Epothilone D (KOS-862 or BMS-241027) is an intermediary obtained in the synthesis of members of the epothilone family and is a small-molecule microtubule stabilizer. It was investigated in Phase II trials in colorectal, metastatic breast and non-small-cell lung cancers. However, development was discontinued in 2007 in favor of a second-generation analog with a better safety profile. This drug also was studied for the treatment of Alzheimer's disease. The study ended in October 2013, and evaluation of epothilone D for Alzheimer's disease was subsequently discontinued. The mechanism by which epothilones induce microtubule polymerization appears to be similar to that of paclitaxel, in that epothilones compete with paclitaxel for binding to microtubules and suppress microtubule dynamics in a manner similar to that of paclitaxel.

Pelitinib (EKB-569) is a 3-cyanoquinoline pan-ErbB tyrosine kinase inhibitor with potential antineoplastic activity. Pelitinib irreversibly binds covalently to epidermal growth factor receptors, thereby inhibiting receptor phosphorylation and signal transduction and resulting in apoptosis and suppression of proliferation in tumor cells that overexpress these receptors. Pelitinib had been in phase II clinical trials for the treatment of non-small cell lung cancer and colorectal cancer. Treatment-emergent adverse events were diarrhea, abdominal pain, gastrointestinal carcinoma, intestinal obstruction and vomiting.

Picropodophyllin (also known as picropodophyllotoxin (PPP)), an orally active insulin-like growth factor 1 receptor (IGF1R) inhibitor that exhibits no activity at the insulin receptor, FGFR, PDGFR or EGFR. Picropodophyllin possesses antineoplastic activity. PPP is currently tested as an orally administrated single agent treatment in an open-label combined Phase I/II clinical study in advanced cancer patients with solid tumors which progress in spite of several lines of treatment. In addition, it effectively inhibits rhambodmyosarcomas tumor proliferation and metastasis in vitro and in an animal model.

Tetrahydrouridine is a potent competitive reversible inhibitor of cytidine deaminase. Tetrahydrouridine can inhibit cell proliferation by regulation of the cell cycle independent of cytidine deaminase (CDA) expression levels. Tetrahydrouridine may be useful for researching potential treatments for high CDA-expressing tumors. Tetrahydrouridine use, alone or in combination with the DNA methyltransferase inhibitor 5-fluoro-2’-deoxycytidine, is being evaluated in animal models and clinical trials for diseases, including cancer and mitochondrial DNA depletion syndrome.

SANT-1 is antagonist of Smoothened (Smo), a distant relative of G protein-coupled receptors, mediates Hedgehog (Hh) signaling during embryonic development and can initiate or transmit ligand-independent pathway activation in tumorigenesis. It suppressed cancer cell viability, proliferation and colony formation.

DMH1 is a potent and selective inhibitor of BMP signaling. DMH1 is a direct inhibitor of ALK2 BMP type-I receptor ALK2 (activin receptor like kinase-2). DMH1 potently inhibits neoplastic phenotype in cancer cells.

Grindelic acid is a labdane-type diterpene that was reported as the main secondary metabolite from Grindelia chiloensis Cabr and G. pulchella Dunal var. pulchella (Asteraceae). Recent studies demonstrated potential pharmaceutical applications for grindelic acid and its synthetic derivatives. Grindelic acid is a NOX4 inhibitor (IC50 2 uM). Grindelic acid’s mechanism of action is unknown, but it inhibited neither ROS in a cell-free membrane-based NOX4 assay nor from the purified NOX4 dehydrogenase domain. Grindelic acid demonstrates in vitro antitumor activity against human breast, cervix, lung,colon cancer.

PF-06439015 is a potent and selective inihibitor that overcomes clinical ALK (receptor tyrosine kinase anaplastic lymphoma kinase) mutations resistant to Crizotinib. PF-06439015 is potent across a broad panel of ALK mutant cell lines with an IC50 of 6.6 nM for tumor growth inhibition in a crizotinib-resistant cell line (H3122-L1196M).

AZ5104 is a demethylated metabolite of Osimertinib. AZ5104 potently and irreversibly inhibits both wild-type and mutant (exon 19 and L858R) EGFR and demonstrates good anti-cancer effect in both cell-based and in vivo experiments. Although AZ5104 was tested on preclinical models of lung cancer, it is used only in the prodrug form.

4-Amino-N-(3-chloro-4-fluorophenyl)-N'-hydroxy-1,2,5-oxadiazole-3-carboximidamide (Epacadostat) is an orally available hydroxyamidine and inhibitor of indoleamine 2,3-dioxygenase (IDO1), with potential immunomodulating and antineoplastic activities. epacadostat targets and binds to IDO1, an enzyme responsible for the oxidation of tryptophan into kynurenine. By inhibiting IDO1 and decreasing kynurenine in tumor cells, epacadostat increases and restores the proliferation and activation of various immune cells, including dendritic cells (DCs), NK cells, and T-lymphocytes, as well as interferon (IFN) production, and a reduction in tumor-associated regulatory T cells (Tregs). Activation of the immune system, which is suppressed in many cancers, may inhibit the growth of IDO1-expressing tumor cells. IDO1 is overexpressed by a variety of tumor cell types and DCs. Epacadostat is in clinical development as a novel orally active immuno-oncological therapy.