PD-217014 or PD-217,014, a new GABA analog was developed by Pfizer as a potent alpha(2)delta ligand of voltage-gated calcium channel, that and possessed visceral analgesic activity. This compound was undergoing phase II clinical trials for the treatment of overactive bladder (OAB) and irritable bowel syndrome (IBS). In addition, PD-217014 was investigated for postherpetic neuralgia treatment. However, all these studies were discontinued.

Decoglurant is a negative allosteric modulator of the mGlu2 and mGlu receptors developed by Roche. Decoglurant was investigated in a phase 2 clinical trials in patients with major depressive disorder. Negative results were reported and the development was discontinued in 2015.

Norbuprenorphine is a major metabolite of buprenorphine and potent agonist of μ, δ, and κ opioid receptors. Norbuprenorphine is the only known active metabolite of buprenorphine. It has been shown to be a respiratory depressant in rats, but only at concentrations at least 50-fold greater than those observed following application to humans of BuTrans 20 mcg/h. Compared with buprenorphine, norbuprenorphine causes minimal antinociception but greater respiratory depression. In rats, nor-buprenorphine had 1/50th the analgesic potency of buprenor-phine but 10-fold greater respiratory depressant potency. Norbuprenorphine is an in vitro substrate of the efflux transporter P-glycoprotein (Mdr1). Norbuprenorphine is an in vitro and in vivo substrate of P-glycoprotein. P-glycoprotein-mediated efflux influences brain access and antinociceptive, but not the respiratory, effects of norbuprenorphine.

Bleomycin A6 (also known as boanmycin) was developed in China as an antineoplastic antibiotic. This drug participated in clinical trials for the treatment of Squamous Cell Lung Cancer. It was shown that besides the antitumor effect, Bleomycin A6 had the ability to alter the tumor microenvironment and could contribute toward lung cancer relapse and metastasis on long-term treatment. The development of this drug, apparently, was discontinued.

Chromic Phosphate Cr-51 is a radiopharmaceutical compound that has been extensively used in nuclear medicine. When administered intraperitoneally, the particulate form of chromic phosphate is pocketed in various areas of the peritoneum, or filtered out by the first lymph nodes encountered, because of the too large particle size, whereas the colloidal form is carried over to the lymphatic system. The larger particles originally present in its size spectrum or formed in vivo by aggregation of smaller particles are trapped by the first line of lymph nodes, and the remainder goes into the thoracic duct, with posterior incorporation into the blood circulation and final removal by the reticuloendothelial system: liver, spleen and bone marrow.

Borocaptate sodium B10 (also known as sodium borocaptate), a boron compound for use in boron neutron capture therapy. After parenteral administration, sodium borocaptate accumulates preferentially in tumor cells. When exposed to neutron irradiation, borocaptate absorbs neutrons and self-destructs releasing short-range alpha radiation and 'recoil' lithium in tumor cells, resulting in alpha radiation-induced tumor cell death. This highly selective, localized radio targeting of tumor cells, known as boron neutron capture therapy, spares adjacent normal tissues. Borocaptate sodium B10 was involved in phase I clinical trial in treating patients with glioblastoma multiforme removed during surgery to study the side effects. In addition, this compound participated in phase I clinical trials in tissues of patients with primary, metastatic, or recurrent thyroid cancer, head and neck cancer, or liver metastases from colorectal cancer to study the side effects. Besides, borocaptate sodium B10 was involved in phase-I clinical trials for Glioma in the European Union, however, this study was discontinued.

Adrenochrome is a member of a class of chemicals known as aminochromes, each one derived by the oxidation of its precursor amine. Adrenochrome was proposed for the biogenesis of schizophrenia in 1952. Since that time the adrenochrome theory has been one of the most established and discussed theories in this field. It is known, that adrenochrome is toxic to myocar-dial tissue and may be responsible for fibril-lation and sudden death under stress. Aminochrome has been suggested as a physiological preclinical model capable of inducing five of the six mechanisms of Parkinson's disease. Until now, there is no evidence that aminochrome induces glial activation related to neuroinflammation, an important mechanism involved in the loss of dopaminergic neurons, but was shown, aminochrome neuroinflammatory ability and supported the hypothesis that it might be a better PD preclinical model to find new pharmacological treatment that stop the development of this disease.

BX 471 is an oral nonpeptide chemokine receptor1 (CCR1) antagonist that was under clinical development with Bayer Healthcare Pharmaceuticals (formerly Bayer Schering Pharma AG and Berlex) for the treatment of various inflammation-related disorders, including endometriosis. The CCR1 antagonist was also thought to have potential application in diagnostic imaging, particularly as an imaging biomarker for the diagnosis of Alzheimer's disease. Berlex initiated the development of the radiolabelled small molecule CCR1 antagonist, BX 471, for a specific diagnostic test for both early detection and for tracking disease progression following the discovery that the CCR1 protein was found in the brains of patients with Alzheimer's disease, and that increased levels of this protein were correlated with advancement of the disease. However, development of the agent for diagnostic imaging appears to have been discontinued. BX 471 was also in development for the treatment of autoimmune diseases, including multiple sclerosis and psoriasis; however, development in these indications, as well as multiple myeloma and endometriosis, also appears to have been discontinued. A phase II study of BX 471 in endometriosis had been completed.