Drug-induced phospholipidosis: Prediction, detection, and mitigation strategies

Abstract

In the fast-paced and resource-intensive process of the discovery and development of novel medicines, issues pertaining to safety often appear leading to a loss of valuable resource and time for the pharmaceutical industry. Drug-induced phospholipidosis (DIPL) is one such issue that often shows up late in the discovery process, especially after repeat-dose toxicity studies in animals. DIPL is long debated as to whether it is a manifestation of toxicity or just an adaptation response due to drug accumulation in a tissue. Irrespective of the argument on either side, the conservative approach is to avoid DIPL due to closely associated toxicities and pathological similarity with phospholipid storage disorders. Therefore, high importance is given to predict the potential of a novel drug compound/series and to identify/confirm their potential to induce phospholipidosis (PLD) to help steer structure-activity relationship (SAR) to avoid this potential early in discovery. Several drugs with similar physicochemical properties are known to cause PLD, and these are generally referred to as cationic amphiphilic drugs (CADs). Using these known CADs, several in silico, in vitro, and hybrid methods have been developed to predict the potential to induce PLD. Also, a few biomarkers have shown promise of being able to monitor for DIPL during an ongoing animal study without the need to confirm PLD in tissues from necropsy. Early prediction, detection, and mitigation strategies are of immense value in developing novel medicines without PLD-inducing potential.