Comment by dgacmu

They're determining safety and tolerability, not efficacy. For this, they just need adequately compensated trial volunteers who take one of several different doses of the medicine and track/report symptoms, have some doctor visits, and get a lot of blood drawn. Oh, and for this one, sample urine and feces. You can read the clinical trial doc: https://clinicaltrials.gov/ct2/show/NCT05628961