Companion Diagnostics For Breakthrough Drugs Also Getting Swift Attention, FDA Says-graysheet: CDRH is using its regulatory flexibility to ensure that development and evaluation of companion diagnostics for “breakthrough” therapies keep pace with the speedier timelines envisioned for such drugs under the FDA Safety and Innovation Act. Speaking at a Sept. 6 conference on drug/diagnostic co-development for breakthrough therapies, CDRH officials highlighted a number of formal and informal actions they are taking or potentially could take to prevent the slow development of companion diagnostics from impeding the speed at which breakthrough therapies can reach the market.