"Clinical trials should have only one primary endpoint -- hence the "primary" designation. The primary endpoint should be the most meaningful result in a clinical trial. An example of a primary endpoint in cancer clinical trials is survival. Survival has long been considered the "gold standard" endpoint for cancer therapies, based on the importance of survival to cancer patients. Other results that contribute to the interpretation of the clinical trial are then considered "secondary endpoints." A clinical trial can have, and often does have, many secondary endpoints. Still, when a clinical trial attempts to capture too many endpoints, complications can arise that impede the critical goal of answering a primary question. If multiple endpoints yield conflicting results, the study cannot be interpreted meaningfully. Multiple endpoints also increase the chance of a Type 1 error (when a difference is shown when there is no actual difference)."
>>>"Now this is confusing, to say the least! If OS is more important, then why didn't the SPA designate OS the primary endpoint and DRR the secondary endpoint?"<<<
Shirley, Your question has been asked and answered already, but I will answer again.
While the FDA considers Overall Survival as the most important of all endpoints, they are willing to grant other endpoints so that trials can be conducted quicker and enrolled faster.
There are numerous studies being conducted in the Oncology area, where the FDA has granted a primary endpoint other than OS, so as to help speed up the ability to get drugs through the process.
That does NOT mean that they NO longer consider OS to be of the most importance.
Just because your Cardiologist prescribes that you take Lovaza capsules (fish oil), to protect your cardio vascular system, does NOT mean that it is better than eating a diet high in fatty fish.
There are a lot of things that "WE" do in society( such as using PFS progression free survival rather than actual OS) to make it easier and quicker to accomplish a task.
Eating an orange is much healthier than drinking non pulp orange juice. Eating a balanced diet that is at least half from fruits and vegetables is healthier than taking vitamin pills to make up for a lousy diet.
DRR is a SURROGATE endpoint for OS..... It is NOT better!
Using DRR as the primary endpoint, which is a form of progression free survival, was granted by the FDA so that Vical could more easily enroll and complete a trial.