A Phase 1 interventional study of BEAM-103 and Placebo Comparator in Healthy Subjects and Healthy Participant Study, sponsored by Beam Therapeutics Inc.. Recruiting at 1 site in United Kingdom. Open to participants aged 18 Years to 55 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-12-26.
Sponsored by Beam Therapeutics Inc. · Phase 1, Interventional, and Basic science
The purpose of this Phase I single ascending dose study is to evaluate the safety, pharmacokinetics (PK), and pharmacodynamics (PD) of BEAM-103 in healthy subjects between the ages of 18 and 55. The main questions the study aims to answer are:
Researchers will determine and establish the therapeutic window of the antibody and select optimal doses for future trials in patients.
Subjects will:
Beam Therapeutics Inc. is the lead sponsor of 6 studies on the registry; 4 are open to participants now.
Counted across the registry records on this site, refreshed daily.
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.
Exclusion Criteria:
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.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
The number of neutrophils, white blood cells that help fight infection, in a given amount of blood. Too few raises the risk of infection.
It is a count, not a percentage of the white cells. Limits are written in units that mean the same: ≥ 1.5 × 10⁹/L is ≥ 1,500 per mm³ (µL). Each lab has its own reference range.
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
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.
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.
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.
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.
Vaccines made with a weakened form of the germ, such as measles–mumps–rubella (MMR), chickenpox and yellow fever. They can be risky when the immune system is weakened. Flu injections are not live; the nasal flu spray is.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Absolute neutrophil count (ANC)
The number of neutrophils, white blood cells that help fight infection, in a given amount of blood. Too few raises the risk of infection.
It is a count, not a percentage of the white cells. Limits are written in units that mean the same: ≥ 1.5 × 10⁹/L is ≥ 1,500 per mm³ (µL). Each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hemoglobin (Hb)
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Platelets
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ECG (electrocardiogram)
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
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.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Live vaccines
Vaccines made with a weakened form of the germ, such as measles–mumps–rubella (MMR), chickenpox and yellow fever. They can be risky when the immune system is weakened. Flu injections are not live; the nasal flu spray is.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
BEAM-103 is a monoclonal antibody that will be administered in single dose ascending dose cohorts as an intravenous infusion through the arm.
Drug: BEAM-103
Normal Saline Solution will be administered as a matching place in single dose ascending dose cohorts as an intravenous infusion through the arm.
Drug: Placebo Comparator
• BEAM-103 is a monoclonal antibody administered as a single intravenous dose
• The matching placebo comparator is administered as a single intravenous dose
To determine the safety and tolerability of single ascending doses of BEAM-103
Incidence of treatment-emergent AEs, serious AEs, severe AEs, AEs related to BEAM-103
Time frame: from enrollment to the end of study at 5 months
Change in Free Stem Cell Factor (SCF) in Peripheral Blood Over Time
Concentration of SCF in peripheral blood measured in nanograms per milliliter (mL)
Time frame: from the start of treatment to the end of study at 5 months
Change in Tryptase Level in Peripheral Blood Over Time
Serum tryptase concentration measured in nanograms per milliliter (ng/mL)
Time frame: from the start of treatment to the end of study at 5 months
Change in Reticulocyte Count in Peripheral Blood Over Time
Absolute reticulocyte count measured in cells per microliter (cells/µL)
Time frame: From enrollment to end of study at 5 months
Change in Neutrophil Count in Peripheral Blood Over Time
Absolute neutrophil count measured in cells per microliter (cells/µL)
Time frame: From enrollment to end of study at 5 months
Maximum Observed Plasma Concentration (Cmax)
Cmax will be calculated as the highest observed plasma/blood/serum concentration following drug administration
Time frame: From enrollment to end of study at 5 months
Area Under the Plasma Concentration-Time Curve to Last Quantifiable Concentration (AUClast)
AUClast will be calculated from time zero to the time of the last quantifiable concentration
Time frame: From enrollment to end of study at 5 months
Area Under the Plasma Concentration-Time Curve to Infinity (AUC∞)
AUC∞ will be calculated as AUClast plus Clast divided by λz
Time frame: From enrollment to end of study at 5 months
Terminal Elimination Half-Life (t½)
t½ will be estimated from the terminal elimination phase of the plasma concentration-time curve
Time frame: From enrollment to end of study at 5 months
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
No contact was published for this record. The registry link below has the sponsor’s details.
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Beam Therapeutics Inc.