Ziopharm Oncology Inc. /zigman2/quotes/200291745/composite ZIOP -1.28% said Monday the U.S. Food and Drug Administration has placed a clinical hold on a Phase 1 trial of a treatment for cancer. The trial sought to evaluate CD19-specific CAR-T therapies made with Sleeping Beauty technology as an investigational treatment for patients with relapsed or refractory, CD19 leukemias and lymphomas, the company said in a statement. Ziopharm specializes in developing therapies to treat a range of cancers, using Sleeping Beauty, a non-viral approach to genetically modify chimeric antigen receptor (CAR(+) ) and T-cell receptor (TCR(+) ) T cells, which target specific antigens in blood cancers and neoantigens in solid tumors. "CAR(+) T cells very-rapidly manufactured with the Sleeping Beauty platform for this third-generation trial are designed to co-express CD19-specific chimeric antigen receptor, or CAR, membrane-bound interleukin 15 and a safety switch," it said. The FDA is seeking additional information from the company, which is expects to provide in a timely manner, it said. Shares fell 7% premarket on the news, but are up about 3.9% in 2018, matching the S&P 500's /zigman2/quotes/210599714/realtime SPX +1.36% gain.