Randomized, double-blind, placebo-controlled study to characterize the immune response after repeated KLH immunizations in healthy volunteers

1. Signed informed consent prior to any study-mandated procedure;
2. Healthy male subjects, 18 to 45 years of age (inclusive). Health status is
defined by absence or evidence of any active or chronic disease following a
detailed medical and surgical history, a complete physical examination
including vital signs, 12-lead ECG, haematology, blood chemistry, blood
serology and urinalysis. In the case of uncertain or questionable results,
tests performed during screening may be repeated before randomization to
confirm eligibility or judged to be clinically irrelevant for healthy subjects;
3. Body mass index (BMI) between 18 and 30 kg/m2, inclusive, and with a minimum
bodyweight of 50 kg;*
4. Fitzpatrick skin type I-III.
5. Has the ability to communicate well with the Investigator in the Dutch
language and willing and able to comply with the study restrictions.

1. Evidence of any active or chronic disease or condition that could interfere
with, or for which the treatment of might interfere with, the conduct of the
study, or that would pose an unacceptable risk to the subject in the opinion of
the investigator (following a detailed medical history, physical examination,
vital signs (systolic and diastolic blood pressure, pulse rate, body
temperature) and 12-lead electrocardiogram (ECG)). Minor deviations from the
normal range may be accepted, if judged by the Investigator to have no clinical
relevance;
2. Clinically significant abnormalities, as judged by the Investigator, in
laboratory test results (including haematology panel, chemistry panel and
urinalysis). In the case of uncertain or questionable results, tests performed
during screening may be repeated before randomization to confirm eligibility or
judged to be clinically irrelevant for healthy subjects;
3. Positive Hepatitis B surface antigen (HBsAg), Hepatitis C antibody (HCV Ab),
or human immunodeficiency virus antibody (HIV Ab) at screening;
4. Any disease associated with immune system impairment, including immune
mediated diseases, transplantation patients and any confirmed significant
allergic reactions (urticaria or anaphylaxis) against any drug or multiple drug
allergies (non-active hay fever is acceptable);
5. Use of any medications (prescription or over-the-counter [OTC]), within 21
days prior to initial KLH immunization, or less than 5 half-lives (whichever is
longer). An exception is made for paracetamol (up to 4 g/day). Other exceptions
will only be made if the rationale is clearly documented by the Investigator;
6. Use of immunosuppressive or immunomodulatory medication within 30 days prior
to initial KLH immunization or planned to use during the course of the study;
7. Any vaccination within 30 days prior to initial KLH immunization or planned
during the course of the study with exception of vaccination for SARS-CoV-2;
8. Vaccination for SARS-CoV-2 within 14 days prior to initial KLH immunization,
or planned during the course of the study;
9. Use of antibiotic therapy within 90 days prior to initial KLH immunization
or planned to use during the course of the study;
10. Alcohol will not be allowed from at least 24 hours before screening and
each scheduled visit. At other times during the course of the study no more
than 2 units of alcohol per day will be allowed;
11. History of abuse of addictive substances (alcohol, illegal substances) or
current use of more than 14 units alcohol per week, drug abuse, or regular user
of sedatives, hypnotics, tranquillisers, or any other addictive agent;
12. Positive test for drugs of abuse or alcohol breath test at screening;
13. Smoker of more than 5 cigarettes per day prior to screening or who use
tobacco products equivalent to more than 5 cigarettes per day and unable to
abstain from smoking whilst in the unit.
14. Previous known exposure to Immucothel® or KLH;
15. History of Schistosomiasis (infection with Schistosoma parasite);
16. Participation in an investigational drug or device study (last dosing of
previous study was within 90 days prior to initial KLH immunization of this
study and participation more than 4 times a year);
17. Loss or donation of blood over 500 mL within 90 days prior to screening or
intention to donate blood or blood products during the study;
18. Have any current and / or recurrent clinically significant skin condition
at the treatment area (i.e. atopic dermatitis); including tattoos;
19. Any known factor, condition, or disease that might interfere with treatment
compliance, study conduct or interpretation of the results such as drug or
alcohol dependence or psychiatric disease.