RLA-4842

RLA-4842 is a research-stage ferrous iron-activatable drug conjugate (FeADC) designed for the selective treatment of metastatic castration-resistant prostate cancer (mCRPC). It functions as a prodrug consisting of the antiandrogen RD58 (an analogue of enzalutamide) conjugated to a 1,2,4-trioxolane moiety via an N,N'-dimethylethylene-diamine linker. The compound leverages the elevated levels of labile ferrous iron (Fe2+) characteristic of the mCRPC tumor microenvironment for site-specific activation. Upon reaction with Fe2+, the trioxolane trigger undergoes a Fenton-like reaction to release the active RD58 payload, which then binds to and inhibits the androgen receptor. This targeted delivery mechanism is intended to improve the therapeutic index of antiandrogen therapy by concentrating the active drug within the tumor while minimizing systemic exposure and associated toxicities, such as the central nervous system effects often seen with second-generation androgen signaling inhibitors.