Ph1b/2 Study of the Safety and Efficacy of T-DXd Combinations in Advanced HER2-expressing Gastric Cancer (DESTINY-Gastric03)

DRUG

Fluorouracil (5-FU)

5-FU: administered as an IV infusion

DRUG

Capecitabine

Capecitabine: administered orally

BIOLOGICAL

Durvalumab

Durvalumab: administered as an IV infusion

DRUG

Oxaliplatin

Oxaliplatin: administered as an IV infusion

BIOLOGICAL

Trastuzumab

Trastuzumab: administered as an IV infusion

DRUG

Trastuzumab deruxtecan

T-DXd: administered as an IV infusion

DRUG

Cisplatin

Cisplatin: administered as an IV infusion

BIOLOGICAL

Pembrolizumab

Pembrolizumab: administered as an IV infusion

BIOLOGICAL

Volrustomig

Volrustomig: administered as an IV infusion

BIOLOGICAL

Rilvegostomig

Rilvegostomig: administered as an IV infusion

Part 1: Occurrence of adverse events (AEs) and serious adverse events (SAEs), graded according to NCI CTCAE v5.0

Time frame: Safety will be assessed up to the follow-up period, approximately 24 months.

Occurrence of AEs and SAEs graded according to NCI CTCAE v5.0

Part 1: Ocurrence of dose-limiting toxicities (DLTs)

Time frame: Safety will be assessed up to the follow-up period, approximately 24 months.

Occurrence of dose limiting toxicities

Part 1: Changes from baseline in laboratory parameters

Time frame: Safety will be assessed up to the follow-up period, approximately 24 months.

Changes in laboratory parameters (every in appropriate units) compared to baseline results.

Part 1: Changes from baseline in vital signs

Time frame: Safety will be assessed up to the follow-up period, approximately 24 months.

Changes in vital signs results compared to baseline results.

Part 1: Changes from baseline in electrocardiogram (ECG) results

Time frame: Safety will be assessed up to the follow-up period, approximately 24 months.

Changes in ECG results compared to baseline results.

Part 2, Part 3, Part 4 and Part 5: Endpoint assessed by Investigator per RECIST v1.1: Confirmed Objective Response Rate (ORR)

Time frame: (Endpoint: ORR) Efficacy will be assessed at an average of approximately 12 months

Confirmed ORR per RECIST 1.1 is the percentage of patients with Complete Response or Partial Response that is subsequently confirmed.

What is a clinical trial?

A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.

Is it safe to participate?

Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.

Will I be compensated?

Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.

Will I receive a placebo instead of treatment?

When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.

Can I leave a trial if I change my mind?

Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.

How long does a clinical trial last?

Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.