Nanterinone [UK 61260], a phosphodiesterase III inhibitor, was undergoing II evaluation with Pfizer in the US for the treatment of heart failure. Nanterinone is a positive inotropic and balanced-type vasodilating drug, only partially based on phosphodiesterase III inhibition. Preliminary data from controlled studies suggest satisfactory long-term efficacy and safety.

Olpimedone was developed as an anti-rheumatic agent and analgesic, however, the drug that has never been marketed. Information about the current use of olpimedone is not available.

Nanafrocin (nanaomycin A) belongs to the class of quinone antibiotics isolated from a strain OS-3966 of Streptomyces rosa var. notoensis. Nanafrocin (nanaomycin A) mode of action is dependent on its reduction by the respiratory chain-linked NADH or flavin dehydrogenase of the organism. The reduced form of nanafrocin (nanaomycin A) is quickly auto-oxidized by molecular oxygen producing singlet molecular oxygen (O2−). The ability to produce O2− is related to the antimicrobial activity of nanafrocin (nanaomycin A).

Naminterol [VAL 479], a phenethanolamine derivative, is a β2 adrenoceptor agonist with bronchodilatory properties. The compound was undergoing phase II clinical trials for asthma in Italy.

Octaverine possesses a spasmolytic activity. Information about the current development of this compound is not available.

Patamostat (E-3123) is a protease inhibitor in vivo and in vitro. Inhibitory activity was shown toward trypsin, thrombin, plasmin, cathepsin-B and kallikrein. Patamostat is effective toward experimental pancreatitis and disseminated intravascular coagulation (animal models).

Litracen revealed very potent thymoleptic properties with a weak sedative action. Melitracen is gradually metabolized to litracen, and after repeated doses of melitracen, the organs will, for the most part, contain the metabolite. Litracen was developed as an antidepressant agent.

Apricoxib, (CS-706, 1) 2-(4-ethoxyphenyl)-4-methyl-1-(4-sulfamoylphenyl)-pyrrole, a small-molecule, orally active, selective COX-2 inhibitor was discovered by investigators at Daiichi Sankyo in 1996. Apricoxib binds to and inhibits the enzyme cyclooxygenase-2 (COX-2), thereby inhibiting the conversion of arachidonic acid into prostaglandins. Apricoxib-mediated inhibition of COX-2 may induce tumor cell apoptosis and inhibit tumor cell proliferation and tumor angiogenesis. COX-related metabolic pathways may represent crucial regulators of cellular proliferation and angiogenesis. Clinical studies demonstrated potent analgesic activity and preclinical studies demonstrated good pharmacokinetics, pharmacodynamics and gastrointestinal tolerability. As an anticancer agent, preclinical studies demonstrated efficacy in biliary tract cancer models and colorectal carcinoma. Phase IIa trial data indicated that apricoxib was a potent analgesic in the treatment of pain in postoperative dental surgery. Apricoxib, a novel once-daily selective cyclooxygenase-2 inhibitor, was investigated in combination with erlotinib for recurrent stage IIIB/IV nonsmall cell lung cancer. Apricoxib plus erlotinib was well tolerated and yielded a 60% disease control rate. A phase II trial was investigating 400 mg/day apricoxib plus 150 mg/day erlotinib in patients selected based on change in urinary PGE-M. However, in 2015 development was abandoned due to poor clinical trial results.

Murabutide is a safe synthetic immunomodulator derived from muramyl dipeptide, the smallest bioactive unit of bacterial peptidoglycan. In contrast to muramyl dipeptide, Murabutide is devoid of pyrogenic activity and lacks somnogenic activity. Murabutide acts as a ligand for the intracellular receptor NOD2 and has the capacity to synergize with selected therapeutic cytokines to drive the release of Th1 cytokines. Murabutide has been found to suppress human immunodeficiency virus type-1 (HIV-1) replication, in macrophages, through regulated expression of cellular factors needed at different steps in the virus replication cycle.