In clinical trials, different "endpoints" are used to measure how well a treatment works.

Primary endpoints are the main goals of the study — think of them as the big question the trial is trying to answer, such as how long the treatment keeps myeloma from growing (PFS) or how long patients live (OS). These are the key results the FDA and other organizations use when deciding if a treatment should be approved.

Secondary endpoints go a bit further and help give a bigger picture of the treatment’s impact. These might look at things like how long a patient's response lasts (duration of response or DoR), whether myeloma cells are still detectable after treatment (minimal residual disease or MRD negativity), or how the treatment affects daily life and well-being (quality of life or QoL). They add more detail and help show the overall effects of a treatment.

Myeloma specialists, like Dr. Ola Landgren, break down primary and secondary endpoints of myeloma clinical trials in the video from HealthTree University here: