2-chloroethyl-3-sarcosinamide-1-nitrosourea (SarCNU) is an alkylating chloroethylnitrosourea with antineoplastic activity. It is a selective cytotoxin that enters cells via the extraneuronal transporter for monoamine transmitters (EMT). Both in vitro and in vivo studies demonstrated that SarCNU was more effective than BCNU against human gliomas. Selectively accumulating in some tumor cells, SarCNU forms covalent linkages with nucleophilic centers in DNA, causing depurination, base pair miscoding, strand scission, and DNA-DNA cross-linking, which may result in cytotoxicity. SarCNU crosses the blood-brain-tumour-barrier and is taken orally. Phase II trial of SarCNU in malignant glioma revealed unexpected pulmonary toxicity. SarCNU was not FDA approved for orphan indication of malignant glioma.

CEP-37440 is a potent ATP-competitive, highly kinase selective, and orally active inhibitor of FAK1 and anaplastic lymphoma kinase (ALK). In addition to a favorable metabolic stability and pharmacokinetic profile preclinically, CEP-37440 is also a brain penetrant. CEP-37440 was able to inhibit the proliferation of certain IBC cells by decreasing the levels of phospho-FAK1 (Tyr 397); none of the cells expressed ALK. Studies using IBC xenograft models showed that CEP-37440 also effectively reduces the growth of the primary tumor xenografts and inhibits the development of brain metastases in mice.

ABT-751 is an orally bioavailable antimitotic sulfonamide, which binds to the colchicine-binding site on beta-tubulin and inhibits the polymerization of microtubules, leads to a block in the cell cycle at the G2M phase, resulting in cellular apoptosis. ABT-751 had been in phase Ⅱ clinical studies for the treatment of breast cancer; colorectal cancer; non-small cell lung cancer; renal cancer, prostate cancer, but these researches have been discontinued.

RO-5045337 (RG7112) is a small molecule that binds to a MDM2, a negative regulator of tumor-supressor protein p53. It was discovered by Roche and investigated in clinical trials against solid tumors, leukemias and sarcomas.

Serabelisib (INK1117 and TAK-117) is an orally bioavailable, PI3K p110α- isoform-specific inhibitor with an in vitro IC50 of 15 nM, highly selective against other isoforms (p110β, p110γ, and p110δ) and mTOR (no significant inhibitions at 1 μM concentration). It displayed significant efficacy in several PI3Kα mutant-specific preclinical mouse xenograft tumor models, and blocked signaling to Akt and inhibited the growth of cancer cells harboring wild-type or mutated p110α. Preclinical studies showed TAK-117 to have the low potential for disrupting glucose metabolism or for causing cardiac adverse events; in rats and monkeys, doses up to 50 mg/kg/day were well tolerated. Serabelisib is currently under clinical evaluation.

Naquotinib (ASP8273) is an orally available, irreversible, mutant-selective, epidermal growth factor receptor (EGFR) inhibitor, with potential antineoplastic activity. Naquotinib was found by mass spectrometry to covalently bind to a mutant EGFR (L858R/ T790M) via cysteine residue 797 in the kinase domain of EGFR with long-lasting inhibition of EGFR phosphorylation for 24 h. In the NSCLC cell lines harboring the above EGFR mutations, Naquotinib had IC50 values of 8-33 nM toward EGFR mutants, more potently than that of WT EGFR (IC50 value of 230 nM). In mouse xenograft models, Naquotinib induced complete regression of the tumors after 14 days of treatment. ASP8273 even showed activity in mutant EGFR cell line which is resistant to other EGFR TKIs. Naquotinib is in phase III clinical trials for the oral treatment of EGFR mutated non-small cell lung cancer (NSCLC).

KOSN-1724, also known as iso-fludelone, is the third-generation epothilone B analogue. It binds to tubulin and induces microtubule polymerization/reduces microtubule depolymerization, resulting in the inhibition of cell division and induction of apoptosis. KOSN-1724 is in phase I clinical trials for the treatment of solid tumors.

Sepantronium bromide (YM155) is a selective survivin suppressant that exhibits potent antitumor activities by inducing apoptosis and autophagy in various types of cancer. Sepantronium bromide inhibited the growth of various human cancer cell lines in vitro with GI50 values in the low nM range. Sepantronium bromide blocked the growth of 119 human cancer cell lines, with the greatest inhibition in lines derived from non-Hodgkin's lymphoma, hormone-refractory prostate cancer, ovarian cancer, sarcoma, non-small-cell lung cancer, breast cancer, leukemia, and melanoma, with an average GI50 of 15 nM. Sepantronium bromide inhibited the growth of tumor cell lines regardless of their p53 status and demonstrated significant antitumor activity in 5 mice xenograft models. It also caused tumor regressions in vivo, possibly by its effects in reducing intratumoral survivin expression levels and increasing apoptosis. Sepantronium Bromide had been in phase II clinical trials by Astellas for the treatment of prostate cancer, melanoma, non-Hodgkin's lymphoma, breast cancer, diffuse large B cell lymphoma, non-small cell lung cancer (NSCLC) and other solid tumors. This compound had also been in clinical trials by National Cancer Institute (NCI) for the treatment of solid tumors (phase I) and advanced non-small cell lung cancer (NSCLC) (phase II). However, all these researches about this compound for all indications were discontinued.

Roniciclib (BAY1000394) is a pan-cyclin-dependent kinase inhibitor that has been developed for treatment in small cell lung carcinoma and solid tumors. Roniciclib targets certain key proteins that are essential for the survival of cancer cells, resulting in decreased tumor growth. Phase I studies to evaluate the safety, tolerability and pharmacokinetics of roniciclib have been completed successfully. In phase II studies, roniciclib was found to be well tolerated and showed promising efficacy when combined with chemotherapy in small cell lung carcinoma patients. However, due to an observed safety signal (treatment-emergent adverse events) in one phase II study, other clinical trials have been discontinued and further development of roniciclib was terminated.