A Study Evaluating the Safety, Pharmacokinetics, and Preliminary Activity of GDC-1261 in Participants With Advanced or Metastatic Prostate Cancer

NCT07567846 | Recruiting Phase 1 FDA Drug

• 1 other identifier: GO46445
• Study Type: interventional
• Target: 260
• Locations: 2 countries
• Sites: 4

Brief Summary

The purpose of this study is to evaluate the safety, pharmacokinetics (PK), and preliminary activity of GDC-1261 in participants with advanced or metastatic prostate cancer. It's also to identify a recommended dose(s) and regimen for GDC-1261 for subsequent studies.

Conditions

Advanced Prostate Cancer; Metastatic Prostate Cancer

Outcome Measures

Primary Outcomes (2)

• Percentage of Participants With Adverse Events (AEs)

  Up to approximately 24 months

• Incidence and Nature of DLTs Dose-limiting Toxicities (DLTs)

  From Day 1-28 of Cycle 1 (1 Cycle = 28 days)

Secondary Outcomes (7)

• Plasma Concentration of GDC-1261

  Up to approximately 24 months

• Plasma Concentration of GDC-1261 Either in Fasted or Fed State

  Up to approximately 24 months

• Prostate-Specific Antigen-30% (PSA30) Response Rate

  Up to approximately 24 months

• PSA50 Response Rate

  Up to approximately 24 months

• PSA90 Response Rate

  Up to approximately 24 months

Study Arms (1)

Dose Escalation + Expansion

EXPERIMENTAL

Participants will receive GDC-1261 as per the schedule described in the protocol.

Drug: GDC-1261

Interventions

GDC-1261 DRUG

Participants will receive GDC-1261 as per the schedule described in the protocol.

Dose Escalation + Expansion

Eligibility Criteria

• Age: 18 Years+
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Eastern Cooperative Oncology Group (ECOG) Performance Status of \<=1
• Life expectancy is \>= 3 months
• Histologically or cytologically confirmed prostate adenocarcinoma
• Disease progression during or following the direct prior line of therapy
• Ongoing androgen deprivation therapy (ADT) with gonadotropin-releasing hormone (GnRH) agonist or antagonist, or have had bilateral orchiectomy
• Metastatic disease
• Adequate end organ function

You may not qualify if:

• Treatment with any approved systemic anti-cancer therapy within 14 days or 5 drug elimination half-lives
• Structurally unstable bone lesions suggest an impending fracture
• Untreated central nervous system (CNS) metastases or leptomeningeal disease
• Uncontrolled pain
• History of malignancy within 5 years
• Infection requiring systemic IV antibiotics within 14 days or oral antibiotics within 7 days prior to screening, or any evidence of current infection
• Any medical condition or abnormal clinical laboratory finding that, in the investigator's judgment, would preclude the individual's safe participation in and completion of the study or could affect the interpretation of the results

Sponsors & Collaborators

• Genentech, Inc.: lead

Study Sites (4)

Honor Health Research Institute

Scottsdale, Arizona, 85258-4566, United States

RECRUITING

Sarah Cannon Research Institute

Nashville, Tennessee, 37203, United States

RECRUITING

St Vincent's Hospital Sydney

Darlinghurst, New South Wales, 2010, Australia

RECRUITING

Austin Hospital

Heidelberg, Victoria, 3084, Australia

RECRUITING

Related Links

• Please use this form to submit your questions for a faster response: https://www.gene.com/contact-us/submit-medical-inquiry. Do not include or attach any medical records when emailing or completing the form. A nurse will respond within 24 business hours.

MeSH Terms

Conditions

Prostatic Neoplasms

Condition Hierarchy (Ancestors)

Genital Neoplasms, Male; Urogenital Neoplasms; Neoplasms by Site; Neoplasms; Genital Diseases, Male; Genital Diseases; Urogenital Diseases; Prostatic Diseases; Male Urogenital Diseases

Study Officials

• Clinical Trials

  Genentech, Inc.

  STUDY DIRECTOR

Central Study Contacts

Reference Study ID Number: GO46445 https://forpatients.roche.com/ No attachments to email below.

CONTACT

888-662-6728; global-roche-genentech-trials@gene.com

Fastest response: use the inquiry form. https://www.gene.com/contact-us/submit-medical-inquiry

CONTACT

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SEQUENTIAL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: April 13, 2026
• First Posted: May 5, 2026
• Study Start: April 29, 2026
• Primary Completion (Estimated): November 30, 2027
• Study Completion (Estimated): December 30, 2027
• Last Updated: July 9, 2026

Record last verified: 2026-07

Data Sharing

• IPD Sharing: Will share

Locations

AU (2); US (2)