Arno Therapeutics Inc operates as a biopharmaceutical company. It develops drug candidates to treat patients with cancer and other life-threatening diseases. It develops pre-clinical and clinical-stage product under the following name: Onapristone, AR-42, and AR-12. Onapristone is indicated for endometrial, prostate and breast cancer indications, AR-42 is provided for hematological malignancies and solid tumors indications and AR-12 is offered for solid tumors and hematological malignancies, and various anti-microbial targets.