Starting a clinical trial requires a sequence of regulatory, ethical, and operational steps that typically takes 12 to 18 months from initial concept to enrolling your first participant. The process centers on three pillars: developing a rigorous study protocol, securing regulatory and ethical approval, and building the infrastructure to run the trial safely. Here’s how each piece fits together.
Define Your Study Phase and Design
Before anything else, you need to know what question your trial is answering and which phase of development your intervention falls into. The phase determines your trial’s size, duration, and primary objective.
Phase 1 trials enroll 20 to 100 participants (often healthy volunteers) over several months to establish safety and appropriate dosing. Phase 2 trials expand to several hundred people who have the disease or condition, running several months to two years, with the goal of measuring whether the treatment actually works while tracking side effects. Phase 3 trials enroll 300 to 3,000 participants over one to four years to confirm efficacy and monitor for adverse reactions across a larger, more diverse population.
Your phase shapes nearly every downstream decision: how many sites you need, how large your budget will be, what safety monitoring structures are required, and how long enrollment will take. Getting clear on this first saves you from redesigning your protocol later.
Write the Study Protocol
The protocol is the backbone of your trial. It’s the document that tells everyone involved, from investigators to regulators, exactly what you’re studying, how you’re studying it, and how you’ll know if it worked. International guidelines lay out 16 standard sections, and while the specifics vary by trial design, certain elements are non-negotiable.
Start with background information: a summary of what’s known about your investigational product from lab studies and any earlier human data, the known and potential risks and benefits, and a justification for your chosen dose, route, and treatment duration. This section establishes why your trial is worth conducting.
The trial design section is where the scientific rigor lives. You’ll need to define your primary endpoint (the main outcome you’re measuring) and any secondary endpoints. Describe the type of design you’re using, whether that’s double-blind, placebo-controlled, parallel group, or something else. Spell out how you’ll minimize bias through randomization and blinding, detail the schedule of study visits and assessments, state how long each participant will be involved, and set clear stopping rules that define when a participant should be taken off treatment or when the entire trial should halt.
Safety assessment deserves its own detailed section. Specify exactly which safety parameters you’ll track, how and when you’ll measure them, and your procedures for recording and reporting adverse events. Include the type and duration of follow-up after any adverse event occurs. For data handling, define what data will be collected, how it will be captured (paper forms or electronic systems), and how long records will be retained.
Prepare and Submit the IND Application
In the United States, you cannot begin testing an investigational drug in humans without submitting an Investigational New Drug (IND) application to the FDA. The IND is organized in a specific order and includes several required components.
- Cover sheet (Form FDA-1571): This includes your commitments to obtain ethics board review and comply with all applicable regulations.
- Table of contents
- Introductory statement and general investigational plan: A summary of the drug, its formulation, and the broad objectives of your investigation.
- Investigator’s brochure: A compilation of clinical and nonclinical data relevant to the study of the product in humans.
- Protocols: One for each planned study.
- Chemistry, manufacturing, and control information: Details on how the drug is made, its composition, and quality controls.
- Pharmacology and toxicology information: Results from animal and lab studies showing the drug’s biological effects and safety profile.
- Previous human experience: Any data from prior use in people, if it exists.
Once submitted, the FDA has 30 calendar days to review your IND. If you don’t receive a clinical hold notice within that window, you may proceed. A clinical hold means the FDA has identified safety concerns or protocol deficiencies that must be resolved before enrollment can begin.
Secure Ethics Board Approval
Every clinical trial involving human participants must be reviewed and approved by an Institutional Review Board (IRB) before enrollment begins. The IRB’s job is to protect participants’ rights and welfare, both before the trial starts and through periodic reviews as it progresses.
The board evaluates your protocol and all related materials, including your informed consent documents and investigator brochure. Their review centers on two key questions: are the risks to participants minimized, and are remaining risks reasonable relative to the anticipated benefits? The IRB also pays close attention to vulnerable populations. If your trial might enroll people who could be susceptible to coercion or undue influence, the board will require additional safeguards.
IRB review can run concurrently with your IND submission, which helps compress your timeline. Many sponsors submit to both at roughly the same time.
Build Your Informed Consent Document
Federal regulations require eight specific elements in every informed consent document. These aren’t suggestions; they’re legal requirements that your IRB will verify before granting approval.
Your consent form must include: a clear statement that the study involves research, with an explanation of its purpose, expected duration, and which procedures are experimental; a description of foreseeable risks or discomforts; a description of potential benefits to the participant or others; disclosure of alternative treatments that might be available; a description of how participant confidentiality will be maintained, with a note that the FDA may inspect records; for trials involving more than minimal risk, an explanation of whether compensation or medical treatment is available if injury occurs; contact information for questions about the research, participants’ rights, or research-related injuries; and a statement that participation is entirely voluntary, with no penalty for refusing or withdrawing at any time.
Write this document in plain language. If a participant can’t understand what they’re agreeing to, the consent process fails its fundamental purpose regardless of how legally complete the form is.
Select and Qualify Your Trial Sites
Choosing the right sites can make or break your timeline. Site feasibility assessments evaluate whether a location has the infrastructure, staff, and patient population to execute your protocol.
On the infrastructure side, you’ll need to confirm that each site can handle your trial’s specific requirements: proper drug storage conditions, equipment for processing biological samples (such as refrigerated centrifuges), and the capability to use electronic data capture systems. If a site lacks something critical, determine whether it can be procured and installed before enrollment opens.
Staffing matters just as much. Assess whether the site operates as a hospital or outpatient clinic, its prior experience running clinical trials, and the availability of study coordinators, pharmacists, and nurses. A brilliant investigator without a trained coordinator will struggle with protocol compliance, data quality, and participant retention. Look for sites where the team has both medical knowledge and practical trial experience.
Establish Safety Monitoring
Depending on your trial’s risk level and complexity, you may need an independent Data Safety Monitoring Board (DSMB). This is a group of outside experts who periodically review accumulating safety and efficacy data while the trial is still running, with the authority to recommend modifications or early termination if needed.
A typical DSMB consists of three to seven members and should include, at minimum, one or more experts in the clinical aspects of the disease being studied, at least one biostatistician, and investigators experienced in clinical trial methodology. The board operates independently from the sponsor and has access to unblinded data that the study team does not see.
The DSMB’s charter should define how often they meet, what data they review, the statistical boundaries that would trigger a recommendation to stop the trial early (for either harm or overwhelming benefit), and how their recommendations are communicated to the sponsor.
Register Your Trial
U.S. law requires registration of applicable clinical trials on ClinicalTrials.gov. The responsible party, whether that’s the sponsor or the designated principal investigator, must submit the required trial information no later than 21 calendar days after enrolling the first participant.
This isn’t optional. Failure to register can trigger civil monetary penalties from the FDA. For federally funded studies, non-compliance can result in withholding of remaining or future grant funds. The FDA can also issue a Notice of Noncompliance, which is posted publicly on its website. Violations fall into three categories: failure to submit required information, submission of false or misleading information, and failure to report primary and secondary outcomes.
Beyond legal compliance, registration serves a scientific purpose. It creates a public record of your trial’s existence and design before results are known, which helps prevent selective reporting and publication bias.
Follow Good Clinical Practice Standards
Good Clinical Practice (GCP) is the international standard governing the design, conduct, recording, and reporting of trials involving human participants. It’s not a single rule but a framework of principles that ensures two things: the data your trial generates is credible, and participants are protected throughout the process.
GCP compliance touches every aspect of your trial. It requires that all clinical staff be trained and qualified, that source documents are maintained and verifiable, that investigational products are handled and stored according to protocol, and that deviations from the protocol are documented and reported. Before your first participant is enrolled, every member of your study team should complete GCP training. Most sponsors require updated training every two to three years.
Regulatory agencies worldwide recognize GCP, which means a trial conducted under these standards in one country can support a drug application in another. Cutting corners on GCP doesn’t just create ethical problems; it can invalidate your entire dataset.