Cancer drugs are prescribed to the patients based on results from trials. Usually, these are superiority trials meaning the cancer drugs prove that they are better than the treatment we already have.

Recently, more and more cancer drugs are approved on the basis of non-inferiority trials. In these trials, the cancer drugs only prove that they are not worse than the treatment we already have ( instead of proving they are better). Such an approach is considered justified if the new drug provides any other benefit such as lower cost, easy to administer or improved quality of life.