ABT-925, also known as A-437203 or as LU-201640, is a selective dopamine D3 receptor antagonist which was under development for the treatment of schizophrenia but was never marketed. It is taken orally.
The drug shows affinity for the dopamine D3 receptor and to a much lesser extent for the dopamine D2 receptor, with Ki values of 0.97–3.2nM and 75nM, respectively, and with 45- to 120-fold selectivity for the dopamine D3 receptor over the dopamine D2 receptor. It showed little activity in classical tests of antipsychotic-like activity in rodents, for instance inhibition of methamphetamine-induced hyperlocomotion and inhibition of apomorphine-induced climbing behavior. The drug does not produce catalepsy and does not affect prolactin levels in rodents. The occupancy of the dopamine D3 receptor by ABT-925 has been studied in humans.
ABT-925 was first described in the scientific literature by 1997. At the time, it was the most potent and selective dopamine D3 receptor antagonist yet known. In addition, the drug has been said to have been the first selective dopamine D3 receptor antagonist. It was under development by Abbott Laboratories. The drug reached phase 2 clinical trials prior to the discontinuation of its development. ABT-925 is known to have been in active phase 2 trials between 2001 and 2007. It failed to show antipsychotic effectiveness in acute schizophrenia in a phase 2 trial published in 2011.
See also List of investigational antipsychotics
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