Pembrolizumab + Trastuzumab + Chemotherapy for Gastric Cancer

Recruiting in Palo Alto (17 mi)

+191 other locations

Age: 18+

Sex: Any

Travel: May Be Covered

Time Reimbursement: Varies

Trial Phase: Phase 3

Waitlist Available

Sponsor: Merck Sharp & Dohme LLC

No Placebo Group

Pivotal Trial (Near Approval)

Prior Safety Data

Breakthrough Therapy

Trial Summary

What is the purpose of this trial?The study will compare the efficacy and safety of pembrolizumab plus trastuzumab in combination with standard of care (SOC) chemotherapy versus trastuzumab in combination with SOC chemotherapy in participants with HER2-positive gastric cancer. The primary hypotheses of the study are that pembrolizumab plus trastuzumab in combination with chemotherapy is superior to trastuzumab plus chemotherapy in terms of 1) progression free survival (PFS) per Response Evaluation Criteria in Solid Tumors 1.1 (RECIST 1.1) as assessed by blinded independent central review (BICR), and 2) overall survival (OS).

Eligibility Criteria

This trial is for adults with untreated advanced HER2+ gastric or GEJ adenocarcinoma. Participants must have measurable disease, be in good physical condition (ECOG 0-1), and expect to live more than 6 months. They should have proper organ function and agree to use contraception. Exclusions include recent radiotherapy, other active cancers within 5 years, autoimmune diseases treated in the past 2 years, infections needing systemic therapy, poorly controlled diarrhea, significant cardiac issues or hypersensitivities.

Inclusion Criteria

Has measurable disease as defined by RECIST 1.1 as determined by the site investigator

I agree to use contraception as required.

My cancer is advanced stomach or GEJ cancer that has not been treated and is HER2 positive.

+5 more

Exclusion Criteria

I have received treatment for advanced stomach cancer that cannot be surgically removed.

I have another cancer that has gotten worse or needed treatment in the last 5 years.

I have had fluid buildup needing drainage or water pills in the last 2 weeks.

+19 more

Participant Groups

The study tests if pembrolizumab plus trastuzumab with standard chemotherapy works better for HER2+ gastric cancer than just trastuzumab with chemotherapy. It measures how long patients live without their cancer getting worse (PFS) and overall survival (OS). Patients are randomly assigned to receive either the new combination of drugs or the current standard treatment.

4Treatment groups

Experimental Treatment

Active Control

Group I: Japan Trastuzumab + S-1 Plus OxaliplatinExperimental Treatment4 Interventions

Participants received matched placebo to pembrolizumab IV Q3W plus trastuzumab (8mg/kg loading dose, 6mg/kg maintenance thereafter) IV Q3W in combination with SOX chemotherapy.

Group II: Japan Pembrolizumab + Trastuzumab + S-1 Plus OxaliplatinExperimental Treatment4 Interventions

Participants received 200 mg pembrolizumab IV every 3 weeks (Q3W) plus trastuzumab (8 mg/kg loading dose, 6 mg/kg maintenance thereafter) IV Q3W in combination with SOX chemotherapy.

Group III: Global Pembrolizumab + Standard of Care First CourseExperimental Treatment6 Interventions

Participants received 200 mg pembrolizumab IV every 3 weeks (Q3W) plus trastuzumab (8 mg/kg loading dose, 6 mg/kg maintenance thereafter) IV Q3W in combination with investigator's choice of FP or CAPOX chemotherapy.

Group IV: Global Standard of CareActive Control6 Interventions

Participants received matched placebo to pembrolizumab IV Q3W plus trastuzumab (8mg/kg loading dose, 6mg/kg maintenance thereafter) IV Q3W in combination with investigator's choice of FP or CAPOX chemotherapy.

5-FU is already approved in United States, European Union, Canada, Japan for the following indications:

🇺🇸 Approved in United States as Fluorouracil for: