Ann: Ethics Approval Received to start Ph 1 Clinical of IHL 675A, page-17

I've worked in this field for the last 17 years so here's how drug development goes, in general:

Ph 1 - Small number of Healthy Volunteers to test safety and tolerability
Ph 2 - Dose finding studies in larger group of patients (with the condition to be studied). This will guide the company to see which dose is the appropriate balance between efficacy and safety/tolerability
Ph 3 - Larger confirmatory trials with the dose from Ph 2, typically compared to the current standard of care. If there is no current standard of care, it may be compared against a placebo

If a drug makes it through Ph 3 - it is then submitted for regulatory approval with the FDA, TGA etc.

Ph 4 - Post marketing studies - i.e. when the drug is registered, the company (and sometimes regulatory authorities) would like to know how does the drug work and how is it tolerated in a larger number of patients.