Oral BAY 43-9006 was well tolerated and appeared to provide some clinical benefits. Based on the results of this study, BAY 43-9006 at 400 mg bid continuous is recommended for ongoing and future studies.

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LEARNING OBJECTIVESAfter completing this course, the reader will be able to:1. Describe the mechanisms of action of sorafenib.2. Discuss the safety and toxicity data from phase I trials of sorafenib.3. Evaluate phase I and II trials of sorafenib with activity data. 4. Discuss future areas for research in the development of this drug.Access and take the CME test online and receive 1 AMA PRA Category 1 Credit ™ at CME.TheOncologist.com CME CME ABSTRACTSorafenib is an oral multikinase inhibitor that inhibits Raf serine/threonine kinases and receptor tyrosine kinases involved in tumor growth and angiogenesis. It has demonstrated preclinical and clinical activity in several tumor types. Sorafenib 400 mg twice daily (bid) has been approved in several countries worldwide for the treatment of renal cell carcinoma. This review summarizes key safety, pharmacokinetic, and efficacy data from four phase I, single-agent, dose-escalation studies with sorafenib in patients with advanced refractory solid tumors (n ‫؍‬ 173). These trials followed different treatment regimens (7 days on/7 days off, n ‫؍‬ 19; 21 days on/7 days off, n ‫؍‬ 44; 28 days on/7 days off, n ‫؍‬ 41; or continuous dosing, n ‫؍‬ 69) to establish the optimum dosing schedule. Sorafenib was generally well tolerated; most adverse events were mild to moderate in severity up to the defined maximum-tolerated dose of 400 mg twice daily (bid). The most frequently reported drugrelated adverse events at any grade included fatigue (40%), anorexia (35%), diarrhea (34%), rash/desquamation (27%), and hand-foot skin reaction (25%). Sorafenib demonstrated preliminary antitumor activity, particularly among patients with renal cell carcinoma or hepatocellular carcinoma: overall, two of 137 evaluable patients achieved partial responses and 38 (28%) had stable disease. Although there was high interpatient variability in plasma pharmacokinetics across these studies, this was not associated with an increased incidence or severity of toxicity. Preliminary studies suggest that phosphorylated extracellular signal-related kinase in tumor cells or peripheral blood lymphocytes may be a useful biomarker for measuring and, ultimately, predicting the effects of sorafenib. Based on these findings, continuous daily 400 mg bid sorafenib was chosen as the optimal regimen for phase II/III studies. Trials are ongoing in renal cell carcinoma, hepatocellular carcinoma, melanoma, and non-small cell lung cancer. The Oncologist 2007;12: 426 -437 Disclosure of potential conflicts of interest is found at the end of this article.

Topoisomerase I cleavage complexes can be induced by a variety of DNA damages and by the anticancer drug camptothecin. We have developed a ligation-mediated PCR (LM-PCR) assay to analyze replication-mediated DNA double-strand breaks induced by topoisomerase I cleavage complexes in human colon carcinoma HT29 cells at the nucleotide level. We found that conversion of topoisomerase I cleavage complexes into replicationmediated DNA double-strand breaks was only detectable on the leading strand for DNA synthesis, which suggests an asymmetry in the way that topoisomerase I cleavage complexes are metabolized on the two arms of a replication fork. Extension by Taq DNA polymerase was not required for ligation to the LM-PCR primer, indicating that the 3 DNA ends are extended by DNA polymerase in vivo closely to the 5 ends of the topoisomerase I cleavage complexes. These findings suggest that the replication-mediated DNA double-strand breaks generated at topoisomerase I cleavage sites are produced by replication runoff. We also found that the 5 ends of these DNA double-strand breaks are phosphorylated in vivo, which suggests that a DNA 5 kinase activity acts on the double-strand ends generated by replication runoff. The replication-mediated DNA doublestrand breaks were rapidly reversible after cessation of the topoisomerase I cleavage complexes, suggesting the existence of efficient repair pathways for removal of topoisomerase I-DNA covalent adducts in ribosomal DNA.DNA topoisomerases are ubiquitous enzymes that regulate the topological state of DNA. They participate in essential cellular processes, including replication, transcription, chromosome segregation, and recombination (22,34,71). Eukaryotic DNA topoisomerase I (top1) acts as a monomer, and its catalytic activity can be divided into four steps (61): (i) binding of the enzyme to duplex DNA, (ii) single-stranded DNA cleavage by a transesterification reaction in which a top1 tyrosinehydroxyl group becomes covalently linked to the 3Ј phosphate of a DNA phosphodiester bond to generate a 5Ј-hydroxyl DNA terminus, (iii) DNA relaxation by controlled rotation around the intact DNA strand (61); and (iv) religation of the cleaved DNA by nucleophilic attack from the 5Ј-hydroxyl DNA end and dissociation of the top1 tyrosyl residue from the 3Ј end. The topoisomerase-linked DNA breaks are commonly referred to as cleavage complexes (22,34,71). Under physiological conditions, they are short-lived catalytic intermediates.A number of physiological and environmental DNA modifications can inhibit top1 by inducing top1 cleavage complexes. These include DNA mismatches or abasic sites (37, 48, 73), oxidative base damage (47), base alkylation and carcinogenic adducts (44, 66), UV photoproducts (50, 62), and DNA breaks (11, 45). Trapping of top1 cleavage complexes is also the primary mechanism of action of camptothecin (CPT), a potent anticancer agent which reversibly inhibits the religation step of the top1 catalytic cycle (25,29,39,40). The cytotoxicity of top1 cleavage complexes is atte...

BackgroundPeritoneal carcinomatosis (PC) is an unmet medical need. Despite recent improvements, systemic chemotherapy has limited efficacy. We report the first application of intraperitoneal chemotherapy as a pressurized aerosol in human patients. MethodsThree end-stage patients with advanced PC from gastric, appendiceal, and ovarian origin were treated as a compassionate therapy. All patients had received previous systemic chemotherapy. A pressurized aerosol of CO2 loaded with doxorubicin 1.5 mg/m2 and cisplatin 7.5 mg/m2 (pressurized intraperitoneal aerosol chemotherapy, PIPAC) was applied into the abdomen for 30 min at a pressure of 12 mmHg and a temperature of 37 °C.ResultsNo side-effects >2 CTCAE were observed, and the procedures were well tolerated. Early hospital discharge was possible (days 2–5). Nuclear presence of doxorubicin was documented throughout the peritoneum, reaching high local concentration (≤4.1 μmol/g) and plasma concentration was low (4.0–6.2 ng/ml). PIPAC created no significant adhesions, could be repeated, and was applied 6×, 4×, and 2×. Two patients showed a complete and one a partial histological remission. Mean survival after the first PIPAC was 288 days. One patient is alive after 567 days.ConclusionsPIPAC shows superior pharmacological properties with high local concentration and low systemic exposure. PIPAC can induce regression of PC in chemoresistant tumors, using 10 % of a usual systemic dose.Electronic supplementary materialThe online version of this article (doi:10.1245/s10434-013-3213-1) contains supplementary material, which is available to authorized users.

BAY 43-9006 is a novel dual-action Raf kinase and vascular endothelial growth factor receptor (VEGFR) inhibitor that targets tumour cell proliferation and tumour angiogenesis. This Phase I study was undertaken to determine the safety profile, maximum tolerated dose (MTD), dose-limiting toxicities (DLTs), pharmacokinetics, and tumour response profile of oral BAY 43-9006 in patients with advanced, refractory solid tumours. BAY 43-9006 was administered daily for repeated cycles of 21 days on/7 days off. A total of 44 patients were enrolled at doses from 50 to 800 mg b.i.d. Pharmacokinetic profiles of BAY 43-9006 in plasma were determined during the first treatment cycle. The most frequently reported adverse events over multiple cycles were gastrointestinal (75%), dermatologic (71%), constitutional (68%), pain (64%), or hepatic (61%) related. A MTD of 400 mg b.i.d. BAY 43-9006 was defined. BAY 43-9006 was absorbed rapidly; steady-state conditions were reached within 7 days. BAY 43-9006 exposure increased nonproportionally with increasing dose. In all, 32 patients were evaluated for tumour response: 15 patients showed tumour progression, 16 patients experienced stable disease (46 months in eight patients), and one patient with renal cell carcinoma achieved a partial response. BAY 43-9006 given for 21 days with 7 days off treatment was safe, well tolerated, and showed antitumour activity.

The mitogen activated protein kinases (MAPKs) are conserved proteins that regulate cell growth, division and death. Although activated in the cytosol, the MAPKs translocate to the nucleus upon activation and phosphorylate a large number of nuclear proteins. Investigating how Ras transmits extracellular growth signals, the MAPK pathway has emerged as the crucial route between membrane-bound Ras and the nucleus. The MAPK pathway represents a cascade of phosphorylation events including three pivotal kinases, namely Raf, MEK (MAP kinase kinase), and ERK (MAP kinase). These kinases present new opportunities for the development of novel anti-cancer drugs designed to be target-specific and probably less toxic than conventional chemotherapeutic agents. A number of drugs inhibiting Ras, Raf or MEK are currently under clinical investigation. This review addresses the rationale for targeting the MAP kinase pathway and the current status of various pharmacological approaches.

Background:In a phase I dose-escalation study, regorafenib demonstrated tolerability and antitumour activity in solid tumour patients. The study was expanded to focus on patients with metastatic colorectal cancer (CRC).Methods:Patients received oral regorafenib 60–220 mg daily (160 mg daily in the extension cohort) in cycles of 21 days on, 7 days off treatment. Assessments included toxicity, response, pharmacokinetics and pharmacodynamics.Results:Thirty-eight patients with heavily pretreated CRC (median 4 prior lines of therapy, range 0–7) were enrolled in the dose-escalation and extension phases; 26 patients received regorafenib 160 mg daily. Median treatment duration was 53 days (range 7–280 days). The most common treatment-related toxicities included hand–foot skin reaction, fatigue, voice change and rash. Twenty-seven patients were evaluable for response: 1 achieved partial response and 19 had stable disease. Median progression-free survival was 107 days (95% CI, 66–161). At steady state, regorafenib and its active metabolites had similar systemic exposure. Pharmacodynamic assessment indicated decreased tumour perfusion in most patients.Conclusion:Regorafenib showed tolerability and antitumour activity in patients with metastatic CRC. This expanded-cohort phase I study provided the foundation for further clinical trials of regorafenib in this patient population.