Verubecestat (MK 8931) is a potentially first-in-class, potent β-site amyloid precursor protein cleaving enzyme 1 (BACE1) inhibitor being developed by Merck. Verubecestat (MK-8931) is a selective, structurally unique BACE1 inhibitor that reduced plasma, cerebrospinal fluid (CSF), and brain concentrations of Aβ40, Aβ42, and sAPPβ (a direct product of BACE1 enzymatic activity) after acute and chronic administration to rats and monkeys. Verubecestat was under investigation for the treatment of Alzheimer's disease, prodromal Alzheimer's disease, and amnestic mild cognitive impairment. In November 2013, Merck began the APECS trial in 1,500 participants with prodromal AD, aka mild cognitive impairment due to AD (aMCI). These patients have measurable cognitive deficits and a positive PET scan with the newly FDA-approved amyloid tracer flutemetamol, but are not functionally impaired. APECS compared 12 and 40 mg once-daily doses to placebo; treatment was to last for two years. APECS usef change from baseline on the Clinical Dementia Rating Sum of Boxes (CDR-SB), a continuous measure, as its primary outcome. Secondary outcomes evaluated a range of newer measures, including a cognitive composite, CSF tau, brain imaging of hippocampal volume and amyloid load, and others. This trial was being conducted in more than 90 locations worldwide; it completed enrollment in November 2016 and was expected to complete data collection for its primary outcome in 2019. In February 2018, APECS was discontinued and Merck no longer listed verubecestat in its research pipeline. APECS participants on 40 mg verubecestat scored worse than the placebo group on the CDR-SB and ADAS-Cog13 starting at 13 weeks. The effect was small and did not progress over time. The 12 mg treatment group also performed slightly worse than controls, with the difference reaching significance at scattered time points.

Octamoxine (ximaol), a monoamine oxidase inhibitor was used as an antidepressant to treat mental depression. Now this drug is no longer marketed.

4SC-202 is an epigenetic oncology compound with a unique therapeutic profile, which was developed by biotechnology company: 4SC. 4SC-202 works as a selective inhibitor of LSD1 (lysine-specific demethylase 1) and HDAC (histone deacetylase) 1, 2 and 3. 4SC-202 also strengthens the endogenous immune response to cancer tissue. This compound demonstrated successfully completed Phase I of the clinical study, where it was proved safe and well tolerated in patients with advanced hematologic cancer. In addition, 4SC-202 shows substantial anti-tumor activity in a broad range of cancer cell lines including hepatocellular carcinoma, Urothelial Carcinoma Cell Lines and colorectal cancer.

CUDC-907 is a small molecule inhibitor of histone deacetylase and PI3 kinase developed by Curis. It is investigated in clinical trials for the treatment of relapsed or refractory lymphomas, thyroid cancer, multiple myeloma, breast cancer and other malignancies.

Pinometostat, also known as EPZ-5676, is a small molecule inhibitor of histone methyltransferase with potential antineoplastic activity. Upon intravenous administration, EPZ-5676 specifically blocks the activity of the histone lysine-methyltransferase DOT1L, thereby inhibiting the methylation of nucleosomal histone H3 on lysine 79 (H3K79) that is bound to the mixed lineage leukemia (MLL) fusion protein which targets genes and blocks the expression of leukemogenic genes. Epizyme is developing pinometostat, a small molecule inhibitor of DOT1L, for the treatment of patients with MLL-r, a genetically defined acute leukemia. Epizyme is conducting a phase 1 clinical trial in pediatric patients. Epizyme is evaluating preclinical combinations of pinometostat with other anti-cancer agents in MLL-r leukemia. Pinometostat is being developed in collaboration with Celgene. Epizyme retains all U.S. rights to pinometostat and has granted Celgene an exclusive license to pinometostat outside of the U.S.

LY2606368 (Prexasertib) is a small-molecule Chk-1 inhibitors invented by Array and being developed by Eli Lilly and Company. Lilly is responsible for all clinical development and commercialization activities. LY2606368 is advancing in Phase 2 clinical trials for cancer. Prexasertib preferentially binds to and inhibits CHK1 and, to a lesser extent, inhibits CHK2. Chk-1 is a protein kinase that regulates the tumor cell's response to DNA damage often caused by treatment with chemotherapy. In response to DNA damage, Chk-1 blocks cell cycle progression in order to allow for repair of damaged DNA, thereby limiting the efficacy of chemotherapeutic agents. Inhibiting Chk-1 in combination with chemotherapy can enhance tumor cell death by preventing these cells from recovering from DNA damage.

Entospletinib (GS-9973) is an adenosine triphosphate competitive inhibitor of Syk that disrupts kinase activity, which is currently in clinical trials for multiple B-cell malignancies. The most common treatment-emergent serious adverse events included dyspnea, pneumonia, febrile neutropenia, dehydration, and pyrexia.