A Study of Bispecific Antibody MCLA-158 in Patients With Advanced Solid Tumors

July 28, 2026 updated by: Merus B.V.

Phase 1/2 Dose Escalation and Cohort Expansion Study Evaluating MCLA-158 (Petosemtamab) as Single Agent or in Combination in Advanced Solid Tumors

This is a Phase 1/2 open-label, multi-center, multi-national study with an initial dose escalation part to determine the recommended Phase II dose (RP2D) of MCLA-158 single agent in patients with mCRC.

The dose escalation part has been completed and the RP2D will be further evaluated in an expansion part of the study. Cohorts of selected solid tumor indications for which there is evidence of EGFR dependency and potential sensitivity to EGFR inhibition will be evaluated including head and neck cancer and metastatic colorectal cancer (mCRC).

The study will further assess the safety, tolerability, PK, PD, immunogenicity, and anti-tumor activity of MCLA-158 in monotherapy or in combination with other therapies.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Study Design:

This open label, multicenter, first-in-human study consists of 2 parts. Part 1 is a dose escalation to find the recommended Phase II dose (RP2D) of MCLA-158 studying patients with metastatic colorectal cancer (mCRC). Enrollment in the dose escalation part has been completed.

In the dose expansion (single-agent cohorts) part of the study, the activity, safety, and tolerability of MCLA-158 at 1500 mg every 2 weeks (Q2W) (preliminary RP2D) as a single agent will be evaluated in cohorts of selected solid tumor indications with dependency on EGFR signaling. The most recently enrolled cohorts were in patients with head and neck squamous cell carcinoma (HNSCC). Enrollment into the HNSCC cohort of single-agent MCLA-158 for the treatment of patients with second/third line (2L/3L) HNSCC is closed. In the dose expansion part of the study, safety was also characterized at two dose levels in this setting. Other closed cohort indications included gastric/ gastroesophageal junction adenocarcinoma (GEA) with EGFR amplification and/or high EGFR expression, esophageal carcinoma, and pancreatic adenocarcinoma. Enrollment is currently being explored in mCRC (RAS/RAF wild type) patients in the 3L/4L/5L setting.

Additionally, in the dose expansion (combination cohorts) part of the study, the activity, safety, and tolerability of MCLA-158 at 1500 mg Q2W will be evaluated in combination with other therapies. Enrollment in the combination cohort of treatment of MCLA-158 with pembrolizumab for the treatment of patients with first line (1L) HNSCC is closed. Additionally, two combination cohorts of MCLA-158 with FOLFIRI or with FOLFOX chemotherapy (i.e., 5-fluorouracil [5-FU], leucovorin, and irinotecan (FOLFIRI) or oxaliplatin (FOLFOX)) will be explored in mCRC (RAS/RAF wild type) patients in the 1L/2L setting.

Other expansion cohorts may be considered for monotherapy or combination treatment in the future

Study Type

Interventional

Enrollment (Estimated)

560

Phase

  • Phase 2
  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • Belgium
      • Brussels, Belgium
        • Recruiting
        • Cliniques universitaires Saint-Luc
        • Contact:
          • Roxane Watterman
      • Brussels, Belgium
        • Completed
        • Institut Jules Bordet
      • Ghent, Belgium
        • Recruiting
        • Uz Gent
      • Namur, Belgium
        • Recruiting
        • Chu Ucl Namur Site De Sainte-Elisabeth
        • Contact:
          • Dominique Crasson
  • France
      • Bordeaux, France
        • Recruiting
        • Hopital Saint Andre, CHU Bordeaux
        • Contact:
          • Delphine Padenon
      • Lyon, France
        • Recruiting
        • Centre Leon Berard
        • Contact:
          • Martin Porret
      • Marseille, France
        • Recruiting
        • Hôpital La Timone
        • Contact:
          • Leyla Ameur, MD
      • Montpellier, France
        • Recruiting
        • Institut Regional du Cancer de Montpellier
        • Contact:
          • Justine Rochet
      • Nice, France
        • Recruiting
        • Centre Antoine Lacassagne
        • Contact:
          • Morgane Sgorlon
      • Paris, France
        • Recruiting
        • Institut Curie
        • Contact:
          • Lucas Frezouls
      • Paris, France
        • Recruiting
        • Institut Gustave Roussy
        • Contact:
          • Thinhinane Ould Taleb
      • Rouen, France
        • Recruiting
        • Centre Henri Becquerel
        • Contact:
          • Amelie Poullain
  • Italy
      • Milan, Italy, 20162
        • Recruiting
        • ASST Grande Ospedale Metropolitano Niguarda
  • Netherlands
      • Amsterdam, Netherlands
        • Recruiting
        • NKI - Antoni van Leeuwenhoek
        • Contact:
          • Lotte Heimans
      • Nijmegen, Netherlands
        • Recruiting
        • UMC Radboud
        • Contact:
          • Mirte Meijerinck
      • Utrecht, Netherlands
        • Recruiting
        • UMC Utrecht
        • Contact:
          • Sanne Bouwhuis
  • Spain
      • Barcelona, Spain
        • Recruiting
        • Vall d'Hebron
        • Contact:
          • Antonio Molina
      • Madrid, Spain
      • Pamplona, Spain
        • Recruiting
        • Clinica Universidad de Navarra
        • Contact:
          • Mercedes Egana
      • Pamplona, Spain
        • Recruiting
        • Hospital Universitario de Navarra
        • Contact:
          • Teresa Prieto
      • Valencia, Spain
  • United Kingdom
      • Cambridge, United Kingdom
        • Completed
        • Cambridge University Hospitals NHS Foundation Trust
      • London, United Kingdom
        • Recruiting
        • Sarah Cannon Research Institute
        • Contact:
          • Valentina Achugo
  • United States
    • California
      • La Jolla, California, United States, 92093
        • Recruiting
        • UCSD
        • Contact:
          • Petrea Monson
          • Phone Number: 858-246-5674
      • Los Angeles, California, United States, 90033
        • Active, not recruiting
        • USC Norris Comprehensive Cancer Center
      • San Diego, California, United States, 92123
        • Recruiting
        • Sharp Healthcare
        • Contact:
          • Danica Griffin
    • Colorado
      • Lone Tree, Colorado, United States, 80124
        • Recruiting
        • Rocky Mountain Cancer Centers
        • Contact:
          • Jennifer Hege
    • Florida
      • Fort Myers, Florida, United States, 33901
        • Active, not recruiting
        • Florida Cancer Specialists
      • Gainesville, Florida, United States, 32610
        • Recruiting
        • University of Florida
      • Orlando, Florida, United States, 32827
        • Recruiting
        • Sarah Cannon Research Institute (Lake Nona)
        • Contact:
          • Ingrid Acker
          • Phone Number: 689-216-8500
    • Georgia
      • Atlanta, Georgia, United States, 30322
        • Recruiting
        • Emory University
    • Massachusetts
      • Boston, Massachusetts, United States, 02114
        • Recruiting
        • Massachusetts General Hospital - Dana Farber
        • Contact:
          • Rowan Cutler
    • Michigan
      • Detroit, Michigan, United States, 48201
        • Completed
        • Karmanos Cancer Institute
    • Missouri
      • St Louis, Missouri, United States, 63110
        • Completed
        • SSM Health Saint Louis University Hospital
      • St Louis, Missouri, United States, 63110
        • Recruiting
        • Washington University School of Medicine at St Louis
    • New York
      • Ithaca, New York, United States, 14850
        • Recruiting
        • Cayuga Medical Center
        • Contact:
          • Danielle Rao
      • New York, New York, United States, 10029
        • Recruiting
        • Mt. Sinai
      • New York, New York, United States, 10065
        • Recruiting
        • Memorial Sloan Kettering Cancer Center
      • Syracuse, New York, United States, 13057
        • Recruiting
        • Hematology-Oncology Associates of Central New York
        • Contact:
          • Kimberly Desimone
    • Ohio
      • Cleveland, Ohio, United States, 44195
        • Recruiting
        • Cleveland Clinic
        • Contact:
      • Columbus, Ohio, United States, 43221
        • Recruiting
        • Ohio State University
      • Maumee, Ohio, United States, 43537
        • Recruiting
        • Taylor Cancer Research Center
        • Contact:
          • Stephanie Ambrose
    • Oklahoma
      • Oklahoma City, Oklahoma, United States, 73102
        • Recruiting
        • SSM OKC Hightower Clinical
        • Contact:
          • Caitlin Merrick
          • Phone Number: 405-464-7300
    • Pennsylvania
      • Philadelphia, Pennsylvania, United States, 19104
        • Recruiting
        • University of Pennsylvania
    • Tennessee
      • Memphis, Tennessee, United States, 38103
        • Recruiting
        • The University Of Tennessee Health Science Center
        • Contact:
      • Nashville, Tennessee, United States, 37203
        • Completed
        • Sarah Cannon Research Institute
    • Texas
      • Dallas, Texas, United States, 75246
      • Houston, Texas, United States, 77030
        • Recruiting
        • Oncology Consultants
        • Contact:
          • Carlos Cortez
          • Phone Number: 713-600-0978
      • Tyler, Texas, United States, 75702
    • Utah
      • Salt Lake City, Utah, United States, 84106
      • Salt Lake City, Utah, United States, 84112
        • Recruiting
        • University of Utah Health Huntsman Cancer Hospital
        • Contact:
          • Devin Baxter
          • Phone Number: 801-587-4767
    • Virginia
      • Roanoke, Virginia, United States, 24014
    • Washington
      • Georgetown, Washington, United States, 20007
        • Recruiting
        • Georgetown University Medical Center
      • Spokane, Washington, United States, 99202
        • Recruiting
        • Cancer Care Northwest
        • Contact:
          • Krystal Swenson
          • Phone Number: 509-228-1682

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Histologically or cytologically confirmed solid tumors with evidence of metastatic or locally advanced disease not amenable to standard therapy with curative intent.
  • A baseline fresh tumor sample (FFPE) from a metastatic or primary site (if safe/feasible).
  • Amenable for biopsy (if safe/feasible).
  • Measurable disease as defined by RECIST version 1.1 by radiologic methods.
  • Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1.
  • Life expectancy ≥ 12 weeks, as per investigator.
  • Left ventricular ejection fraction (LVEF) ≥ 50% by echocardiogram (ECHO) or multiple gated acquisition scan (MUGA).
  • Adequate organ function
  • Expansion cohorts: patients with locally advanced unresectable or metastatic disease for the following indications:

SINGLE AGENT:

  • SECOND-/THIRD-LINE HNSCC PATIENTS (cohort closed to enrolment): patients who have progressed on or after, or are intolerant to, anti-PD-(L)1 therapy and platinum therapy as monotherapy or in combination with other agents and no previous exposure to EGFR inhibitors. Patients treated with platinum-containing therapy only in the adjuvant setting, or in the context of multimodal therapy for locally advanced disease should have disease progression within 6 months of the last dose of platinum containing therapy. Patients with no more than 2 prior lines of treatment in recurrent or metastatic disease. • Human papilloma virus (HPV) status determined by p16 immunohistochemistry (IHC) or molecular HPV test for all oropharyngeal tumors should be reported when available.
  • The eligible HNSCC primary tumor locations are oropharynx, oral cavity, hypopharynx, and larynx.
  • 3L+ mCRC (cohort open to enrolment) patients must have:
  • No oncogenic missense mutations in KRAS, NRAS, BRAF, or EGFR ectodomain, and no HER2 (ERBB2) or KRAS amplification, as detected in plasma by ctDNA NGS central testing performed during screening.
  • A microsatellite stable (MSS) tumor.

  • Received ≥2 and no more than 4 lines of prior therapy in the metastatic setting including:

    1. Chemotherapy with oxaliplatin, irinotecan, and a fluoropyrimidine,
    2. Targeted therapy with an anti-VEGF therapy

COMBINATION:

  • FIRST-LINE HNSCC (cohort closed to enrolment): patients eligible to receive pembrolizumab as first-line monotherapy with tumors expressing programmed cell death protein ligand 1 (PD-L1), combined positive score (CPS) ≥1, as determined by a Food and Drug Administration (FDA) approved test in the US, or by an approved equivalent test in other countries; patients should not have previous systemic therapy administered in the recurrent or metastatic setting, although previous systemic therapy as part of multimodal treatment for locally advanced disease is allowed if ended ≥6 months prior to signing the ICF. The eligible HNSCC primary tumor locations are oropharynx, oral cavity, hypopharynx, and larynx. Previous treatments with anti PD-(L)1 or anti-EGFR therapies are not allowed.

  • mCRC (cohorts open to enrolment): Patients should have been previously diagnosed with histologically or cytologically confirmed unresectable or metastatic adenocarcinoma of the colon or rectum. Patients must be RAS/ RAF WT as determined using tumor tissue (primary or metastatic) by an appropriate tumor tissue based assay, to be confirmed by the sponsor, and must have an MSS tumor. Patients must be naive to prior anti-EGFR therapy.

    i. Cohort to be treated with petosemtamab and FOLFIRI: patients may have received up to 1 prior chemotherapy regimen for the metastatic setting, consisting of 1L fluoropyrimidine-oxaliplatin-based chemotherapy ± bevacizumab.

ii. Cohort to be treated with petosemtamab and FOLFOX: patients may have received up to 1 prior chemotherapy regimen in the metastatic setting consisting of 1L fluoropyrimidine-irinotecan-based chemotherapy ± bevacizumab

Exclusion Criteria:

  • Central nervous system metastases that are untreated or symptomatic, or require radiation, surgery, or continued steroid therapy to control symptoms within 14 days of study entry.
  • Known leptomeningeal involvement.
  • Participation in another clinical study or treatment with any investigational drug within 4 weeks prior to study entry.
  • Any systemic anticancer therapy within 4 weeks or 5 half-lives whichever is shorter of the first dose of study treatment. For cytotoxic agents that have major delayed toxicity ( e.g. mitomycin C,nitrosoureas), or anticancer immunotherapies, a washout period of 6 weeks is required.
  • Requirement for immunosuppressive medication (e.g. methotrexate, cyclophosphamide)
  • Major surgery or radiotherapy within 3 weeks of the first dose of study treatment. Patients who received prior radiotherapy to ≥25% of bone marrow are not eligible, irrespective of when it was received.
  • Persistent grade >1 clinically significant toxicities related to prior antineoplastic therapies (except for alopecia); stable sensory neuropathy ≤ grade 2 NCI-CTCAE v4.03 is allowed.
  • History of hypersensitivity reaction to any of the excipients of petosemtamab, human proteins or any non-IMP treatment required for this study.
  • Uncontrolled hypertension (systolic blood pressure [BP] > 150 mmHg and/or diastolic BP > 100 mmHg) with appropriate treatment or unstable angina. History of congestive heart failure of Class II-IV New York Heart Association (NYHA) criteria, or serious cardiac arrhythmia requiring treatment (except atrial fibrillation, paroxysmal supraventricular tachycardia). History of myocardial infarction within 6 months of study entry.
  • History of prior malignancies with the exception of excised cervical intraepithelial neoplasia or nonmelanoma skin cancer, or curatively treated cancer deemed at low risk for recurrence with no evidence of disease for 3 years.
  • Current dyspnea at rest of any origin, or other diseases requiring continuous oxygen therapy. Patients with a history of interstitial lung disease (e.g., pneumonitis or pulmonary fibrosis) or evidence of ILD on baseline chest computerized tomography (CT) scan.
  • Current serious illness or medical conditions including, but not limited to uncontrolled active infection,clinically significant pulmonary, metabolic or psychiatric disorders.

  • Patients with known infectious diseases:

    i. Active hepatitis B infection (hepatitis B surface antigen [HBsAg] positive) without receiving antiviral treatment.

ii. Positive test for hepatitis C ribonucleic acid (HCV) RNA).

• Pregnant or breastfeeding patients; patients of childbearing potential must use highly effective contraception methods prior to study entry, for the duration of study participation, and for 6 months after the last dose of MCLA-158.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

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

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: MCLA-158 + Pembrolizumab
MCLA-158 in combination with pembrolizumab will be explored first in head and neck squamous cell carcinoma patients eligible to receive pembrolizumab as first-line monotherapy.
Combination product: MCLA-158 + Pembrolizumab
MCLA-158 in combination with pembrolizumab will be explored first in HNSCC patients eligible to receive pembrolizumab as first-line monotherapy.
Other Names:
  • petosemtamab
Experimental: MCLA-158 + FOLFIRI combination chemotherapy
MCLA-158 in combination with FOLFIRI will be explored in mCRC patients with up to 1 line of prior regimen.
Combination product: MCLA-158 + FOLFIRI
MCLA-158 in combination with FOLFIRI will be explored in mCRC patients with up to 1 line of prior regimen.
Other Names:
  • petosemtamab
Experimental: MCLA-158 + FOLFOX combination chemotherapy
MCLA-158 in combination with FOLFOX will be explored in mCRC patients with up to 1 line of prior regimen.
Combination product: MCLA-158 + FOLFOX
MCLA-158 in combination with FOLFOX will be explored in mCRC patients with up to 1 line of prior regimen.
Other Names:
  • petosemtamab
Experimental: MCLA-158 (Single-Agent)
In Part 1, the dose escalation phase, patients with metastatic CRC will receive escalating doses of MCLA-158 (every 2 weeks) until MTD or RP2D is reached. Each Cycle is 28 days. Single agent treatment. In Part 2, the expansion phase, participants with metastatic CRC and certain other solid tumors will receive intravenous infusion (i.v.) of MCLA-158 at the recommended Phase II dose (RP2D) every 2 weeks, at Day 1 and Day 15. The duration of each treatment cycle is 28 days. In addition, in the expansion phase, one randomized cohort will evaluate 2 doses (1100 mg and 1500 mg) of MCLA-158 in head and neck squamous cell carcinoma patients. Also in the expansion phase, a subcutaneous formulation of MCLA-158 will be evaluated.
Drug: MCLA-158
full-length IgG1 bispecific antibody targeting EGFR and LGR5
Other Names:
  • petosemtamab

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Escalation: Number of patients with Dose Limiting Toxicities (DLTs) during Cycle 1
Time Frame: 4 weeks
Evaluation of the number and severity of participants with treatment related toxicities observed during the dose escalation.
4 weeks
Expansion (Single agent - randomized expansion in 2/3L Head and Neck cancer, and combination cohorts): Safety and tolerability: AEs and SAEs
Time Frame: 6-12 months
Incidence, severity, and relationship of AEs and SAEs
6-12 months
Expansion (Single agent - randomized expansion in 2/3L Head and Neck cancer): Treatment discontinuations and dose modifications due to AEs
Time Frame: 6-12 months
Treatment discontinuations due to AEs and dose modifications due to AEs
6-12 months
Expansion (single agent - randomized expansion in 2/3L Head and Neck cancer): Best overall response (BOR)
Time Frame: 36 months
Evaluation of clinical benefit assessed by RECIST v1.1 determining Best overall response (BOR)
36 months
Expansion (Single agent - non-randomized, and combination cohorts): Objective response rate (ORR)
Time Frame: 36 months
Evaluation of clinical benefit assessed by RECIST v1.1 determining objective response rate (ORR)
36 months
Expansion (single agent - randomized expansion in 2/3L Head and Neck cancer): exposure-safety relationship of petosemtamab administered at 1100 mg and 1500 mg: TEAEs
Time Frame: 8 weeks
Incidence of TEAEs at Week 8
8 weeks
Expansion: (mCRC subcutaneous cohort): Bioavailability of subcutaneous vs intravenous administration
Time Frame: 6 weeks
Bioavailability of subcutaneous vs intravenous administration
6 weeks
Expansion: (mCRC subcutaneous cohort): Area under the concentration versus time curve from time zero to time t [AUC0-t]
Time Frame: 6 weeks
Area under the concentration versus time curve from time zero to time t [AUC0-t]
6 weeks
Expansion: (mCRC subcutaneous cohort): Maximum plasma concentration [Cmax]
Time Frame: 8 weeks
Maximum plasma concentration as measured from all individual plasma concentrations
8 weeks
Expansion: (mCRC subcutaneous cohort): Minimum plasma drug concentration [Ctrough]
Time Frame: 6 weeks
Minimum plasma concentration as measured from all individual plasma concentrations
6 weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Escalation & Expansion: Incidence of anti-drug antibodies against MCLA-158
Time Frame: 36 months
Number of participants with anti-drug antibodies against MCLA-158
36 months
Escalation & Expansion: End of infusion (EOI) plasma concentration [Ceoi]
Time Frame: 36 months
End of infusion (EOI) plasma concentration [Ceoi] as measured from all individual plasma concentrations
36 months
Escalation & Expansion: Maximum plasma concentration [Cmax]
Time Frame: 36 months
Maximum plasma concentration as measured from all individual plasma concentrations
36 months
Escalation & Expansion: Plasma concentration at 0 hours [C0h]
Time Frame: 36 months
Plasma concentration at 0 hours [C0h] as measured from all individual plasma concentrations
36 months
Escalation & Expansion: Area under the concentration versus time curve from time zero to time t [AUC0-t]
Time Frame: 36 months
Area under the concentration versus time curve from time zero to time t [AUC0-t]
36 months
Escalation & Expansion: Area under the concentration versus time curve [AUC0-∞]
Time Frame: 36 months
Area under the concentration versus time curve [AUC0-∞]
36 months
Escalation & Expansion: Clearance of plasma [CL]
Time Frame: 36 months
Clearance of plasma [CL]
36 months
Escalation & Expansion: Volume of distribution at steady state [Vss]
Time Frame: 36 months
Volume of distribution at steady state [Vss]
36 months
Escalation & Expansion: Half-life [t1/2]
Time Frame: 36 months
Half-life [t1/2]
36 months
Escalation and Expansion: Safety and tolerability: laboratory values
Time Frame: 6-12 months
Number of participants with abnormal laboratory tests results
6-12 months
Escalation and Expansion: Safety and tolerability: (ECG)
Time Frame: 6-12 months
Number of participants with abnormal ECG readings
6-12 months
Escalation and Expansion: Safety and tolerability: vital signs
Time Frame: 6-12 months
Number of participants with abnormal vital signs
6-12 months
Expansion: Progression Free Survival (PFS)
Time Frame: 36 months
Evaluation of clinical benefit assessed by RECIST v1.1 determining progression free survival (PFS)
36 months
Expansion (mCRC combination cohorts): Progression Free Survival (PFS) rate at 4 months
Time Frame: 4 months
Evaluation of clinical benefit assessed by RECIST v1.1 determining progression free survival (PFS) rate at 4 months
4 months
Expansion (Single agent - non-randomized cohorts): Overall survival (OS)
Time Frame: 36 months
Evaluation of clinical benefit determining overall survival (OS)
36 months
Escalation & Expansion (single agent - non-randomized cohorts): Safety and tolerability: AEs and SAEs
Time Frame: up to 30 days post-last dose
Incidence, severity, and relationship of AEs and SAEs
up to 30 days post-last dose
Escalation & Expansion (Single agent - non-randomized and Combination cohorts): Treatment discontinuations and dose modifications due to AEs
Time Frame: up to 30 days post-last dose
Treatment discontinuations due to AEs and dose modifications due to AEs
up to 30 days post-last dose
Expansion (Single agent - randomized expansion in 2/3L Head and Neck cancer): exposure-efficacy relationship of petosemtamab administered at 1100 mg and 1500 mg: Target Lesions
Time Frame: 8 weeks
Percentage change from baseline in sum of the diameters of target lesions at Week 8
8 weeks
Expansion (Single agent - randomized expansion in 2/3L Head and Neck cancer): exposure-safety relationship of petosemtamab administered at 1100 mg and 1500 mg: Grade 3-4 TEAEs
Time Frame: 8 weeks
Incidence of Grade 3-4 TEAEs at Week 8
8 weeks
Expansion (Single agent - randomized expansion in 2/3L Head and Neck cancer): exposure-safety relationship of petosemtamab administered at 1100 mg and 1500 mg: IRR TEAEs
Time Frame: 8 weeks
Incidence of IRR TEAEs at Week 8
8 weeks
Expansion (Single agent - randomized expansion in 2/3L Head and Neck cancer): exposure-safety relationship of petosemtamab administered at 1100 mg and 1500 mg : non-IRR TEAEs
Time Frame: 8 weeks
Incidence of non-IRR TEAEs at Week 8
8 weeks
Expansion (Single agent - randomized expansion in 2/3L Head and Neck cancer): Objective response rate (ORR)
Time Frame: 36 months
Evaluation of clinical benefit assessed by RECIST v1.1 determining objective response rate (ORR)
36 months
Escalation: Cytokine Panel Expression Profile
Time Frame: 36 months
Evaluation of the cytokine expression profile
36 months
Escalation & Expansion: (mCRC subcutaneous cohort): Best Overall Response (BOR)
Time Frame: 36 months
Evaluation of clinical benefit assessed by RECIST v1.1 determining Best overall response (BOR)
36 months
Expansion: Duration of response (DOR)
Time Frame: 36 months
Evaluation of clinical benefit assessed by RECIST v1.1 determining duration of response (DOR)
36 months

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Escalation & Expansion: Biomarkers for Wnt signaling proteins
Time Frame: 36 months
Evaluation of biomarker results for Wnt signaling proteins
36 months
Escalation & Expansion: Biomarkers for genetic aberrations in ctDNA
Time Frame: 36 months
Evaluation of biomarker results in genetic aberrations in ctDNA
36 months
Escalation & Expansion: Biomarkers for differential expression of miRNA
Time Frame: 36 months
Evaluation of biomarker results for differential expression of miRNA
36 months
Escalation & Expansion: Biomarkers for differential expression of mRNA
Time Frame: 36 months
Evaluation of biomarker results for differential expression of mRNA
36 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Merus B.V.

Collaborators

Chiltern International Inc.
Q2 Solutions
Oncology Therapeutic Development (OTD)
4Clinics

Investigators

  • Study Director: Silke Thiele, MD, Merus B.V.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

May 2, 2018

Primary Completion (Estimated)

May 1, 2028

Study Completion (Estimated)

November 1, 2028

Study Registration Dates

First Submitted

April 4, 2018

First Submitted That Met QC Criteria

May 15, 2018

First Posted (Actual)

May 16, 2018

Study Record Updates

Last Update Posted (Actual)

July 29, 2026

Last Update Submitted That Met QC Criteria

July 28, 2026

Last Verified

July 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • MCLA-158-CL01
  • 2017-004745-24 (EudraCT Number)
  • 2024-513627-16-01 (Ctis)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Individual participant data are made available only to the individual patient upon specific request of that individual patient or its treating physician.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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