Etanidazole (also known as Radinyl) is a 2-nitroimidazole with radiosensitizing properties. Etanidazole exerts its therapeutic action by depleting glutathione and inhibiting glutathione S-transferase, thus enhancing the anticancer effects of radiation therapy. Etanidazole was tested in Phase III clinical trials in patients with advanced head and neck cancer, however, its development was stopped. A fluorinated etanidazole (EF5) may also be useful as an imaging agent for identification of hypoxic, drug-resistant regions of primary tumors and metastases.

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.

Apilimod is a small molecule inhibitor of interleukin-12 and interleukin-23 synthesis thereby preventing IL-12/IL-23 mediated immune responses. Apilimod is also observed to inhibit the nuclear accumulation of NF-kappB protein family, and viral infections dependent on phosphatidylinositol-3-phosphate 5-kinase (PIKfyve). Apilimod has been investigated as a potential treatment for a number of autoimmune conditions.

Motesanib (AMG 706), a novel nicotinamide, was identified as a potent, orally bioavailable inhibitor of the VEGFR1/Flt1, VEGFR2/kinase domain receptor/Flk-1, VEGFR3/Flt4 and Kit receptors. Motesanib was expected to reduce vascular permeability and blood flow in human tumours. A phase III trial of motesanib in combination with paclitaxel and carboplatin in non-squamous NSCLC has been terminated by Takeda and subsequently the development was discontinued. Motesanib has also been investigated up to phase II in breast, thyroid, colorectal and gastrointestinal stromal tumours. However, development has been discontinued in these indications.

Japan Tobacco developed JTV-519 (known also as K201) as an antiarrhythmic agent. This drug was in Phase II trials for the potential treatment of Atrial Fibrillation, but study was terminated. In experimental myofibrillar overcontraction models, JTV-519 demonstrated greater cardioprotectant effects than propranolol, also, this drug investigated against heart failure, but then these researches have been discontinued. In addition, K201 was in phase II clinical trial for investigation its topical implementation for Atopic Dermatitis. The mechanism of its action is both complex and controversial, known that it is a non-specific blocker of sodium, potassium and calcium channels (multiple-channel blocker). It is believed to stabilize the closed state of the RyR2 (cardiac ryanodine receptor) by increasing its affinity for the FKBP12.6 (12.6 kDa FK506 binding protein), in addition was suggested, that suppression of spontaneous Ca2 release and the activity of RyR2 contributes, at least in part, to the anti-arrhythmic properties of K201.

Afuresertib (GSK2110183 ) is an orally bioavailable inhibitor of the serine/threonine protein kinase Akt (protein kinase B) with potential antineoplastic activity. Afuresertib binds to and inhibits the activity of Akt, which may result in inhibition of the PI3K/Akt signaling pathway and tumor cell proliferation and the induction of tumor cell apoptosis. Activation of the PI3K/Akt signaling pathway is frequently associated with tumorigenesis and dysregulated PI3K/Akt signaling may contribute to tumor resistance to a variety of antineoplastic agents. Preclinically, AKT inhibition by afuresertib can reverse platinum resistance in ovarian cancer cell lines isolated from patients with platinum-resistant ovarian cancer. Afuresertib is well tolerated and demonstrates clinical activity as monotherapy in heavily pretreated MM patients. Is in phase II clinical trials for Chronic lymphocytic leukaemia; Haematological malignancies; Histiocytosis.

Abexinostat (PCI-24781) is a novel, second-generation phenyl hydroxamic acid–based, orally bioavailable HDAC inhibitor that has previously been shown to have activity in vitro and in vivo against a broad array of cancers, including hematopoietic malignancies and bone and soft-tissue sarcomas. Abexinostat is a pan-HDAC inhibitor mostly targeting HDAC1 with Ki of 7 nM, modest potent to HDACs 2, 3, 6, and 10 and greater than 40-fold selectivity against HDAC8. Abexinostat exhibits potent antitumor activity against a variety of tumor cell lines with GI50 ranging from 0.15 uM to 3.09 uM. PCI-24781 also has an antiproliferative effect on HUVEC endothelial cells with GI50 of 0.43 uM. Abexinostat treatment causes dose-dependent accumulation of both acetylated histones and acetylated tubulin in HCT116 or DLD-1 cells, induces expression of p21, and leads to PARP cleavage and accumulation of the γH2AX. It has also shown good tolerability and activity in Phase I and II clinical trials against lymphoma, as well as against solid tumors in Phase-I trials. Additionally, it acts as a potent radiosensitizing agent and is synergistic with cytotoxic chemotherapy, such as doxorubicin in preclinical models.

NMED-160 (also known as MK-6721, NP-118809, Z-160) is a potent N-type calcium channel blockers, which has good selectivity over L-type calcium channels. Neuromed Pharmaceuticals developed this compound for the treatment of the chronic pain. However, that study was discontinued in 2007 in spite of absence of adverse events, but because drug did not demonstrate the ideal, pharmaceutical characteristics considered necessary to advance the compound further in development. Then Zalicus, Inc. was developing that drug for the treatment of chronic neuropathic pain associated with lumbosacral radiculopathy and post-herpetic neuralgia and drug was in the phase II clinical trial. Nevertheless, based on the result from trials, where Z160 did not meet the primary endpoint, Zalicus was also discontinuing the Z160 program.

Otenabant (CP-945,598) is Pfizer developed as a potent and selective cannabinoid receptor CB1 antagonist with Ki of 0.7 nM, which exhibits 10,000-fold greater selectivity against human CB2 receptor, for treatment of obesity. In clinical trial III Pfizer decided to discontinue the development program based on changing regulatory perspectives on the risk/benefit profile of the CB1 class and likely new regulatory requirements for approval.

Imiloxan is a highly selective alpha2B adrenoceptor antagonist and was developed for depression in the 1980s. In Phase 1 clinical trials imiloxan dosing led to hypersensitivity reactions; the molecule's development was discontinued.