Phenserine, a derivative of physostigmine, was first described as an inhibitor of acetylcholinesterase (AChE) and was shown to improve cognition in various experimental paradigms in rodents and dogs. It was clinically tested for Alzheimer's disease, with moderate success in initial Phase II studies. Phenserine is also unique because of differing actions of its enantiomers: (-)-phenserine is the active enantiomer for inhibition of AChE, whereas ( )-phenserine (Posiphen®) has weak activity as an AChE inhibitor and can be dosed much higher. Posiphen® is a small, hydrophobic, orally available molecule that enters the brain readily. It is the only drug ever described that inhibits more than one neurotoxic aggregating protein. Posiphen® inhibits synthesis of amyloid precursor protein (APP), tau and α-Synuclein. mRNA translation of neurotoxic aggregating proteins is up-regulated by iron (Fe) and down-regulated by iron regulatory protein-1 (IRP1). Posiphen® interferes with this second step of the common cascade of the aggregating proteins. It enhances the binding and/or activity of IRP1 to the iron response element (IRE) stem loop in the 5’UTR of the mRNAs of neurotoxic aggregating proteins, therefore specifically lowering their synthesis. By potentiating the IRE/IRP1 complex, Posiphen® lowers the level of free mRNA to be translated by the ribosome. Posiphen® is in development for the treatment neurodegenerative diseases.

UM171 is a potent agonist of human hematopoietic stem cell renewal, independently of AhR suppression. UM171 act differently than other small molecule stimulators of hematopoiesis, such as the aryl hydrocarbon receptor (AhR) antagonist StemRegenin 1 (SR1). Addition of UM171 to cultures containing SR1 and cytokines further enhances the ex vivo expansion of normal HSCs, including CD34+ cells.

Esuberaprost (314d) is an active enantiomer of beraprost, a prostacyclin analog. The pharmacologic action of esuberaprost is mediated by specifically binding to PGI2 receptors in smooth muscle cells (the blood vessel’s endothelium) and platelets. Upon binding, the compound widened blood vessels, preventing the formation of blood clots, and lowering blood pressure in the lungs. As a result, it was expected to improve the symptoms of pulmonary arterial hypertension. United Therapeutics announced it has ended its Phase 3 BEAT trial testing esuberaprost as an add-on therapy to its product Tyvaso (inhaled treprostinil) for clinically symptomatic patients with pulmonary arterial hypertension (PAH). According to a company press release, the study failed to reach its main endpoint of delaying the time to first clinical worsening events.

Lifirafenib (BGB-283 or BEIGENE-283), a dual inhibitor targeting BRAF kinase and EGFR, was studied for the treatment of different cancer types harboring mutations in BRAF, KRAS, and NRAS. Lifirafenib participates in Phase II clinical trial in combination with PD-0325901 to treat the patients with solid tumor.

GZD824 is a novel orally bioavailable Bcr-Abl inhibitor for Bcr-Abl(WT) and Bcr-Abl(T315I) with IC50 of 0.34 nM and 0.68 nM, respectively. In vivo efficacy studies in mouse xenograft or allograft models of human leukemia demonstrated that GZD824 successfully suppressed the growth of tumors driven by native Bcr-Abl, Bcr-Abl T315I, Bcr-Abl G250E, Bcr-Abl Q252H, Bcr-Abl E255K and Bcr-Abl F317L. GZD824 also provided a significant survival benefit leukemia model mice allografted with luciferase-expressing Ba/F3 cells driven by the mutant Bcr-Abl T315I kinase. The potential for compound GZD824 to overcome all of the Bcr-Abl mutations that result in clinically acquired resistance to imatinib indicates that this novel Bcr-Abl inhibitor is a promising lead candidate for further development. GZD824 has also being shown to suppresses pre-B ALL cells through inhibition of the SRC kinase and PI3K/AKT pathways and may be a potential therapeutic agent for the management of pre-B ALL.

Prazarelix is gonadorelin (GnRH) antagonist. It is primarily used in assisted reproduction to control ovulation. The drug works by blocking the action of GnRH upon the pituitary, thus rapidly suppressing the production and action of luteinizing hormone (LH) and follicle-stimulating hormone (FSH).