M40419 (now GC4419) is a Mn(II)-containing pentaazamacrocyclic selective superoxide dismutase mimetic. It is a first-in-class, small molecule enzyme mimetic that converts superoxide to hydrogen peroxide and molecular oxygen. GC4419 is currently being evaluated in an ongoing randomized Phase 2 clinical trial to assess its effect on the incidence, severity and duration of severe oral mucositis (OM) when given to patients with squamous cell cancers of the head and neck in combination with radiation and chemotherapy. GC4419 has received Breakthrough Therapy and Fast Track designations from the U.S. Food and Drug Administration.

Capeserod is benzodioxanoxadiazolone derivative patented by patented by pharmaceutical company Synthelabo S. A. as a novel 5-hydroxytryptamine4 receptor partial agonist with potent cognition-enhancing properties. In cells expressing the 5-HT4(b) and 5-HT4(e) splice variants, Capeserod acted as a partial agonist, stimulating cAMP prodn. with a maximal effect of 40 to 50% of serotonin. However, in the rat esophagus preparation, Capeserod acted as a 5-HT4 antagonist with a pKb of 8.81. In addition, Capeserod potently improved performance in several tests of learning and memory. In the object recognition task, it improved retention at 24 h when administered i.p. or p.o. (0.001-0.1 mg/kg). This effect was antagonized by the 5-HT4 antagonist SDZ 205,557, itself without effect, demonstrating that the promnesic effects of Capeserod are mediated by 5-HT4 agonism. Capeserod also reversed the cognitive deficits of aged rats in the linear maze task and the scopolamine-induced deficit of mice in the water maze task. Furthermore, the combined administration of an inactive dose of Capeserod with the cholinesterase inhibitor rivastigmine resulted in a significant promnesic effect, suggesting a synergistic interaction. Capeserod was devoid of unwanted cardiovascular, gastrointestinal, or central nervous system effects with doses up to more than 100-fold higher than those active in the cognitive tests. These results characterize Capeserod as a novel promnesic agent acting via 5-HT4 receptors, with an excellent preclinical profile.

N-acetylmannosamine (ManNAc), a hexosamine monosaccharide, is the first committed biological precursor of Neu5Ac. N-acetylmannosamine is being investigated as a potential treatment for GNE myopathy. N-acetylmannosamine has being reported to improve the cognitive function in aged animals. It has potential therapeutic application for cognitive dysfunction. N-acetylmannosamine is under investigation for GNE myopathy.

Resiquimod is an imidazoquinolinamine and Toll-like receptor (TLR) agonist with potential immune response modifying activity. Resiquimod exerts its effect through the TLR signaling pathway by binding to and activating TLR7 and 8 mainly on dendritic cells, macrophages, and B-lymphocytes. This induces the nuclear translocation of the transcription activator NF-kB as well as activation of other transcription factors. This may lead to an increase in mRNA levels and subsequent production of cytokines, especially interferon-alpha (INF-a) and other cytokines, thereby enhancing T-helper 1 (Th1) immune responses. In addition, topical application of resiquimod appears to activate Langerhans' cells, leading to an enhanced activation of T-lymphocytes. Resiquimod is used as a topical gel[1] in the treatment of skin lesions[2] such as those caused by the herpes simplex virus[3][4] and cutaneous T cell lymphoma. Due to its immunostimulatory activity, this agent may potentially be used as a vaccine adjuvant.

Omtriptolide (previously known as PG490-88 or F60008), an immunosuppressant that has been shown to be the safe and potent antitumor agent and it has been approved entry into Phase I clinical trial for the treatment of prostate cancer in the USA. In addition, the drug is participating in phase I clinical trial for the treatment of myeloid leukemia. Experiments on animals have shown omtriptolide was highly effective in the prevention of murine graft-versus-host disease (GVHD). The immunosuppressive effect of the drug was mediated by inhibition of alloreactive T cell expansion through interleukin-2 production. However, this study was discontinued. Recently published article has shown omtriptolide possesses the potential as a prophylactic agent to prevent ischemia/reperfusion (I/R)-induced lung injury.