Oglemilast (GRC-3886), is a potent and selective PDE4 inhibitor (IC50: 2.5 nM (PDE4B) and 1.7 nM (PDE4D)). Oglemilast is in phase II clinical trials for the treatment of asthma and chronic obstructive pulmonary disease (COPD). Oglemilast was originally developed by Glenmark Pharmaceuticals, and licensed to Forest (acquired by Actavis in 2014) for the rights in North America in 2004. Teijin Pharma obtained the rights of the compound in Japan in 2005.

Cimemoxin (INN), or cyclohexylmethylhydrazine, is a hydrazine monoamine oxidase inhibitor and antidepressant which was never marketed. Currently, Cimemoxin used as a reagent in organic synthesis.

Carbazeran is a potent PDE-II and PDE-III inhibitor. Potently inhibits cAMP hydrolysis. Shows chronotropic and inotropic effect in vivo (EC50 = 100 μM, ionotropic effects, independent of adrenergic mechanisms). Carbazeran is a potent cardiac stimulant. Phosphodiesterase inhibition and elevation of intracellular cyclic AMP concentration may be involved, at least in part, in carbazeran`s cardiac effect.

Intoplicine is a pyrido[4,3-b]indole derivative patented by Rhone-Poulenc Sante as an antitumor agent. Intoplicine acts via inhibiting DNA nicking and closing reactions by stabilizing the cleavable complex, a transient intermediate in the religation reaction involving topoisomerase I and II and DNA. Intoplicine was active in a range of solid tumors in mice, including colon adenocarcinoma 51, MA16/C, MA14/A, MA13/C, early-stage pancreatic ductal adenocarcinoma 03, Glasgow osteogenic sarcoma and B16 melanoma. In Phase I clinical studies using a 24-h infusion, the maximum tolerated dose was established as 270 mg/m2 every 3 weeks, with hepatotoxicity rather than myelosuppression being dose-limiting, although cardiac toxicity was also seen. Preclinical cytotoxic concentrations were not achieved at the dose levels studied and clinical development was discontinued.

Odanacatib is a potent, selective, and neutral cathepsin K inhibitor, an enzyme involved in bone resorption. Merck & Co was developing odanacatib, a once-weekly, oral Odanacatib, for the treatment of postmenopausal osteoporosis and osteoporosis in men. Merck & Co. has discontinued development of its cathepsin K inhibitor odanacatib, citing an increased risk of cardiovascular events for the osteoporosis drug.

Wyeth was developing the small molecule plasminogen activator inhibitor-1 (PAI-1) antagonist aleplasinin for the treatment of Alzheimer's disease in the US. PAZ-417 inhibits PAI-I (Plasminogen activator inhibitor-1), thereby increasing the activation of plasminogen to form plasmin. There is some evidence that plasmin can increase the cleavage of amyloid precursor protein at the alpha cleavage site, which could reduce the formation or increase the clearance of amyloid beta, a suspected culprit in Alzheimer's disease. However, it`s development for Alzheimer's disease treatment was discontinued.

Begacestat (GSI-953 or PF-5212362), a gamma-secretase inhibitor (GSI) that selectively inhibits cleavage of APP over Notch, was discovered for the treatment of Alzheimer's disease. The drug has shown promise results in phase I clinical trials, however further studies were discontinued.

Amipizone is an antithrombotic agent. It is antihypersensive and platelet-aggregation inhibitor. Amipizone is a pyridazinone that is active as cardiotonic agent.

Sinefungin, a natural nucleoside isolated from cultures of Streptomyces incarnatus and S. griseolus, is structurally related to S-adenosylhomocysteine and S-adenosylmethionine. Sinefungin is a DNA methyltransferase (DNMT) inhibitor (IC₅₀ = 0.1 - 20 uM). Sinefungin has been shown to inhibit the development of various fungi and viruses, but its major attraction to date resides in its potent antiparasitic activity. This compound has been reported to display antiparasitic activity against malarial, trypanosomal, and leishmanial species. Sinefungin inhibits pneumococcal biofilm growth in vitro and colonization in vivo, decreases AI-2 production, and downregulates luxS, pfs, and speE gene expressions. Sinefungin was significantly suppressive against both L. donovani and L. braziliensis panamensis infections in hamsters when compared with meglumine antimonate. An immunosuppressed rat model was used to investigate the anti-Cryptosporidium parvum activity of sinefungin. In infected animals, oral sinefungin therapy resulted in a dose-related suppression of oocyst shedding, which correlated with oocyst disappearance from ileal sections. When administered prior to or on the day of oocyst challenge, sinefungin successfully prevented infection. These data suggest that sinefungin could be considered as a candidate molecule in the treatment of human cryptosporidiosis, considered to be the most significant enteric opportunistic infection in AIDS.

2-Cyano-3,12-dioxooleana-1,9-diene-28-oic acid (CDDO, also known as Bardoxolone) is a synthetic triterpenoid that displays potent anti-inflammatory and antitumorigenic activities. CDDO was in the clinical trial phase I for the treatment patients with Solid tumors and leukemia, but that studies were discontinued. It is known, that CDDO blocks the cellular synthesis of inducible nitric oxide synthase and inducible COX-2. In addition, was discovered, that CDDO disrupted intracellular redox balance and thereby induce apoptosis. Moreover, CDDO is a ligand for peroxisome proliferator-activated receptor that it induces genes regulated by Nrf2, including heme oxygenase-1 and eotaxin-1, which play a role in antioxidant response element signaling activity.