medical Center
Los Angeles, California, 90048
University of California Los Angeles
Los Angeles, California, 90095
Sara Cannon Research Institution (SCRI) - Tennessee Oncology Nashville
Nashville, Tennessee, 37203
Fox Chase Cancer Center
Philadelphia, Pennsylvania, 19111
START (South Texas Accelerated Research Therapeutics)
San Antonio, Texas, 78229
Fred Hutchinson Cancer Center
Seattle, Washington, 98109
Moffitt Cancer Center
Tampa, Florida, 33612

Other trials in United States

About this study

Official title: A Phase 1 Study of KZR-261, a Small Molecule Sec61 Inhibitor, in Subjects With Advanced Solid Malignancies

A first-in-human, open-label, multicenter, Phase 1 study of KZR-261 designed to assess the safety and tolerability, preliminary anti-tumor activity, and pharmacokinetics (PK) of KZR-261, as well as identify the recommended Phase 2 dose (RP2D). The study comprised a Part 1 (Dose Escalation) and a Part 2 (2A Dose Expansion and 2B Dose Optimization) in solid organ tumors (melanoma/uveal melanoma, mesothelioma, colorectal cancer, castration-resistant prostate cancer, and "All-Tumors").

Read the detailed description

The first-in-human, open-label, multicenter, Phase 1 study of KZR-261, Study KZR-261-101, was conducted in two parts (dose escalation and dose expansion) to evaluate the safety and tolerability, pharmacokinetics, pharmacodynamics, and evaluate the preliminary anti-tumor activity of KZR-261 in participants with locally advanced or metastatic solid malignancies for whom no therapeutics are available (or available therapeutics were refused) that can confer a reasonable likelihood of clinical benefit. The 5 tumor cohorts in the dose expansion part include advanced malignant:

melanoma/uveal melanoma
mesothelioma
colorectal cancer
castration-resistant prostate cancer
"All-Tumors" (other advanced solid malignancies)

Part 1 (Dose Escalation) and Part 2 (2A Dose Expansion and 2B Dose Optimization) comprised a 4-week Screening Period, a Treatment Period lasting approximately 24 weeks, 4-6-week Safety Follow-up, and a 12-month Long-Term Follow-up Period (after last dose of study treatment), for a total study duration of approximately 20 months.

Conditions: Advanced/Metastatic Solid Tumor
Being tested: KZR-261
Keywords: melanoma, uveal melanoma, colorectal cancer, castration-resistant prostate cancer, mesothelioma
Medical subject headings: Neoplasm Metastasis, Melanoma, Uveal Melanoma, Colorectal Neoplasms, Mesothelioma

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

KZR-261Drug
Also called KZR-261 for Injection
KZR-261 for Injection is a lyophilized drug product supplied in single-use vials delivering 75 mg of KZR-261.

Study groups in NCT05047536
Study group	Role	What they receive
KZR-261 with standard therapy: open-label	Experimental	Part 1 (Dose Escalation): The initial dose cohort of the Dose Escalation received 1.8 mg/m2 of KZR-261. Participants received 3 doses in a 28-day cycle as an intravenous (IV) infusion for up to 6 cycles. _________________ Part 2A (Dose Expansion): Following safety review of all Dose Escalation cohorts and determination of the maximum tolerated dose (MTD) or maximum administered dose (MAD), KZR-261 was to be evaluated for safety and preliminary efficacy in 4 tumor-specific cohorts and 1 all-tumor cohort to determine the recommended phase 2 dose (RP2D). The 4 tumor-specific cohorts will include: * melanoma (including uveal melanoma) * colorectal cancer * castration-resistant prostate cancer * mesothelioma Part 2B (Dose Optimization): Dose optimization in tumor-specific cohorts could have been initiated based on the totality of data after the MTD/MAD had been determined. Participants were to receive KZR-261 at the MTD/MAD or a lower clinically active dose of KZR-261. Receives: Drug: KZR-261

What is being measured

The primary outcome is the main question the study is designed to answer.

Number and Percentage of Participants Experiencing Adverse Events as Assessed by CTCAE v5.0 (Part 1 & 2)
Incidence and percentage of adverse events and serious adverse events will be collected from start of enrollment
Measured: 20 months
Number and Percentage of Participants Experiencing Dose-limiting Toxicities
Number and percentage of participants experiencing dose-limiting toxicities (DLT) collected from start of enrollment through the first 28 days of Cycle 1 as assessed by CTCAE v5.0 (Part 1).
Measured: 28 days
Maximum Plasma Concentration of KZR-261 (Part 1)
This is the maximum observed plasma concentration (Cmax) observed after administration of KZR-261 in Cycle 1 (Days 1 and 15) and Cycle 2 (Days 1 and 15). The PK parameters were calculated using all timepoints at which the concentration was measured, ie. predose, 15 minutes post start of infusion, end of infusion, and 5, 15, 30 minutes, 1, 2, 4, 6, 24, 48, and 96 hours post infusion.
Measured: Cycle 1: Day 1, Cycle 1: Day 15, Cycle 2: Day 1, and Cycle 2: Day 15
The Plasma Concentration Time Curve of KZR-261 (Part 1)
This is the area under the curve (AUC) from predose through postdose observed after administration of KZR-261 in Cycle 1 (Days 1 and 15) and Cycle 2 (Days 1 and 15). The PK parameters were calculated using all timepoints at which the concentration was measured, ie. predose, 15 minutes post start of infusion, end of infusion, and 5, 15, 30 minutes, 1, 2, 4, 6, and 24 hours post infusion.
Measured: Cycle 1: Day 1, Cycle 1: Day 15, Cycle 2: Day 1, and Cycle 2: Day 15

Secondary outcomes (4)

Objective Response (ORR) Following KZR-261
The objective response following KZR-261 defined as a best overall response of Complete Response (CR) or Partial Response (PR) per Response Evaluation Criteria in Solid Tumors (RECIST) v1.1. A CR is defined as the disappearance of all target lesions and a PR is defined as at least a 30% decrease in the sum of the diameters of target lesions, taking as reference the baseline sum of longest lesion diameters.
Measured: 20 months
Participants With Clinical Benefit of Stable Disease Following KZR-261
The clinical benefit rate defined as the number of participants achieving a best response of complete response (CR)/partial response (PR) or stable disease over at least 2 consecutive response assessment time points. Stable disease is defined as neither sufficient decrease to qualify for PR nor sufficient increase to qualify for progressive disease, taking as reference the smallest sum of longest diameters of target lesions while on study.
Measured: 20 months
Progression-free Survival of Participants Treated With KZR-261
The number of participants with progression-free survival (PFS), defined as the date of initiation of study treatment to the date of documented PD or death from any cause, whichever occurs first, at 4 months and 6 months. PFS is based on the number of subjects in each group in the response evaluable population at the specific timepoints (4 or 6 months).
Measured: 4 months and 6 months
Overall Survival of Participants Treated With KZR-261
Time of overall survival for participants treated with KZR-261.
Measured: 20 months

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

30 Sep 202117 Jan 2025

First posted17 Sep 2021
Study start30 Sep 2021
Primary completion17 Jan 2025
Study completion17 Jan 2025

Why it stopped: Sponsor decision.

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
Other trials for Advanced/Metastatic Solid TumorStudies of the same condition, open and under way.
What the trial phases meanHow a treatment moves from first tests in people to approval.

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design

Study type: Interventional
Phase: Phase 1
Primary purpose: Treatment
Allocation: Not applicable
Intervention model: Single group
Model description: All participants received 30 to 60-minute intravenous infusion of KZR-261 via a central line on Days 1, 8, and 15 of a 4-week (28-day) treatment cycle. Up to approximately 50 participants were to be enrolled and treated with KZR-261 in Part 1 (Dose Escalation). In Part 2A (Dose Expansion), up to 175 participants (15-35 per tumor cohort \[melanoma, uveal melanoma, colorectal cancer, castration-resistant prostate cancer, mesothelioma, and "All-Tumor"\]) were to be enrolled. In Part 2B (Dose Optimization), up to 120 participants from up to 4 tumor types from the Dose Expansion were to be enrolled.
Masking: None (open label)
Enrolment: 61 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT05047536
Sponsor's protocol ID: KZR-261-101
Status last verified: Dec 2025
First submitted: 3 Sep 2021
Last updated: 19 Dec 2025
Results posted: Yes, on ClinicalTrials.gov
FDA-regulated drug: Yes
FDA-regulated device: No

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

See locations

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All Advanced/Metastatic Solid Tumor trials

Study at a glance

From the registry record, last updated by the sponsor on 19 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: A Phase 1 Study of KZR-261, a Small Molecule Sec61 Inhibitor, in Subjects With Advanced Solid Malignancies
ClinicalTrials.gov ID: NCT05047536
Acronym / sponsor ID: KZR-261-101
Conditions: Advanced/Metastatic Solid Tumor
Keywords: melanoma, uveal melanoma, colorectal cancer, castration-resistant prostate cancer, mesothelioma
Phase: Phase 1
Study type: Interventional
Recruitment status: TerminatedReason stopped: Sponsor decision.
Enrolment: 61 participants (actual)
Lead sponsor: Kezar Life Sciences, Inc.Industry (pharma, biotech, devices)
Study start: 30 Sep 2021 (actual)
Primary completion: 17 Jan 2025 (actual)
Study completion: 17 Jan 2025 (actual)
First posted: 17 Sep 2021 (actual)
Results: Posted 19 Dec 2025

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

Detailed description

melanoma/uveal melanoma
mesothelioma
colorectal cancer
castration-resistant prostate cancer
"All-Tumors" (other advanced solid malignancies)

Study design

Primary purpose: Treatment
Allocation: Not applicable
Intervention model: Single group
Masking: None (open label)
Number of arms: 1
Model description: All participants received 30 to 60-minute intravenous infusion of KZR-261 via a central line on Days 1, 8, and 15 of a 4-week (28-day) treatment cycle. Up to approximately 50 participants were to be enrolled and treated with KZR-261 in Part 1 (Dose Escalation). In Part 2A (Dose Expansion), up to 175 participants (15-35 per tumor cohort [melanoma, uveal melanoma, colorectal cancer, castration-resistant prostate cancer, mesothelioma, and "All-Tumor"]) were to be enrolled. In Part 2B (Dose Optimization), up to 120 participants from up to 4 tumor types from the Dose Expansion were to be enrolled.

Arm	Type	Receives
KZR-261 with standard therapy: open-label	Experimental	Drug: KZR-261Part 1 (Dose Escalation): The initial dose cohort of the Dose Escalation received 1.8 mg/m2 of KZR-261. Participants received 3 doses in a 28-day cycle as an intravenous (IV) infusion for up to 6 cycles. _________________ Part 2A (Dose Expansion): Following safety review of all Dose Escalation cohorts and determination of the maximum tolerated dose (MTD) or maximum administered dose (MAD), KZR-261 was to be evaluated for safety and preliminary efficacy in 4 tumor-specific cohorts and 1 all-tumor cohort to determine the recommended phase 2 dose (RP2D). The 4 tumor-specific cohorts will include: * melanoma (including uveal melanoma) * colorectal cancer * castration-resistant prostate cancer * mesothelioma Part 2B (Dose Optimization): Dose optimization in tumor-specific cohorts could have been initiated based on the totality of data after the MTD/MAD had been determined. Participants were to receive KZR-261 at the MTD/MAD or a lower clinically active dose of KZR-261.

Who may qualify

Ages: 18 years and older
Sex: All
Healthy volunteers: Not accepted
Age groups: Adult, Older adult

Key inclusion criteria (6 listed)

Histologic or cytologic evidence of malignant solid tumor with advanced disease (except primary central nervous system [CNS] neoplasms), defined as cancer that is either metastatic or locally advanced and unresectable (and for which additional radiation therapy or other locoregional therapies are not considered to result in reasonable clinical benefit).
Disease that is resistant to or relapsed following available standard systemic therapy, or for which there is no standard systemic therapy or reasonable therapy in the Investigator's judgement likely to result in clinical benefit, or if such therapy has been refused by the subject. Documentation of the reason must be provided for subjects who have not received a standard therapy likely to result in clinical benefit.
Eastern Cooperative Oncology Group Performance Status score of 0 or 1.
Adequate baseline hematologic and organ function.
Willing to use contraception.

Key exclusion criteria (10 listed)

Subjects who have participated in Part 1 dose escalation are not eligible to enroll in Part 2 dose expansion.
Persistent clinically significant toxicities from previous anticancer therapy (excluding alopecia).
Treatment with cytotoxic, biologic, or targeted therapies for advanced cancer within 14 days before administration of the subject's first dose of KZR-261.
Treatment with an investigational drug within 28 days before administration of the subject's first dose of KZR-261.
Radiation therapy within 14 days of before administration of the subject's first dose of KZR-261.

Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.

Interventions

Intervention	Type	Arms
KZR-261Also: KZR-261 for InjectionKZR-261 for Injection is a lyophilized drug product supplied in single-use vials delivering 75 mg of KZR-261.	Drug	KZR-261 with standard therapy: open-label

Primary outcome

Number and Percentage of Participants Experiencing Adverse Events as Assessed by CTCAE v5.0 (Part 1 & 2)
Time frame: 20 months
Incidence and percentage of adverse events and serious adverse events will be collected from start of enrollment
Number and Percentage of Participants Experiencing Dose-limiting Toxicities
Time frame: 28 days
Number and percentage of participants experiencing dose-limiting toxicities (DLT) collected from start of enrollment through the first 28 days of Cycle 1 as assessed by CTCAE v5.0 (Part 1).
Maximum Plasma Concentration of KZR-261 (Part 1)
Time frame: Cycle 1: Day 1, Cycle 1: Day 15, Cycle 2: Day 1, and Cycle 2: Day 15
This is the maximum observed plasma concentration (Cmax) observed after administration of KZR-261 in Cycle 1 (Days 1 and 15) and Cycle 2 (Days 1 and 15). The PK parameters were calculated using all timepoints at which the concentration was measured, ie. predose, 15 minutes post start of infusion, end of infusion, and 5, 15, 30 minutes, 1, 2, 4, 6, 24, 48, and 96 hours post infusion.
The Plasma Concentration Time Curve of KZR-261 (Part 1)
Time frame: Cycle 1: Day 1, Cycle 1: Day 15, Cycle 2: Day 1, and Cycle 2: Day 15
This is the area under the curve (AUC) from predose through postdose observed after administration of KZR-261 in Cycle 1 (Days 1 and 15) and Cycle 2 (Days 1 and 15). The PK parameters were calculated using all timepoints at which the concentration was measured, ie. predose, 15 minutes post start of infusion, end of infusion, and 5, 15, 30 minutes, 1, 2, 4, 6, and 24 hours post infusion.

4 secondary outcomes

Objective Response (ORR) Following KZR-261
Time frame: 20 months
Participants With Clinical Benefit of Stable Disease Following KZR-261
Time frame: 20 months
Progression-free Survival of Participants Treated With KZR-261
Time frame: 4 months and 6 months
Overall Survival of Participants Treated With KZR-261
Time frame: 20 months

Results and safety

Results posted to the registry on 19 Dec 2025, as reported by the sponsor. Figures are copied from the record, not re-analysed. Full results on ClinicalTrials.gov.

Participant flow

Group	Started	Completed
Dose 1	2	1
Dose 2	2	0
Dose 3	2	1
Dose 4	6	0
Dose 5	6	1
Dose 6	6	3
Dose 7	5	1
Dose 8	17	0
Dose 9	8	0
Melanoma Expansion Cohort	7	0

Primary outcome: Number and Percentage of Participants Experiencing Adverse Events as Assessed by CTCAE v5.0 (Part 1 & 2)

Time frame: 20 months. Number. Unit: participants

Measure	Dose 1 n = 2	Dose 2 n = 2	Dose 3 n = 2	Dose 4 n = 6	Dose 5 n = 6	Dose 6 n = 6	Dose 7 n = 5	Dose 8 n = 17	Dose 9 n = 8	Melanoma Expansion Cohort n = 7
Mild (Grade 1)	2	2	0	0	0	2	1	0	0	0
Moderate (Grade 2)	0	0	1	2	1	0	1	0	0	2
Severe (Grade 3)	0	0	0	3	4	4	1	5	2	0
Life-threatening (Grade 4)	0	0	0	0	0	0	2	12	5	5
Death (Grade 5)	0	0	0	1	1	0	0	0	0	0

Population analysed: All participants who received at least 1 dose of study treatment (KZR-261).

Primary outcome: Number and Percentage of Participants Experiencing Dose-limiting Toxicities

Time frame: 28 days. Count of participants. Unit: Participants

Measure	Dose 1 n = 2	Dose 2 n = 2	Dose 3 n = 2	Dose 4 n = 5	Dose 5 n = 6	Dose 6 n = 5	Dose 7 n = 5	Dose 8 n = 14	Dose 9 n = 5
Value	0	0	0	1	1	0	0	0	1

Population analysed: The DLT Evaluable Population consists of all participants who either met the following minimal exposure criteria and have sufficient safety evaluations without having a DLT, or have experienced a DLT during the DLT assessment period. Participants who did not experience a DLT in Dose Escalation must have received all of their scheduled doses (Days 1, 8, and 15) during the DLT assessment period with completed follow-up data available through 28 days of Cycle 1 to be DLT-assessable.

Primary outcome: Maximum Plasma Concentration of KZR-261 (Part 1)

Time frame: Cycle 1: Day 1, Cycle 1: Day 15, Cycle 2: Day 1, and Cycle 2: Day 15. Geometric mean (Geometric Coefficient of Variation). Unit: ng/mL

Measure	Dose 1 n = 2	Dose 2 n = 2	Dose 3 n = 2	Dose 4 n = 5	Dose 5 n = 6	Dose 6 n = 6	Dose 7 n = 5	Dose 8 n = 17	Dose 9 n = 8
Cycle 1, Day 1	601.5 (26.9)	1414.9 (1.5)	1536.1 (34.7)	2793.5 (44.9)	5126.6 (37.8)	7475.8 (10.9)	9531.2 (39.5)	12159.8 (27.8)	16346.5 (27.4)
Cycle 1, Day 15	580.6 (35.5)	2160.0 (NA)	2413.2 (46.0)	4149.8 (45.6)	4409.6 (40.2)	7571.7 (23.8)	11906.8 (23.6)	12917.1 (36.0)	25955.5 (154.2)
Cycle 2, Day 1	566.5 (13.3)	1724.4 (46.7)	2406.6 (57.4)	3712.8 (54.5)	4359.1 (18.7)	6686.2 (21.1)	14497.6 (42.2)	12208.5 (36.0)	31491.0 (260.2)
Cycle 2, Day 15	603.2 (20.7)	1334.6 (61.3)	2128.8 (36.3)	3510.7 (27.5)	4409.6 (28.6)	7343.5 (24.9)	12218.5 (11.0)	15342.7 (31.4)	18300.0 (NA)

Population analysed: The PK analyses were performed for all subjects in the PK population (all subjects that received at least one dose plasma KZR-261 concentration measurement during Cycles 1 and 2 of treatment).

Primary outcome: The Plasma Concentration Time Curve of KZR-261 (Part 1)

Time frame: Cycle 1: Day 1, Cycle 1: Day 15, Cycle 2: Day 1, and Cycle 2: Day 15. Geometric mean (Geometric Coefficient of Variation). Unit: hr*ng/mL

Measure	Dose 1 n = 2	Dose 2 n = 2	Dose 3 n = 2	Dose 4 n = 5	Dose 5 n = 6	Dose 6 n = 6	Dose 7 n = 5	Dose 8 n = 17	Dose 9 n = 8
Cycle 1, Day 1	653.2 (14.5)	1483.4 (101.6)	2252.7 (13.7)	5592.0 (74.6)	6427.1 (30.8)	9919.2 (11.1)	15766.7 (15.3)	22918.9 (45.4)	34948.3 (31.7)
Cycle 1, Day 15	528.6 (20.5)	2596.4 (NA)	2511.2 (42.4)	4259.1 (26.4)	6280.1 (31.8)	8944.0 (16.4)	14624.8 (13.9)	18088.1 (27.0)	38084.6 (96.2)
Cycle 2, Day 1	532.2 (2.9)	1506.8 (68.2)	2485.0 (12.1)	6536.5 (80.4)	7030.0 (21.6)	10171.0 (18.0)	20581.5 (36.2)	20847.3 (57.6)	48172.7 (92.3)
Cycle 2, Day 15	568.6 (21.8)	1304.5 (78.3)	2126.4 (22.7)	5135.9 (53.6)	6246.6 (28.2)	8958.0 (23.2)	17093.8 (16.0)	22390.0 (31.7)	37991.6 (NA)

4 secondary outcomes are reported in the full results.

Adverse events

Time frame: Through end of study, up to 2.25 years. Other adverse events reported at 0% frequency or more

Group	Serious adverse events	Other adverse events	Deaths
Dose 1	0 of 2 (0%)	2 of 2 (100%)	0 of 2
Dose 2	0 of 2 (0%)	2 of 2 (100%)	0 of 2
Dose 3	0 of 2 (0%)	1 of 2 (50%)	0 of 2
Dose 4	3 of 6 (50%)	6 of 6 (100%)	1 of 6
Dose 5	3 of 6 (50%)	6 of 6 (100%)	1 of 6
Dose 6	3 of 6 (50%)	6 of 6 (100%)	0 of 6
Dose 7	0 of 5 (0%)	5 of 5 (100%)	0 of 5
Dose 8	8 of 17 (47.1%)	17 of 17 (100%)	0 of 17
Dose 9	4 of 8 (50%)	7 of 8 (87.5%)	0 of 8
Melanoma Expansion Cohort	4 of 7 (57.1%)	7 of 7 (100%)	0 of 7

Loading the posted results from ClinicalTrials.gov…

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 19 Dec 2025.
Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
Kezar Life Sciences, Inc. corporate websiteLink provided by the sponsor.

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Referral and contact

AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.

Kezar Study Director study director

Kezar Life Sciences, Inc.

12 sites in 1 country: see every site and its status.

Questions about this trial

What is this clinical trial studying?

A Phase 1 study testing KZR-261 in people with Advanced/Metastatic Solid Tumor, run by Kezar Life Sciences, Inc. at 12 sites in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 6 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: stopped early, as of the sponsor's last update on 19 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 12 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

Yes. Results are posted in the registry (first posted 19 Dec 2025). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Number and Percentage of Participants Experiencing Adverse Events as Assessed by CTCAE v5.0 (Part 1 & 2) (time frame: 20 months). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT05047536.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 19 Dec 2025.