|BIA 10-2474 was believed to be reversible inhibitor of fatty acid amide hydrolase (FAAH). It was the cause of a disastrous clinical trial in France which left one participant dead and several others with serious neurological adverse events. The compound is claimed in patent WO2010074588 . The structure of BIA 10-2474 was disclosed in a clinical trial protocol with EudraCT No: 2015-001799-24. Pharmacological inhibition of FAAH was being investigated in the search for novel analgesic drugs [4-6]. More information surrounding this compound and its unfortunate clinical trial outcome is available in two blogposts by our curator Christopher Southan (The unfortunate case of BIA-10-2474 and Molecular details related to BIA 10-2474).
Subsequent analysis of BIA 10-2474's pharmacology is reported by van Esbroeck et al. (2017) . This anaylsis suggests that BIA 10-2474's interaction with FAAH is in fact irreversible. Using activity-based protein profiling (ABPP), this same study reveals that BIA 10-2474 (and its metabolite BIA 10-2639) engages numerous human off-targets including FAAH2 and several lipid serine hydrolases, such as ABHD6, ABHD11, LIPE, and PNPLA6, and xenobiotic drug-metabolizing enzymes CES1, CES2, and CES3, with greater inhibition of ABHD6 and CES2 compared to PNPLA6. The authors postulate that BIA 10-2474 may act to dramatically alter brain lipid metabolism and that this action may have contributed to the compound's neurotoxicity. In the same assays, this action was not replicated by the clinically tested FAAH inhibitor PF-04457845.
Update: August 2018. BIAL have finally published a primary paper describing their internal characterisation of BIA-10-2474 along with the SAR of that series but only with %inhibition rather than IC50 values .