Equivalence Trials

- to check that change in formulation does not change the efficacy of the compound
- to assess whether generic and original drugs have identical therapeutic effectiveness

### Clinical Equvalence
- based on clinical outcomes

### Bioequvalence
- based on pharmacokinetics (PK) parameters, which is clearly defined and have lower variability
- basic assumption: the same # of drug compound molecules occupying he same # of receptors will have similar clinical effects.

### Noninferiority Trials
- where superiority trials would not be appropriate due to ethical or practical constraints
- where efficacious treatments already exits and the demonstration of noinferiority, as well as secondary benefits, is sufficient for regulatory approval.
- to demonstrate that the new treatment is not worse than the comparator by more than a specified margin, delta.
- the choice of delta is critically important and needs to be prespecified and justified when designing the trial.