ClinicalTrials.gg
RecruitingNCT06796907Updated Nov 2, 2026

A Study of Mocertatug Rezetecan in Combination With Anti-cancer Therapies for Advanced Solid Tumors (BEHOLD-2)

A Phase 1/2 interventional study of Mo-Rez and Dostarlimab in Tumours, Gynecological, sponsored by GlaxoSmithKline. Recruiting at 83 sites in 23 countries. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-11-02.

Sponsored by GlaxoSmithKline · Phase 1/2, Interventional, and Treatment

From the registry’s dates

  • Started Mar 2025; still recruiting 1 year 8 months later.
Updated Nov 2, 20269 sites added7 sites removedGo to Updates ↓
Phase
Phase 1/2
Study type
Interventional
Enrollment
305
Allocation
Randomized
Ages
18 Years and older
Sex
All
01

Study summary

Advanced solid tumors are cancers that have spread to other parts of the body. While many treatments exist, most people become resistant to them, and the cancer returns. Researchers are developing new treatments that combine different medicines for those who do not respond to single medicine. This study is looking at how safe and tolerable Mocertatug Rezetecan (Mo-Rez) is, how the body handles it, and how well it works when used with other cancer medicines. The study will include participants with advanced solid tumors who have either not responded to standard treatments or cannot tolerate them or have no available effective treatment.

02

Conditions studied

  • Tumours, Gynecological

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Keywords

  • Solid Tumors
  • Mocertatug Rezetecan
  • Mo-Rez
  • GSK5733584
  • BEHOLD-2
03

In context

Neoplasms

10,818 studies on the registry are indexed under Neoplasms; 2,324 are open to participants now.

This study's planned enrollment of 305 is above the median of 60 across 7,703 interventional studies indexed under Neoplasms.

Browse Neoplasms studies →

Lead sponsor

GlaxoSmithKline is the lead sponsor of 3,650 studies on the registry; 118 are open to participants now.

Of its 264 completed or terminated interventional studies of FDA-regulated products, 241 (91%) have results posted.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • Participants must be 18 years of age inclusive or older, at the time of signing the , or the legal age of consent in the jurisdiction in which the study is taking place.
  • Participant capable of giving signed informed consent including compliance with the requirements and restrictions listed in the Informed consent form (ICF) and in this protocol.
  • Participants with confirmed advanced solid tumor specific for study Module (key local diagnostic molecular and/or immunophenotyping testing results/tumor cell phenotype results for confirmed diagnosis should be provided) with no more than 4 lines of prior systemic therapies. Please note:

    1. Adjuvant +/- considered one
    2. Maintenance therapy will be considered as part of the preceding line of therapy (i.e., not counted independently)
    3. Unplanned addition or switching to a new drug in a different class is considered a separate line of therapy. If an agent in a regimen is switched to another agent in the same class due to toxicity or intolerance (e.g. reaction) this is considered part of the same line (i.e. not counted independently).
  • Requirements for tumor tissue samples: Archival or fresh tumor tissue is required for retrospective central assessment of B7H4 expression by immunohistochemistry (IHC) and other biomarker analysis. The should be from the most recent procedure (ideally obtained after the last anti-cancer treatment). If an archival tissue is not available a new biopsy should be performed, and the newly obtained tissue provided.
  • Participants have at least one target lesion as assessed per 1.1. A target lesion is defined as a that has not undergone locoregional treatment such as irradiation or that has unequivocal progression following locoregional treatment, with the longest diameter of ≥ 10 millimeter (mm) at Baseline (for lymph node lesions, the short axis should be ≥ 15 mm).
  • Participants have a of at least 12 weeks per investigator assessment based on disease burden and extent of supportive care needed.

Inclusion criteria of participants under arm Module 1 (Mo-Rez +Dostarlimab) Endometrial Cancer Part 1A:

a. Participants with histologically documented, advanced ( and/or unresectable) or recurrent endometrial cancer who have failed in adequate standard treatments, do not have effective standard treatment or are intolerant to standard of care, and who are not candidates for further curative external radiotherapy or brachytherapy.

Inclusion criteria of participants under arm Module 1 (Mo-Rez +Dostarlimab) Endometrial Cancer Part 1B:

  1. Diagnosis of endometrial cancer with confirmed mismatch repair proficient (MMRp) or microsatellites stable (MSS) tumor status by local test.
  2. Participants who have progressed on or are intolerant to at least 1 line of standard prior systemic therapy (including neoadjuvant or adjuvant as prior line), and who are not candidates for curative external radiotherapy or brachytherapy. Maintenance therapy will be considered part of the preceding line of therapy (i.e, not counted independently).

Inclusion criteria of participants under arm Module 2 (Mo-Rez +/- Bevacizumab) Ovarian Cancer Part 2A:

a. Participants with histologically or cytologically confirmed advanced epithelial ovarian cancer/fallopian tube/peritoneal cancer (any epithelial histology - mucinous, clear cell, carcinosarcoma, high/low grade serous, endometrioid) who have failed in adequate standard treatments, do not have effective standard treatment or are intolerant to standard of care.

Inclusion criteria of participants under arm Module 2 (GSK5733584 +/- Bevacizumab) Ovarian Cancer Part 2B:

  1. Participants whose advanced ovarian cancer/fallopian tube/peritoneal cancer has more than 6 months from the last dose of platinum before enrollment, i.e., platinum sensitive.
  2. Participants who have progressed on or are intolerant to at least 1 line of standard prior lines of chemotherapy and are not candidates for second cytoreductive surgery.

    • Participants willing to use adequate .

Female participants:

A female participant is eligible to participate if she is not pregnant or breastfeeding, and one of the following conditions applies:

  • Is a Woman of non- (WONCBP) OR
  • Is a Woman of childbearing potential (WOCBP) and using a contraceptive method that is highly effective.
  • A WOCBP must have a negative highly sensitive pregnancy test (urine or serum as required by local regulations) within 24 hours before the first dose of study intervention

    • Has an performance status of 0 to 1.
    • Participants with normal organ and bone marrow function.

Exclusion criteria

Exclusion Criteria:

  • Has a second (except disease under study) that has progressed or required active treatment within the past 24 months except for basal cell or squamous cell carcinomas of the skin or in-situ carcinomas [e.g., breast, cervix, bladder] that have been resected with no evidence of disease.
  • Has had any major surgery within 28 days prior to enrolment.
  • Has any history of prior allogenic or bone marrow transplant or other solid organ transplant.
  • Has known sensitivity to study intervention components, Mo-Rez (antibody-drug conjugate, antibody, free cytotoxin GSK5757810A) and combination partner, or its or other allergy that, in the opinion of the investigator, contraindicates participation in the study.
  • Has any following cardiological examination abnormality:

    1. history in prior year of or uncontrolled cardiac disease, acute myocardial infarction, Class III or IV congestive heart failure or clinically significant arrhythmia not controlled by standard of care therapy.
    2. Interval (QTcF) >450 millisecond (msec) or QTcF >480 msec for participants with bundle branch block
  • Has untreated brain or or brain/CNS metastases rapidly progressing requiring urgent medical intervention.
  • Any evidence of current interstitial lung disease (ILD) or pneumonitis or a prior history of ILD or non-infectious pneumonitis.
  • Has a history of disease that has required systemic treatments in the 2 years prior to screening (i.e., with use of disease modifying agents, , or drugs). Replacement therapy is not considered a form of systemic therapy (e.g., thyroid hormone for autoimmune thyroiditis or insulin is not exclusionary).
  • Clinically significant bleeding symptoms, significant bleeding tendency, or bleeding tumors within 1 month prior to the first dose of study treatment.
  • Serious or poorly controlled hypertension, including history of hypertensive crisis, hypertensive encephalopathy; adjustment of antihypertensive medications due to poor blood pressure control within 2 weeks prior to the first dose of study treatment;
  • Has any active renal condition (e.g., infection, requirement for dialysis, or any other active significant renal condition or dehydrated condition that could affect the participant's safety). Note: renal obstruction successfully managed by stenting is permitted.
  • Has any serious and/or unstable medical condition (such as clinical symptoms of intestinal obstruction) or psychiatric disorder or other condition(s) (including laboratory assessment abnormalities) that could interfere with the participant's safety, obtainment of , or compliance to the study procedures.
  • Participants with known history of (HIV).

Exclusion criteria of participants under arm Module 1 (Mo-Rez +Dostarlimab) Endometrial Cancer:

  1. Has mesenchymal tumor of the uterus (uterine sarcoma).
  2. Has experienced symptomatic pericarditis of any etiology within 6 months of study treatment or any of the following with prior immunotherapy: any imAE ≥ Grade 3, immune-mediated severe neurologic events of any-grade (e.g., myasthenic syndrome/myasthenia gravis, encephalitis Guillain-Barré Syndrome, or transverse myelitis), exfoliative dermatitis of any grade (SJS, TEN, or DRESS syndrome), or myocarditis of any grade.

Exclusion criteria of participants under arm Module 2 (Mo-Rez +/-Bevacizumab) Ovarian Cancer:

  1. Participants with wound healing complications or incompletely healed wounds.
  2. Participants with history or evidence of gastrointestinal perforation, tracheoesophageal fistula, or any grade 4 fistula; participants with gastrointestinal fistula, visceral fistula, or abdominal abscess within 6 months prior to the first dose, participants with history of osteonecrosis of the jaw.
  3. Participants who have evidence of recto-sigmoid involvement by pelvic examination or bowel involvement on CT scan or clinical symptoms of bowel obstruction.
  4. Participants with congenital bleeding diathesis, acquired coagulopathy, recent pulmonary haemorrhage/ haemoptysis (> 2.5 mL of red blood or ½ teaspoon) within the last 3 months. Participants receiving treatment for thromboembolism are permitted as long as they have been on a stable dose of anticoagulation for at least 1 month.
  5. Participant has history of congestive heart failure (CHF) or baseline \<50% or institutional lower limits of normal.
  6. Participant with history of nephrotic syndrome or grade 3 proteinuria. Participants has proteinuria as demonstrated by urine dipstick for proteinuria ≥2 (participants discovered to have ≥2 proteinuria on dipstick at baseline should undergo 24-hour urine collection and must demonstrate ≤1 g of protein in 24 hours to be eligible).

    • Has an (ALT) value >2.5x (ULN) and for participants with documented liver metastases/tumor infiltration has an ALT value >5x ULN.
    • Has a total value >1.5x ULN.
    • Has documented presence of and/or HBcAb, or HBsAb (except for presence of HBsAb attributable to previous vaccination) at screening or within 3 months prior to the first dose of study intervention.
    • Has a positive antibody test result at screening or within 3 months prior to the first dose of study intervention.
    • Has received prior therapy with topoisomerase-1 inhibitors or ADC with topoisomerase-1 inhibitor warhead, or B7H4 targeted therapy.
    • Has received treatment with any cytotoxic chemotherapy drugs or other anti-tumor drugs (including endocrine therapy, molecular targeted therapy, immunotherapy, biotherapy, and drug) within 30 days or 5 half-lives, whichever is shorter of a medicinal product prior to the first dose of study drug; or need to continue these drugs during the study.
    • Use of inhibitors of P-gp, breast cancer resistance protein (BCRP) or OATP1B1/1B3 within 7 days prior to the first dose of study drug. P-gp inducers should be discontinued for at least 14 days before the start of the study.
    • Have received locoregional radiation therapy within 2 weeks prior to the first dose of study drug; more than 30% of bone marrow irradiation or wide-field radiation therapy within 4 weeks prior to the first dose of study treatment.
    • Has serious infections within 4 weeks prior to the first dose, including but not limited to infectious complications, bacteremia, severe pneumonia treated with intravenous antibiotics for ≥2 weeks.
Terms in these criteria, in plain language(32)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

Histologically or cytologically confirmed

The diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).

Your pathology report is the document that shows this.

Adjuvant and neoadjuvant

Neoadjuvant treatment is given before the main treatment (usually surgery), often to shrink a tumour. Adjuvant treatment is given after it, to lower the chance of the cancer coming back.

Line of therapy

A line of therapy is one course of treatment, which may combine several drugs. First-line is the first course given; second-line follows when that stops working or is not tolerated.

“Two prior lines” means two courses that count separately under the study’s rules — not simply two drugs. Ask the study team if you are unsure how yours are counted.

Hypersensitivity

An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.

Biopsy and archival tissue

A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.

Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.

RECIST

The standard rules for measuring tumours on CT or MRI scans, to tell whether a cancer is shrinking, stable or growing during treatment.

“Measurable disease per RECIST 1.1” usually means at least one tumour 10 mm or more at its longest on a CT scan, or a lymph node 15 mm or more across its short axis.

Measurable disease

The amount of disease can be tracked with a defined measurement, so the study can see whether it shrinks or grows. It might be a tumour measured on a scan or, in some blood cancers such as myeloma, a marker measured in blood or urine.

The criteria or the study team say which measurement counts — having no tumour visible on a scan does not by itself rule you out.

Life expectancy

The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.

Metastases

Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.

Relapsed and refractory

Relapsed: the illness came back after treatment had worked. Refractory: it did not respond to treatment, or stopped responding while still on it.

Contraception

Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.

Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.

Childbearing potential

Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).

Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.

ECOG performance status

A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.

0
Fully active, no restrictions.
1
Limited in strenuous activity, but walking and able to do light work, such as housework or office work.
2
Walking and able to look after yourself, but unable to work; up and about more than half of waking hours.
3
Able to look after yourself only in part; in bed or a chair more than half of waking hours.
4
Unable to look after yourself at all; in bed or a chair all day.

Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.

Cancer (malignancy)

Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.

Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.

Allogeneic and autologous transplant

Stem cell (bone marrow) transplants. Allogeneic uses cells from a donor; autologous uses your own cells, collected earlier and given back.

Excipients

The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.

Clinically significant

Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.

NYHA class (heart failure)

The New York Heart Association’s four classes of how much heart failure limits physical activity.

I
No limits: ordinary activity causes no undue tiredness or breathlessness.
II
Slight limits: comfortable at rest, ordinary activity causes symptoms.
III
Marked limits: comfortable at rest, less than ordinary activity causes symptoms.
IV
Symptoms even at rest; any activity makes them worse.

Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.

QT and QTc

On an ECG, the QT interval is the time the heart’s lower chambers take to activate electrically and recover in each beat. QTc is that time adjusted for heart rate (QTcF by Fridericia’s formula, QTcB by Bazett’s). Some medicines lengthen it, and a long QTc can raise the risk of a dangerous heart rhythm.

The study may name a correction formula and a limit in milliseconds, often around 450–480.

Brain metastases

Cancer deposits in the brain from a cancer that started elsewhere in the body (CNS metastases include the spinal cord).

Studies differ: some leave out any brain metastases, some accept ones treated and stable for some weeks. Check what this study allows.

Autoimmune disease

A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.

Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.

Corticosteroids (steroids)

Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.

Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.

Immunosuppression

A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.

Read whether the line is about a condition or about medicines, and which medicines and doses it means.

HIV

The human immunodeficiency virus, which weakens the immune system.

Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.

LVEF (left ventricular ejection fraction)

The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.

ALT and AST (liver enzymes)

Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.

Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.

ULN (upper limit of normal)

The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.

“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.

Bilirubin

A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.

Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.

Hepatitis B tests

Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.

Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.

Hepatitis C tests

Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.

After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.

Investigational drug or device

A drug or device being studied in a clinical trial.

It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.

05

Study design

Phase
Phase 1 / Phase 2
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
None (open label)
Enrollment
305 participants (estimated)

Study arms

  • Experimental
    Module 1 (Mo-Rez +Dostarlimab) Endometrial Cancer

    Drug: Mo-Rez · Drug: Dostarlimab

  • Experimental
    Module 2 (Mo-Rez +/-Bevacizumab) Ovarian Cancer

    Drug: Mo-Rez · Drug: Bevacizumab

Interventions

  • DrugMo-Rez

    Mo-Rez will be administered intravenously (IV).

  • Dostarlimab will be administered IV.

  • Bevacizumab will be administered IV.

06

What researchers measure

Primary outcomes

  1. Part A: Percentage of participants with dose limiting toxicities (DLTs)

    Time frame: Approximately 7 months

  2. Part A: Number of participants with adverse events (AEs), immune-mediated adverse events (imAEs), adverse events of special interest (AESI), serious adverse events (SAEs) by Severity

    Time frame: Up to approximately 22 months

  3. Part A: Number of participants with adverse events (AEs), immune-mediated adverse events (imAEs), adverse events of special interest (AESI), serious adverse events (SAEs) by Frequency

    Time frame: Up to approximately 22 months

  4. Part B: Confirmed Objective Response Rate (ORR)

    ORR is defined as the percentage of participants with a best overall confirmed (BOR) of Partial Response (PR) or better per Response Evaluation Criteria in Solid Tumors (RECIST 1.1)

    Time frame: Up to approximately 37 months

Secondary outcomes

  1. Part A: Confirmed Objective Response Rate (ORR)

    ORR is defined as the percentage of participants with a best overall confirmed (BOR) of Partial Response (PR) or better per Response Evaluation Criteria in Solid Tumors (RECIST 1.1)

    Time frame: Up to approximately 22 months

  2. Parts A and B: Duration of response (DoR)

    DoR is defined as the time from date of first documented evidence of PR or better to the date of disease progression or death due to any cause.

    Time frame: Up to approximately 37 months

  3. Parts A and B: Progression-free survival (PFS)

    PFS is defined as time from the date of randomization (Part B) / first dose of study intervention (Part A or B if single arm) to the date of disease progression according to investigator assessment or death due to any cause, whichever occurs first.

    Time frame: Up to approximately 37 months

  4. Part B: Overall Survival (OS)

    OS is defined as the time from randomization (or date of first dose if single arm) to the date of death due to any cause.

    Time frame: Up to approximately 37 months

  5. Part B: Proportion of participants with CA-125 response

    Time frame: Up to approximately 37 months

  6. Parts A and B: Maximum observed concentration (Cmax) of Mo-Rez

    Time frame: Up to approximately 37 months

  7. Parts A and B: Time to reach Cmax (tmax) of Mo-Rez

    Time frame: Up to approximately 37 months

  8. Parts A and B: Trough concentration (Ctrough) of Mo-Rez

    Time frame: Up to approximately 37 months

  9. Parts A and B: Area under the concentration-time curve (AUC) of Mo-Rez

    Time frame: Up to approximately 37 months

  10. Parts A and B: Number of participants with Anti-drug antibodies (ADA)

    Time frame: Up to approximately 37 months

  11. Parts A and B: Number of participants with neutralizing antibody (nAb)

    Time frame: Up to approximately 37 months

  12. Parts A and B: Titers of ADA to Mo-Rez

    Time frame: Up to approximately 37 months

  13. Parts A and B: Number of Participants with Clinically Significant Changes in Vital Signs, Laboratory parameters, and Electrocardiogram (ECG)

    Time frame: Up to approximately 37 months

  14. Part B: Number of participants with adverse events (AEs), immune-mediated adverse events (imAEs), adverse events of special interest (AESI), serious adverse events (SAEs) by Frequency

    Time frame: Up to approximately 37 months

  15. Part B: Number of participants with adverse events (AEs), immune-mediated adverse events (imAEs), adverse events of special interest (AESI), serious adverse events (SAEs) by Severity

    Time frame: Up to approximately 37 months

  16. Parts A and B: Change from Baseline in Eastern Cooperative Oncology Group Performance Scale (ECOG PS) score

    ECOG PS is used for measuring how the disease impacts a participant's daily living abilities. The grades for the scale range from 0 (fully active) to 5 (dead), with increasing severity.

    Time frame: Baseline and up to approximately 37 months

07

Study locations

80 of 83 sites recruiting
  • GSK Investigational Site
    La Jolla, California 92093, United States
    Recruiting
  • GSK Investigational Site
    Aurora, Colorado 80045-2517, United States
    Recruiting
  • GSK Investigational Site
    Rochester, New York 55905-0001, United States
    Recruiting
  • GSK Investigational Site
    Durham, North Carolina 27710, United States
    Recruiting
  • GSK Investigational Site
    Columbus, Ohio 43210-1240, United States
    Recruiting
  • GSK Investigational Site
    Buenos Aires, C1181ACH, Argentina
    Recruiting
  • GSK Investigational Site
    Buenos Aires, C1280AEB, Argentina
    Recruiting
  • GSK Investigational Site
    CABA, C1187, Argentina
    Recruiting
  • GSK Investigational Site
    Viedma, R8500ACE, Argentina
    Recruiting
  • GSK Investigational Site
    Liverpool, New South Wales 2170, Australia
    Recruiting
  • GSK Investigational Site
    Wollongong, New South Wales 2500, Australia
    Recruiting
  • GSK Investigational Site
    Brussels, 1200, Belgium
    Recruiting
  • GSK Investigational Site
    Ghent, 9000, Belgium
    Recruiting
  • GSK Investigational Site
    Leuven, 3000, Belgium
    Recruiting
  • GSK Investigational Site
    Liège, 4000, Belgium
    Recruiting
  • GSK Investigational Site
    Barretos, 14784-400, Brazil
    Recruiting
  • GSK Investigational Site
    Goiânia, 74605-070, Brazil
    Recruiting
  • GSK Investigational Site
    Natal, 59075-740, Brazil
    Recruiting
  • GSK Investigational Site
    Porto Alegre, 90020-090, Brazil
    Recruiting
  • GSK Investigational Site
    São Paulo, 01246-000, Brazil
    Recruiting
  • GSK Investigational Site
    Vitória, 29043-260, Brazil
    Recruiting
  • GSK Investigational Site
    Vancouver, British Columbia V5Z 4E6, Canada
    Recruiting
  • GSK Investigational Site
    Toronto, Ontario M5G 2M9, Canada
    Recruiting
  • GSK Investigational Site
    Montreal, Quebec H2X 0A9, Canada
    Recruiting
  • GSK Investigational Site
    Montreal, Quebec H4A 3J1, Canada
    Recruiting
  • GSK Investigational Site
    København Ø, Capital Region 2100, Denmark
    Recruiting
  • GSK Investigational Site
    Herlev, Denmark
    Recruiting
  • GSK Investigational Site
    Helsinki, 00029, Finland
    Recruiting
  • GSK Investigational Site
    Tampere, 33520, Finland
    Recruiting
  • GSK Investigational Site
    Lyon, 69373, France
    Recruiting
  • GSK Investigational Site
    Marseille, 13273, France
    Recruiting
  • GSK Investigational Site
    Montpellier, 34298, France
    Recruiting
  • GSK Investigational Site
    Pierre-Bénite, 69495, France
    Recruiting
  • GSK Investigational Site
    Villejuif, 94805, France
    Recruiting
  • GSK Investigational Site
    München, Bavaria 81377, Germany
    Recruiting
  • GSK Investigational Site
    Mainz, Rhineland-Palatinate 55131, Germany
    Recruiting
  • GSK Investigational Site
    Cologne, 50931, Germany
    Recruiting
  • GSK Investigational Site
    Leipzig, 04103, Germany
    Recruiting
  • GSK Investigational Site
    Panórama, Central Macedonia 552 36, Greece
    Recruiting
  • GSK Investigational Site
    Athens, 11528, Greece
    Recruiting
  • GSK Investigational Site
    Athens, 12462, Greece
    Recruiting
  • GSK Investigational Site
    Pylaia Thessaloniki, 570 01, Greece
    Recruiting
  • GSK Investigational Site
    Milan, MI 20159, Italy
    Recruiting
  • GSK Investigational Site
    Roma, RM 00168, Italy
    Recruiting
  • GSK Investigational Site
    Milan, 20141, Italy
    Recruiting
  • GSK Investigational Site
    Naples, 80131, Italy
    Recruiting
  • GSK Investigational Site
    Padova, 35128, Italy
    Recruiting
  • GSK Investigational Site
    Chiba, 277-8577, Japan
    Recruiting
  • GSK Investigational Site
    Fukuoka, 811-1395, Japan
    Recruiting
  • GSK Investigational Site
    Tokyo, 104-0045, Japan
    Recruiting
  • GSK Investigational Site
    Tokyo, 135-8550, Japan
    Recruiting
  • GSK Investigational Site
    San Pedro Garza García, Nuevo León 66260, Mexico
    Recruiting
  • GSK Investigational Site
    Mexico City, 14080, Mexico
    Recruiting
  • GSK Investigational Site
    Amsterdam, 1066 CX, Netherlands
    Recruiting
  • GSK Investigational Site
    Amsterdam, 1081 HV, Netherlands
    Recruiting
  • GSK Investigational Site
    Rotterdam, 3015 GD, Netherlands
    Recruiting
  • GSK Investigational Site
    Oslo, 0379, Norway
    Recruiting
  • GSK Investigational Site
    Panama City, Panama
    Recruiting
  • GSK Investigational Site
    Panama City, Panama
    Recruiting
  • GSK Investigational Site
    Punta Pacifica Panama City Panama, Panama
    Recruiting
  • GSK Investigational Site
    Bialystok, 15-027, Poland
    Recruiting
  • GSK Investigational Site
    Gliwice, 44-102, Poland
    Recruiting
  • GSK Investigational Site
    Józefów, 05-410, Poland
    Recruiting
  • GSK Investigational Site
    Warsaw, 01-748, Poland
    Completed

    Not enrolling at this site — choose another above.

  • GSK Investigational Site
    Seoul, 05505, South Korea
    Recruiting
  • GSK Investigational Site
    Seoul, 120-752, South Korea
    Recruiting
  • GSK Investigational Site
    Seoul, 135-710, South Korea
    Recruiting
  • GSK Investigational Site
    A Coruña, 15009, Spain
    Recruiting
  • GSK Investigational Site
    Barcelona, 08023, Spain
    Recruiting
  • GSK Investigational Site
    Barcelona, 08035, Spain
    Recruiting
  • GSK Investigational Site
    Barcelona, 08036, Spain
    Recruiting
  • GSK Investigational Site
    Madrid, 28033, Spain
    Recruiting
  • GSK Investigational Site
    Madrid, 28041, Spain
    Recruiting
  • GSK Investigational Site
    Madrid, 28050, Spain
    Recruiting
  • GSK Investigational Site
    Málaga, 29010, Spain
    Recruiting
  • GSK Investigational Site
    Valencia, 46009, Spain
    Recruiting
  • GSK Investigational Site
    Zaragoza, 50009, Spain
    Recruiting
  • GSK Investigational Site
    Stockholm, 17164, Sweden
    Recruiting
  • GSK Investigational Site
    Ankara, 06590, Turkey (Türkiye)
    Recruiting
  • GSK Investigational Site
    Ankara, 6170, Turkey (Türkiye)
    Recruiting
  • GSK Investigational Site
    Istanbul, 34010, Turkey (Türkiye)
    Recruiting
  • GSK Investigational Site
    Glasgow, G12 0YN, United Kingdom
    Withdrawn

    Not enrolling at this site — choose another above.

  • GSK Investigational Site
    London, NW1 2BU, United Kingdom
    Completed

    Not enrolling at this site — choose another above.

08

References and documents

Publications

  • Lheureux S, Provencher D, Baka S, Kowalyszyn R, Schutte T, Urun Y, Zeng X, Oaknin A, Lorusso D, Ray-Coquard I, Moreno V, Jalkanen K, Liu Burstrom L, van Dongen MGJ, Boni V, Lee JY, Bedard PL, Malinowska IA, Kaisermann M, McKean W. BEHOLD-1 and -2: phase 1/2 randomized studies evaluating the B7 homolog 4 protein-targeted antibody-drug conjugate mocertatug rezetecan in patients with solid tumors, including endometrial and ovarian cancers. Int J Gynecol Cancer. 2026 Sep 7:105607. doi: 10.1016/j.ijgc.2026.105607. Online ahead of print. PubMed 42850140 ↗

Individual participant data

Plan to share: Yes — Study Sponsor will assess requests from qualified researchers for anonymized individual patient-level data and related study documents. Data sharing is subject to certain criteria, conditions, and exceptions. For further information, refer to https://www.gsk-studyregister.com/gsk-patient-level-data-sharing-july2025.pdf

Supporting information: Study protocol, Statistical analysis plan, Informed consent form, Clinical study report

Time frame: Anonymized IPD will be made available within 6 months of publication of primary, key secondary and safety results for studies in product with approved indication(s) or asset(s) with development terminated across all indications.

Access criteria: Anonymized IPD is shared with researchers whose proposals are approved by an Independent Review Panel and after a Data Sharing Agreement is in place. Access is provided for an initial period of 12 months, but an extension may be granted, when justified, for up to 6 months.

Data sharing details ↗ · www.gsk-studyregister.com

09

Timeline

2 registry updates since Sep 25, 2026
ElapsedEstimatedEstimated, not yet reachedSimilar studies: half by the dot; the band is the middle halfHalf of similar studies reached it by the dot; the band is the middle half, from a quarter to three quarters

Started Mar 2025 (actual). Primary completion is estimated for Jun 2027, 27 months after the start.

Of 194 industry-sponsored phase 1/2 interventional studies under Neoplasms, half reached primary completion within 61 months of starting (the median), counting those still running; a quarter within 41 and three quarters within 88. This study's planned 27 months is below that.

Counting every sponsor, half of 296 studies reached it within 60 months; a quarter within 39 and three quarters within 89.

Neoplasms covers many different conditions, not one, so the studies compared here vary widely. Read these figures as a rough guide.

How these figures are worked out, and which studies are left out of them.

Registered
Jan 22, 2025
First posted
Jan 28, 2025
StartActual
Mar 4, 2025
Primary completionEst.
Jun 21, 2027
CompletionEst.
Oct 10, 2028
Last update
Nov 2, 2026
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
Sites
9 sites added, 7 sites removed
Show 9 added (3 Italy, 2 Germany, 2 Mexico, 1 Denmark, 1 Greece)
  • GSK Investigational Site · København Ø, Denmark
  • GSK Investigational Site · München, Germany
  • GSK Investigational Site · Mainz, Germany
  • GSK Investigational Site · Panórama, Greece
  • GSK Investigational Site · Milan, Italy
  • GSK Investigational Site · Roma, Italy
  • GSK Investigational Site · San Pedro Garza García, Mexico
  • GSK Investigational Site · Mexico City, Mexico
  • GSK Investigational Site · Padova, Italy
Show 7 removed
  • GSK Investigational Site · Copenhagen, Denmark
  • GSK Investigational Site · Mainz, Germany
  • GSK Investigational Site · München, Germany
  • GSK Investigational Site · Thessaloniki, Greece
  • GSK Investigational Site · Roma, Italy
  • GSK Investigational Site · DF, Mexico
  • GSK Investigational Site · San Pedro Garza García, Mexico
across 2 updates, Oct 2, 2026 – Nov 2, 2026
Site contacts
Changed at 2 sites. See the sites
Show 2 sites
  • GSK Investigational Site · Barretos, BrazilContact person changed (no phone or email listed)
  • GSK Investigational Site · Seoul, South KoreaContact person changed (no phone or email listed)
Oct 2, 2026
Show all 2 updates
  1. Nov 2, 2026
    1 site added
    Show site
    • GSK Investigational Site · Padova, Italy
    + 2 other changes: identifiers and verification date
  2. Oct 2, 2026
    8 sites added, 7 sites removed
    Show 8 added (2 Germany, 2 Italy, 2 Mexico, 1 Denmark, 1 Greece)
    • GSK Investigational Site · København Ø, Denmark
    • GSK Investigational Site · München, Germany
    • GSK Investigational Site · Mainz, Germany
    • GSK Investigational Site · Panórama, Greece
    • GSK Investigational Site · Milan, Italy
    • GSK Investigational Site · Roma, Italy
    • GSK Investigational Site · San Pedro Garza García, Mexico
    • GSK Investigational Site · Mexico City, Mexico
    Show 7 removed
    • GSK Investigational Site · Copenhagen, Denmark
    • GSK Investigational Site · Mainz, Germany
    • GSK Investigational Site · München, Germany
    • GSK Investigational Site · Thessaloniki, Greece
    • GSK Investigational Site · Roma, Italy
    • GSK Investigational Site · DF, Mexico
    • GSK Investigational Site · San Pedro Garza García, Mexico
    Site contacts Changed at 2 sites. See the sites
    Show 2 sites
    • GSK Investigational Site · Barretos, BrazilContact person changed (no phone or email listed)
    • GSK Investigational Site · Seoul, South KoreaContact person changed (no phone or email listed)
    + 1 other change: verification date

From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗

10

Registry details

Key details

Study ID
NCT06796907
Lead sponsor
GlaxoSmithKline
Responsible party
Sponsor
First posted
Jan 28, 2025
Start date
Mar 4, 2025
Primary completion
Jun 21, 2027 (estimated)
Completion
Oct 10, 2028 (estimated)
Last update
Nov 2, 2026

Study contacts

US GSK Clinical Trials Call Center
Contact
GSKClinicalSupportHD@gsk.com
877-379-3718
EU GSK Clinical Trials Call Center
Contact
GSKClinicalSupportHD@gsk.com
+44 (0) 20 89904466

Oversight

Data monitoring committee
No
FDA-regulated drug
Yes
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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Discussion

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Studies of the drug tested here: Bevacizumab

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