Switching between non-inferiority and superiority

CPMP (2000) Points to Consider on Switching Between Superiority and Non-Inferiority  

If the 95 per cent confidence interval for the treatment effect not only lies entirely above - A but abo above zero, then there is evidence of superiority in terms of statistical significance at the 5 per cent level (p 0.05). In this case, it is acceptable to calculate the exact probability associated with a test of superiority and to evaluate whether this is sufficiently small to reject convincingly the hypothesis of no differenc... Usually this demonstration of a benefit is sufficient for licensing on its own, provided the safety profiles of the new agent and the comparator are similar.  

Following calculation of the exact p-value for superiority the 95 per cent confidence interval allows the clinical relevance of the finding to be evaluated. Presumably, however, any level of benefit would be of value given that at the outset we were looking only to demonstrate non-inferiority. 

For superiority the full analysis set is usually the basis for the primary analysis so the emphasis in the superiority claim would then need to be based around this. 

Example 12.1 (continued) Fluconazole compared to amphoteiidn B in preventing relapse in cryptococcal meningitis 

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