SPI-77 (Sequus Pharmaceuticals, Inc.)

SPI-77 (also known as STEALTH cisplatin) is a pegylated liposomal formulation of the platinum-based chemotherapeutic agent cisplatin. Developed by Sequus Pharmaceuticals (later acquired by ALZA Corporation and Johnson & Johnson), it utilizes 'STEALTH' technology—liposomes coated with polyethylene glycol (PEG)—to evade immune detection and prolong circulation time in the bloodstream. This delivery system was intended to enhance tumor accumulation via the enhanced permeability and retention (EPR) effect while minimizing systemic toxicities like nephrotoxicity and ototoxicity. Once at the tumor site, the encapsulated cisplatin is released and exerts its cytotoxic effect by binding to DNA, forming intra-strand and inter-strand cross-links that disrupt DNA replication and transcription. Despite successfully reducing toxicity in clinical trials for ovarian cancer, non-small-cell lung cancer (NSCLC), and head and neck cancer, SPI-77 failed to demonstrate significant clinical efficacy, leading to the termination of its development.

Other names

STEALTH cisplatinliposomal cisplatinpegylated liposomal cisplatin