Pimonidazole (developed as RO 038799) is a derivative of 2-nitroimidazole, which forms adducts (binds to thiol-containing proteins) only at low oxygen tension. Pimonidazole is a novel nontoxic hypoxia marker for the complementary study of tumor hypoxia and cell proliferation in different types of cancer. The drawback of pimonidazole as a hypoxic marker is that it detects only severe hypoxia.

Cevipabulin is a synthetic, water-soluble tubulin-binding agent with potential antineoplastic activity. Cevipabulin appears to bind at the vinca-binding site on tubulin but seems to act more similar to taxane-site binding agents in that it enhances tubulin polymerization and does not induce tubulin depolymerization. The disruption in microtubule dynamics may eventually inhibit cell division and reduce cellular growth.

Taltobulin, also known as HTI-286 and SPA-110, is a fully synthetic analog of the natural tripeptide hemiasterlin, inhibits tubulin polymerization and circumvents transport-based resistance to taxanes. Taltobulin was a potent inhibitor of proliferation (mean IC50 = 4 nm in 18 human tumor cell lines) and had substantially less interaction with multidrug resistance protein (P-glycoprotein) than currently used antimicrotubule agents, including paclitaxel, docetaxel, vinorelbine, or vinblastine. Taltobulin showed strong antitumor activity both in androgen-dependent and androgen- independent tumors and may be a promising agent in second- line treatment strategies for patients suffering from docetaxel- refractory prostate cancer.

A second generation of HDACs, synthetic benzamide-containing HDACs such as Tacedinaline (CI-994), have reached phase I and II clinical trials. It has been investigated for its applications to the treatment of cancers such as Breast cancer and Colorectal cancer. Tacedinaline has been in phase III clinical trials by Pfizer for the treatment of advanced non-small cell lung cancer and pancreatic cancer combined with gemcitabine. However, this research has been discontinued. Mechanism of Action: Angiogenesis inhibitors; Histone deacetylase inhibitors. Pharmacokinetics showed that CI-994 absorption and disposition were unaffected by carboplatin and paclitaxel coadministration.

Filanesib is a highly selective, targeted KSP inhibitor with a mechanism of action distinct from currently available myeloma therapies such as immunomodulatory drugs (IMiDs®) and proteasome inhibitors. Across multiple studies, filanesib has demonstrated activity in heavily pretreated multiple myeloma patients, with a consistent safety profile including no drug-induced peripheral neuropathy and limited non-hematologic toxicity. Adverse events are generally limited to transient, non-cumulative and predominantly asymptomatic myelosuppression (decreases in blood counts) when supportive measures are used. Alpha 1-acid glycoprotein (AAG), a plasma protein, is a potential patient selection marker for filanesib. AAG is undergoing further investigation in clinical trials and could represent the first patient selection marker for a myeloma therapy. Filanesib is in Phase II for Multiple myeloma treatment.

Rabusertib is a Chk1 kinase inhibitor which was developed by ICOS for the treatment of cancer. The drug was tested in phase II of clinical trials for pancreatic cancer and non small cell lung carcinoma, but its development was discontinued. Now the drug is undergoing phase I trial in Japanese patients with solid tumors.

Pilaralisib (XL147, SAR245408) is a potent and highly selective inhibitor of class I phosphatidylinositol 3-kinase (PI3K) (α, β, γ, and δ). In cellular assays, XL147 inhibits the formation of PIP3 in the membrane, and inhibits phosphorylation of AKT, p70S6K, and S6 in multiple tumor cell lines with diverse genetic alterations affecting the PI3K pathway. In a panel of tumor cell lines, XL147 inhibits proliferation with a wide range of potencies, with evidence of an impact of genotype on sensitivity. Repeat-dose administration of XL147 results in significant tumor growth inhibition in multiple human xenograft models in nude mice. Pilaralisib, was being developed by Exelixis and its licensee, Sanofi (formerly sanofi-aventis), for the treatment of solid tumours. However, the product was not listed on Sanofi's early stage pipeline as of end of July 2015 and there have been no recent reports on development identified.

Enciprazine also known as WY-48624 or, D-3112 is a GABA A receptor agonist which was in the phase III of clinical trial for the treatment of anxiety disorders. Enciprazine was well tolerated, with low levels of sedative and asthenic side effects reported. However, research was discontinued.

Nefiracetam is a cyclic derivative of gamma-aminobutyric acid (GABA). It is thought to act by normalising dysfunctional acetylcholine, GABA and possibly monoamine neurotransmitter systems, but it may also facilitate N/L-type calcium channel opening. Nefiracetam has received attention as a treatment for seizures, depression, and dementia. Nefiracetam was found to be extremely testicular toxic in both rats and dogs; it was found to significantly decrease the levels of testicular testosterone leading to atrophy and malformation of sperm.

AZD1775 selectively targets and inhibits WEE1, a tyrosine kinase that phosphorylates cyclin-dependent kinase 1 (CDK1, CDC2) to inactivate the CDC2/cyclin B complex. Inhibition of WEE1 activity prevents the phosphorylation of CDC2 and impairs the G2 DNA damage checkpoint. This may lead to apoptosis upon treatment with DNA damaging chemotherapeutic agents. Current ongoing trials of AZD1775 include monotherapy and combination therapy with certain DNA damaging agents in solid tumors, ovarian tumors, gynaecological cancer, non-small cell lung cancer. AZD1775 is genotoxic, which is considered to be a result of its mechanism of action. Common serious adverse events (with chemotherapy) include: febrile neutropenia, neutropenia, thrombocytopenia.