Fenretinide (N-(4-hydroxyphenyl)retinamide; 4-HPR) (INN) is a synthetic retinoid derivative.

It has been investigated for potential use in the treatment of cancer, as well as in the treatment of cystic fibrosis,[1] rheumatoid arthritis, acne, psoriasis, and has been found to also slow the production and accumulation of a toxin that leads to vision loss in Stargardt's patients.

[2] In cancer studies, Fenretinide treatment may cause ceramide (a wax-like substance) to build up in tumor cells and is associated with the accumulation of reactive oxygen species (ROS), resulting in cell death through apoptosis and/or necrosis.

[4][5] Phase III clinical trial data has suggested that fenretinide reduces breast cancer relapse in pre-menopausal women.

Specific types of cancer under investigation include or have included ovarian, prostate, cervical, lung, renal, bladder, breast, glioma, skin, head and neck carcinoma, non-Hodgkin's lymphoma, neuroblastoma, and Ewing's sarcoma.