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What is a clinical trial?

Although there are many definitions of clinical trials, they are generally considered to be biomedical or health-related research studies in human beings that follow a pre-defined protocol. includes both interventional and observational types of studies. Interventional studies are those in which the investigator assigns the research subjects to a treatment or other intervention, and their outcomes are measured. Observational studies are those in which individuals are observed, and the investigators measure their outcomes.

Why participate in a clinical trial?

Participants in clinical trials can play a more active role in their own health care, gain access to new research treatments before they are widely available, and help others by contributing to medical research.

Who can participate in a clinical trial?

All clinical trials have guidelines about who can participate. Using inclusion/exclusion criteria is an important principle of medical research that helps to produce reliable results. The factors that allow someone to participate in a clinical trial are called "inclusion criteria" and those that disallow someone from participating are called "exclusion criteria". These criteria are based on such factors as age, gender, the type and stage of a disease, previous treatment history, and other medical conditions. Before joining a clinical trial, a participant must qualify for the study. Some research studies seek participants with illnesses or conditions to be studied in the clinical trial, while others need healthy participants. It is important to note that inclusion and exclusion criteria are not used to reject people personally. Instead, the criteria are used to identify appropriate participants and keep them safe. The criteria help ensure that researchers will be able to answer the questions they plan to study.


The clinical trial process depends on the kind of trial being conducted (See What are the different types of clinical trials?) The clinical trial team includes doctors and nurses as well as social workers and other health care professionals. They check the health of the participant at the beginning of the trial, give specific instructions for participating in the trial, monitor the participant carefully during the trial, and stay in touch after the trial is completed.

Some clinical trials involve more tests and doctor visits than the participant would normally have for an illness or condition. For all types of trials, the participant works with a research team. Clinical trial participation is most successful when the protocol is carefully followed and there is frequent contact with the research staff.

What is informed consent?

Informed consent is the process of learning the key facts about a clinical trial before deciding whether or not to participate. It is also a continuing process throughout the study to provide information for participants. To help someone decide whether or not to participate, the doctors and nurses involved in the trial explain the details of the study. If the participant's native language is not English, translation assistance can be provided. Then the research team provides an informed consent document that includes details about the study, such as its purpose, duration, required procedures, and key contacts. Risks and potential benefits are explained in the informed consent document. The participant then decides whether or not to sign the document. Informed consent is not a contract, and the participant may withdraw from the trial at any time.

What are the benefits and risks of participating in a clinical trial?

Clinical trials that are well-designed and well-executed are the best approach for eligible participants to:

  •  Play an active role in their own health care.
  •  Gain access to new research treatments before they are widely available.
  •  Obtain expert medical care at leading health care facilities during the trial.
  •  Help others by contributing to medical research.

There are risks to clinical trials.

  •  There may be unpleasant, serious, or even life-threatening side effects to experimental treatment.
  •  The experimental treatment may not be effective for the participant.
  •  The protocol may require more of their time and attention than would a non-protocol treatment, including trips to the study site, more treatments, hospital stays, or complex dosage requirements.

What are the side effects and adverse reactions?

Side effects are any undesired actions or effects of the experimental drug or treatment. 

What is a protocol?

A protocol is a study plan on which all clinical trials are based. The plan is carefully designed to safeguard the health of the participants as well as answer specific research questions. A protocol describes what types of people may participate in the trial, the schedule of tests, procedures, medications, dosages, and the length of the study. While in a clinical trial, participants following a protocol are seen regularly by the research staff to monitor their health and to determine the safety and effectiveness of their treatment.

What is a placebo?

A placebo is an inactive pill, liquid, or powder with no treatment value. In clinical trials, experimental treatments are often compared with placebos to assess the experimental treatment's effectiveness. In some studies, the participants in the control group will receive a placebo instead of an active drug or experimental treatment.

What is a control or control group?

It is a standard by which experimental observations are evaluated. In many clinical trials, one group of patients will be given an experimental drug or treatment. In contrast, the control group is assigned either a standard treatment for the illness or a placebo.

What are the different types of clinical trials?

  •  Treatment trials test experimental treatments, new combinations of drugs, or new approaches to surgery or radiation therapy.
  •  Prevention trials look for better ways to prevent disease in people who have never had the disease or to prevent a disease from returning. These approaches may include medicines, vaccines, vitamins, minerals, or lifestyle changes.
  •  Diagnostic trials are conducted to find better tests or procedures for diagnosing a particular disease or condition.
  •  Screening trials test the best way to detect certain diseases or health conditions.
  •  Quality of Life trials (or Supportive Care trials) explore ways to improve comfort and the quality of life for individuals with a chronic illnesses.

What are the phases of clinical trials?

Clinical trials are conducted in phases. The trials at each phase have a different purpose and help scientists answer different questions:

  •  In Phase I trials, researchers test an experimental drug or treatment in a small group of people for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.
  •  In Phase II trials, the experimental study drug or treatment is given to a larger group of people to see if it is effective and to further evaluate its safety.
  •  In Phase III trials, the experimental study drug or treatment is given to large groups of people to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the experimental drug or treatment to be used safely.
  •  In Phase IV trials, post-marketing studies delineate additional information, including the drug's risks, benefits, and optimal use.

Inclusion criteria

Subjects with Parkinson’s Disease

  1. Clinically established Parkinson’s disease based on Movement Disorder Society (MDS) Clinical Diagnostic Criteria for Parkinson's disease and a modified Hoehn & Yahr scale of 1-3.
  2. No suspected atypical parkinsonian syndromes due to drugs, metabolic disorders, encephalitis, or degenerative diseases.

Subjects with ALS

  1. Confirmed diagnosis of ALS with both upper and lower motor neuron involvement.

Age, Gender, Informed Consent, Pregnancy and Contraception

  1. Male and female subjects 18 years and older at the time of signing the informed consent.
  2. Ability to undergo retinal imaging.
  3. Subject or legally authorized representative must provide signed informed consent (or signed assent form) prior to study entry and have the ability and willingness to attend and comply with the necessary study procedures and visits at the study site. For subjects unable to physically sign the informed consent, a guardian or trusted care giver can sign on their behalf in presence of an independent witness.
  4. Contraception use by study subjects of childbearing potential (male and female) and female partners of childrearing potential male subjects should be consistent with local regulations regarding the methods of contraception for those participating in clinical studies.
  5. Female subjects of childbearing potential and female partners of childbearing potential male subjects must refrain from oocyte donation for up to 30 days after study drug administration.
  6. Male subjects must refrain from sperm donation for 90 days after study drug administration.
  7. Females of childbearing potential must have a negative serum pregnancy test at Screening and a negative urine pregnancy test on Day -1. Females not of childbearing potential must be surgically infertile or postmenopausal (defined as cessation of regular menstrual periods for at least 12 months)at Screening.

Exclusion criteria

Subject meeting ANY of the following exclusion criteria are NOT eligible to be enrolled in the study:


Medical Conditions

  1. Presence of any underlying physical or psychological medical condition that, in the opinion of the investigator, would make it unlikely that the subject will complete the study per protocol.
  2. Clinically significant laboratory abnormalities were assessed by the investigator.
  3. Active malignancy and/or history of malignancy in the past 5 years, with the exception of completely excised non-melanoma skin cancer or low-grade cervical intraepithelial neoplasia.
  4. Prolonged QTcF (>450 ms for males and >470 ms for females), cardiac arrhythmia, or any clinically significant abnormality in the resting ECG, as judged by the investigator.
  5. Presence of any ocular condition that, in the opinion of the investigator, would significantly hinder the ability to detect and quantify hyper-fluorescent puncta (e.g., eyes with significant hyper-autofluorescence that would mask the ability to detect, quantify, and discern post-injection hyper-fluorescent signal from pre-injection hyper-autofluorescence signal). These conditions may include, but are not limited to; age-related macular degeneration, central serous chorioretinopathy, diabetic retinopathy, macular dystrophies such as Stargardt disease, retinitis pigmentosa, choroideremia, white dot syndromes, and drug toxicities such as hydroxychloroquine toxicity.

    Prior/Concomitant Prohibited Therapy
  6. Use of any new prescription therapies or vaccines within 7 days prior to the study drug administration.
  7. Drugs with potential phototoxicity per Package Insert are prohibited within 48 hours or 5 half-lives, whichever is longer, prior to first study drug until End-of-study (EOS) visit, except for those required for treatment of underlying disease. Examples of such drugs include the following: Chloroquine (Aralen), hydroxychloroquine (Plaquenil), Thioridazine (Mellaril), Topiramate (Topamax), vemurafenib, voriconazole, doxycycline, hydrochlorothiazide, amiodarone, furosemide, allopurinol, phenothiazine, and chlorpromazine.

    Prior/Concurrent Clinical Study Experience
  8. Administration of investigational product in another study within 30 days prior to the first study drug administration, or five half-lives, whichever is longer.

    Other Exclusions
  9. Females who are pregnant or breastfeeding.
  10. Ocular media of both eyes are not sufficiently clear to obtain acceptable quality images. Positive urine test for drugs of abuse at screening or Day 1 (healthy subjects only)