[Show abstract][Hide abstract] ABSTRACT: Background:Myelotoxicity during initial cycles of chemotherapy for Hodgkin lymphoma is associated with better outcome, supporting the concept of individualised dosing based on pharmacodynamic end points to optimise results. This study was performed to identify the maximum tolerated dose (MTD) of doxorubicin within cycles 1-3 ABVD (doxorubicin, bleomycin, vinblastine, dacarbazine). Circulating biomarkers of response (nucleosomal DNA, nDNA) and epithelial toxicity (Cytokeratin 18, CK18) were also measured.Methods:Dose escalation of doxorubicin in cycles 1-3 ABVD supported by pegfilgrastim was performed on a six-patient cohort basis (35, 45 and 55 mg m(-2)) with doxorubicin reduced to 25 mg m(-2) or omitted in cycles 4-6 to maintain cumulative exposure of 103-130% standard ABVD. BVD was given at standard doses throughout. Six additional subjects were recruited at the MTD.Results:Twenty-four subjects were recruited. Dose-limiting toxicities (DLTs) of grade 3 neuropathy, pneumonitis, palmar-plantar erythema and neutropenic infection were observed at 55 mg m(-2), so 45 mg m(-2) was declared the MTD. In patients who subsequently experienced DLT at any time, large increases in CK18 were seen on day 3 of cycle 1 ABVD.Conclusion:Escalated ABVD incorporating doxorubicin at 45 mg m(-2) in cycles 1-3 can be delivered safely with pegfilgrastim support. Circulating cell death biomarkers may assist in the development of future individualised dosing strategies.British Journal of Cancer advance online publication, 17 October 2013; doi:10.1038/bjc.2013.605 www.bjcancer.com.
British Journal of Cancer 10/2013; · 5.08 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: There is increasing use of circulating cell death biomarkers in patients and clinical trials. Knowledge of the potential noise and confounders in assays are vital for biomarker interpretation. The daily and diurnal variability and effect of menstruation and exercise on nucleosomal DNA (nDNA), total cytokeratin 18 (tK18) and apoptotic specific cytokeratin 18 (cK18) were assessed in 3 cohorts of healthy volunteers; 12 pre-menopausal women to establish the effect of menstruation, 12 men to perform exercise and 12 post-menopausal women. All 36 subjects were evaluated to establish daily and diurnal variability. Estimates of variability were derived in a linear mixed effects model and presented as the back transformed coefficient of variation (%CV). Minimal variation was seen in cK18 (11%CV) and tK18 (11%CV) but higher variability was seen in nDNA (85%CV). K18 results appeared stable throughout the day but a possible peak in nDNA was seen at 15:00. Menstruation had minimal effects but exercise led to immediate short-lived elevations in cell death biomarkers. There is no evidence of significant daily variability in K18 assays. We recommend subjects should not exercise for 6h before blood sampling.
Journal of pharmaceutical and biomedical analysis 06/2013; 84C:184-188. · 2.45 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background:Circulating total cytokeratin 18 (tCK18) and/or caspase cleaved cytokeratin 18 (cCK18) (measured by M65 and M30 enzyme-linked immunosorbent assays (ELISAs), respectively) are used as pharmacodynamic (PD) biomarkers of epithelial cell death in clinical trials. Having validated these ELISAs, we assessed their utility in colorectal cancer (CRC).Methods:We applied the assays in several settings: 53 controls; 97 patients undergoing surgery and 74 patients with metastatic CRC undergoing chemotherapy (55 first line; 56 patients with repeated sampling through chemotherapy). Prognostic significance was evaluated using Kaplan-Meier life tables and Cox models; PD utility was assessed by analysis of repeated measures.Results:Median cCK18 and tCK18 levels were elevated in patients with cancer (both P=0.0001), and among cancer patients, there were increasing trends from early to advanced stages (both P(trends)=0.0001). Increasing tCK18 predicted for reduced survival after surgery with curative intent (adjusted hazard ratio (HR) for doubling in concentration 1.77, 95% CI: 1.04, 3.01) and after first-line chemotherapy in metastatic disease (adjusted HR per doubling in concentration=1.78, 95% CI: 1.37, 2.30). In patients with progressive disease during chemotherapy, repeated sampling revealed profiles with high baselines and progressive upwardly increases after cycle 1.Conclusion:This study provides evidence for cytokeratin 18 (CK18) as a prognostic and PD biomarker in patients with CRC and supports continued deployment of circulating CK18 in biomarker-enhanced trials.
British Journal of Cancer 09/2012; 107(9):1518-24. · 5.08 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The endothelin axis and the endothelin A (ET(A)) receptor have been implicated in tumor development and bone metastasis. This study aimed to investigate the pharmacokinetic (PK) and safety profiles of the specific ET(A) receptor antagonist, zibotentan, in elderly, male Chinese patients with advanced solid tumors. The PK data generated in these Chinese patients were further compared with those previously reported in Japanese and Caucasian patient populations.
In this Phase I, open-label study, patients received a single dose of zibotentan 10 mg on Day 1, followed by a 72-h washout period and 12 consecutive days of once-daily zibotentan 10 mg.
Fifteen patients received at least one dose of zibotentan 10 mg. Exposure was demonstrated in all patients and the PK profiles following single dosing and multiple dosing showed relatively rapid absorption, decline in a monophasic manner, a modest amount of accumulation, and relatively low apparent clearance and volume of distribution. Zibotentan was well tolerated with no new safety concerns. Adverse events reported in >1 patient were pyrexia (n = 4), constipation (n = 3), headache (n = 3) and peripheral edema (n = 2). Comparative analysis found no evidence of significant differences in zibotentan exposure between the Chinese patients in our study, and the previous Japanese and Caucasian studies.
The PK and safety profiles of zibotentan determined in this Chinese patient population are similar to those previously reported. Our findings suggest no clinically relevant inter-ethnic differences in zibotentan disposition between the patient populations analyzed.
Cancer Chemotherapy and Pharmacology 05/2012; 70(1):57-63. · 2.80 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Olaparib (AZD2281) is a potent oral poly(ADP-ribose) polymerase inhibitor with anti-tumour activity and acceptable toxicity as monotherapy in patients with BRCA-deficient cancers. The vascular endothelial growth factor receptor inhibitor bevacizumab has been incorporated into standard of care with chemotherapy in various tumours. This phase I study established the safety, tolerability and clinical pharmacokinetics of olaparib alone and in combination with bevacizumab.
Patients with advanced solid tumours received increasing doses of continuous oral olaparib (100, 200 and 400 mg b.i.d. capsule formulation) in combination with bevacizumab (10 mg kg(-1) intravenous q2w).
In all, 12 patients enrolled and received treatment. The most common adverse events (AEs) related to olaparib were grade 1/2 nausea and fatigue. No haematological parameters were reported as AEs. No serious AEs related to olaparib or dose-limiting toxicities (DLTs) were reported. Three patients discontinued due to AEs, two patients discontinued both olaparib and bevacizumab and one patient discontinued olaparib. Five patients received combination treatment for over 6 months. There was no evidence that bevacizumab affected olaparib.
The combination of olaparib 400 mg b.i.d. with bevacizumab 10 mg kg(-1) q2w was generally well tolerated with no DLTs. This combination could be considered for future clinical investigation.
British Journal of Cancer 01/2012; 106(3):468-74. · 5.08 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This trial describes a first-in-man evaluation of RH1, a novel bioreductive drug activated by DT-diaphorase (DTD), an enzyme overexpressed in many tumours.
A dose-escalation phase I trial of RH1 was carried out. The primary objective was to establish the maximum tolerated dose (MTD) of RH1. Secondary objectives were assessment of toxicity, pharmacokinetic determination of RH1 and pharmacodynamic assessment of drug effect through measurement of DNA cross linking in peripheral blood mononuclear cells (PBMCs) and tumour, DTD activity in tumour and NAD(P)H:quinone oxidoreductase 1 (NQO1) polymorphism status.
Eighteen patients of World Health Organization performance status of zero to one with advanced refractory solid malignancies were enrolled. MTD was 1430 μg/m(2)/day with reversible bone marrow suppression being dose limiting. Plasma pharmacokinetic analysis showed RH1 is rapidly cleared from blood (t(1/2) = 12.3 min), with AUC increasing proportionately with dose. The comet-X assay demonstrated dose-related increases in DNA cross linking in PBMCs. DNA cross linking was demonstrated in tumours, even with low levels of DTD. Only one patient was homozygous for NQO1 polymorphism precluding any conclusion of its effect.
RH1 was well tolerated with predictable and manageable toxicity. The MTD of 1430 μg/m(2)/day is the dose recommended for phase II trials. The biomarkers of DNA cross linking, DTD activity and NQO1 status have been validated and clinically developed.
Annals of Oncology 03/2011; 22(7):1653-60. · 7.38 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Treatment efficacy and toxicity are difficult to predict in lymphoma patients. In this study, the utility of circulating biomarkers in predicting and/or monitoring treatment efficacy/toxicity were investigated.
Circulating biomarkers of cell death (nucleosomal DNA (nDNA) and cytokeratin 18 (CK18)), and circulating FLT3 ligand, a potential biomarker of myelosuppression, were assessed before and serially after standard chemotherapy in 49 patients with Hodgkin and non-Hodgkin lymphoma. Cytokeratin 18 is not expressed in lymphoma cells so is a potential biomarker of epithelial toxicity in this setting. Tumour response was assessed before and after completion of chemotherapy by 2D and 3D computed tomography radiological response.
Baseline nDNA level was significantly higher in all lymphoma subtypes compared with 61 healthy controls and was prognostic for progression-free survival in diffuse large B-cell lymphoma (DLBCL). Decreases in nDNA levels were observed in the first week after chemotherapy; in FL, early falls in nDNA predicted for long remission following therapy. In DLBCL, elevations in nDNA occurred in cases with progressive disease. Circulating CK18 increased within 48 h of chemotherapy and was significantly higher in patients experiencing epithelial toxicity graded >3 by Common Terminology for Classification of Adverse Events criteria. FLT3 ligand was elevated within 3-8 days of chemotherapy initiation and predicted those patients who subsequently developed neutropenic sepsis.
These data suggest circulating biomarkers contribute useful information regarding tumour response and toxicity in patients receiving standard chemotherapy and have potential utility in the development of individualised treatment approaches in lymphoma. These biomarkers are now being tested within multicentre phase III trials to progress their qualification.
British Journal of Cancer 02/2011; 104(4):719-25. · 5.08 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Genetic alterations can determine the natural history of cancer and its treatment response. With further advances in DNA sequencing technology, multiple novel genetic alterations will be discovered which could be exploited as prognostic, predictive and pharmacodynamic biomarkers in the development and use of cancer therapeutics. As such, the importance in clinical practice of efficient and robust somatic mutation testing in solid tumours cannot be overemphasized in the current era of personalized medicine. However, significant challenges remain regarding the testing of genetic biomarkers in clinical practice. Reliance on archived formalin fixed, paraffin embedded tumour, obtained from diagnostic biopsies, for testing somatic genetic alterations could restrict the scientific community in asking relevant questions about a patient's cancer biology. Problems inherent with using formalin fixed, archival tissue are well recognized and difficult to resolve. It could be argued that to achieve rapid and efficient incorporation of genetic biomarkers into clinical practice, somatic mutation testing in cancer patients should be simpler, less invasive using a readily available clinical sample, whilst maintaining robustness and reproducibility. In this regard, use of circulating free DNA (cfDNA) from plasma or serum as an alternative and/or additional source of DNA to test cancer specific genetic alterations is an attractive proposition. In light of encouraging results from recent studies, this mini review will discuss the current role and future potential of somatic mutation testing from circulating or cell free DNA derived from the blood of patients with solid tumours.
[Show abstract][Hide abstract] ABSTRACT: To investigate potential differences in zibotentan pharmacokinetics between Japanese and Caucasian patients with hormone-resistant prostate cancer (HRPC) following single and multiple dosing.
In the Japanese study, 18 patients received a single dose of zibotentan 5, 10 or 15 mg followed by 72 h washout before 26 days' once-daily dosing. In the Caucasian study, 21 patients received a single dose of zibotentan 5, 10 or 15 mg followed by 72 h washout before 12 days' once-daily dosing.
Pharmacokinetic parameters were similar between populations. Absorption of zibotentan was rapid with maximum plasma concentrations typically achieved within 3 h of dosing. Mean clearance, 17.9 and 18.7 ml/min in Japanese and Caucasian patients, respectively (range 7.0 - 36.3 ml/min in Japanese patients and 7.8 - 29.5 ml/min in Caucasian patients) and volume of distribution, 14.0 and 15.6 l for Japanese and Caucasian patients, respectively (range 7.9 - 29.1 l in Japanese patients and 9.6 - 23.8 l in Caucasian patients) were relatively low, and t1/2 was approximately 12 h (range 5.7 - 18.8 h in Japanese patients and 5.0 - 22.9 h in Caucasian patients) following single dosing. Little accumulation was observed following daily dosing and multiple-dose pharmacokinetics were predictable. Exposure levels achieved in some Japanese patients receiving zibotentan 15 mg were higher than those observed in Caucasian patients, however, this may be due to differences in body weight, as exposure levels were similar when data were normalized for body weight. Zibotentan was well tolerated in both populations.
There are no clinically relevant differences in the disposition and pharmacokinetics of zibotentan between Japanese and Caucasian patients with HRPC.
International journal of clinical pharmacology and therapeutics 11/2010; 48(11):708-17. · 1.20 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Erlotinib and pemetrexed are approved single agents for second-line treatment of non-small-cell lung cancer (NSCLC) and, in combination, have shown synergistic antitumor activity in NSCLC cell lines. We investigated the safety, pharmacokinetics and preliminary efficacy of combined erlotinib-pemetrexed in patients with refractory advanced NSCLC.
A nonrandomized, open-label, phase IB study was performed in patients with advanced NSCLC whose disease had progressed on or following first-line chemotherapy with a platinum-containing regimen or for whom the erlotinib-pemetrexed combination was considered appropriate. Patients received i.v. pemetrexed 500-700 mg/m² every 3 weeks and oral erlotinib 100-150 mg/day.
Twenty patients were recruited. The most common adverse events (AEs) were rash, diarrhea and fatigue. Serious AEs occurred in eight patients (three treatment related) and there were eight deaths (none treatment related). Dose-limiting toxic effects were not experienced up to erlotinib 150 mg/day plus pemetrexed 600 mg/m². Concurrent administration did not affect pharmacokinetic parameters. Two patients achieved partial responses and nine had stable disease.
Erlotinib-pemetrexed combination is well tolerated at doses equal to the licensed single-agent doses (150 mg/day and 500 mg/m², respectively). The good tolerability profile and promising efficacy indicate that this combination warrants further investigation for patients with advanced NSCLC.
Annals of Oncology 05/2010; 21(11):2233-9. · 7.38 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: An intravenous (IV) erlotinib formulation has not been characterized in cancer patients but may be useful in those with gastrointestinal abnormalities that impact on the ability to take oral medication. This study sought to determine the maximum tolerated dose (MTD) of erlotinib administered as a single 30-min infusion in patients with advanced solid tumors and absolute bioavailability of erlotinib tablets at matched doses.
This was a two-center, open label, Phase I, dose-escalation and bioavailability study of single dose IV and oral erlotinib.
The highest escalated IV erlotinib dose achieved was 100 mg, with only mild adverse events reported. The MTD for IV erlotinib was not reached as a predetermined erlotinib plasma concentration cap of 4 microg/mL was exceeded in 3/6 patients. No dose-limiting toxicity was observed. Median bioavailability of erlotinib tablets was 76%.
A 100 mg single IV dose of erlotinib, given as a 30-min infusion, was well tolerated with only minor adverse events and the high level of bioavailability of oral erlotinib was confirmed.
Cancer Chemotherapy and Pharmacology 12/2009; 66(1):53-8. · 2.80 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Evasion of apoptosis contributes to the pathogenesis of solid tumours including non-small cell lung cancer (NSCLC). Malignant cells resist apoptosis through over-expression of inhibitor of apoptosis proteins (IAPs), such as X-linked IAP (XIAP).
A phenylurea-based small molecule inhibitor of XIAP, XIAP antagonist compound (XAC) 1396-11, was investigated preclincally to determine its ability to sensitise to clinically relevant cytotoxics, potentially allowing dose reduction while maintaining therapeutic efficacy.
XIAP protein expression was detected in six NSCLC cell lines examined. The cytotoxicity of XAC 1396-11 against cultured NSCLC cell lines in vitro was concentration- and time-dependent in both short-term and clonogenic assays. XAC 1396-11-induced apoptosis was confirmed by PARP cleavage and characteristic nuclear morphology. XAC 1396-11 synergised with vinorelbine+/-cisplatin in H460 and A549 NSCLC cells. The mechanism of synergy was enhanced apoptosis, shown by increased cleavage of caspase-3 and PARP and by the reversal of synergy by a pan-caspase inhibitor. Synergy between XAC 1396-11 and vinorelbine was augmented by optimising drug scheduling with superior effects when XAC 1396-11 was administered before vinorelbine.
These preclinical data suggest that XIAP inhibition in combination with vinorelbine holds potential as a therapeutic strategy in NSCLC.
British Journal of Cancer 11/2009; 102(1):97-103. · 5.08 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This study investigated the potential clinical utility of circulating free DNA (cfDNA) as a source of BRAF mutation detection in patients enrolled into a phase II study of AZD6244, a specific MEK1/2 inhibitor, in patients with advanced melanoma.
BRAF mutations were detected using Amplification Refractory Mutation System allele-specific PCR. BRAF mutation status was assessed in serum-derived cfDNA from 126 patients enrolled into the study and from 94 matched tumour samples.
Of 94 tumour samples, 45 (47.9%) were found to be BRAF mutation positive (BRAF+). Serum-derived cfDNA was BRAF+ in 33 of 126 (26.2%) samples, including in five samples for which tumour data were unavailable. Of BRAF+ tumours, 25 of 45 (55.6%) were BRAF+ in cfDNA. In three cases in which the tumour was negative, cfDNA was BRAF+. Progression-free survival (PFS) of patients with BRAF+ tumour and cfDNA was not significantly different compared with tumour BRAF+ but cfDNA BRAF-negative patients, indicating that cfDNA BRAF detection is not associated with poorer prognosis on PFS in stage III/IV advanced melanoma.
These data demonstrate the feasibility of BRAF mutation detection in cfDNA of patients with advanced melanoma. Future studies should aim to incorporate BRAF mutation testing in cfDNA to further validate this biomarker for patient selection.
British Journal of Cancer 11/2009; 101(10):1724-30. · 5.08 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: AZD5438 is an orally bioavailable inhibitor of cyclin E-cdk2, cyclin A-cdk2 and cyclin B-cdk1 complexes. Three phase I studies assessed the clinical safety, tolerability, pharmacokinetics and pharmacodynamics of AZD5438 when administered in different dosing schedules.
AZD5438 was administered four times daily, once every 7 days (study 1), for 14 consecutive days followed by 7 days of rest (study 2), or continuously (study 3), to patients with advanced solid tumours. Dose escalation proceeded until the emergence of dose-limiting toxic effects.
Sixty-four patients were included across the three studies (19, 17 and 28, respectively). Nausea and vomiting were the most common adverse events. When dosed continuously, 40 mg four times daily was considered intolerable, and due to safety issues, all studies were terminated prematurely. Consequently, no intolerable dose was identified during the weekly schedule. Pharmacokinetics demonstrated dose-proportional exposure, high interpatient variability and accumulation after multiple doses. Skin biopsies indicated reduced retinoblastoma protein phosphorylation at cdk2 phospho-sites; other pharmacodynamic assessments did not reveal consistent trends.
AZD5438 was generally well tolerated in a weekly dosing schedule, but not in continuous schedules. The clinical development programme for AZD5438 was discontinued owing to tolerability and exposure data from these studies.
Annals of Oncology 10/2009; 21(4):884-94. · 7.38 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Lomeguatrib, an O(6)-methylguanine-DNA methyltransferase inactivator, was evaluated in an extended dosing regimen with temozolomide, designed according to pharmacodynamic data from previous studies. Patients with unresectable stage 3 or 4 cutaneous or unknown primary melanoma metastases were treated with lomeguatrib 40 mg, b.i.d. for 10 or 14 days and temozolomide 75-100 mg m(-2) on days 1-5. Drugs were administered orally with cycles repeated every 28 days, for up to six cycles. A total of 32 patients were recruited to the study. Lomeguatrib for 10 days with temozolomide 75 mg m(-2) was established as the optimal extended lomeguatrib dosing schedule, with haematological toxicity being dose limiting. There were two partial responses to treatment giving an overall response rate of 6.25%. Extending lomeguatrib administration beyond that of temozolomide requires a reduced dose of the latter agent. Only limited clinical activity was seen, suggesting no advantage for this regimen over conventional temozolomide administration in the treatment of melanoma.
British Journal of Cancer 05/2009; 100(8):1245-9. · 5.08 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Patients and methods Results Discussion References Acknowledgements Figures and TablesWe evaluated the pharmacodynamic effects of the O6-methylguanine-DNA methyltransferase (MGMT) inactivator lomeguatrib (LM) on patients with melanoma in two clinical trials. Patients received temozolomide (TMZ) for 5 days either alone or with LM for 5, 10 or 14 days. Peripheral blood mononuclear cells (PBMCs) were isolated before treatment and during cycle 1. Where available, tumour biopsies were obtained after the last drug dose in cycle 1. Samples were assayed for MGMT activity, total MGMT protein, and O6-methylguanine (O6-meG) and N7-methylguanine levels in DNA. MGMT was completely inactivated in PBMC from patients receiving LM, but detectable in those on TMZ alone. Tumours biopsied on the last day of treatment showed complete inactivation of MGMT but there was recovery of activity in tumours sampled later. Significantly more O6-meG was present in the PBMC DNA of LM/TMZ patients than those on TMZ alone. LM/TMZ leads to greater MGMT inactivation, and higher levels of O6-meG than TMZ alone. Early recovery of MGMT activity in tumours suggested that more protracted dosing with LM is required. Extended dosing of LM completely inactivated PBMC MGMT, and resulted in persistent levels of O6-meG in PBMC DNA during treatment.Keywords: O6-methylguanine-DNA methyltransferase, lomeguatrib, temozolomide, melanoma
British Journal of Cancer 04/2009; 100(8):1250-1256. · 5.08 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Within the era of molecularly targeted anticancer agents, it has become increasingly important to provide proof of mechanism as early on as possible in the drug development cycle, especially in the clinic. Selective activation of apoptosis is often cited as one of the major goals of cancer chemotherapy. Thus, the present minireview focuses on a discussion of the pros and cons of a variety of methodological approaches to detect different components of the apoptotic cascade as potential biomarkers of programmed cell death. The bulk of the discussion centres on serological assays utilising the technique of ELISA, since here there is an obvious advantage of sampling multiple time points. Potential biomarkers of apoptosis including circulating tumour cells, cytokeratins and DNA nucleosomes are discussed at length. However, accepting that a single biomarker may not have the power to predict proof of concept and patient outcome, it is clear that in the future more emphasis will be placed on technologies that can analyse panels of biomarkers in small volumes of samples. To this end the increased throughput afforded by multiplex ELISA technologies is discussed.
British Journal of Cancer 10/2008; 99(6):841-6. · 5.08 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To evaluate the tumour response to lomeguatrib and temozolomide (TMZ) administered for 5 consecutive days every 4 weeks in patients with metastatic colorectal carcinoma. Patients with stage IV metastatic colorectal carcinoma received lomeguatrib (40 mg) and TMZ (50-200 mg m(-2)) orally for 5 consecutive days every 4 weeks. Response was determined every two cycles. Pharmacokinetics of lomeguatrib and TMZ as well as their pharmacodynamic effects in peripheral blood mononuclear cells (PBMC) were determined. Nineteen patients received 49 cycles of treatments. Despite consistent depletion of O(6)-methylguanine-DNA methyltransferase in PBMC, none of the patients responded to treatment. Three patients had stable disease, one for the duration of the study, and no fall in carcinoembryonic antigen was observed in any patient. Median time to progression was 50 days. The commonest adverse effects were gastrointestinal and haematological and these were comparable to those of TMZ when given alone. This combination of lomeguatrib and TMZ is not efficacious in metastatic colorectal cancer. If further studies are to be performed, emerging data suggest that higher daily doses of lomeguatrib and a dosing period beyond that of TMZ should be evaluated.
British Journal of Cancer 06/2008; 98(10):1614-8. · 5.08 Impact Factor