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RecruitingLast updated: 15 May 2026

Testing a new treatment called GDC-1261 for people with advanced or metastatic prostate cancerA Phase I/II Dose-escalation and Expansion Study Evaluating the Safety, Pharmacokinetics, and Preliminary Activity of GDC-1261 in Patients With Advanced or Metastatic Prostate Cancer

Trial purpose

Medical clipboardCancer treatment

Tumor type

Urinary System Cancers Genitourinary

Age

People18+

Clinical summary

Summary

This study is looking at a new treatment called GDC-1261 for people with advanced prostate cancer to understand how safe it is, how it works in the body, and whether it shows early signs of helping treat the cancer, while also finding the most suitable dose for future studies.

You may be eligible for this study if you have locally advanced or metastatic prostate cancer that has progressed during or after prior treatment. You should also be having ongoing androgen deprivation therapy (ADT) or have had a bilateral orchiectomy.

All eligible participants will receive GDC-1261.

Conditions

This trial is treating people with locally advanced or metastatic prostate cancer

Eligibility

Inclusion

  • 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

Exclusion

  • 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

Inclusion

  • Your cancer has spread to other parts of the body (metastatic) or has grown into nearby parts of the body (locally advanced).
  • You have had a certain type of treatment or surgical procedure.

Exclusion

  • You have been diagnosed with a prior or secondary type of cancer.
  • You have certain types of non-cancer medical conditions.
  • You have had certain treatments, surgical procedures or drugs.
Message

Clinical trials have complex eligibility criteria, and other criteria may apply for this trial. Ask your doctor about whether this trial could be right for you.

Participating hospitals

Recruiting hospitals

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More information

Trial Identifiers

Information on this page is partially produced from ClinicalTrials.gov *. View further details about this trial on the registry via the links below:

Trial sponsor

Genentech, Inc.

Scientific Title

A Phase I/II Dose-escalation and Expansion Study Evaluating the Safety, Pharmacokinetics, and Preliminary Activity of GDC-1261 in Patients With Advanced or Metastatic Prostate Cancer

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