2,2-DIMETHYLBUTYRIC ACID (HQK-1001) is an orally administered SCFAD (Short Chain Fatty Acid Derivative), which has shown an excellent safety profile and biologic effects on fetal hemoglobin induction and red blood cell production in the laboratory, relevant animal models, and in clinical trials carried out in healthy human subjects as well as patients with sickle cell disease and beta thalassemia. The compound has received Orphan Drug Designation in the United States and Europe for both sickle cell disease and beta thalassemia. HemaQuest Pharmaceuticals was developing HQK-1001 for the oral treatment of sickle cell anaemia and beta thalassaemia. HQK-1001 has been evaluated in phase II trials for beta thalassaemia and sickle cell anaemia.

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.

Rimiducid (AP1903) is a lipid-permeable tacrolimus analogue with homodimerizing activity. Rimiducid homodimerizes an analogue of human protein FKBP12 (Fv) which contains a single acid substitution (Phe36Val). This agent is used to homodimerize the Fv-containing drug-binding domains of genetically engineered proteins such as the iCD40 receptor, Fas intracellular domain or iCaspase 9 resulting in downstream signaling activation during cell therapy. Orphan designation was granted for rimiducid (AP1903) for the treatment of graft-versus-host disease.

D-aspartic acid is an essential amino acid and a key ingredient in various testosterone boosting anti-estrogen supplements. D-aspartic acid is not used to build proteins; instead, it plays a role in making and releasing hormones in the body. It is an endogenous NMDA receptor agonist with similar activity to the L-isomer. D-aspartic acid also enhances the release of luteinizing hormone (LH) and testosterone. This action is mediated in the pituitary by cGMP and in the testis by cAMP, which acts as the second messengers in the signal transduction in the pituitary and testes respectively. The pituitary and testis possess a D-Aspartate racemase, which provides the necessary production of this isomer.

CPP-115 is a gamma-aminobutyric acid aminotransferase activator, developed by Catalyst Pharmaceutical Partners, Inc. The compound does not exhibit other GABAergic or off-target activities and is rapidly and completely orally absorbed and eliminated. In rats, CPP-115 produced inhibition of cocaine-induced increases in extracellular dopamine and in synaptic dopamine in the nucleus accumbens. CPP-115 decreased spasms in the multiple-hit rat model of infantile spasms. CPP-115 was found to have high therapeutic potential for the treatment of cocaine addiction and for a variety of epilepsies, has successfully completed a Phase I safety clinical trial, and was found to be effective in the treatment of infantile spasms (West syndrome).

TAK-875 (Fasiglifam) is the potent, selective and orally bioavailable GPR40 agonist. The drug was in Phase III clinical trials for the treatment of type 2 diabetes mellitus. Termination phase III development of TAK-875 for the potential treatment of type-2 diabetes mellitus was announced in 2013 due to concerns about liver safety.

Samatasvir (also known as IDX 719) was developed by Idenix Pharmaceuticals as a pan-genotypic inhibitor of the hepatitis C (HCV) non-structural protein 5A (NS5A). This drug was studied in phase II clinical trials for the treatment of Hepatitis C, and Chronic Hepatitis C Infection. However, the development of samatasvir was discontinued.

Fozivudine tidoxil is a thioether lipid–Zidovudine (ZDV) conjugate. After intake it is split intracellularly into the lipid moiety and ZDV-monophosphate, which is subsequently phosphorylated to the active metabolite ZDV-triphosphate. The rationale behind the development of fozivudine (FZD) was to take advantage of the high cleavage activity in mononuclear cells and other organs resulting in increased amounts of intracellular ZDV available for phosphorylation to the active metabolite, and a very low activity in red blood and stem cells, which should result in reduced haematologic toxicity. It is member of the family of nucleoside reverse transcriptase (RT) inhibitors. Fozivudine tidoxil has been in Phase II clinical trials for the treatment of HIV infection. There were three adverse events possibly related to fozivudine: urine abnormality, gastrointestinal pain and abnormal dreams.

Glutathione arsenoxide (GSAO) is a peptide trivalent arsenical that has potential anti-angiogenic capability, suggesting that it could be used for treatment in cancers where tumor metastasis relies on new blood vessel formation (angiogenesis). Endothelial cell proliferation drives new blood vessel formation. GSAO treatment causes a concentration-dependent increase in superoxide levels, ATP depletion, mitochondrial depolarization, and apoptosis in proliferating, but not endothelial cells. GSAO is able to block blood flow to solid tumors in mice, thereby inhibiting tumor growth in mice with no apparent toxicity at efficacious doses. Initial experiments have implicated GSAO in perturbing mitochondrial function. Other molecular effects of GSAO in human cells, for example on the phosphorylation of proteins, are still largely unknown. A phase I clinical trial has been terminated.