A Study to Evaluate the Safety and Antitumor Activity of GS-1206 in Adults With Solid Tumors

A Phase 1 Study to Evaluate the Safety, Tolerability, and Antitumor Activity of GS-1206 in Adults With Solid Tumors

The goal of this clinical study is to learn more about the study drug GS-1206, including its safety, tolerability, and antitumor activity in adult participants with solid tumors.

Study Overview

• Status: Not yet recruiting
• Conditions: Solid Tumor
• Intervention / Treatment: Drug: GS-1206

• Study Type: Interventional
• Enrollment (Estimated): 302
• Phase: Phase 1

Contacts and Locations

• Study Contact: Name: Gilead Clinical Study Information Center; Phone Number: 1-833-445-3230 (GILEAD-0); Email: GileadClinicalTrials@gilead.com

Participation Criteria

Eligibility Criteria

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

Description

Key Inclusion Criteria:

• All individuals must have a tumor with protocol-specified mutation as determined by local health-authority approved test.
• For Part A (including backfill cohorts): Individuals with histologically confirmed advanced or metastatic solid tumors who have progressed following treatment in the advanced or metastatic setting known to confer clinical benefit, unless the individual refused, is intolerant to, or is not eligible for standard-of-care (SOC) treatment.
• For Part B dose expansion, individuals with protocol-specified tumor types will be enrolled.

Key Exclusion Criteria:

• Use of any of the therapies listed below within the specified time frames:

  1. Investigational drugs (drugs not marketed for any indication) within 28 days prior to Cycle 1 Day 1.
  2. Anticancer biologic agent or immunotherapy within 28 days prior to Cycle 1 Day 1.
  3. Anticancer chemotherapy or targeted approved small molecule therapy within 21 days prior to Cycle 1 Day 1, or 42 days for nitrosoureas or mitomycin.
  4. Hormonal or other adjunctive therapy for cancers other than the cancer under evaluation in this study that started within 14 days prior to planned Cycle 1 Day 1 are not permitted. Exceptions: hormonal therapy, bisphosphonates, somatostatin analogues, and leuprolide are permitted if started at least 14 days prior to Cycle 1 Day 1.
  5. Major surgery (excluding minor procedures, eg, placement of vascular access, gastrointestinal/biliary stent, biopsy) within 28 days prior to Cycle 1 Day 1, and any toxicity or complications have recovered to Grade 1 or less.
  6. Radiation therapy within 21 days prior to Cycle 1 Day 1. Exception: limited (eg, pain palliation) radiation therapy is allowed if any radiation associated toxicity is resolved to Grade 1 or less, and the radiation is not administered to a target lesion.

Note: Other protocol defined Inclusion/Exclusion criteria may apply.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Non-Randomized
• Interventional Model: Sequential Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Part A: Dose Escalation; Participants will receive escalating doses of GS-1206 monotherapy one time daily up to 35 cycles.	Drug: GS-1206; Administered Orally
Experimental: Part B: Dose Expansion; Participants will be enrolled in different indication specific cohorts. Participants will receive GS-1206 monotherapy at the recommended dose one time daily up to 35 cycles.	Drug: GS-1206; Administered Orally

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Percentage of Participants Experiencing any Dose-limiting Toxicities (DLTs)	First dose up to 21 days post first dose
Percentage of Participants Experiencing Treatment-Emergent Adverse Events (AEs) and Serious Adverse Events (SAE) Based on National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events (CTCAE) v6.0.	First dose date up to 30 days post last dose (Up to 3 years)
Percentage of Participants Experiencing Clinical Laboratory Abnormalities Based National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events (CTCAE) v6.0.	First dose date up to 30 days post last dose (Up to 3 years)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Plasma Concentrations of GS-1206 and its Metabolites After Single Dose and Repeated Dose Administration		Predose and postdose up to end of treatment (up to 2 years)
Pharmacokinetic (PK) Parameter: Cmax of GS-1206 and its Metabolites	Cmax is defined as the maximum observed concentration of drug	Up to 2 years
PK Parameter: Tmax of GS-1206 and its Metabolites	Tmax is defined as the time (observed time point) of Cmax	Up to 2 years
PK Parameter: AUC0-24h of GS-1206 and its Metabolites	AUC0-24h is defined as the partial area under the concentration versus time curve from time 0 to time 24	Up to 2 years
Objective Response Rate (ORR)	ORR is defined as the percentage of participants who have measurable disease at baseline and have achieved complete response (CR) or partial response (PR) according to Response Evaluation Criteria in Solid Tumors (RECIST) v1.1 and assessed by the investigator at the local site.	Up to 3 years
Duration of Response (DOR)	DOR is defined as the measurement from the time of first response (CR or PR) as assessed by the investigator at local site, per RECIST v1.1 until the date of first documented disease progression or death, whichever occurs first.	Up to 3 years
Best Overall Response (BOR)	BOR is defined as the best response recorded from first dosing date until disease progression identified by RECIST v1.1, death, or the participant discontinues study treatment, whichever occurs first.	Up to 3 years
Progression-Free Survival (PFS)	PFS is defined as the time from first dosing date until disease progression or death from any cause, whichever comes first as measured per RECIST v1.1.	Up to 3 years
Disease Control Rate (DCR)	DCR is defined as the measurement by the percentage of participants who achieve confirmed response of CR or PR or stable disease.	Up to 3 years

Collaborators and Investigators

• Sponsor: Gilead Sciences
• Investigators: Study Director: Gilead Study Director, Gilead Sciences

Study record dates

Study Major Dates

• Study Start (Estimated): August 1, 2026
• Primary Completion (Estimated): September 1, 2029
• Study Completion (Estimated): September 1, 2029

Study Registration Dates

• First Submitted: July 8, 2026
• First Submitted That Met QC Criteria: July 8, 2026
• First Posted (Actual): July 15, 2026

Study Record Updates

• Last Update Posted (Actual): July 15, 2026
• Last Update Submitted That Met QC Criteria: July 8, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: GS-US-723-7652

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