FDA Removes Clinical Hold on RespireRX’s CX1739

The FDA removed a clinical hold on RespireRx Pharmaceuticals’ experimental drug CX1739.

The agency placed the hold in December 2015 after toxicity was seen in animal studies. The company subsequently conducted an additional safety study and was cleared to resume trials.

The drugmaker plans to begin Phase 2a clinical trials in March for the treatment of opioid-induced respiratory depression.