PF-03654746 is a potent, selective antagonist of the human H3 receptor, developed by Pfizer. It was in the clinical trial phase II for the treatment of excessive daytime sleepiness (EDS) associated with narcolepsy, Tourette syndrome as well as potential anti-allergy applications and in phase I of clinical trial for the treatment of Schizophrenia and Alzheimer's disease, but these investigations were discontinued.

Losoxantrone is an anthrapyrazole that induces both single and double strand breaks in DNA and is a potent inhibitor of DNA synthesis. The drug is in clinical trials for the treatment of breast cancer and of prostate cancer that is refractory to androgen ablation. Acute toxicity is negligible. Losoxantrone may be less cardiotoxic than doxorubicin. Up to 40% of patients encounter alopecia. 3% of patients develop congestive heart failure. Losoxantrone had been in phase II clinical trial for the treatment of breast and prostate cancer. However, this development was discontinued.

Carvotroline [WY 47791] is a novel γ-carboline derivative with a preclinical profile suggestive of antipsychotic activity. Carvotroline has an affinity for the dopamine D2 receptor and cortical 5-HT2 receptor that is ten times greater than serotonin. Carvotroline administration to rats leads to a decrease of plasma corticosterone levels and demonstrated a moderating effect on the rotational-stress induced rise in plasma corticosterone levels.

Inocoterone acetate (USAN) (also known as RU-38882, RU-882) is the acetate ester of inocoterone a steroid-like nonsteroidal antiandrogen (NSAA) that was developed for topical administration to treat acne but was never marketed. Inocoterone acetate is actually not a silent antagonist of the androgen receptor but rather a weak partial agonist, similarly to steroidal antiandrogens like cyproterone acetate. In this double-blind study of 126 male subjects with acne, a topical solution of the antiandrogen inocoterone produced a modest but statistically significant reduction in the number of inflammatory acne lesions.

Saprisartan (formerly known as GR 138950) was developed as a potent long-lasting angiotensin II (AT1) receptor antagonist with high oral bioavailability. The drug was used for the treatment of hypertension and heart failure. However, these studies were discontinued.

LANEPITANT is a selective nonpeptide antagonist for the neurokinin-1 receptor. It inhibits neurogenic dural inflammation. LANEPITANT was under development as a potential analgesic drug for the treatment of migraine, arthritis and diabetic neuropathy. However, it failed to show sufficient efficacy to support further development.

Ibutamoren (L-163,191 MK-0677) is a spiropiperidine agonist of the ghrelin receptor and a growth hormone secretagogue. Ibutamoren mimics the actions of growth hormone releasing peptide-6 to increase serum levels of serum insulin-like growth factor-I (IGF-I). Orally active Ibutamoren was being developed by Merck & Co. for a variety of indications, including fibromyalgia, muscle wasting/weakness in patients with chronic kidney disease, Alzheimer's disease and fractures.However, there has been no recent development reported or development has been discontinued for these indications.

Sonepiprazole exhibits highly specific binding to the D4 dopamine receptor with more than 100-fold selectivity for the D4 receptor over other receptors, including dopamine, serotonin, and adrenergic receptors. It is a neutral antagonist at the D4 dopamine receptor and is devoid of dopamine agonist activity. Sonepiprazole selectively induces c-fos expression in the prefrontal cortex and blocks behavioral, biochemical, and genomic effects of repeated amphetamine administration in rats. Sonepiprazole was investigated as an antipsychotic for the treatment of schizophrenia in a placebo-controlled clinical trial, but in contrast to its comparator olanzapine no benefits were found and it was not researched further for this indication.

Salethamide was developed as an anti-inflammatory agent to use as an analgesic. However, information about the further study of this compound is not available.

CP-866087 is a mu opioid receptor antagonist, discovered by Pfizer. The compound was able to antagonize the effect of morphine in a rodent tail flick assay and produced a dose-dependent decrease in alcohol intake in alcohol-preferring rats. The compound was investigated in clinical trials for the treatment of obesity, alcoholism and female sexual arousal disorder. In the later study, although improvements were seen with CP-866,087 in the key efficacy endpoints, there was no clinical treatment benefit over placebo.