The study was designed to measure progression-free survival, which is a measurement of the time from the start of treatment until the disease gets worse or the patient dies, and overall survival, which is a measurement of time from the start of treatment until death.

WSJ: Roche Breast-Cancer Treatment Advances

In a tougher measure of efficacy that takes into account how long patients lived, called progression-free survival, Thalomid more than doubled the length of time patients lived, to 57 weeks.

FORBES: Thalomid Fuels Celgene's Rise