Erlotinib

Which is comparable with the 9.1 months observed with docetaxel and 9.4 months with pemetrexed in similar patient subsets Table 1 ; . The lack of efficacy data with docetaxel and pemetrexed in patients with a PS score of 3 makes erlotinib a preferred second-line therapy option in this group. Interestingly, the survival advantage with second-line therapy of advanced NSCLC occurs despite a low response rate 10% ; . This suggests that the clinical benefit derived from salvage therapy is achieved primarily through disease stabilization. Clinical trials are currently under way to compare the efficacy of erlotinib with that of single-agent chemotherapy for salvage therapy of advanced NSCLC. Although erlotinib has shown significant survival benefit across most patient subtypes, there are some subtypes that appear to exhibit greater benefit such as never smokers or those with bronchioloalveolar histology ; , and this is also being investigated further in clinical studies. Response to prior chemotherapy is another factor that may determine the choice of optimal second-line therapy. For instance, will second-line chemotherapy be equally efficacious in a patient experiencing rapid disease progression as in a responder to first-line therapy? Prior treatment with paclitaxel does not appear to reduce the second-line efficacy of either docetaxel or pemetrexed [36, 38], but for patients who do progress rapidly following firstline chemotherapy, would a mechanistically distinct chemotherapeutic agent or a targeted biologic agent be a better second-line choice? The answers to these questions are unclear at this time, and warrant further clinical evaluation. In the lung cancer study, in which 444 patients were treated with erlotinib and 229 with placebo, these correlations increased with rash severity. Figure 3. Induction of apoptosis in BxPC-3, HPAC, PANC-1, and MIAPaCa human pancreatic cancer cells. Cells were treated with erlotinib OSI ; 10 Amol L ; , celecoxib Cel; 10 Amol L ; , or the combination as described in Materials and Methods. There was a significant potentiation of apoptosis observed in BxPC-3, HPAC, and PANC-1 cells treated with erlotinib and celecoxib compared with cells treated with either agent alone. No potentiation of apoptosis was observed in the MIAPaCa cell line.
Validation is confirmed for several specific genes that may influence radiosensitization by erlotinib including egr-1, cxcl1, and il-1beta!

Enrolled in this trial Table 2 ; .7, 39 Of the 485 patients 76%developedrash anygrade ; placeboarm P 0.001 ; .7Severerash grade3-5 ; occurredin dosereductionswererequired 8 days; 87% of erlotinib-treated patients developed rash in 3 Tumor response significantly increased in patients treated witherlotinib 9%vs.1%withplacebo; P 0.001 ; 2.2monthswith erlotinib vs. 1.8 months with placebo; HR, 0.61; P 0.001 ; andmedianOS 6.7monthsand4.7months, respectively; HR, 0.7; P 0.001 ; werealsonotedintheerlotinibarm. tumorresponse and survival were favorably associated with development of rash.39The response to erlotinib treatment was higher in overall RR, ; , as was the median OS 11.1 months in 220 patients and 6.9 respectively; P 0.0001 ; .Interestingly, patientstreatedwitherlotinib treatedwithplacebo 2.2monthsvs.4.7months, respectively ; . 4.2 monthsvs.2.2months; HR, 1.85; P 0.0001 ; . survivingfor 28days, thusexcludingpatientswhodiedearly months in 136 patients with grade 1 rash compared with 3.4 amongpatientswhohadbeenalivefor 28days; however, no 7.4monthsin11 ; . dependingon theoccurrenceofrash, hasalsobeenperformedinthephaseIII TALENT TarcevaLungCancerInvestigation ; andTRIBUTE ; trials, which randomized patients to receive platinum agentbased chemotherapy in combination with erlotinib or IVNSCLC.25, 26In eithertrial, chemotherapy alone in the entire patient population TALENT trial: 9.9 months in the erlotinib arm vs. 10.1 months in the placebo arm; P 0.4863, and TRIBUTE trial: 10.6 months vs. 10.5 months, respectively; HR, 0.995; P 0.95 ; . However, in both trials, longer median OS was demonstrated didnot.IntheTALENTtrial, graderashwitherlotinib 10.6monthswithgrade1rash[28% of patients], 10.3 months with grade 2 rash [30% of patients], and 12.7 months with grade 3 rash [10% of patients] vs. 7.4 monthswithnorash[34%ofpatients]; P 0.0001 ; .25Although also observed in the placebo arm 12.3 months with grade 1 of patients] vs. 10.1 months with no rash [81% of patients]; P 0.3827 ; , TRIBUTEtrial, arm 10.8monthswithgrade1rash, 13.5monthswithgrade2 rash, and13.2monthswithgrade3 4rashvs.8.4monthswith norash ; 12.7monthswithgrade1rashand ; .42 and ertapenem.

TA-59. RESPONSE RATE TO SINGLE AGENT THERAPY WITH THE EGFR TYROSINE KINASE INHIBITOR ERLOTINIB IN RECURRENT GLIOBLASTOMA MULTIFORME: RESULTS OF A PHASE II STUDY Michael A. Vogelbaum, David Peereboom, Glen H.J. Stevens, Gene H. Barnett, and Cathy Brewer; Brain Tumor Institute and Department of Neurosurgery, Cleveland Clinic Foundation, Cleveland, Ohio, USA Erlotinib Tarceva, OSI-774 ; is an orally available, small-molecule epidermal growth factor receptor EGFR ; tyrosine kinase inhibitor. We have evaluated, in a single center Phase II trial, the response rate of erlotinib in single agent therapy of recurrent glioblastoma multiforme GBM ; . Patients with documented recurrent or progressive GBM who had received previous radiation therapy and cytotoxic chemotherapy were eligible for enrollment. No enzyme-inducing anti-epileptic agents were allowed. Patients were treated with 150 mg of erlotinib per day until tumor progression or study withdrawal. Tumor response was determined by MRI. Analysis for EGFR amplification was performed. Response data are available for 24 patients as of 5 2004; an additional 6 patients will have response rate data available prior to 11 2004. Of the 24 patients, 5 patients have shown partial responses PRs ; , 1 showed a PR of his original tumor but also developed a separate unresponsive focus, and 5 have had disease stabilization for greater than 3 months SD ; . Ten patients have had MRI-confirmed tumor progression PD ; within 3 months of starting erlotinib, and an additional 3 patients were taken off study because of neurological deterioration but without MRI evidence of tumor progression. Although a response has been seen in 10 of patients 5 PR 5 the responses have not been durable; the median time to progression of responders has been 154 days after the start of therapy N 7 ; . Seventeen patients have died since the start of the study. The pattern of subsequent treatment failure in responders has suggested a diffuse spread of tumor e.g., gliomatosis cerebri or leptomeningeal spread ; . Although these results are preliminary in nature, we are encouraged by the response rate observed to date. The relationship of response to EGFR amplification and or mutation will be discussed. The apparent lack of durability of response and the pattern of post-response failure may be due, in part, to limited drug penetration into the brain, an inadequate dose, and or tumor heterogeneity. The morphology of the suspension cells can be seen in Figure 1. The dark-grown cells do not accumulate chlorophyll, but do have a yellow appearance presumably due to accumulation of carotenoids or other pigments Fig. 1A ; . Under light microscopy, the suspension cells appear to be predominantly small clumps of cells, with the nucleus apparent and large cytoplasm with no obvious vacuole. No other subcellular organelles are visible at this magnification Fig. 1B ; . To determine the morphology of plastids in these cells, transmission electron microscopy was performed and compared to chloroplasts found in leaf mesophyll cells of in vitro grown plants. The leaf cell chloroplasts have well-developed membrane structures, are relatively uniform in size, and are localized around the periphery of the cell Fig. 1C ; . In contrast, plastids in the tobacco suspension cells are randomly distributed throughout the cell cytoplasm, heterogeneous in size but much smaller than in leaf cells, and have little to no apparent internal membrane structure. The plastids in suspension cells also contain large amounts of starch relative to leaf cell chloroplasts Fig. 1D ; . Confocal scanning microscopy was used to obtain a more precise measure of the diameter and volume of plastids in the different cell types. For this analysis, leaf tissue and suspension cells were derived from homoplasmic plastid transformed lines that express green fluorescent protein GFP; see below ; and measurements were based on GFP fluorescence visualized by the confocal microscope. From this analysis, the undeveloped plastids present in the suspension cells had an average diameter of 2.1 microns and volume of 4.9 cubic microns. In contrast, leaf cell chloroplasts had an average diameter of 7.7 microns and volume of 239 cubic microns data not shown ; . Therefore, the average leaf chloroplast diameter is approximately 4-fold and esmolol. The addition of erlotinib resulted in a statistically significant benefit in survival hazard ratio , 81; 95% confidence interval , 67- 97; p 5.

Abstract x ; , asco gi symposium 200 shepherd fa, pereira te, ciuleanu eh, et al a randomized placebo-controlled trial of erlotinib in patients with advanced non-small cell lung cancer nsclc ; following failure of 1st line or 2nd line chemotherapy. OSI Pharmaceuticals, Farmingdale, NY Treatment of second and third line patients with non-small cell lung carcinoma NSCLC ; with the EGF receptor kinase inhibitor erlotinib significantly increased survival relative to placebo. The molecular determinants which confer cell sensitivity in wild type wt ; EGFR tumors remain unclear. Anti-phosphotyrosine affinity chromatography and membrane isolation methods were used to select specific protein populations for identification and quantitation. Isobaric peptide labeling and uLC-MSMS mass spectrometry methods were employed to measure signaling networks associated in NSCLC lines sensitive H292, H358 ; , moderately sensitive H441, A549 ; and insensitive H460, H1703, Calu6 ; to the downsteam effects of EGFR kinase inhibition. Phosphoprotein and protein complexes associated with the differential temporal sensitivity and with cell-specific responses to EGFR pharmacological inhibition were identified using a multiplex isobaric peptide tagging approach. This methodology allowed for quantitation of protein abundance under several conditions within a single LC-MS MS experiment. In wt EGFR tumors, kinase blockade markedly disrupted complexes containing immediate signaling proteins, membrane adhesion complexes and internalization complexes in a manner correlating with sensitivity to erlotinib. The importance of an EGFR-dependent PI3 kinase pathway to erlotinib sensitivity was reinforced. We demonstrate that wild-type EGF receptor containing NSCLC lines grown both in culture and as xenografts show a range of sensitivities to EGF receptor inhibition dependent on the degree to which they have undergone an epithelial to mesenchymal transition EMT ; . NSCLC lines which express E-cadherin or to a lesser extent  -catenin showed greater sensitivity to EGF receptor inhibition in vitro and in xenografts. This was demonstrated by immunoblot and fluorescence confocal microscopy. In contrast NSCLC lines having undergone EMT, expressing vimentin and or fibronectin, were insensitive to the growth inhibitory effects of EGF receptor kinase inhibition in vitro and in xenografts, as shown by immunoblot, confocal microscopy and mass spectrometry. Analysis of pancreatic tumor lines sensitive or insensitive to EGF receptor inhibition also indicated E-cadherin epithelial ; expressing cells were erlotinib sensitive, while vimentin fibronectin mesenchymal ; expressing cells were insensitive. The loss of E-cadherin associated with EMT has been shown to correlate with poor prognosis in multiple solid tumor types. These data suggest EMT also may be a general biological switch rendering non-small cell lung and pancreatic tumors sensitive or insensitive to EGF receptor inhibition and etodolac.
TYKERB Product Information EGFR ; was found to be slower for lapatinib than for erlotinib and gefitinib. Lapatinib inhibits tumour cell proliferation in vitro, and inhibits the growth of ErbB1 EGFR ; and HER2 over-expressing xenograft tumours in mice. Inhibition of tumour growth was associated with decreased phosphorylation of ErbB1 EGFR ; and HER2 in tumour tissue. The growth inhibitory effects of lapatinib were evaluated in trastuzumab-conditioned cell lines. Lapatinib retained significant activity against breast cancer cell lines selected for resistance to trastuzumab by long-term growth in trastuzumab-containing medium in vitro. These findings suggest non-cross-resistance between these two HER2 directed agents. Pharmacokinetics Absorption: Absorption following oral administration of lapatinib is highly variable. Serum concentrations appear after a median lag time of 0.25 hours range 0 to 1.5 hours ; . Peak plasma concentrations Cmax ; of lapatinib are achieved approximately 4 hours after administration. Daily dosing of 1250 mg produces steady state geometric mean 95% confidence interval ; Cmax values of 2.43 1.57 to 3.77 ; g mL and AUC values of 36.2 23.4 to 56 ; g * mL. The absolute bioavailability of lapatinib has not been determined. Systemic exposure to lapatinib is increased when administered with food See Dosage and Administration and Interactions ; . Lapatinib AUC values were approximately 3and 4-fold higher Cmax approximately 2.5 and 3fold higher ; when administered with a low fat 5% fat [500 calories] ; or with a high fat 50% fat [1, 000 calories] ; meal, respectively. Distribution: Lapatinib is highly bound greater than 99% ; to plasma proteins. Metabolism: Lapatinib undergoes extensive metabolism, primarily by CYP3A4 and CYP3A5, with minor contributions from CYP2C19 and CYP2C8 to a variety of oxidated metabolites, none of which account for more than 14% of the dose recovered in the faeces or 10% of the lapatinib concentration in plasma. Furthermore, it is unlikely that any of these metabolites would contribute to the pharmacological activity of lapatinib. Lapatinib significantly inhibited the metabolism of the substrates of the recombinant CYP enzymes, CYP3A4 and CYP2C8 in vitro at clinically relevant concentrations ~ 5 M Lapatinib did not significantly inhibit the following enzymes in human liver microsomes: CYP2C9, CYP2C19 and CYP2D6 or UGT enzymes in vitro IC50 values were greater than or equal to 6.9 g mL ; . Lapatinib was reported to and ertapenem.