Structures of rucaparib, 18F fluorthanatrace
(18F-FTT) and 125I KX-1. Fluoroethyl and iodo
moieties were added to rucaparib scaffold to enable radiofluorination
and radioiodination. Both radioactive analogs exhibit high binding
affinities toward PARP-1. The PET radiotracer, 18F-FTT, was
used for the preclinical and clinical imaging studies, while
125I KX-1 (18F-FTT analog) was used for PET
tracer evaluation. FDA = Food and Drug Administration, PARPi = poly
(adenosine diphosphate–ribose) polymerase inhibitor.