RE:RE:RE:RE:RE:RE:How does Accelerated Approval work " Breakthrough therapy designation (BTD) is granted for drugs aimed at treating serious or life-threatening diseases for which there is promising preliminary clinical evidence that shows superiority over current therapies. BTD does not guarantee future positive results in trials or successful approval, given that this designation is based only on preliminary data. As additional data are acquired, a BTD drug may no longer show superiority over current drugs and the designation may be rescinded to conserve agency resources. Preliminary clinical data are expected to be provided with the investigational new drug (IND) application or no later than the phase 2 meeting, and these data must demonstrate the superiority of the new drug by direct comparison with the current therapy or with valid historical data. "