UK-432097 is a selective adenosine A2a agonist which was in development with Pfizer as an inhaled treatment for asthma and chronic obstructive pulmonary disease. UK-432097 had been in phase II clinical trials by Pfizer for the treatment of chronic obstructive pulmonary disease (COPD). However, this study was terminated prematurely due to futility based on results of interim analysis.

Bisfentidine (DA-5047), a histamine-2 receptor antagonist was studied for the treatment of colds and gingivitis.

Bitipazone was developed as an antiprotozoal agent that acts upon Coccidia parasites.

The new chemical entity KC12615 is a potent f neutral endopeptidase inhibitor with additional endothelin-converting enzyme (ECE)–inhibitory activity.2 KC12615 is the hydrolyzed form of the oral prodrug SLV306 (daglutril). In plasma, the compound increases natriuretic peptide levels and prevents the formation of endothelin-1 by inhibiting the degradation of its precursor, big endothelin. It is investigated for use/treatment in congestive heart failure and hypertension.

Dacisteine is a derivative of a N-acetylcysteine, where a second acetyl group is attached to a sulfur atom. Dacisteine is marketed in France under tradename Mucothiol for the treatment of disorders of bronchial secretion, acute bronchitis and acute episode of chronic bronchopneumopathies. Dacisteine exerts its action on the gel phase of the mucus, presumably by breaking the disulfide bonds of the glycoproteins, and thus promotes the expectoration.

Ciclosidomine is morpholine derivative and nitric oxide donors developed for vascular diseases treatment.

Proxicromil is substituted chromone patented in the late 1970s by Fisons Ltd. for the treatment of allergic asthma. Proxicromil acts on to FcεRIreceptor in mast cells, thereby inhibiting the production of histamines. Proxicromil is tested through a variety of independent studies for its beneficial effect as an anti-allergen, its efficacy against migraine, asthma and tumor enhancement. It shows no effect as a prophylactic against migraine. The reported side effects during this study related mainly to transient gastrointestinal troubles and were generally of a mild nature. For asthma and exercise-induced bronchospasm, Proxicromil was found to be mildly effective. But the investigation was discontinued when malignancies occurred in long-term animal studies.

Primidolol (also known as UK-11,443) is an imidazolidinone derivative patented by American pharmaceutical corporation Pfizer Corp as a specific β-adrenergic blocker. In clinical trials, Primidolol shows some antihypertensive activity but the overall change in the cardiovascular parameters failed to demonstrate a significant difference compared to placebo.