Plasma ESR1 mutations and outcome to first-line paclitaxel and bevacizumab in patients with advanced ER-positive/HER2-negative breast cancer.

BACKGROUND: ESR1 mutations have been identified as mechanism for endocrine resistance and are also associated with a decreased overall survival. We assessed ESR1 mutations in circulating tumor DNA (ctDNA) for impact on outcome to taxane-based chemotherapy in advanced breast cancer patients. METHODS: ESR1 mutations were determined in archived plasma samples from patients treated with paclitaxel and bevacizumab (AT arm, N = 91) in the randomized phase II ATX study. Samples collected at baseline (n = 51) and at cycle 2 (n = 13, C2) were analyzed using a breast cancer next-generation sequencing panel. This study was powered to detect a benefit in progression-free survival (PFS) at six months for patients treated with paclitaxel/bevacizumab compared to historical trials with fulvestrant. PFS, overall survival (OS), and ctDNA dynamics were exploratory analyses. RESULTS: PFS at six months was 86% (18/21) in patients with an ESR1 mutation detected and 85% (23/27) in wildtype ESR1 patients. In our exploratory analysis, median progression-free survival (PFS) was 8.2 months [95% CI, 7.6-8.8] for ESR1 mutant patients versus 8.7 months [95% confidence interval (CI), 8.3-9.2] for ESR1 wildtype patients [p = 0.47]. The median overall survival (OS) was 20.7 months [95% CI, 6.6-33.7] for ESR1 mutant patients versus 28.1 months [95% confidence interval (CI), 19.3-36.9] for ESR1 wildtype patients [p = 0.27]. Patients with ≥ two ESR1 mutations had a significantly worse OS, but not PFS, compared to those who did not [p = 0.003]. Change in ctDNA level at C2 was not different between ESR1 and other mutations. CONCLUSIONS: Presence of ESR1 mutations in baseline ctDNA might not be associated with inferior PFS and OS in advanced breast cancer patients treated with paclitaxel/bevacizumab.

Sunitinib-induced hypertension in CYP3A4 rs4646437 A-allele carriers with metastatic renal cell carcinoma.

The single nucleotide polymorphism (SNP) rs4646437G>A in CYP3A4 was suggested to be related to sunitinib toxicity. Our objective was to perform an in-depth investigation of the association between this SNP and sunitinib toxicity and efficacy using a large cohort of metastatic renal cell carcinoma (mRCC) patients. We collected DNA and clinical information of mRCC patients treated with sunitinib. SNP rs4646437 in CYP3A4 was tested for associations with toxicity using logistic regression. Cox regression modeling was used for association analysis of rs4646437 with progression-free survival (PFS) and overall survival (OS). In a total of 287 patients, the A-allele of CYP3A4 rs4646437 was associated with an increased risk for hypertension (odds ratio=2.4, 95% confidence interval: 1.1-5.2, P=0.021) and showed no significant association with PFS or OS. In conclusion, hypertension is more likely to occur in A-allele carriers of the CYP3A4 rs4646437 variant in our cohort of mRCC patients treated with sunitinib.

Phase I study of saracatinib (AZD0530) in combination with paclitaxel and/or carboplatin in patients with solid tumours.

BACKGROUND: As a prelude to combination studies aimed at resistance reversal, this dose-escalation/dose-expansion study investigated the selective Src kinase inhibitor saracatinib (AZD0530) in combination with carboplatin and/or paclitaxel. METHODS: Patients with advanced solid tumours received saracatinib once-daily oral tablets in combination with either carboplatin AUC 5 every 3 weeks (q3w), paclitaxel 175 mg m(-2) q3w, paclitaxel 80 mg m(-2) every 1 week (q1w), or carboplatin AUC 5 plus paclitaxel 175 mg m(-2) q3w. The primary endpoint was safety/tolerability. RESULTS: A total of 116 patients received saracatinib 125 (N=20), 175 (N=44), 225 (N=40), 250 (N=9), or 300 mg (N=3). There were no clear dose-related trends within each chemotherapy regimen group in number or severity of adverse events (AEs). However, combining all groups, the occurrence of grade ≥3 asthenic AEs (all causality) was dose-related (125 mg, 10%; 175 mg, 20%; ≥225 mg, 33%), and grade ≥3 neutropenia occurred more commonly at doses ≥225 mg. There was no evidence that saracatinib affected exposure to carboplatin or paclitaxel, or vice versa. Objective responses were seen in 5 out of 44 patients (11%) receiving carboplatin plus paclitaxel q3w, and 5 out of 24 (21%) receiving paclitaxel q1w. CONCLUSION: Saracatinib doses up to 175 mg with paclitaxel with/without carboplatin showed acceptable toxicity in most patients, and are suitable for further trials.

Potential drug interactions in cancer therapy: a prevalence study using an advanced screening method.

BACKGROUND: In cancer patients, drug interactions may intensify adverse events or reduce antitumour effects. We assessed the prevalence of potential drug interactions (PDIs) among ambulatory cancer patients on i.v. treatment using an advanced screening method. PATIENTS AND METHODS: Data on drugs used for comorbidities, anticancer agents, over-the-counter (OTC) drugs, and comorbidities were collected by means of a structured interview among the patients and review of medical charts. PDIs were identified using electronic (Drug Interaction Facts software, version 4.0) and manual screening methods (peer-reviewed reports). RESULTS: In this study, 278 patients were enrolled. We identified 348 PDIs. Of all patients, 161 (58%) had at least one PDI. Of all PDIs, 34% was classified as major and 60% as moderate. Coumarins, quinolones, antiepileptics, and hydrochlorothiazide were frequently part of a PDI. Interactions that potentially cause QT interval prolongation, gastrointestinal toxicity, and central nervous system depression were also common. In multivariate analysis, an increasing number of drugs [odds ratio (OR) = 1.4, confidence interval (CI) 1.23-1.52; P < 0.001] and the use of an OTC drug (OR = 0.56, CI 0.32-0.97; P = 0.045) were risk factors. CONCLUSIONS: PDIs are common in patients treated for an (haemato-) oncological disease. Screening for potential interactions should take place routinely before administering chemotherapy.

Phase I trial of SU14813 in patients with advanced solid malignancies.

BACKGROUND: this phase I, open-label, dose-escalation study investigated SU14813, an oral multitargeted tyrosine kinase inhibitor, in adults with solid tumors. PATIENTS AND METHODS: seventy-seven patients received once-daily SU14813, either for 4 weeks followed by 1 week off treatment (schedule 4/1) or continuously [continuous daily dosing (CDD)]. The primary end point was to determine the maximum tolerated dose (MTD). Safety, pharmacokinetics, pharmacodynamics, and efficacy were assessed. RESULTS: MTDs were 200 mg/day on schedule 4/1 and 100 mg/day with CDD. Adverse events included fatigue (64%), diarrhea (61%), nausea (44%), anorexia (43%), and vomiting (42%). SU14813 steady state was attained by day 8. Exposure increased in a generally dose-proportional manner and SU14813 was eliminated with a mean terminal half-life of 9-34 h. Target plasma concentrations (>100 ng/ml SU14813) were achieved and sustained over 12 h at ≥ 100 mg/day. Progression-free survival among the 1 complete responder and 12 partial responders was 1.4-53.2 months. Fifteen patients remained on treatment at 1 year and 3 patients at 2 years. CONCLUSION: SU14813 has manageable safety and tolerability and allows once-daily continuous oral dosing. SU14813 shows dose-proportional pharmacokinetics, with target plasma concentrations achieved at doses ≥ 100 mg/day. Clinically meaningful activity with durable responses was observed, meriting further study.

A phase I, dose-finding study of sunitinib in combination with irinotecan in patients with advanced solid tumours.

BACKGROUND: Sunitinib is a multitargeted, oral tyrosine kinase inhibitor with antitumour and antiangiogenic activity. We investigated the safety and pharmacokinetics of sunitinib in combination with irinotecan in patients with advanced, refractory solid tumours. METHODS: Sunitinib was initially administered once daily at 37.5 mg per day on days 1-14 of a 21-day cycle, in which irinotecan 250 mg m(-2) was given on day 1. In a second cohort, the sunitinib dose was reduced to 25 mg per day. Blood samples were collected for pharmacokinetic studies. RESULTS: In the sunitinib 37.5 mg per day cohort, 3 out of 10 evaluable patients had objective responses, but dose-limiting toxicities (DLTs) of neutropenia, pneumococcal sepsis, and fatigue were observed. There were no DLTs in the sunitinib 25 mg per day cohort. Paired observations of pharmacokinetic parameter values of sunitinib and irinotecan alone vs the combination did not reveal significant drug-drug interactions. The maximum tolerated dose was defined as sunitinib 25 mg per day (days 1-14) with irinotecan 250 mg m(-2) (day 1), but no activity was observed at this dose. CONCLUSION: Although a higher sunitinib dose of 37.5 mg per day (days 1-14) with irinotecan showed preliminary evidence of antitumour activity, this dose was poorly tolerated. Therefore, this particular combination will not be pursued for further studies.

Choi response criteria for early prediction of clinical outcome in patients with metastatic renal cell cancer treated with sunitinib.

BACKGROUND: Because sunitinib can induce extensive necrosis in metastatic renal cell cancer (mRCC), we examined whether criteria defined by Choi might be valuable to predict early sunitinib efficacy. METHODS: Computed tomography was used for measurement of tumour lesions in mm and lesion attenuation in Hounsfield units (HUs). According to Choi criteria partial response (PR) was defined as > or =10% decrease in size or > or =15% decrease in attenuation. RESULTS: A total of 55 mRCC patients treated with sunitinib were included. At first evaluation, according to the Response Evaluation Criteria in Solid Tumours (RECIST) 7 patients had PR, 38 stable disease (SD), and 10 progressive disease (PD), whereas according to Choi criteria 36 patients had PR, 6 SD and 13 PD. Median tumour attenuation decreased from 66 to 47 HUs (P< or =0.001). In patients with PR, Choi criteria had a significantly better predictive value for progression-free survival and overall survival (both Ps<0.001) than RECIST (P=0.685 and 0.191 respectively). The predictive value for RECIST increased (P=0.001 and <0.001 respectively), when best response during treatment was taken into account. CONCLUSION: Choi criteria could be helpful to define early mRCC patients who benefit from sunitinib, but the use of these criteria will not change the management of these patients.

Spontaneous remission of unidentified Cushing's disease revealed by hair cortisol analysis.

Pituitary apoplexy is an infrequent but life-threatening complication of pituitary adenomas. When apoplexy occurs in a hormonally active adenoma, this may induce spontaneous remission of the clinical syndrome. In these cases, clinical suspicion of Cushing's disease or acromegaly may arise at presentation, but due to spontaneous remission of active hormone production, it is not possible to biochemically confirm this diagnosis in retrospect. Resolution of clinical symptoms during follow up retrospectively suggests the diagnosis. However, we describe a patient with Cushing's disease presenting with pituitary apoplexy, who was biochemically in remission at presentation. The diagnosis could be confirmed in retrospect using hair cortisol analysis, thereby enabling clinicians to adequately anticipate remission of Cushing's disease.

Predictive factors for severe toxicity of sunitinib in unselected patients with advanced renal cell cancer.

Sunitinib has been registered for the treatment of advanced renal cell cancer (RCC). As patient inclusion was highly selective in previous studies, experience with sunitinib in general oncological practice remains to be reported. We determined the efficacy and safety of sunitinib in patients with advanced RCC included in an expanded access programme. ECOG performance status >1, histology other than clear cell and presence of brain metastases were no exclusion criteria. Eighty-two patients were treated: 23% reached a partial response, 50% had stable disease, 20% progressed and six patients were not evaluable. Median progression-free survival (PFS) was 9 months and median overall survival (OS) was 15 months. Importantly, 47 patients (57%) needed a dose reduction, 35 (43%) because of treatment-related adverse events, 10 (12%) because of continuous dosing, and two because of both. Stomatitis, fatigue, hand-foot syndrome and a combination of grade 1-2 adverse events were the most frequent reasons for dose reduction. In 40 patients (49%), there was severe toxicity, defined as dose reduction or permanent discontinuation, which was highly correlated with low body surface area, high age and female gender. On the basis of age and gender, a model was developed that could predict the probability of severe toxicity.

Ewing's sarcoma and primitive neuroectodermal tumour in adults: single-centre experience in The Netherlands.

BACKGROUND: Ewing's sarcoma and peripheral primitive neuroectodermal tumours (PNET) are rare tumours and closely related. They occur most often in children and adolescents. Few studies have been published on treatment outcome in adult patients. METHODS: We performed a retrospective analysis of patients aged >16 years who were primarily treated at our university hospital for Ewing's sarcoma or PNET. In general, treatment consisted of long-term multiagent chemotherapy, interrupted by individualised local treatment consisting of surgery and/or radiotherapy. We reviewed clinical features and outcomes to present our experience with Ewing's sarcoma and PNET in adults. RESULTS: From 1979 to 2002, 27 patients with Ewing's sarcoma (20) or PNET (7) were treated. There were 22 men and 5 women, with a median age of 25 years (range 17-49). Ten patients presented with metastases predominantly in lungs (4) or bones (6). Combination therapy consisted of chemotherapy (27), surgery (16) and radiotherapy (16). After a median follow-up of ten years, 14 patients have died (toxicity = 2, progressive disease = 12) and 13 patients are alive and free of disease. Five-year overall survival was 58%. All four patients with bone metastases died, while all five patients presenting with lung metastases are disease-free. CONCLUSION: The five-year overall survival of 58% in this small series on adult patients is in line with paediatric study outcomes. Patients with lung metastases may even be cured by multimodality therapy. We therefore strongly advocate referral of patients with this rare disease to a specialised oncology centre.

[Adverse effects of the tyrosine-kinase inhibitor sunitinib, a new drug for the treatment of advanced renal-cell cancer]. / Bijwerkingen van de tyrosinekinaseremmer sunitinib, een nieuw middel voor de behandeling van gemetastaseerd niercelcarcinoom.

Three patients with advanced renal-cell cancer were treated with sunitinib 50 mg daily for 4 weeks followed by a rest period of 2 weeks because of progressive disease. The first patient developed stomatitis and a painful blister on his foot. Complaints disappeared after temporary discontinuation of treatment. Re-treatment at a lower dosage was successful until disease progression. The second patient developed skin discolouration, fatigue, fever and diarrhoea. After treatment was interrupted shortly, these symptoms disappeared and sunitinib was recommenced at a lower dosage. The patient went on to develop stomatitis, thrombocytopenia and hypertension (treated with amlodipine). She subsequently had hand-foot syndrome. She died due to brain metastases. In the third patient symptoms of disease returned during the rest period, because of which he received a reduced dosage of sunitinib on a continuous base. He developed diarrhoea which disappeared after a short interruption of the drug. Sunitinib has been approved for the treatment of advanced renal-cell cancer and imatinib-resistant gastro-intestinal stromal tumours. This novel targeting molecule is a tyrosine-kinase inhibitor of vascular endothelial growth-factor receptors, platelet-derived growth-factor receptors and c-Kit. It can induce adverse events that differ from those observed in treatment with conventional cytotoxic agents. The adverse effects are reduced by lowering the dosage and in the rest period within the treatment cycle.

Effects of recombinant human granulocyte-macrophage colony-stimulating factor on myelosuppression induced by multiple cycles of high-dose chemotherapy in patients with advanced breast cancer.

In this study, 18 patients with advanced breast cancer were treated with multiple cycles of doxorubicin (75 or 90 mg/m2) plus cyclophosphamide (750 or 1000 mg/m2) every 21 days. Granulocyte-macrophage colony-stimulating factor (GM-CSF) (250 micrograms/m2 per day) was administered by continuous infusion during 10 days (days 2-12), starting in the first or second cycle of chemotherapy. Sixteen (89%) of 18 patients (95% confidence interval, 65%-99%) achieved an objective remission, five (28%) of which were complete. The median duration of response was 7 months. When GM-CSF was used for the first time, it had an effect on the kinetics of all blood cells, including neutrophils, lymphocytes, thrombocytes, and reticulocytes. However, in subsequent cycles of chemotherapy, the stimulatory effect of GM-CSF on hematopoiesis was substantially diminished. World Health Organization grade 3 and 4 neutropenia and thrombocytopenia necessitated dose reductions of doxorubicin and cyclophosphamide from cycle 2 onward in all patients treated with the highest dose. Side effects of GM-CSF included fever, general weakness, and hypotension. These toxic effects mimicked sepsis, and hospital admission for treatment with intravenous antibiotics was required for 73 days in 61 cycles of chemotherapy that included GM-CSF. Dose-intensive chemotherapy produced a high response rate in patients with advanced breast cancer. However, GM-CSF administered from day 2 to day 12 at a dose of 250 micrograms/m2.

Human IgM monoclonal antibody 16.88: pharmacokinetics and immunogenicity in colorectal cancer patients.

Twenty colorectal cancer patients were given an intravenous injection of human IgM monoclonal antibody (MAb) 16.88 (8 mg) conjugated to 131I for tumor localization. After a 2-week interval, a second injection with 200, 500, or 1000 mg of unlabeled antibody added was given to groups of five patients each. at the end of the 2-hour infusion, 66% of the radioactivity remained in the circulation. Blood clearance of the 131I-labeled MAb 16.88 was biphasic with a mean half-life (T1/2 alpha) of 12 hours and T1/2 beta of 45 hours. Clearance rate was 0.09 L/hour. More than 90% of the 131I in serum was protein bound, with an immunoreactive fraction of 80% in the first 48 hours. Size exclusion chromatography indicated no degradation products other than 131I in serum and urine. The urinary excretion rate of 131I increased to 1.5% of the dose per hour at 24 hours, with 50% of the dose excreted in 34 hours. The pharmacokinetic profile of 131I-labeled MAb 16.88 was neither influenced by the total protein dose of antibody administered nor affected by specific uptake in tumor tissue in individual patients, as determined on early immunoscintigrams. The larger antibody doses showed a slightly slower excretion of 131I. The assays applied to determine immunogenicity were enzyme-linked immunosorbent assay, radioimmunoassay, and the dot-blot assay. They had sensitivities ranging from 5 ng/mL to 0.5 micrograms/mL for goat or rabbit antihuman IgM. The assays did not reveal antihuman antibody responses.

Specific killing of human melanoma cells by 125I-labeled 9.2.27 monoclonal antibody.

The anti-melanoma antibody 9.2.27 localizes to melanoma cells when administered i.v. to melanoma patients, but high doses of this antibody alone have no specific cytotoxic effect in vivo. To determine whether radiolabeled antibodies would exhibit specific antimelanoma cytotoxicity in vitro, cell survival curves were established for NCl-N892 human melanoma cells treated with 125I-labeled 9.2.27 monoclonal antibody. The binding capacity per cell was 5 X 10(5) molecules of 9.2.27 immunoglobulin G, and the association constant of binding was 10(10) M-1. Antibody preparations with specific radioactivities of 9-80 microCi/micrograms were used. Colony-forming ability after in vitro exposure to 125I-9.2.27 was determined by a 1-h antibody incubation at saturating concentrations, washing, and cell freezing for various exposure durations. Colony survival was dose dependent, varying with the radioactivity per cell and the exposure time. The survival curves demonstrated no shoulder effect and had a 37% incremental survival dose of 0.5-0.9 X 10(5) decays/cell. Selective killing of melanoma cells was demonstrated in experiments where NCl-N417 lung cancer cells were mixed with the melanoma cells prior to antibody treatment. The NCl-N417 cells did not express the melanoma-associated antigen, were more sensitive to conventional external irradiation than were the melanoma cells, and could easily be distinguished from them by different growth morphology. In spite of a growth advantage for the melanoma cells in the clonogenic assay, the antigen-negative lung cancer cells selectively survived the treatment and were the only surviving cells after 15 days of exposure.

Time dependence of the selective modulation of cisplatin-induced nephrotoxicity by WR2721 in the mouse.

2-(3-Aminopropylamino)ethylphosphorothioic acid (WR2721; ethiofos) was shown to selectively protect nontumor tissues from cis-diamminedichloroplatinum(II) (cisplatin)-induced toxicity, when administered 30 min prior to the platinum drug. Selectivity of protection by WR2721 is probably due to the preferential formation and uptake of the thiol metabolite 2-(3-aminopropylamino)ethanethiol (WR1065), which can inactivate toxic platinum-species inside the cell. We investigated the protective potential of WR2721, when administered at different time points relative to cisplatin. BALB/c mice treated with WR2721 (200 mg/kg i.p.) either 30 min or 5 min prior to cisplatin (i.p.) allowed a 2.2-fold increase in cisplatin dose to 19 mg/kg before the occurrence of nephrotoxicity as expressed by an increase in plasma urea. A small part of the protection could be ascribed to the mannitol (200 mg/kg), present in the formulated WR2721. WR2721 (200 mg/kg) 30 min after 14.5-16-mg/kg cisplatin did not offer any protection against the rise in plasma urea. WR2721 (200 mg/kg) 5 min before 19-mg/kg cisplatin did not cause liver toxicity (increase in serum glutamic pyruvic transaminase or serum glutamic oxaloacetic transaminase). Furthermore, WR2721 (200 mg/kg) 5 min prior to cisplatin did not reduce antitumor activity in nude mice bearing well-established human ovarian cancer xenografts. Under protection of WR2721, the dose of cisplatin could be increased by a factor of 1.6 to 8 mg/kg (administered twice weekly), resulting in an increased antitumor activity.

Comparative activity and distribution studies of five platinum analogues in nude mice bearing human ovarian carcinoma xenografts.

The antitumor activity of four new platinum analogues was compared at equitoxic doses to that of cisplatin in B10 LP/cpb nude mice bearing xenografts of human ovarian carcinomas. The two tumor lines used, MRI-H-207 and Pe, differ in histology, tumor doubling time, and sensitivity to cisplatin. Complete remission of MRI-H-207 was observed with cisplatin, carboplatin, iproplatin, and JM-40, while spiroplatin only gave growth delay. Cisplatin and carboplatin caused some growth delay of Pe, while JM-40, spiroplatin, and iproplatin failed to affect tumor growth. Platinum tissue distribution was also measured for each compound in groups of five to seven tumor-bearing mice. Platinum concentrations in the two tumors at 24 hr were similar for cisplatin and carboplatin, but differed for iproplatin, spiroplatin, and JM-40. Organ distribution was similar for each analogue, and concentrations were significantly higher in kidneys than in liver, except for iproplatin with comparable concentrations in these organs. Our findings show a good correlation between analogue activity in ovarian cancer in the clinic and that in MRI-H-207. Platinum concentrations in tumor tissue did not predict antitumor activity.

Development and molecular characterization of a 2',2'-difluorodeoxycytidine-resistant variant of the human ovarian carcinoma cell line A2780.

2',2'-Difluorodeoxycytidine (gemcitabine, dFdCyd) is a deoxycytidine analogue with promising antitumor activity. In order to be active it must be phosphorylated by deoxycytidine kinase (dCK). We induced resistance to dFCyd in the human ovarian carcinoma cell line A2780 by exposure to increasing concentrations of dFdCyd. The IC50, defined as the concentration of dFdCyd causing 50% growth inhibition, at 72 h exposure increased from 0.6 nM dFdCyd in A2780 to 92 microM in the resistant variant, named AG6000. Although the resistant cell line is routinely cultured in 6 microM dFdCyd, the resistant phenotype can be maintained for at least 10 passages without dFdCyd. AG6000 is cross-resistant to other drug which require activation by dCK, such as 1-beta-D-arabinofuranosylcytosine, 5-aza-2'-deoxycytidine, and 2-chlorodeoxyadenosine. There was no specific dCK activity in extracts from AG600 cells. Western blot analysis using a polyclonal anti-dCK antibody did not reveal any dCK protein in AG6000 cell extracts. Reverse-transcribed and PCR-amplified mRNA, using specific dCK primers, demonstrated that AG6000 expressed a normal length amplicon of 701 base pairs, besides an aberrant amplicon of 500 base pairs. Chromosome spreads from the cell lines showed no major differences between A2780 and AG6000. The latter cell line was also cross-resistant to 2',2'-difluorodeoxyurdine, the deamination product of dFdCyd. Additionally, cross-resistance to the multidrug resistant drugs doxorubicin and vincristine was observed. This was not associated with the induction of P-glycoprotein, as determined by the RNase protection assay. Injection of AG6000 cells s.c. into nude mice demonstrated that the cell line had retained its tumorigenicity; AG6000 xenografts were not sensitive to dFdCyd treatment, in contrast to the parental A2780 tumors. No dFdCyd triphosphate accumulation was found in the resistant tumors, in contrast to the parental A2780 tumors. These results indicate that the dFdCyd resistance phenotype is stable, and mainly due to dCK deficiency.

Phase II preclinical drug screening in human tumor xenografts: a first European multicenter collaborative study.

In a European joint project carried out in 6 laboratories a disease-oriented program was set up consisting of a panel of 7 tumor types, each represented by 4 to 8 different human tumor lines, for secondary screening of promising anticancer drugs. Human tumor lines were selected on the basis of differences in histology, growth rate, and sensitivity to conventional cytostatic agents. Xenografts were grown s.c. in nude mice, and treatment was started when tumors reached a mean diameter of 6 mm in groups of mice where at least 6 tumors were evaluable. Drugs were given at the maximum tolerated dose. For evaluation of drug efficacy, median tumor growth curves were drawn, and specific growth delay and treated/control x 100% were calculated. Doxorubicin (8 mg/kg i.v. days 1 and 8) was effective (treated/control < 50%, and specific growth delay > 1.0) in 0 of 2 breast cancers, 1 of 3 colorectal cancers, 2 of 5 head and neck cancers, 3 of 6 non-small cell lung cancers, 4 of 6 small cell lung cancers, 0 of 3 melanomas, and 3 of 6 ovarian cancer lines. Amsacrine (8 mg/kg i.v. days 1 and 8) was not effective, while datelliptium (35 mg/kg i.p. days 1 and 8) was active against 2 of 6 small cell lung cancer lines. Brequinar sodium (50 mg/kg i.p. days 1-5) showed efficacy in 4 of 5 head and neck cancers, 5 of 8 non-small cell lung cancers, and 4 of 5 small cell lung cancer lines. The project has been shown to be a feasible approach. Clinical activity for doxorubicin and inactivity for amsacrine against solid tumor types was confirmed in the human tumor xenograft panel. Additional anticancer drugs will be studied in the European joint project to further define the reliability of this novel, promising screening approach.

The role of pharmacogenetics in capecitabine efficacy and toxicity.

Capecitabine is an oral prodrug of 5-fluorouracil (5-FU) and approved for treatment of various malignancies. Hereditary genetic variants may affect a drug's pharmacokinetics or pharmacodynamics and account for differences in treatment response and adverse events among patients. In this review we present the current knowledge on genetic variants, commonly single-nucleotide polymorphisms (SNPs), tested in cohorts of cancer patients and possibly useful for prediction of capecitabine efficacy or toxicity. Capecitabine is activated to 5-FU by CES, CDA and TYMP, of which SNPs in CDA and CES2 were found to be associated with efficacy and toxicity. In addition, variants in genes of the 5-FU metabolic pathway, including TYMS, MTHFR and DPYD also influenced capecitabine efficacy and toxicity. In particular, well-known SNPs in TYMS and DPYD as well as putative DPYD SNPs had an association with clinical outcome as well as adverse events. Inconsistent findings may be attributable to factors related to ethnic differences, sample size, study design, study endpoints, dosing schedule and the use of multiple agents. Of the SNPs described in this review, dose reduction of fluoropyrimidines based on the presence of DPYD variants *2A (rs3918290), *13 (rs55886062), -2846A>T (rs67376798) and -1236G>A/HapB3 (rs56038477) has already been recommended. Other variants merit further validation to establish their definite role in explanation of interindividual differences in the outcome of capecitabine-based therapy.

Pharmacokinetics and metabolism of epidoxorubicin and doxorubicin in humans.

Pharmacokinetics of doxorubicin (DOX), epidoxorubicin (EPI), and their metabolites in plasma have been performed in eight patients receiving 40 to 56 mg/m2 of both anthracyclines as a bolus injection in two sequential cycles. Terminal half-life and volume of distribution appeared to be smaller in case of EPI, whereas plasma clearance and cumulative urinary excretion was larger in comparison to DOX. The major metabolite of DOX was doxorubicinol (Aol) followed by 7-deoxy-doxorubicinol (7d-Aolon). Metabolism to glucuronides was found in case of EPI only. The area under the curves (AUC) of the metabolites of EPI decreased in the order of the glucoronides E-glu greater than Eol-glu, 7d-Aolon greater than epirubicinol (Eol). The AUC of Eol was half of the value in its counterpart Aol. In the case of EPI, the AUC of 7d-Aolon was twice the level of that of the corresponding metabolite of DOX. The terminal half-lives of the cytostatic metabolites Aol and Eol were similar, but longer than the corresponding values of their parent drugs. Half-lives of the glucuronides (E-glu, Eol-glu) were similar to the half-life of their parent drug. 7d-Aolon had a somewhat shorter half-life in comparison to both DOX and EPI. Approximately 6.2% of EPI and 5.9% of DOX were excreted by the kidney during the initial 48 hours. Aol was found in the urine of patients treated with DOX, whereas Eol, E-glu, and Eol-glu were detected in urine of patients treated with EPI. The cumulative urinary excretion appeared to be 10.5% for EPI and its metabolites, and 6.9% for DOX and its metabolite. The plasma concentration v time curves of (7d)-aglycones showed a second peak between two and 12 hours after injection, suggesting an enterohepatic circulation for metabolites lacking the daunosamine sugar moiety. The plasma concentrations of the glucuronides were maximal at 1.2 hours for E-glu and 1.9 hours for Eol-glu. All other compounds reached their maximum plasma concentration during the first minutes after the administration of DOX and EPI. Deviating plasma kinetics were observed in one patient, probably due to prior drug administration.