PG-116800 is a member of the hydroxyproline-based hydroxamic acid class of matrix metalloproteinase (MMP) inhibitors. PG-116800 did not modify matrix structure in osteoarthritic patients. Also, it had unexpected side effects on muscle and skeleton; it limited joint mobility, and caused arthralgia, hand oedema, palmar fibrosis, Dupuytren’s contracture and persistent tendon thickness or nodules. PG-116800 failed to reduce left ventricular remodeling or improve clinical outcomes after myocardial infarction.

Luteolin, 3',4',5,7-tetrahydroxyflavone, is a common flavonoid that exists in many types of plants including fruits, vegetables, and medicinal herbs. Plants rich in luteolin have been used in Chinese traditional medicine for treating various diseases such as hypertension, inflammatory disorders, and cancer. Luteolin possesses a variety of pharmacological activities, including antioxidant, anti-inflammatory, antimicrobial and anticancer activities. Numerous studies have shown that luteolin possesses beneficial neuroprotective effects both in vitro and in vivo.

8-Chloroadenosine-3',5'-cyclic-monophosphate (8-Cl-cAMP), an analog of c-AMP, is a novel antineoplastic agent. It has been shown to be effective against different human cancer cell lines modulating the cellular signal transduction pathway, thereby causing growth inhibition, cell differentiation, and apoptosis. 8-Cl-cAMP preferentially binds to the R2 subunit of protein kinase A (PKA) and induces rapid R2 up-regulation and eventual R1 subunit down-regulation. It has potent inhibitory effects on a wide variety of human cancer cell lines, with an IC50 ranging from 0.1 to 20 uM. The IC50 falls with the length of drug exposure. It can suppress c-myc and c-ras proto-oncogenes in vitro and in vivo. It was shown that 8-Cl-cAMP induces cell growth inhibition through AMP-activated protein kinase (AMPK) activation with p38 MAPK acting downstream of AMPK in this signaling pathway. 8-Cl-cAMP induced apoptosis, apparently through activation of the p38 MAPK pathway by inducing progressive phosphorylation of the p38 mitogen-activated protein kinase (MAPK), via activation of AMPK by its metabolite 8-Cl-adenosine. 8-Cl-cAMP does not significantly inhibit the growth of NIH 3T3 cells, rat kidney fibroblasts, mammary epithelial cells, or peripheral blood lymphocytes, nor does it inhibit the growth of parental cells whose progeny have been transformed. Such selectivity makes it an attractive candidate for cancer therapy suggesting that it should not cause the toxicity of conventional cytotoxic agents but should inhibit tumor growth. 8-Cl-cAMP has been evaluated in phase I/II clinical trials.

Rivenprost (ONO-4819) is a potent and selective EP4 receptor agonist. This compound can increase bone formation by stimulating osteoblast differentiation and function, possibly by modulating mesenchymal cell differentiation. Rivenprost has also been studied for its potential to prevent bone loss (in osteoporosis) and stabilize bone implants. Combined with risedronate, rivenprost may be an effective treatment for osteoporosis. A phase II study evaluating rivenprost in ulcerative colitis was terminated in 2009.

Cromakalim is an ATP-sensitive potassium (KATP) channel opener, which was studied for the treatment of gastric ulcer, hypertension and preventing a cardiomyopathy. But the development of this drug was discontinued due to heart lesions found in monkey chronic toxicity studies.

Poziotinib is an inhibitor of EGFR tyrosine kinase family. The drug is being tested in phase II of clinical trials for different cancers: breast cancer, lung adenocarcinoma, head and neck squamous cell carcinoma, HER-2 positive advanced gastric cancer (in combination with Paclitaxel and Trastuzumab).

Ebiratide (Hoe 427) is a peptide analog of corticotrophin (ACTH 4-9). Ebiratide is endocrinologically inert. Ebiratide is highly lipophilic and has prolonged metabolic stability. Ebiratide exerts neurotrophic properties in vivo. It also was proven to have significant effects on acetylcholine metabolism. It has been investigated in the treatment of Alzheimer's disease.

PBI 4050, a synthetic analog of a medium-chain fatty acid that displays agonist and antagonist ligand affinity toward GPR40 and GPR84, that was developed for managing inflammatory and fibrosis-related diseases. In addition, PBI-4050 may exert antifibrotic activity in the liver through a novel mechanism of action involving modulation of intracellular ATP levels and the LKB1/AMPK/mTOR pathway in stellate cells. This drug participated in clinical trials for the treatment of acute lung injury, cystic fibrosis, diabetic nephropathies; idiopathic pulmonary fibrosis; metabolic syndrome; scleroderma; type 2 diabetes mellitus. Besides, this drug has granted a Rare Pediatric Disease Designation for the treatment of Alström syndrome (AS). PBI-4050 was also previously granted Orphan Drug Designation by the FDA and the EMA for the treatments of AS and idiopathic pulmonary fibrosis (IPF) as well as PIM (Promising Innovative Medicine) designation by the Medicines and Healthcare products Regulatory Agency (MHRA) for the treatment of IPF and AS. The FDA grants Rare Pediatric Disease Designations for serious or life-threatening diseases wherein the serious or life-threatening manifestations primarily affect individuals aged from birth to 18 years, including age groups, often called neonates, infants, children, and adolescents. Now Prometic Life Sciences plans to file investigational new drug application for pivotal phase III trial for Alstrom's syndrome in the second half of 2019.