Learn center · Glossary

Every term, in plain language.

Reviewed by clinical staff. If you see a term on a trial detail page that isn't here, ask in chat — we'll add it.

A

Adverse event (AE): Any unwanted medical occurrence in a trial participant, whether or not it's caused by the trial treatment. Trials track AEs by severity grade and whether they appear related to the investigational drug.
Arm: A group of participants in a trial who receive a specific treatment. Most randomized trials have at least two arms — for example, the experimental treatment arm and a control arm receiving standard care.

B

Biomarker: A measurable indicator of biology — a protein in blood, a gene mutation, an imaging finding. Many trials use biomarkers to decide who is eligible (e.g., HER2-positive, EGFR-mutated) and how the treatment is working.
BRCA1 / BRCA2: Two human genes whose mutations significantly raise the risk of breast and ovarian cancer. Many oncology trials test treatments specifically for people with these mutations.

C

Caregiver: A spouse, family member, or friend who supports a participant through trial visits and treatment. MyTrial supports caregiver delegation — caregivers can view your Health Passport with your permission.
CDISC: Clinical Data Interchange Standards Consortium — sets the data formats (CDASH for collection, SDTM for submission) that the FDA expects. Most modern trials follow CDISC standards.

E

ECOG performance status: A 0-to-5 scale describing how well a person is functioning physically. ECOG 0 means fully active; ECOG 1 means symptoms but ambulatory; ECOG 2 means up and about more than half the day. Many oncology trials require ECOG 0 or 1.
Eligibility criteria: The list of conditions a person must meet to enroll in a trial. Inclusion criteria are things you must have; exclusion criteria are things that disqualify you. MyTrial parses these and shows them in plain language alongside the original protocol text.
Enrollment: The act of officially joining a trial as a participant — distinct from screening, which is the visit that confirms you're eligible. Enrollment happens after you sign informed consent and pass screening.

F

FDA 1572: The form an investigator files with the FDA to confirm they will conduct a trial under a specific sponsor's oversight. Sites need an active 1572 to run trials; MyTrial verifies this for site profiles.

H

Health Passport: MyTrial's patient-owned, portable, persistent medical profile. Once you build it, you carry it across every trial you apply to. Granular consent — you decide which fields are shared per trial.
HER2: Human Epidermal growth factor Receptor 2 — a protein that, when over-expressed (HER2-positive), drives certain breast and gastric cancers. Several targeted therapies treat HER2-positive cancer specifically.

I

ICF (Informed Consent Form): The document that explains everything you need to know about a trial — what's being tested, what the risks are, what's expected of you — before you decide to enroll. You sign it after a study staff member walks you through it.
ICH-GCP E6(R3): International standard for Good Clinical Practice — the rules that say how trials must be run to be considered ethical and rigorous. Updated in 2024 to be more risk-proportionate and technology-aware.
Inclusion criteria: Things you must have to enroll in a trial (e.g., specific diagnosis, age range, prior treatments). The opposite of exclusion criteria.
Investigator: The clinician — usually an MD or MD-PhD — who is legally responsible for trial conduct at a specific site. The principal investigator (PI) signs the FDA 1572 and oversees the site team.

L

LVEF: Left ventricular ejection fraction — the percentage of blood pumped out of the heart's left ventricle each beat. Many cancer drugs require an LVEF measurement (typically by ECHO or MUGA) within a recent window before you can start.

M

MeSH: Medical Subject Headings — the National Library of Medicine's controlled vocabulary for biomedical terms. MyTrial uses MeSH to map conditions consistently across trials and search results.

N

NCT id: ClinicalTrials.gov identifier — every trial registered with the U.S. National Library of Medicine has one (e.g., NCT05284825). MyTrial uses NCT ids as canonical trial references.

P

Protocol: The document that defines exactly how a trial is run — eligibility, schedule, what's measured, what's allowed, what's not. The protocol is the rulebook for the trial.
Protocol Feedback Loop: MyTrial's free, sponsor-side product that runs a draft protocol against the eligible-population data and recommends modifications. A single relaxation can save $10–50M in recruitment costs.

R

Randomization: Assigning participants to a specific arm by chance, not choice. Randomization is the gold standard for comparing two treatments because it removes selection bias.

S

Screening: The visit (or visits) that confirm you actually meet a trial's eligibility criteria. Screen failure means you didn't meet a criterion at the screening visit. Different from enrollment, which happens after you pass screening.
Site: The hospital, clinic, or academic medical center where the trial is run. Sites recruit participants, conduct visits, collect data, and report to the sponsor. MyTrial connects participants to sites.
Site Performance Index: MyTrial's transparent, anonymized site metrics — enrollment velocity, screen-fail rate, retention, response time. Sponsors use it to choose sites with data, not relationships.
SNOMED CT: A clinical terminology system used to encode diagnoses, procedures, and findings in a standardized way. The Patient Matcher uses SNOMED to normalize across protocols and Health Passport entries.
Sponsor: The pharmaceutical company, biotech, academic institution, or government agency that designs and funds a trial. Sponsors set the protocol; sites run it.

T

T-DXd (trastuzumab deruxtecan): An antibody-drug conjugate approved for HER2-positive cancers. The antibody finds the cancer cell; a chemotherapy payload is delivered specifically there. Example trial: NCT05284825.

Adverse event (AE)

Any unwanted medical occurrence in a trial participant, whether or not it's caused by the trial treatment. Trials track AEs by severity grade and whether they appear related to the investigational drug.

Arm

A group of participants in a trial who receive a specific treatment. Most randomized trials have at least two arms — for example, the experimental treatment arm and a control arm receiving standard care.

Biomarker

A measurable indicator of biology — a protein in blood, a gene mutation, an imaging finding. Many trials use biomarkers to decide who is eligible (e.g., HER2-positive, EGFR-mutated) and how the treatment is working.

BRCA1 / BRCA2

Two human genes whose mutations significantly raise the risk of breast and ovarian cancer. Many oncology trials test treatments specifically for people with these mutations.

Caregiver

A spouse, family member, or friend who supports a participant through trial visits and treatment. MyTrial supports caregiver delegation — caregivers can view your Health Passport with your permission.

CDISC

Clinical Data Interchange Standards Consortium — sets the data formats (CDASH for collection, SDTM for submission) that the FDA expects. Most modern trials follow CDISC standards.

ECOG performance status

A 0-to-5 scale describing how well a person is functioning physically. ECOG 0 means fully active; ECOG 1 means symptoms but ambulatory; ECOG 2 means up and about more than half the day. Many oncology trials require ECOG 0 or 1.

Eligibility criteria

The list of conditions a person must meet to enroll in a trial. Inclusion criteria are things you must have; exclusion criteria are things that disqualify you. MyTrial parses these and shows them in plain language alongside the original protocol text.

Enrollment

The act of officially joining a trial as a participant — distinct from screening, which is the visit that confirms you're eligible. Enrollment happens after you sign informed consent and pass screening.

Health Passport

MyTrial's patient-owned, portable, persistent medical profile. Once you build it, you carry it across every trial you apply to. Granular consent — you decide which fields are shared per trial.

HER2

Human Epidermal growth factor Receptor 2 — a protein that, when over-expressed (HER2-positive), drives certain breast and gastric cancers. Several targeted therapies treat HER2-positive cancer specifically.

ICH-GCP E6(R3)

International standard for Good Clinical Practice — the rules that say how trials must be run to be considered ethical and rigorous. Updated in 2024 to be more risk-proportionate and technology-aware.

Inclusion criteria

Things you must have to enroll in a trial (e.g., specific diagnosis, age range, prior treatments). The opposite of exclusion criteria.

Investigator

The clinician — usually an MD or MD-PhD — who is legally responsible for trial conduct at a specific site. The principal investigator (PI) signs the FDA 1572 and oversees the site team.

Protocol

The document that defines exactly how a trial is run — eligibility, schedule, what's measured, what's allowed, what's not. The protocol is the rulebook for the trial.

Protocol Feedback Loop

MyTrial's free, sponsor-side product that runs a draft protocol against the eligible-population data and recommends modifications. A single relaxation can save $10–50M in recruitment costs.

Screening

The visit (or visits) that confirm you actually meet a trial's eligibility criteria. Screen failure means you didn't meet a criterion at the screening visit. Different from enrollment, which happens after you pass screening.

Site

The hospital, clinic, or academic medical center where the trial is run. Sites recruit participants, conduct visits, collect data, and report to the sponsor. MyTrial connects participants to sites.

Site Performance Index

MyTrial's transparent, anonymized site metrics — enrollment velocity, screen-fail rate, retention, response time. Sponsors use it to choose sites with data, not relationships.

SNOMED CT

A clinical terminology system used to encode diagnoses, procedures, and findings in a standardized way. The Patient Matcher uses SNOMED to normalize across protocols and Health Passport entries.