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Chemotherapy

Tucatinib + Trastuzumab + Chemotherapy for Colorectal Cancer (MOUNTAINEER-03 Trial)

Phase 3
Recruiting
Research Sponsored by Seagen Inc.
Eligibility Criteria Checklist
Specific guidelines that determine who can or cannot participate in a clinical trial
Must have
Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 or 1
Histologically and/or cytologically confirmed adenocarcinoma of the colon or rectum which is locally advanced unresectable or metastatic
Must not have
Previous treatment with anti-HER2 therapy
Ongoing Grade 3 or higher neuropathy
Timeline
Screening 3 weeks
Treatment Varies
Follow Up up to approximately 6 years
Awards & highlights
No Placebo-Only Group
Pivotal Trial

Summary

This trial is testing to see if tucatinib in combination with other drugs is more effective than standard of care drugs at treating participants with HER2 positive colorectal cancer.

Who is the study for?
This trial is for adults with HER2 positive, RAS WT metastatic or unresectable colorectal cancer who haven't had systemic anticancer therapy in the metastatic setting. They should have measurable disease and be in good physical condition (ECOG 0-1). Prior adjuvant chemotherapy is allowed if completed over 6 months ago. Excluded are those with recent radiation, ongoing severe neuropathy, GI perforation within a year, or past anti-HER2 treatment.
What is being tested?
The study compares tucatinib combined with trastuzumab and mFOLFOX6 against standard treatments for advanced colorectal cancer. Participants will randomly receive either this new combination or one of the standard options: mFOLFOX6 alone, with bevacizumab, or cetuximab. The goal is to see if tucatinib improves outcomes.
What are the potential side effects?
Potential side effects include reactions related to the immune system's response to drugs like tucatinib and trastuzumab; digestive issues from chemotherapy agents; nerve damage risks from oxaliplatin; and general symptoms such as fatigue and increased risk of infections.

Eligibility Criteria

Inclusion Criteria

You may be eligible if you check “Yes” for the criteria below
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I am fully active or restricted in physically strenuous activity but can do light work.
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My colon or rectum cancer is advanced and cannot be removed by surgery.
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My cancer is HER2 positive based on a specialized lab test.
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I have provided a recent biopsy of my tumor if no older samples were available.
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My cancer can be measured on scans and has grown after any previous radiation.

Exclusion Criteria

You may be eligible for the trial if you check “No” for criteria below:
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I have been treated with anti-HER2 therapy before.
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I have severe nerve pain or damage.
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I have not had radiation therapy in the last 14 days, or 7 days if it was stereotactic radiosurgery.

Timeline

Screening ~ 3 weeks
Treatment ~ Varies
Follow Up ~up to approximately 6 years
This trial's timeline: 3 weeks for screening, Varies for treatment, and up to approximately 6 years for reporting.

Treatment Details

Study Objectives

Study objectives can provide a clearer picture of what you can expect from a treatment.
Primary study objectives
Progression-free survival (PFS) per Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST v1.1) by Blinded Independent Central Review (BICR)
Secondary study objectives
Change from baseline in European Organization for Research and Treatment of Cancer Quality of Life Questionnaire C30 (EORTC QLQC30) score
Confirmed objective response rate (cORR) per RECIST v1.1 by BICR
DOR per RECIST v1.1 by investigator assessment
+8 more

Side effects data

From 2022 Phase 2 trial • 612 Patients • NCT02614794
82%
Diarrhoea
66%
Palmar-plantar erythrodysaesthesia syndrome
60%
Nausea
48%
Fatigue
38%
Vomiting
27%
Decreased appetite
26%
Stomatitis
24%
Headache
23%
Aspartate aminotransferase increased
22%
Anaemia
22%
Alanine aminotransferase increased
20%
Blood bilirubin increased
20%
Arthralgia
18%
Hypokalaemia
17%
Constipation
17%
Cough
16%
Abdominal pain
16%
Blood creatinine increased
15%
Weight decreased
14%
Back pain
13%
Epistaxis
13%
Pain in extremity
13%
Dizziness
13%
Peripheral sensory neuropathy
13%
Dyspnoea
11%
Muscle spasms
11%
Dry skin
11%
Dyspepsia
11%
Upper respiratory tract infection
11%
Urinary tract infection
11%
Oedema peripheral
10%
Pruritus
10%
Insomnia
9%
Neutropenia
9%
Hypomagnesaemia
9%
Abdominal pain upper
8%
Dehydration
8%
Myalgia
8%
Asthenia
8%
Dysgeusia
8%
Oropharyngeal pain
8%
Skin hyperpigmentation
7%
Rash maculo-papular
7%
Thrombocytopenia
7%
Hypophosphataemia
7%
Blood alkaline phosphatase increased
7%
Abdominal distension
7%
Hyperbilirubinaemia
7%
Fall
7%
Rhinorrhoea
6%
Paraesthesia
6%
Dry eye
6%
Hyperglycaemia
6%
Gastrooesophageal reflux disease
6%
Influenza like illness
6%
Pyrexia
6%
Paronychia
6%
Alopecia
5%
White blood cell count decreased
5%
Muscular weakness
5%
Dry mouth
5%
Neutrophil count decreased
5%
Platelet count decreased
5%
Hypertension
5%
Nasopharyngitis
3%
Seizure
2%
Pneumonia
2%
Influenza
1%
Cholecystitis
1%
Sepsis
1%
Ejection fraction decreased
1%
Syncope
1%
Pleural effusion
1%
Pulmonary embolism
1%
Cardiac failure
1%
Gastroenteritis
100%
80%
60%
40%
20%
0%
Study treatment Arm
Tuc+Cap+Tra
Pbo+Cap+Tra

Awards & Highlights

No Placebo-Only Group
All patients enrolled in this study will receive some form of active treatment.
Pivotal Trial
The final step before approval, pivotal trials feature drugs that have already shown basic safety & efficacy.

Trial Design

2Treatment groups
Experimental Treatment
Active Control
Group I: Tucatinib ArmExperimental Treatment6 Interventions
Tucatinib + trastuzumab + mFOLFOX6
Group II: Standard of Care ArmActive Control6 Interventions
mFOLFOX6 + (bevacizumab OR cetuximab). Either (1) mFOLFOX6, (2) mFOLFOX6 and bevacizumab, or (3) mFOLFOX6 and cetuximab
Treatment
First Studied
Drug Approval Stage
How many patients have taken this drug
tucatinib
2021
Completed Phase 3
~810
trastuzumab
2002
Completed Phase 3
~1790
oxaliplatin
2002
Completed Phase 3
~6370
leucovorin
2005
Completed Phase 3
~1200
fluorouracil
1994
Completed Phase 3
~8440

Find a Location

Who is running the clinical trial?

Seagen Inc.Lead Sponsor
210 Previous Clinical Trials
74,030 Total Patients Enrolled
Merck Sharp & Dohme LLCIndustry Sponsor
4,015 Previous Clinical Trials
5,185,933 Total Patients Enrolled
James Ward, MDStudy DirectorSeagen Inc.

Media Library

Fluorouracil (Chemotherapy) Clinical Trial Eligibility Overview. Trial Name: NCT05253651 — Phase 3
Colorectal Cancer Research Study Groups: Tucatinib Arm, Standard of Care Arm
Colorectal Cancer Clinical Trial 2023: Fluorouracil Highlights & Side Effects. Trial Name: NCT05253651 — Phase 3
Fluorouracil (Chemotherapy) 2023 Treatment Timeline for Medical Study. Trial Name: NCT05253651 — Phase 3
~106 spots leftby Aug 2025
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