Volasertib (BI 6727), a dihydropteridinone derivative, is a small-molecule cell cycle inhibitor of polo-like kinase-1 (PLK-1). Volasertib induces G2-M arrest and induction of apoptosis in cancer cells and potently inhibits tumor growth in xenograft models. Boehringer Ingelheim is developing intravenously administered volasertib for the treatment of acute myeloid leukaemia (AML), myelodysplastic syndromes (MDS), chronic myelomonocytic leukaemia (CMML), non-small cell lung cancer, urogenital cancer, ovarian cancer and solid tumours.

Pracinostat is a pan-histone deacetylase inhibitor being tested in phase II of clinical trials for the treatment of sarcoma, prostate cancer, acute myeloid leukemia, myelofibrosis, myelodysplastic syndrome. The drug was shown to be active in vitro on HCT116 and HL-60 cells.

Veliparib (ABT-888) is a potent inhibitor of PARP, has good oral bioavailability, can cross the blood-brain barrier, and potentiates temozolomide, platinums, cyclophosphamide, and radiation in syngeneic and xenograft tumor models. AbbVie is developing veliparib for the treatment of cancers. Clinical trials are underway worldwide, investigating veliparib primarily as part of a combination therapy in oncology indications such as brain, colorectal, melanoma, ovarian, prostate and pancreatic cancers.

Talarozole (formerly R115866) is a new highly potent and selective azole derivative, which inhibits cytochrome-P450-dependent all-trans-retinoic acid catabolism by blocking the cytochrome P450 enzyme isoform CYP26, a retinoic acid hydroxylase. It is in clinical development for the treatment of psoriasis and acne. However, no local pharmacokinetic data on the diffusion behaviour of talarozole in the skin itself are available. As topical application might be an interesting alternative to oral therapy because of the reduced systemic side effects. The distribution of talarozole within the skin was investigated: 80% was located in the epidermis, while the remaining 20% was found in the dermis. The epidermal concentration of talarozole achieved after a single topical application was sufficiently high to enable the potential induction of local retinoid-like effects.

NMS-P937 is a selective PLK1 inhibitor. It was developed by Nerviano Medical Sciences and tested in phase I clinical trials.

Tanzisertib (CC-930) is a potent and selective inhibitor of JNK1/JNK2/JNK3 with IC50 values of 61 nM, 7 nM and 6 nM respectively. Tanzisertib had been in phase II clinical trials for the treatment of idiopathic pulmonary fibrosis and discoid lupus erythematosus. But this research was discontinued in 2012. In 2011, the compound was granted orphan drug designation in the U.S. and the E.U. for the treatment of idiopathic pulmonary fibrosis. The compound was co-developed by Celgene and Ligand.

Imexon (INN, trade name Amplimexon) is a substance that is being studied in the treatment of some types of cancer, including pancreatic, lung, breast, prostate, melanoma, and multiple myeloma. Imexon is a thiol-binding small molecule which induces mitochondrial oxidation, a loss of membrane potential and cytochrome C, leading to apoptosis.

Tivantinib (ARQ 197) is the first non-ATP-competitive small molecule that selectively targets the c-Met receptor tyrosine kinase. Exposure to Tivantinib resulted in the inhibition of proliferation of c-Met-expressing cancer cell lines as well as the induction of caspase-dependent apoptosis in cell lines with constitutive c-Met activity. ArQule and its collaborators Daiichi Sankyo and Kyowa Hakko Kirin are developing tivantinib as a potential therapy for many cancers. c-Met is overexpressed in many cancers. Tivantinib currently is in phase 3 clinical development for the treatment of hepatocellular carcinoma and non-small cell lung cancer.

Salirasib or S-trans,trans-Farnesylthiosalicylic acid (FTS) is a salicylic acid derivative with potential antineoplastic activity. It acts as a potent competitive inhibitor of the enzyme prenylated protein methyltransferase (PPMTase), which methylates the carboxyl-terminal S-prenylcysteine in a large number of prenylated proteins including Ras. In such systems, Salirasib inhibits Ras methylation but not Ras farnesylation. Salirasib selectively disrupts the association of chronically active Ras proteins with the plasma membrane. Salirasib competes with Ras for binding to Ras-escort proteins, which possess putative farnesyl-binding domains and interact only with the activated form of Ras proteins, thereby promoting Ras nanoclusterization in the plasma membrane and robust signals. Salirasib was studied in the clinical trials in patients with solid tumors, however its development was discontinued.

Retaspimycin (IPI-504) was previously under development by manufacturer Infinity Pharmaceuticals in conjunction with MedImmune, a part of AstraZeneca. Retaspimycin is a small-molecule inhibitor of heat shock protein 90 (HSP90) with antiproliferative and antineoplastic activities. Retaspimycin binds to and inhibits the cytosolic chaperone functions of HSP90, which maintains the stability and functional shape of many oncogenic signaling proteins and may be overexpressed or overactive in tumor cells. Retaspimycin-mediated inhibition of HSP90 promotes the proteasomal degradation of oncogenic signaling proteins in susceptible tumor cell populations, which may result in the induction of apoptosis. Orphan drug designation was assigned to the compound by the FDA for the treatment of gastrointestinal stromal cancer (GIST). Infinity Pharmaceuticals has discontinued the development of retaspimycin (IPI-504) an inhibitor of the HSP-90) complex, for the treatment of cancer due to lack of efficacy in 1913.