Enclomiphene (Androxal), in development by Repros Therapeutics Inc, is a non-steroidal estrogen receptor antagonist that promotes gonadotropin-dependent testosterone secretion by the testes. Enclomiphene constitutes the trans-stereoisomer of clomiphene citrate, a drug that has been widely prescribed for several decades for the treatment of female ovulatory dysfunction. Because of the antagonistic effects of enclomiphene, the drug has the potential to increase serum testosterone levels in men with secondary hypogonadism by restoring physiological endogenous testosterone secretion while maintaining testicular volume and, potentially, spermatogenesis. In clinical trials conducted to date, enclomiphene demonstrated significant efficacy in the physiological restoration of testosterone levels in males with secondary hypogonadism. The compound also exhibited an unanticipated favorable effect on fasting plasma glucose; this result has been accompanied by rapidly accumulating evidence from other researchers for a bidirectional relationship between low serum testosterone and obesity/metabolic syndrome (syndrome X) in men.

Piquindone is an antipsychotic pyrroloisoquinoline derivative that binds to dopamine D2 receptors. It is a potent D-2 antagonist. It has a low potential for extrapyramidal effects and tardive dyskinesia. Piquindone exhibited relatively weaker cataleptogenic and antistereotypic activity than haloperidol, and had minimal activity in a rat chronic stereotypy model of receptor supersensitivity. Piquindone almost as potent as haloperidol, with fewer or less intense extrapyramidal effects and low potential for tardive dyskinesia. Piquindone led to moderate but significant improvements in the positive symptoms of schizophrenia and to improvements in negative symptoms just below the level of statistical significance. Therapeutic efficacy of a piquindone antagonist in Tourette Syndrome can be achieved without production of disabling extrapyramidal-side effects.

Ciladopa, is a troponylpiperazine derivative and dopamine agonist that has been shown to influence dopaminergic mechanisms in animals. Preclinical pharmacological studies have suggested that it has antiparkinsonian activity similar to that of bromocriptine but without many of the troublesome side effects. Unfortunately in some clinical trials no significant differences was found among the treatment groups and placebo.

Tesevatinib (EXEL-7647 or XL647) was optimized as an inhibitor of a spectrum of growth-promoting and angiogenic receptor tyrosine kinases (RTKs) to simultaneously block tumor growth and vascularization. In particular, Tesevatinib potently inhibits the EGF/ErbB2, VEGF, and ephrin RTK families. The drug is being developed by Kadmon Corporation under licence from Symphony Evolution (Symphony Capital Partners). Kadmon is developing tesevatinib for the treatment of autosomal polycystic kidney disease and solid cancers.

Tiospirone (TSP) is an atypical antipsychotic drug. Tiaspirone appeared to be a promising antipsychotic agent as it didn`t cause extrapyramidal syndromes. It has 5HT-2 antagonistic properties as well as affinity for D2, 5HT-1a, 5HT-6 and sigma receptors. Tiospirone was in phase III clinical trials for the treatment of attention hyperactivity disorder with Mead Johnson in the USA but its development appears to have been discontinued.

Crenolanib is an orally active, highly selective, small molecule, next generation inhibitor of platelet-derived growth factor receptor (PDGFR) tyrosine kinase. Crenolanib, manufactured by Arog Pharmaceuticals in Dallas, is taken orally with chemotherapy. The compound is currently being evaluated for safety and efficacy in clinical trials for various types of cancer, including acute myeloid leukemia (AML), gastrointestinal stromal tumor (GIST), and glioma. Crenolanib is an orally bioavailable, selective small molecule inhibitor of type III tyrosine kinases with nanomolar potencies against platelet-derived growth factor receptors (PDGFR) (isoforms PDGFRα and PDGFRβ) and Fms-related tyrosine kinase 3 (FLT3). Besides PDGFR and FLT3, crenolanib does not inhibit any other known receptor tyrosine kinase (RTK) (e.g. VEGFR and FGFR) or any other serine/threonine kinase (e.g., Abl, Raf) at clinically achievable concentrations. Preclinical trials have shown Crenolanib to be active in inhibiting both wild-type and mutant FLT3. Crenolanib is cytotoxic to the FLT3/ITD-expressing leukemia cell lines Molm14 and MV411, with IC50s of 7 nM and 8 nM, respectively. In immunoblots, crenolanib inhibited phosphorylation of both the wild-type FLT3 receptor (in SEMK2 cells) and the FLT3/ITD receptor (in Molm14 cells) in culture medium with IC50s of 1-3 nM. Importantly, the IC50 of crenolanib against the D835Y mutated form of FLT3 was 8.8 nM in culture medium. Furthermore, crenolanib had cytotoxic activity against primary samples that were obtained from patients who had developed D835 mutations while receiving FLT3 TKIs. In vitro, the IC50 of crenolanib for inhibition of FLT3/ITD in plasma was found to be 34 nM, indicating a relatively low degree of plasma protein binding. From pharmacokinetic studies of crenolanib in solid tumor patients, steady state trough plasma levels of roughly 500 nM were found to be safe and tolerable, suggesting that crenolanib could potentially inhibit the target in vivo. Crenolanib has no significant activity against c-KIT, which may be an advantage in that myelosuppression can be avoided.1Furthermore, there was no evidence of QTc prolongation in patients treated with crenolanib. In summary, crenolanib offers a number of advantages over other FLT3 TKIs. Clinical trials of crenolanib in AML patients with FLT3 activating mutations are being planned.

Epetirimod (S-30563 or TAK-851) is an immunostimulant. The compound is structurally related to the marketed topical imidazoquinoline drug, imiquimod, an agonist of Toll-like receptor 7. Epetirimod was under development with Takeda Pharmaceutical as a topical treatment for cervical high-risk HPV infection and cervical dysplasia. Takeda has discontinued epetirimod development as it did not meet the predefined efficacy end points in a US Phase II trial.

Metoserpate (SU9064) is a sedative drug used in veterinary. PACITRAN (metoserpate hydrochloride) is indicated as a tranquilizer in stressed poultry.

Delmadinone is a steroid with progestogenic, anti-androgenic and weak glucocorticoid action, synthesized in Syntex S.A. Acetate ester of delmadinone is used in veterinary under tradenames Tardak for cats and dogs for the treatment of excessive or aberrant sexual behaviour, including vagrancy, for the relief of prostatic hypertrophy, circum-anal tumors and for the treatment of certain forms of aggressiveness, nervousness, epileptiform seizures and corticosteroid-resistant pruritus. Delmadinone acetate blocks androgen receptors inhibit 5-reductase, which catalyzes the transformation of testosterone to the more potent androgen 5-dihydrotestosterone and decreases the production of testosterone by inhibiting gonadotropin release.

Indoxole is phenylindene derivative patented by Mead Johnson & Co. as antidepressants. Indoxole have potent activity in the prevention of reserpine-induced ptosis in mice.