Clinical Research
Clinical research is medical research involving people. In summary, clinical research is carried out in order to provide scientific evidence for the safety, and efficacy of a drug or an intervention (for instance medicine, dietary supplements or other non-drug therapies). There are two main types of clinical research: interventional and observational. Within these there are subtypes and the explanations are listed below
👉 Definition:
The researcher actively assigns an intervention (e.g., a new drug, vaccine, surgery, or behavioral program) to participants to see its effect on a specific outcome.
🧠 Key Characteristics:
-Participants are randomized (in most cases).
-Researcher controls the exposure.
-Can establish cause-and-effect relationships.
-Usually more expensive and complex.
-Commonly used in drug and vaccine trials.
📊 Types:
-Randomized Controlled Trials (RCTs) – gold standard for testing efficacy.
-Non-randomized interventional studies – intervention is given but not randomly assigned.
Definition:
An interventional therapeutic is a drug, biologic, device, procedure, or other medical intervention that is intended to produce a clinical benefit by treating, curing, or preventing disease.
Purpose:
-To evaluate efficacy and safety of a therapy.
-To directly improve patient outcomes.
Examples:
-Administering a monoclonal antibody to neutralize TNF-α in rheumatoid arthritis.
-Using insulin to treat diabetes.
-Performing a stent placement to open a blocked artery.
Key point:
-The target is the disease or pathological process itself, and the therapy is the active intervention intended to benefit the patient directly.
✅ In short:
Interventional therapeutic = giving a treatment to directly improve health.
Definition:
An interventional biomarker is a measurable biological characteristic (e.g., protein level, gene expression, imaging finding) that is actively modified or targeted in a clinical study to understand its role in disease or therapy, but is not itself the direct therapy.
Purpose:
To test whether changing a biomarker affects disease outcomes.
To validate the biomarker as a potential mechanistic driver or surrogate endpoint.
To guide or stratify therapy.
Examples:
-Lowering LDL cholesterol with a drug to test whether LDL reduction (the biomarker) causally improves cardiovascular outcomes.
-Modulating amyloid-β plaques in Alzheimer’s disease to test if plaque reduction impacts cognitive decline.
-Increasing hemoglobin F (fetal hemoglobin) in sickle cell disease to see if it reduces crises.
Key point:
-The target is the biomarker, and its modulation is the intervention—but the biomarker itself is not necessarily the therapeutic product.
✅ In short:
Interventional biomarker = manipulating a marker to study its effect on disease.
👉 Definition:
The researcher does not assign any treatment. Instead, they observe and collect data on what happens naturally or in routine care.
🧠 Key Characteristics:
-No randomization or active intervention.
-Researcher only observes existing exposures or behaviors.
-Cannot prove cause-and-effect as strongly as interventional studies (more prone to bias and confounding).
-Usually easier, cheaper, and faster to conduct.
-Useful for studying risk factors, long-term outcomes, or rare side effects.
📊 Types:
-Cohort studies (prospective or retrospective)
-Case-control studies
-Cross-sectional studies
Definition:
An observational study is one where researchers do not intervene — they collect data as it naturally occurs.
- No experimental drug or procedure is given.
- Useful for understanding how diseases progress, how patients respond to standard care, or how biomarkers behave over time.
Key features:
-No randomization.
-No assignment to treatment groups.
-Can be prospective (follow forward in time) or retrospective (look back at records).
Example:
-Following a group of people with type 2 diabetes for 5 years to see how blood sugar levels and complications change with time and usual care.
Definition:
An observational biomarker study is a type of observational study where the main focus is to measure and track biomarkers — not to give any treatment.
Purpose:
-To understand the relationship between biomarkers and disease states or outcomes.
-To discover or validate potential biomarkers.
-To identify subgroups of patients who may respond differently to future therapies.
Key features:
-Still no intervention.
-Focus on collecting biological data (e.g., blood, imaging, molecular profiles).
Example:
-Tracking serum neurofilament light chain (NfL) levels in ALS patients to see if they correlate with disease progression.
-Measuring tumor markers in cancer patients during standard follow-up.
Definition:
An observational natural history study is designed to describe how a disease develops and progresses over time — without any experimental treatment.
Purpose:
-To map the typical course of a disease.
-Identify clinical milestones, prognostic factors, and progression rates.
-Provide baseline data for future interventional trials (especially in rare diseases).
Key features:
-Long-term follow-up.
-May include biomarkers plus clinical outcomes (e.g., symptoms, functional decline, survival).
-Often used to define endpoints and inclusion criteria for future trials.
Example:
-Following children with Duchenne muscular dystrophy to track how muscle function declines over years.
-Studying the progression of Huntington’s disease from pre-symptomatic to symptomatic stages.
How are the trials and studies done?
Everyone who wants to conduct a trial or study needs approval from the authoroties and ethic committees. Drug trials performed in Europe needs approval both from the European Medicines Agency and from the ethic committees in each country where there are participants. These authorities are responsible for vetting the risk/benefit ratio of the trial – their approval does not mean that the therapy is ‘safe’ or effective, only that the trial may be conducted.
Depending on product type and development stage, investigators initially enroll volunteers or patients into small pilot studies and subsequently conduct progressively larger scale comparative studies. Clinical trials can vary in size and cost, and they can involve a single research center or multiple centers, in one country or in multiple countries. Clinical study design aims to ensure the data collected in the study holds high standards and measure the potential effect – positive, negative or no effect – in a scientifically sound way. The procedures has to be publicly available to allow independent evaluation of the reported results.
FROM LABORATORY TO APPROVED TREATMENT
Click below to learn more about how medicines are approved by the European Medicine Agency (EMA)
CLINICAL TRIALS EXPLAINED BY Hoffmann-La Roche
Learn about the stages and types of clinical trials. Find also the frequently asked questions (FAQ) about Huntington’s studies.
WHY SHOULD I GET INVOLVED?
Scientists work constantly to find enhanced ways to treat diseases, but improved treatments can never become a reality without testing in clinical trials with human volunteers. Individuals with HD are urgently needed to participate in the ongoing enrolling clinical trials focused on HD. In some studies, those who are at risk, caregivers and healthy volunteers are also needed. Recruiting and retaining trial participants is now the greatest obstacle, other than funding, to developing the next generation of HD’s treatments.
By participating in clinical research, you can help to accelerate progress and provide valuable insight into potential treatments and methods of prevention.
Benefits of clinical trials
Participating in clinical trials has the potential to help both the individual participant and other individuals who have HD or are at risk of developing it:
- You can play a more active role in your own health care.
- You can gain access to potential treatments before they are widely available.
- You can receive expert medical care at leading healthcare facilities — often free of cost — while participating in important medical research.
- You can help future generations by contributing to HD research.
Risks of participation
Patient safety is the most important aspect of every HD clinical trial. The procedures for each study are reviewed by an expert committee not directly involved in the trial, helping ensure that patient safety is protected.
There are risks, however, when participating in clinical trials:
- There may be unpleasant or even serious side effects related to the potential treatment(s) being studied.
- The experimental treatment may not be effective.
Details of risks related to participation in the clinical study are spelled out in the consent form participants (or their proxies) sign when they agree to participate.
Reasons for optimism
No new treatment advances to the clinical testing phase unless there is strong evidence indicating it will be as effective as, or more effective than, currently available therapies. Every clinical trial contributes valuable knowledge, whether or not the treatment works as hoped.
Participating in clinical studies gives us optimism for today and promise for the future. They provide many participants with access to cutting-edge treatments and expert medical care. And some day they will lead us to the end of HD.
Participants receive a high standard of care
All participants receive regular care related to the trial and opportunities to talk to clinical trial staff. Research shows that people living with the disease who are involved in clinical trials tend to do somewhat better than people in a similar stage of their disease who are not enrolled in clinical trials, regardless of whether the experimental treatment works. Scientists believe this advantage may be due to the general high quality of care provided during clinical trials.
