Metastatic Castration-resistant Prostate CancerPhase 1NCT04740034

A Study of AMG 340 in Subjects With Metastatic Castrate-Resistant Prostate Carcinoma

A Phase 1 study testing AMG 340 in people with Metastatic Castration-resistant Prostate Cancer, run by Amgen at 7 sites in United States.

Terminated

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

Official record

Search all trials

Trial summary

Who is it for?: Ages 18 years and older, men only
Conditions the study is for: Metastatic Castration-resistant Prostate Cancer
What is being tested?: AMG 340
Could I receive a placebo?: No, everyone receives an active treatment
How many people: 42 participants
Where: 7 sitesUnited States
Study dates: 29 Apr 2021to 24 Jun 2024
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
Men only
No healthy volunteers
Adult, Older adult

Who may be able to join

Pathologically confirmed prostatic adenocarcinoma.
History of metastatic disease.
Chemically or surgically castrate.
Subject has received at least 2 lines of systemic therapy approved for mCRPC, with disease progression on the most recent systemic therapy as defined in Prostate Cancer Working Group 3 (PCWG3) recommendations.
Human immunodeficiency virus (HIV), hepatitis B virus (HBV), and/or hepatitis C virus (HCV)-infected subjects that have been cured or who are on effective anti-retroviral therapy with undetectable viral load within 6 months are eligible for this trial.
An Eastern Cooperative Oncology Group (ECOG) Performance Status of ≤ 2.
Subject must have adequate heart, liver, bone marrow and kidney function (e.g. estimated glomerular filtration rate [eGFR] ≥ 50 mL/min, aspartate aminotransferase [AST]/alanine aminotransferase [ALT] ≤ 3 x upper limit of normal [ULN], hemoglobin [Hgb] ≥ 9 g/dL (without blood transfusion within 7 days from screening assessment), platelets ≥ 100,000 / mm^3 (without platelet transfusion within 7 days from screening assessment), absolute neutrophil count [ANC] ≥ 1500 / mm^3).

Who cannot join

Subject has been diagnosed with or treated for another malignancy within the past 2 years whose natural history or treatment may interfere with the safety or efficacy assessment of the investigational regimen.
History of neuroendocrine differentiation in the subject's disease.
Subject has a history of central nervous system (CNS) involvement by their mCRPC. Metastases stemming from bone are allowed.
Subject has clinically significant CNS pathology.
Subject requires chronic immunosuppressive therapy.
Subject has a history of major cardiac abnormalities.

Trial locations and contacts

7 sites in 1 country.

City, postcode or hospital

7 sites in 1 country

United States7 sites

Sarah Cannon Research Institute at HealthONE
Denver, Colorado, 80218
Tennessee Oncology
Nashville, Tennessee, 37203
Tulane Cancer Center
New Orleans, Louisiana, 70112
Icahn School of Medicine at Mount Sinai
New York, New York, 10128
Thomas Jefferson University - Sidney Kimmel Cancer Center
Philadelphia, Pennsylvania, 19107
UCSF
San Francisco, California, 94158
Florida Cancer Specialists
Sarasota, Florida, 34232

Other trials in United States

About this study

Official title: A Multicenter, Phase 1, Open-label, Dose-escalation and Expansion Study of AMG 340, a Bispecific Antibody Targeting PSMA in Subjects With Metastatic Castrate-Resistant Prostate Carcinoma

This is a phase 1, open-label study evaluating the safety, clinical pharmacology and clinical activity of AMG 340, a PSMA x CD3 T-cell engaging bispecific antibody, in subjects with metastatic castrate-resistant prostate cancer (mCRPC) who have received 2 or more prior lines of therapy. The study consists of 2 parts, a monotherapy dose escalation (Arm A) and a monotherapy dose expansion (Arm B). Once the maximum tolerated dose (MTD) or recommended phase 2 dose (RP2D) is identified in Arm A, Arm B will be initiated to further characterize the safety, tolerability and pharmacokinetic (PK) profile of the MTD/RP2D dose of AMG 340 monotherapy in subjects with mCRPC.

Conditions: Metastatic Castration-resistant Prostate Cancer
Being tested: AMG 340
Keywords: Prostate specific membrane antigen, PSMA, Prostate cancer, Metastatic, Castrate-resistant
Medical subject headings: Prostatic Neoplasms, Neoplasm Metastasis

What participants receive

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

AMG 340Drug
AMG 340 is a bispecific antibody targeting prostate-specific membrane antigen (PSMA) on tumor cells and CD3 on T-cells

Study groups in NCT04740034
Study group	Role	What they receive
Dose Escalation	Experimental	Sequential dose escalation cohorts are planned until maximum tolerated dose (MTD) is reached or recommended phase 2 dose (RP2D) is identified. Receives: Drug: AMG 340
Dose Expansion	Experimental	An expansion cohort in subjects with mCRPC will be enrolled after RP2D is established. Receives: Drug: AMG 340

What is being measured

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

Number of Participants Who Experienced Treatment-emergent Adverse Events (TEAEs)
An adverse event (AE) was any untoward medical occurrence in a clinical study participant, regardless of a causal relationship with the study treatment. TEAEs included any event occurring after the participant received the study treatment. A treatment-related AE (TRAE) was defined as any TEAE flagged as possibly caused by AMG 340. Clinically significant changes in vital signs, electrocardiograms, and laboratory tests recorded after treatment administration were documented as TEAEs. Serious TEAEs (SAEs) were any untoward medical occurrences after the first dose, irrespective of a causal link to the study treatment, that led to death, were life-threatening, required hospitalization or its prolongation, caused significant disability, resulted in congenital anomalies, or were considered other medically important events.
Measured: From enrollment up to and including a maximum of 90 days after last dose of AMG 340; median (min, max) duration was 4.3 (0.5, 27.1) months
Number of Participants Who Experienced Dose Limiting Toxicities (DLTs)
A DLT was defined as a TEAE that was not unequivocally due to the participant's underlying malignancy or other extraneous cause, and appeared within 21 days from the first dose of AMG 340. AEs considered DLTs were:
- Transient (≤72 hours) grade 3 or 4 electrolyte abnormalities, hyperglycemia, nausea/vomiting/diarrhea responsive to treatment.
- Alopecia, vitiligo, and grade 3 fatigue lasting <10 days.
- Grade 3 fever lasting ≤24 hours (outside CRS context).
- Grade 3 lab abnormalities resolving within 72 hours (or within 7 days for certain enzymes like ALT, GGT, ALP, and lipase).
- Grade 3 CRS or TLS unresolved to ≤ grade 1 within 72 hours or any grade 4 CRS/TLS.
- Prolonged grade 4 neutropenia (>5 days) or febrile neutropenia.
- Grade 3 thrombocytopenia with bleeding or any grade 4 thrombocytopenia.
- Grade 4 anemia.
- Grade 5 adverse events.
- Lymphopenia is not considered a DLT.
Measured: Up to approximately Day 21
Median Concentration of AMG 340
Blood samples for pharmacokinetics (PK) analysis were collected at specific time points. PK parameters were estimated using standard non-compartmental approaches.
Measured: Cohorts 1-5: Days 1 (pre-dose to 6 hours post-dose), 2, 3, 8, and 10; Cohorts 6-10: Days 1 (pre-dose to 6 hours post-dose), 2, 3, 5 (pre-dose to 6 hours post-dose), 6, 7, 8 (pre-dose to 6 hours post-dose), 9, 10

Secondary outcomes (11)

Percentage of Participants Who Achieved an Objective Response (OR) Per Response Evaluation Criteria in Solid Tumors (RECIST) 1.1
OR was defined as a partial response (PR) or complete response (CR) per RECIST 1.1, confirmed by a repeat assessment at least 4 weeks later. Participants who did not experience a confirmed PR/CR or did not have any follow-up tumor assessments were regarded as non-responders.
Measured: Up to approximately 24 months
Overall Survival (OS)
OS was defined as the time from the date of study Day 1 until death due to any cause.
Measured: Up to approximately 24 months
Prostate Specific Antigen (PSA) Progression Free Survival (PFS)
PSA PFS was defined as the interval from study day 1 to the earlier of a PSA progression or death from any cause; otherwise, PSA PFS was censored on the date of the last PSA measurement. If a participant had no baseline or post-baseline PSA measurement and a vital status of alive or unknown, PSA PFS was censored at study day 1.
Measured: Up to approximately 24 months
Radiographic PFS (rPFS)
rPFS was defined as the interval from study day 1 to radiographic progression or death from any cause, whichever occurred first, in the absence of subsequent anti-cancer therapy; otherwise, rPFS was censored at the last evaluable tumor assessment date prior to subsequent anti-cancer therapy.
If a participant had no post-baseline radiographic tumor assessment and a vital status of alive or unknown, rPFS was censored at study day 1.
Measured: Up to approximately 24 months
Percentage of Participants With rPFS at 6 Months
rPFS was defined as the interval from study day 1 to radiographic progression or death from any cause, whichever occurred first, in the absence of subsequent anti-cancer therapy; otherwise, rPFS was censored at the last evaluable tumor assessment date prior to subsequent anti-cancer therapy.
If a participant had no post-baseline radiographic tumor assessment and a vital status of alive or unknown, rPFS was censored at study day 1.
Measured: 6 months
Percentage of Participants With a 30% Reduction From Baseline in PSA (PSA30)
PSA 30 was defined as a ≥ 30% reduction from the baseline PSA. This PSA response had to be confirmed by a second consecutive value obtained at least three weeks later.
Measured: Up to approximately 24 months
Percentage of Participants With a 50% Reduction From Baseline in PSA (PSA50)
PSA 50 was defined as a ≥ 50% reduction from the baseline PSA. This PSA response had to be confirmed by a second consecutive value obtained at least three weeks later.
Measured: Up to approximately 24 months
Percentage of Participants With a 70% Reduction From Baseline in PSA (PSA70)
PSA 70 was defined as a ≥ 70% reduction from the baseline PSA. This PSA response had to be confirmed by a second consecutive value obtained at least three weeks later.
Measured: Up to approximately 24 months
Percentage of Participants With a 90% Reduction From Baseline in PSA (PSA90)
PSA 90 was defined as a ≥ 90% reduction from the baseline PSA. This PSA response had to be confirmed by a second consecutive value obtained at least three weeks later.
Measured: Up to approximately 24 months
Duration of Response (DOR) Per RECIST 1.1
DOR was defined as the time from the date of an initial objective response per RECIST 1.1, which was subsequently confirmed, until soft-tissue progression per RECIST 1.1 or death, whichever occurred first in the absence of subsequent anti-cancer therapy. Participants who had not ended their response at the time of analysis had DOR censored at their last evaluable tumor assessment by CT/MRI scan prior to subsequent anti-cancer therapy. This endpoint only applied to participants with an objective response (CR or PR) per RECIST 1.1. No participants achieved CR or PR, therefore, no participants could be analyzed for this outcome measure.
Measured: Up to approximately 24 months
Number of Participants With Symptomatic Skeletal Events (SSE)
SSE was defined as time from study day 1 to the first symptomatic skeletal event, otherwise time to symptomatic skeletal event was censored at the last dose of AMG 340 or end of safety follow-up date, whichever was later.
Measured: Up to approximately 24 months

Timeline

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

29 Apr 202124 Jun 2024

First posted5 Feb 2021
Study start29 Apr 2021
Primary completion24 Jun 2024
Study completion24 Jun 2024

Why it stopped: Sponsor strategic 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 Metastatic Castration-resistant Prostate CancerStudies of the same condition, open and under way.
More trials run by AmgenThe sponsor's other registered studies.
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: Non-randomised
Intervention model: Sequential
Masking: None (open label)
Enrolment: 42 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT04740034
Sponsor's protocol ID: TNB585.001
Other IDs: 20210249
Status last verified: May 2025
First submitted: 1 Feb 2021
Last updated: 17 Jun 2025
Results posted: Yes, on ClinicalTrials.gov
Data monitoring committee: No
FDA-regulated drug: Yes
FDA-regulated device: No
Individual data sharing: 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

Not yet recruitingPhase 1/2
STAR0602 With Nivolumab in Non Small Cell Lung Cancer and in Metastatic Castrate-Resistant Prostate Cancer, and STAR0602 Alone in Thymic Carcinoma
NSCLC, Non-Small Cell Lung Cancer
RecruitingPhase 2
A Study to Test Inavolisib Treatment in Participants With Metastatic Castration-Resistant Prostate Cancer
Metastatic Castration-Resistant Prostate Cancer
RecruitingPhase 1/2
Docetaxel and SX-682 in Recurrent/Metastatic Head and Neck Squamous Cell Carcinoma, Salivary Gland Carcinoma, and Advanced Prostate Cancer
Head and Neck Cancer, Head and Neck Squamous Cell Carcinoma
RecruitingObservational study
ARCTIC: Liquid Biomarkers in the Prospective Androgen Receptor Signaling Inhibitors (ARSI) Resistance Clinical Trials
Prostate Cancer, Prostate Adenocarcinoma
Active, not recruitingPhase 2
FPI-2265 (225Ac-PSMA-I&T) and Olaparib for Patients With Metastatic Castration-Resistant Prostate Cancer (mCRPC)
Metastatic Castration-resistant Prostate Cancer

All Metastatic Castration-resistant Prostate Cancer trials

Study at a glance

From the registry record, last updated by the sponsor on 17 Jun 2025. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: A Multicenter, Phase 1, Open-label, Dose-escalation and Expansion Study of AMG 340, a Bispecific Antibody Targeting PSMA in Subjects With Metastatic Castrate-Resistant Prostate Carcinoma
ClinicalTrials.gov ID: NCT04740034
Acronym / sponsor ID: TNB585.001
Conditions: Metastatic Castration-resistant Prostate Cancer
Keywords: Prostate specific membrane antigen, PSMA, Prostate cancer, Metastatic, Castrate-resistant
Phase: Phase 1
Study type: Interventional
Recruitment status: TerminatedReason stopped: Sponsor strategic decision
Enrolment: 42 participants (actual)
Lead sponsor: AmgenIndustry (pharma, biotech, devices)
Study start: 29 Apr 2021 (actual)
Primary completion: 24 Jun 2024 (actual)
Study completion: 24 Jun 2024 (actual)
First posted: 5 Feb 2021 (actual)
Results: Posted 17 Jun 2025

Clinical summary

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

Study design

Primary purpose: Treatment
Allocation: Non-randomised
Intervention model: Sequential
Masking: None (open label)
Number of arms: 2

Arm	Type	Receives
Dose Escalation	Experimental	Drug: AMG 340Sequential dose escalation cohorts are planned until maximum tolerated dose (MTD) is reached or recommended phase 2 dose (RP2D) is identified.
Dose Expansion	Experimental	Drug: AMG 340An expansion cohort in subjects with mCRPC will be enrolled after RP2D is established.

Who may qualify

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

Key inclusion criteria (7 listed)

Pathologically confirmed prostatic adenocarcinoma.
History of metastatic disease.
Chemically or surgically castrate.
Subject has received at least 2 lines of systemic therapy approved for mCRPC, with disease progression on the most recent systemic therapy as defined in Prostate Cancer Working Group 3 (PCWG3) recommendations.
Human immunodeficiency virus (HIV), hepatitis B virus (HBV), and/or hepatitis C virus (HCV)-infected subjects that have been cured or who are on effective anti-retroviral therapy with undetectable viral load within 6 months are eligible for this trial.

Key exclusion criteria (6 listed)

Subject has been diagnosed with or treated for another malignancy within the past 2 years whose natural history or treatment may interfere with the safety or efficacy assessment of the investigational regimen.
History of neuroendocrine differentiation in the subject's disease.
Subject has a history of central nervous system (CNS) involvement by their mCRPC. Metastases stemming from bone are allowed.
Subject has clinically significant CNS pathology.
Subject requires chronic immunosuppressive therapy.

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
AMG 340AMG 340 is a bispecific antibody targeting prostate-specific membrane antigen (PSMA) on tumor cells and CD3 on T-cells	Drug	Dose Escalation, Dose Expansion

Primary outcome

Number of Participants Who Experienced Treatment-emergent Adverse Events (TEAEs)
Time frame: From enrollment up to and including a maximum of 90 days after last dose of AMG 340; median (min, max) duration was 4.3 (0.5, 27.1) months
An adverse event (AE) was any untoward medical occurrence in a clinical study participant, regardless of a causal relationship with the study treatment. TEAEs included any event occurring after the participant received the study treatment. A treatment-related AE (TRAE) was defined as any TEAE flagged as possibly caused by AMG 340. Clinically significant changes in vital signs, electrocardiograms, and laboratory tests recorded after treatment administration were documented as TEAEs. Serious TEAEs (SAEs) were any untoward medical occurrences after the first dose, irrespective of a causal link to the study treatment, that led to death, were life-threatening, required hospitalization or its prolongation, caused significant disability, resulted in congenital anomalies, or were considered other medically important events.
Number of Participants Who Experienced Dose Limiting Toxicities (DLTs)
Time frame: Up to approximately Day 21
A DLT was defined as a TEAE that was not unequivocally due to the participant's underlying malignancy or other extraneous cause, and appeared within 21 days from the first dose of AMG 340. AEs considered DLTs were: * Transient (≤72 hours) grade 3 or 4 electrolyte abnormalities, hyperglycemia, nausea/vomiting/diarrhea responsive to treatment. * Alopecia, vitiligo, and grade 3 fatigue lasting <10 days. * Grade 3 fever lasting ≤24 hours (outside CRS context). * Grade 3 lab abnormalities resolving within 72 hours (or within 7 days for certain enzymes like ALT, GGT, ALP, and lipase). * Grade 3 CRS or TLS unresolved to ≤ grade 1 within 72 hours or any grade 4 CRS/TLS. * Prolonged grade 4 neutropenia (>5 days) or febrile neutropenia. * Grade 3 thrombocytopenia with bleeding or any grade 4 thrombocytopenia. * Grade 4 anemia. * Grade 5 adverse events. * Lymphopenia is not considered a DLT.
Median Concentration of AMG 340
Time frame: Cohorts 1-5: Days 1 (pre-dose to 6 hours post-dose), 2, 3, 8, and 10; Cohorts 6-10: Days 1 (pre-dose to 6 hours post-dose), 2, 3, 5 (pre-dose to 6 hours post-dose), 6, 7, 8 (pre-dose to 6 hours post-dose), 9, 10
Blood samples for pharmacokinetics (PK) analysis were collected at specific time points. PK parameters were estimated using standard non-compartmental approaches.

11 secondary outcomes

Percentage of Participants Who Achieved an Objective Response (OR) Per Response Evaluation Criteria in Solid Tumors (RECIST) 1.1
Time frame: Up to approximately 24 months
Overall Survival (OS)
Time frame: Up to approximately 24 months
Prostate Specific Antigen (PSA) Progression Free Survival (PFS)
Time frame: Up to approximately 24 months
Radiographic PFS (rPFS)
Time frame: Up to approximately 24 months
Percentage of Participants With rPFS at 6 Months
Time frame: 6 months
Percentage of Participants With a 30% Reduction From Baseline in PSA (PSA30)
Time frame: Up to approximately 24 months
Percentage of Participants With a 50% Reduction From Baseline in PSA (PSA50)
Time frame: Up to approximately 24 months
Percentage of Participants With a 70% Reduction From Baseline in PSA (PSA70)
Time frame: Up to approximately 24 months
Percentage of Participants With a 90% Reduction From Baseline in PSA (PSA90)
Time frame: Up to approximately 24 months
Duration of Response (DOR) Per RECIST 1.1
Time frame: Up to approximately 24 months
Number of Participants With Symptomatic Skeletal Events (SSE)
Time frame: Up to approximately 24 months

Results and safety

Results posted to the registry on 17 Jun 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
Cohort 1: AMG 340 Dose A	1	0
Cohort 2: AMG 340 Dose B	1	0
Cohort 3: AMG 340 Dose C	3	0
Cohort 4: AMG 340 Dose D	5	1
Cohort 5: AMG 340 Dose E	6	0
Cohort 6a: AMG 340 Priming Dose (PmD) (High) and Then AMG 340 Dose E	6	0
Cohort 6b: AMG 340 PmD (Low) and Then AMG 340 Dose E	3	0
Cohort 7a: AMG 340 PmD (High) and Then AMG 340 Dose F	5	0
Cohort 8a: AMG 340 PmD (High) and Then AMG 340 Dose G	3	0
Cohort 9: AMG 340 PmD (High) and Then AMG 340 Dose H	7	0
Cohort 10: AMG 340 PmD (High) and Then AMG 340 Dose H and Dose I	2	0

Primary outcome: Number of Participants Who Experienced Treatment-emergent Adverse Events (TEAEs)

Time frame: From enrollment up to and including a maximum of 90 days after last dose of AMG 340; median (min, max) duration was 4.3 (0.5, 27.1) months. Count of participants. Unit: Participants

Measure	Cohort 1: Dose A n = 1	Cohort 2: Dose B n = 1	Cohort 3: Dose C n = 3	Cohort 4: Dose D n = 5	Cohort 5: Dose E n = 6	Cohort 6a: AMG 340 PmD (High) and Then AMG 340 Dose E n = 6	Cohort 6b: AMG 340 PmD (Low) and Then AMG 340 Dose E n = 3	Cohort 7a: AMG 340 PmD (High) and Then AMG 340 Dose F n = 5	Cohort 8a: AMG 340 PmD (High) and Then AMG 340 Dose G n = 3	Cohort 9: AMG 340 PmD (High) and Then AMG 340 Dose H n = 7	Cohort 10: AMG 340 PmD (High) and Then AMG 340 Dose H and Dose I n = 2
All TEAEs	1	1	3	5	6	6	3	5	3	7	2
All SAEs	0	0	2	3	3	4	2	1	2	4	0
All TRAEs	0	0	3	5	6	6	3	5	3	7	2

Population analysed: SAS: All participants who received at least 1 dose of AMG 340.

Primary outcome: Number of Participants Who Experienced Dose Limiting Toxicities (DLTs)

Time frame: Up to approximately Day 21. Count of participants. Unit: Participants

Measure	Cohort 1: Dose A n = 1	Cohort 2: Dose B n = 1	Cohort 3: Dose C n = 2	Cohort 4: Dose D n = 5	Cohort 5: Dose E n = 5	Cohort 6a: AMG 340 PmD (High) and Then AMG 340 Dose E n = 6	Cohort 6b: AMG 340 PmD (Low) and Then AMG 340 Dose E n = 3	Cohort 7a: AMG 340 PmD (High) and Then AMG 340 Dose F n = 5	Cohort 8a: AMG 340 PmD (High) and Then AMG 340 Dose G n = 3	Cohort 9: AMG 340 PmD (High) and Then AMG 340 Dose H n = 6	Cohort 10: AMG 340 PmD (High) and Then AMG 340 Dose H and Dose I n = 2
Value	0	0	0	0	1	1	0	0	0	1	1

Population analysed: DLT evaluable analysis set: All participants who were evaluable for DLTs. A participants was considered DLT evaluable if the participant completed at least the first full treatment cycle or experienced a DLT during the first treatment cycle.

Primary outcome: Median Concentration of AMG 340

Time frame: Cohorts 1-5: Days 1 (pre-dose to 6 hours post-dose), 2, 3, 8, and 10; Cohorts 6-10: Days 1 (pre-dose to 6 hours post-dose), 2, 3, 5 (pre-dose to 6 hours post-dose), 6, 7, 8 (pre-dose to 6 hours post-dose), 9, 10. Median (Full Range). Unit: µg/mL

Measure	Cohort 1: Dose A n = 1	Cohort 2: Dose B n = 1	Cohort 3: Dose C n = 3	Cohort 4: Dose D n = 5	Cohort 5: Dose E n = 6	Cohort 6: AMG 340 PmD (Low) and (High), and Then AMG 340 Dose E n = 9	Cohort 7a: AMG 340 PmD (High) and Then AMG 340 Dose F n = 5	Cohort 8a: AMG 340 PmD (High) and Then AMG 340 Dose G n = 3	Cohort 9: AMG 340 PmD (High) and Then AMG 340 Dose H n = 3	Cohort 10: AMG 340 PmD (High) and Then AMG 340 Dose H and Dose I n = 2
Value	0.352 (0.352 to 0.352)	0.818 (0.818 to 0.818)	2.445 (0.233 to 4.71)	6.78 (0.661 to 16.2)	17.8 (0.116 to 54.5)	19.25 (0 to 52.3)	54.4 (3.61 to 129)	68.0 (17.1 to 149)	75.2 (2.64 to 201)	201 (79.1 to 397)

Population analysed: PK analysis set: Included all participants who received at least 1 dose of AMG 340 and had at least 1 PK sample drawn post dose. Summary statistics are presented per dose level as pre-specified in SAP Section 9.7.

11 secondary outcomes are reported in the full results.

Adverse events

Time frame: Death: From enrollment through end of study; median (min, max) time on study was 7.4 (0.5, 28.2) months. TEAE: From enrollment up to and including a maximum of 90 days after last dose of AMG 340; median (min, max) duration was 4.3 (0.5, 27.1) months.. Other adverse events reported at 5% frequency or more

Group	Serious adverse events	Other adverse events	Deaths
Cohort 1: Dose A	0 of 1 (0%)	1 of 1 (100%)	0 of 1
Cohort 2: Dose B	0 of 1 (0%)	1 of 1 (100%)	1 of 1
Cohort 3: Dose C	2 of 3 (66.7%)	3 of 3 (100%)	2 of 3
Cohort 4: Dose D	3 of 5 (60%)	5 of 5 (100%)	3 of 5
Cohort 5: Dose E	3 of 6 (50%)	6 of 6 (100%)	4 of 6
Cohort 6a: AMG 340 PmD (High) and Then AMG 340 Dose E	4 of 6 (66.7%)	6 of 6 (100%)	4 of 6
Cohort 6b: AMG 340 PmD (Low) and Then AMG 340 Dose E	2 of 3 (66.7%)	3 of 3 (100%)	2 of 3
Cohort 7a: AMG 340 PmD (High) and Then AMG 340 Dose F	1 of 5 (20%)	5 of 5 (100%)	2 of 5
Cohort 8a: AMG 340 PmD (High) and Then AMG 340 Dose G	2 of 3 (66.7%)	3 of 3 (100%)	2 of 3
Cohort 9: AMG 340 PmD (High) and Then AMG 340 Dose H	4 of 7 (57.1%)	7 of 7 (100%)	4 of 7
Cohort 10: AMG 340 PmD (High) and Then AMG 340 Dose H and Dose I	0 of 2 (0%)	2 of 2 (100%)	0 of 2

Loading the posted results from ClinicalTrials.gov…

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 17 Jun 2025.
Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
Individual participant dataSharing planned: No

Related trials for Metastatic Castration-resistant Prostate Cancer

Not yet recruitingPhase 1/2
STAR0602 With Nivolumab in Non Small Cell Lung Cancer and in Metastatic Castrate-Resistant Prostate Cancer, and STAR0602 Alone in Thymic Carcinoma
NSCLC, Non-Small Cell Lung Cancer
RecruitingPhase 2
A Study to Test Inavolisib Treatment in Participants With Metastatic Castration-Resistant Prostate Cancer
Metastatic Castration-Resistant Prostate Cancer
RecruitingPhase 1/2
Docetaxel and SX-682 in Recurrent/Metastatic Head and Neck Squamous Cell Carcinoma, Salivary Gland Carcinoma, and Advanced Prostate Cancer
Head and Neck Cancer, Head and Neck Squamous Cell Carcinoma
RecruitingObservational study
ARCTIC: Liquid Biomarkers in the Prospective Androgen Receptor Signaling Inhibitors (ARSI) Resistance Clinical Trials
Prostate Cancer, Prostate Adenocarcinoma
Active, not recruitingPhase 2
FPI-2265 (225Ac-PSMA-I&T) and Olaparib for Patients With Metastatic Castration-Resistant Prostate Cancer (mCRPC)
Metastatic Castration-resistant Prostate Cancer

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.

MD study director

Amgen

7 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 AMG 340 in people with Metastatic Castration-resistant Prostate Cancer, run by Amgen at 7 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 7 inclusion and 6 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 17 Jun 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 7 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 17 Jun 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 of Participants Who Experienced Treatment-emergent Adverse Events (TEAEs) (time frame: From enrollment up to and including a maximum of 90 days after last dose of AMG 340; median (min, max) duration was 4.3 (0.5, 27.1) months). The study lists 3 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 NCT04740034.

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 17 Jun 2025.