The treatment of non-small-cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) inhibitors is made challenging by acquired resistance caused by somatic mutations. Third-generation EGFR inhibitors have been designed to overcome resistance through covalent binding to the Cys 797 residue of the enzyme, and these inhibitors are effective against most clinically relevant EGFR mutants. However, the high dependence of these recent EGFR inhibitors on this particular interaction means that additional mutation of Cys 797 results in poor inhibitory activity, which leads to tumor relapse in initially responding patients. A new generation of irreversible and reversible mutant EGFR inhibitors was developed with strong noncovalent binding properties, and these compounds show high inhibitory activities against the cysteine-mutated L858R/T790M/C797S EGFR.

EO9 is a novel and fully synthetic bioreductive alkylating indoloquinone. Although structurally-related to mitomycin C, EO9 exhibits a distinct preclinical antitumour profile and there are also differences in its biochemical activation. In this study, EO9 was found to demonstrate preferential cytotoxicity against solid tumours in vitro as compared to leukaemia cell lines both in the Corbett two-tumour assay and in the disease-oriented human tumour cell line panel of the U.S. National Cancer Institute. In the latter system activity was particularly apparent in colon, melanoma and central nervous system lines, together with some renal and non-small cell lung lines. Preferential cytotoxicity towards hypoxic versus aerobic EMT6 mouse mammary tumour cells was observed. In vivo, EO9 was inactive against the P388 murine leukaemia, while exerting significant antiproliferative effects against several murine and human solid tumours, including the generally resistant MAC mouse colon tumours and gastric, ovarian and breast xenografts. These results confirmed in vitro observations of preferential solid tumour activity. In animal toxicology studies, EO9 induced vascular congestion in the gastrointestinal tract, but no significant bone marrow toxicity. The LD10 value of EO9 after a single intravenous injection into mice was 9 mg/kg (27 mg/m2). A dose of one-tenth of the mouse equivalent LD10 (2.7 mg/m2), the recommended starting dose for clinical phase I studies, was found to be safe in rats. Considering its distinct mechanism of bioactivation as compared to mitomycin C, its preferential solid tumour activity, its excellent activity against hypoxic cells, and lack of significant bone marrow toxicity in animals studies, EO9 has been selected for clinical evaluation within the framework of the EORTC.

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Summary 2-(4-Aminophenyl)benzothiazole molecules substituted in the 3 position of the phenyl ring with a halogen atom or methyl moiety comprise a group of compounds that potently inhibit specific human ovarian carcinoma cell lines. G150 values fall within the nm range. Inhibition is highly selective -whereas the G150 value in IGROV1 cells consistently lies at < 10 nM, SK-OV-3 presents G150 values > 10jIM. Biphasic dose-response relationships were observed in sensitive cell lines after 48-h drug exposure. COMPARE analyses revealed the very similar profiles of anti-tumour activity of 3-substituted benzothiazoles and 5-(4-dimethylaminophenylazo)quinoline, with Pearson correlation coefficients > 0.65. Anti-tumour activity extended to preliminary in vivo tests. The growth of OVCAR-3 cells in polyvinylidene fluoride (PVDF) hollow fibres implanted in the peritoneal cavity of mice was inhibited by more than 50% after intraperitoneal (i.p

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We have shown previously that the flavonoid quercetin (3,3',4',5,7-pentahydroxyflavone) enhances the antiproliferative activity of cis-diamminedichloroplatinum(II) (cis-DDP) in vitro. In order to investigate whether this observation could be exploited in cancer treatment, we tested this drug combination in human tumor xenografts. The established human large-cell cancer of the lung (LXFL 529) was implanted s.c. into nude mice. Tumors were allowed to grow to a mean diameter of approximately 5 mm and the animals were subsequently treated intraperitoneally with quercetin, cis-DDP or a combination of both. Treatment was given 3 times at 3-day intervals. Twenty milligrams quercetin per kg body weight caused no inhibition in tumor growth compared to untreated controls; 3 mg cis-DDP per kg body weight with the same time schedule reduced tumor growth, compared to quercetin-treated and control animals. Concomitant treatment with 20 mg quercetin and 3 mg cis-DDP per kg body weight reduced tumor growth to a significantly greater degree than cis-DDP alone. Toxicity of this treatment was relatively low as determined by measurements of the body weight of the mice. A combination of 4 mg or 5 mg cis-DDP with 20 mg quercetin per kg body weight also reduced tumor growth compared to single cis-DDP treatment. The toxicity of treatment with these increased doses was high, as shown by the high lethality and the loss of body weight of surviving animals.

Two series of phosphodiester ether lipid analogs with (N-methylmorpholino)ethyl or (N-methylpiperidino)ethyl polar head groups and long aliphatic or alkoxyethyl chains in the nonpolar portion of the molecule were synthesized as potential antineoplastic agents. The cytotoxic activity of these compounds (9-19) was evaluated in vitro against a panel of six human tumor xenografts and in two biochemical, mechanism-based screens (cdc2 kinase and cdc25 phosphatase). Analogs 13, 14, 17, and 19 showed activity in the in vitro tests. Specifically, 14 and 17 were more active than the reference compound hexadecylphosphocholine (Miltefosine, He-PC) while 13 and 19 possessed activity similar to that of the control. Of the analogs tested the one with the highest potency and least toxicity (17) has an N-methylpiperidino head group and a C16 alkyl chain. In the mechanism-based tests 11 showed weak inhibitory activity in the cdc25 phosphatase screen.