The FDA has granted Siemens Medical Solutions of Hoffman Estates, Ill., an investigational new drug exemption to conduct a Phase I clinical trial on one of its molecular imaging biomarkers. The marker,18F 3'-fluoro-3'-deoxythymidine, could help monitor the proliferation of cancer cells in the context of cancer therapy assessment. Researchers from Memorial Sloan-Kettering Cancer Center in New York will carry out the study at their facility with colleagues from Siemens as part of a PET imaging biomarker research collaboration agreement.