Methoxyamine (TRC102) is an orally bioavailable small molecule with potential adjuvant activity, that may potentiate the antitumor activity of alkylating agents. Methoxyamine covalently binds to apurinic/apyrimidinic (AP) DNA damage sites and inhibits base excision repair (BER) that causes topoisomerase II-dependent irreversible strand breaks and apoptosis. Methoxyamine is currently being studied in multiple Phase 1 and Phase 2 clinical trials sponsored by the National Cancer Institute or Case Comprehensive Cancer Center.

Cemadotin (LU103793) is a cytotoxic water-soluble pentapeptide analogue of dolastatin 15. The dolastatin peptides were originally isolated from the shell-less mollusc Dolabella auricularia. Cemadotin blocks cells at mitosis. It exerts its antitumor activity by suppressing spindle microtubule dynamics through a distinct molecular mechanism by binding at a novel site in tubulin. Cemadotin was in phase II clinical trials as a promising cancer chemotherapeutic agent. However, this agent appears to be inactive in the treatment of advanced non-small-cell lung cancer and other tumors and this research has been discontinued.

Tesevatinib (EXEL-7647 or XL647) was optimized as an inhibitor of a spectrum of growth-promoting and angiogenic receptor tyrosine kinases (RTKs) to simultaneously block tumor growth and vascularization. In particular, Tesevatinib potently inhibits the EGF/ErbB2, VEGF, and ephrin RTK families. The drug is being developed by Kadmon Corporation under licence from Symphony Evolution (Symphony Capital Partners). Kadmon is developing tesevatinib for the treatment of autosomal polycystic kidney disease and solid cancers.

Ralimetinib (LY2228820), a trisubstituted imidazole derivative, is a potent and selective, ATP-competitive inhibitor of the α- and β-isoforms of p38 mitogen-activated protein kinase. LY2228820 produced significant tumor growth delay in multiple in vivo cancer models (melanoma, non-small cell lung cancer, ovarian, glioma, myeloma, breast). Eli Lilly is developing ralimetinib for the treatment of cancer.

AG1478 (also known as Tyrphostin AG 1478 ) is a selective EGFR inhibitor, which induced cell cycle arrest in G1 phase, is developed as potential drug for nasopharyngeal carcinoma treatment. In addition was shown, that AG1478 effectively blocked the leiomyoma cell growth and is unaffected by the presence of physiological concentrations of progesterone and estradiol. The growth-arresting properties of AG1478, unaffected by ovarian steroidal hormones, identify it as a potential lead agent for the non-surgical management of uterine leiomyomas. Also was investigated the action of the combination AG1478 in combination with HGF tyrosine kinase inhibitors on non-small cell lung cancer (NSCLC) cells, and was suggested, that these combinations of drugs could be potentially used for treatment of NSCLC.

Coptisine (COP), a protoberberine alkaloid, is widely found in Chinese medicinal plants (family Berberidaceae, Ranunculaceae and Papaveraceae). It is reported that COP has a wide range of pharmacological and biological activities, including antibacterial, hypoglycemic, anti-tumorigenic, and gastric-mucous membrane protection. Considerable attention has been focused on its activity against central nervous system disorders, such as improving the symptoms of Alzheimer’s disease and even preventing its onset, by exerting antidepressant effects as a potent type A monoamine oxidase inhibitor. Coptisine was found to be an efficient uncompetitive Indoleamine 2,3-dioxygenase inhibitor. Coptisine is a potent inhibitor of human organic cation transporters.

Mobocertinib (EXKIVITY™) is a first-in-class EGFR tyrosine kinase inhibitor being developed for the treatment of EGFR exon 20 insertion (EGFRex20ins) -positive non-small cell lung cancer (NSCLC). Mobocertinib is a kinase inhibitor of the epidermal growth factor receptor (EGFR) that irreversibly binds to and inhibits EGFR exon 20 insertion mutations at lower concentrations than wild type (WT) EGFR. Two pharmacologically-active metabolites (AP32960 and AP32914) with similar inhibitory profiles to mobocertinib have been identified in the plasma after oral administration of mobocertinib. In vitro, mobocertinib also inhibited the activity of other EGFR family members (HER2 and HER4) and one additional kinase (BLK) at clinically relevant concentrations (IC50 values <2 nM). Based on efficacy in patients whose disease had progressed on or after platinum-based therapy in a phase I/II trial, mobocertinib was recently granted accelerated approval in the USA in this indication. The drug is also being assessed for marketing approval in various other countries and territories including the EU and China.

Novobiocin (also known as streptonivicin) is an aminocoumarin antibiotic, active against Staphylococcus epidermidis. Novobiocin and other aminocoumarin antibiotics act as a potent competitive inhibitor of DNA gyrase B. The oral form of the drug was withdrawn from the market in 1999 due to safety or effectiveness reasons. Later it was discovered that novobiocin inhibited Hsp90 and topoisomerase II, and novobiocin was investigated in clinical trials against metastatic breast cancer and non-small cell lung cancer. Topical form of novobiocin was investigated in combination with nalidixic acid for treatment of psoriasis.

Novobiocin (also known as streptonivicin) is an aminocoumarin antibiotic, active against Staphylococcus epidermidis. Novobiocin and other aminocoumarin antibiotics act as a potent competitive inhibitor of DNA gyrase B. The oral form of the drug was withdrawn from the market in 1999 due to safety or effectiveness reasons. Later it was discovered that novobiocin inhibited Hsp90 and topoisomerase II, and novobiocin was investigated in clinical trials against metastatic breast cancer and non-small cell lung cancer. Topical form of novobiocin was investigated in combination with nalidixic acid for treatment of psoriasis.

Since its first isolation in 1844, usnic acid has become the most extensively studied lichen metabolite and one of the few that are commercially available. Lichens belonging to usnic acid-containing genera have been used as crude drugs throughout the world. There are indications of usnic acid being a potentially interesting candidate for such activities as anti-inflammatory, analgesic, healing, antioxidant, antimicrobial, antiprotozoal, antiviral, larvicidal and UV protection. However, some studies reported the liver toxicity and contact allergy. Usnic acid reduced the production of Junin virus in infected Vero cells in a dependent dose manner, and 50% inhibition was obtained at an effective concentration (EC50) of 9.9 µM. Regarding the TCRV arenavirus, the effective concentration was 20.6 uM. The selectivity indexes (CC50/EC50) of usnic acid for JUNV and TCRV arenavirus were 6.8 and 3.2, respectively, indicating a specific antiviral activity against these viruses and not just a general consequence of its action on cellular toxicity.