Phase I and Clinical Pharmacology
Phase I Clinical Study of AZD2171, an Oral Vascular Endothelial Growth Factor Signaling Inhibitor, in Patients With Advanced Solid Tumors
AZD2171 is a highly potent oral selective inhibitor of vascular endothelial growth factor (VEGF) signaling. This phase I study was designed to evaluate the safety and tolerability of increasing doses of AZD2171, with additional assessments of pharmacokinetics, pharmacodynamics, and efficacy.
In part A, 36 patients with solid tumors and liver metastases refractory to standard therapies received once-daily oral AZD2171 (0.5 to 60 mg). Doses were escalated in successive cohorts until the maximum-tolerated dose was identified. In part B, patients with (n = 36) or without (n = 11) liver metastases were randomly assigned to receive once-daily AZD2171 (20, 30, or 45 mg). In both parts, treatment continued until tumor progression or dose-limiting toxicity (DLT) was observed.
Eighty-three patients received AZD2171, which was generally well tolerated at doses of 45 mg/d or less; the most frequently reported dose-related adverse events were diarrhea, dysphonia, and hypertension. The most common DLT was hypertension (n = 7), which occurred at AZD2171 doses of 20 mg and higher. After a single dose, maximum plasma (peak) drug concentration after single-dose administration (Cmax) was achieved 1 to 8 hours postdosing with an arithmetic mean half-life associated with terminal slope of a semilogarithmic concentration-time curve (t1/2λz) of 22 hours. Pharmacodynamic assessments demonstrated time-, dose-, and exposure-related decreases in initial area under the curve, defined over 60 seconds post-contrast arrival in the tissue (iAUC60) using dynamic contrast-enhanced magnetic resonance imaging, as well as dose- and time-dependent reductions in soluble VEGF receptor 2 levels. Preliminary evidence of efficacy included two confirmed partial responses and 22 patients with stable disease; effects on tumor size appeared to be dose related.
Recognition of the importance of angiogenesis in solid tumor growth has led to the search for, and evaluation of, agents with antiangiogenic activity.1 Vascular endothelial growth factor (VEGF) is a key proangiogenic factor that plays a critical role in blood vessel formation,2-8 primarily through activation of VEGF receptor 2 (VEGFR-2; kinase insert domain receptor) located on vascular endothelial cells.9,10
Inhibition of VEGF/VEGFR signaling represents a significant antitumor strategy. Combining bevacizumab, an anti–VEGF-A monoclonal antibody, with certain chemotherapy regimens has demonstrated clinically relevant improvements in survival in colorectal cancer11 and non–small-cell lung cancer12,13; antitumor activity has also been observed in renal cell carcinoma using multikinase inhibitors that possess VEGFR signaling inhibitory effects (sorafenib and sunitinib).14,15 AZD2171 is an oral potent and selective inhibitor of VEGF signaling that inhibits VEGFR-2 tyrosine kinase activity at subnanomolar concentrations (inhibitory concentration of 50% [IC50] < 1 nmol/L) in vitro.16 AZD2171 also potently inhibits VEGFR-1 (IC50 = 5 nmol/L) and VEGFR-3 (IC50 ≤ 3 nmol/L) tyrosine kinase activity.16 The antitumor activity of AZD2171 has been demonstrated in a range of histologically diverse xenograft models, and this activity is consistent with potent inhibition of VEGF signaling and angiogenesis.16
This study (2171IL/0001) was, to our knowledge, the first clinical evaluation of AZD2171, with the primary objective to assess the safety and tolerability of increasing doses of AZD2171 in patients with advanced solid tumors. Secondary objectives included determination of the pharmacokinetic profile of AZD2171 after single and multiple oral doses, investigation of the effect of AZD2171 on markers of biologic activity (dynamic contrast-enhanced magnetic resonance imaging [DCE-MRI] measures and VEGF/VEGFR levels), and preliminary evaluation of efficacy.
Adult patients with histologic or cytologic evidence of metastatic or advanced solid tumors refractory to standard treatments, or for whom no standard treatment existed, were recruited at a single center in Germany. Patients with liver metastases and tumors were required to have a liver lesion assessable using DCE-MRI. Patients were required to have a life expectancy of at least 12 weeks and a WHO performance status of 0 to 2. The main exclusion criteria were significant hematopoietic, hepatic, or renal dysfunction; a history of CNS tumors or metastases; a history of ischemic heart disease, myocardial infarction or unstable cardiac disease; left ventricular ejection fraction of 45% or less; poorly controlled hypertension; and other anticancer agents or surgery within the previous 4 weeks. All patients provided written informed consent, and the trial was conducted in accordance with the Declaration of Helsinki.
This phase I, single-center, open-label study was conducted in two parts (A and B). The overall study design is summarized in Figure A1 (online only). Part A was a dose-escalation study in which successive cohorts of three to eight patients received a single oral dose of AZD2171 (0.5, 1, 2.5, 5, 10, 20, 30, 45, or 60 mg) followed by a 2- to 7-day observation period with safety and pharmacokinetic assessments and subsequent once-daily treatment at the same dose level. The primary objective of part A was to evaluate the safety and tolerability of single and multiple oral doses and to select three potentially active and well-tolerated doses for further assessment of biologic activity and safety in part B. In the open-label, randomized, parallel group, cohort-expansion phase (part B), patients were randomly assigned to once-daily oral AZD2171 (20 [n = 10], 30 [n = 14], or 45 mg [n = 12]). In both parts, patients received AZD2171 until tumor progression or uncontrollable toxicity was observed. All patients in part A had metastatic liver disease. In part B, a minimum of 30 patients with liver lesions were required for the DCE-MRI analysis, but additional patients without liver lesions were also considered eligible to assess the safety of AZD2171 in a broader patient population: Patients with liver lesions were randomly assigned to receive AZD2171 and patients without liver metastases (up to four per dose group) were randomly assigned separately.
In both parts, treatment continued until evidence of tumor progression or dose-limiting toxicity (DLT). If a DLT was observed in at least 50% of patients within a dose cohort, that dose was considered above the maximum-tolerated dose (MTD), and dose escalation was stopped. A DLT was defined as any adverse event (AE) of at least Common Terminology Criteria version 2.0 (CTC 2.0) grade 3 that was considered by the investigator to be related to AZD2171, or an increase from baseline in QT or QTc interval of at least 60 ms and/or a QT or QTc interval of more than 490 ms on two consecutive ECGs recorded at least 24 hours apart that occurred within the first 28 days of daily dosing with AZD2171. A modified CTC 2.0 definition of grade 3 hypertension was used (ie, that which required more intensive therapy than before and did not respond to treatment within 48 hours). Safety review meetings were held for each cohort.
Since this was the first clinical study of AZD2171, extensive safety and tolerability assessments were performed. After full physical examination at enrollment, AEs were recorded throughout the study and graded according to CTC 2.0. Because this was the first study in humans, routine 12-lead ECGs were performed and vital signs measured at screening and throughout the study. Assessments of blood pressure and ECGs were based on internationally standardized methods as described in the Appendix (online only).
Blood samples were collected after single and multiple doses at various time points during the study. Pharmacokinetic assessments are described in the Appendix.
Tumor blood flow and vascular permeability were assessed using DCE-MRI evaluation of liver lesions.17 Changes in DCE-MRI parameters iAUC60 (mmol/L · sec) and area under the curve, defined over 60 seconds post-contrast arrival in the tissue (iAUC60) and transport constant (Ktrans; min−1) were measured as indicators of tumor blood flow and permeability. 18 A review of the DCE-MRI data from the initial cohorts in part A found that iAUC60 was less variable than Ktrans, and subsequently, iAUC60 was selected as the primary DCE-MRI measure for this trial.
Soluble markers of angiogenesis (VEGF, basic fibroblast growth factor [b-FGF], VEGFR-1, VEGFR-2, placental growth factor [PlGF], TIE-2, E-selectin, and interleukin 8 [IL-8] levels) were measured in serum and plasma samples. Details of the methods used to analyze the soluble markers of angiogenesis are described in the Appendix.
Baseline imaging was performed 4 weeks or less before the start of study treatment. Tumor size was evaluated every 4 weeks for the first 12 weeks after the start of daily dosing with AZD2171. Objective tumor response was evaluated by classifying a single lesion, measured predominately in the liver, as a target lesion, with other lesions representative of all involved organs classified and followed as nontarget lesions. Tumor size was assessed using the longest diameter for the target lesion. Response was then classified in an identical manner to Response Evaluation Criteria in Solid Tumors (RECIST)19 with an additional non-RECIST category of minor response, defined as a decrease from baseline of at least 10% and less than 30% on two consecutive visits with no other evidence of progressive disease. An unconfirmed partial response was defined as an isolated partial response without confirmatory follow-up data. Where patients are described as alive and progression free at week 12, a week-12 scan must have been performed to confirm their progression-free status.
Statistical analyses are detailed in the Appendix. Briefly, analysis of covariance models were used to assess the dose response of AZD2171 on tumor size, blood pressure, and the DCE-MRI parameter of iAUC60 for data from the randomly assigned part B. A power model was used to perform a preliminary assessment of dose proportionality for the multiple-dose pharmacokinetic parameters of maximum steady-state drug concentration in plasma during dosing interval (Css,max) and area under plasma concentration-time curve during any dosing interval at steady state (AUCss). Linear models were used to explore the relationship between percentage change from baseline in iAUC60 and the following parameters: AUCss, Css,max, minimum steady-state drug concentration in plasma during dosing interval (Css,min), and dose first received.
Overall, the most commonly occurring AEs were fatigue (n = 47), diarrhea (n = 39), nausea (n = 34), dysphonia (n = 30), hypertension (n = 29), vomiting (n = 26), and anorexia (n = 24; Table 3). Some evidence of a dose response for dysphonia, diarrhea, and hypertension was observed. The incidence of drug-related CTC grade 3 or 4 AEs was low, and there were no events at doses less than 10 mg (Table 4). Grade 3 hypertension was observed in 13 patients, and grade 4 hypertensive crisis in three patients. No standard management plan was in place for hypertension; hypertension was managed according to local clinical practice. In general, hypertension responded well to treatment with calcium channel antagonists and, where necessary, dose interruption and dose reduction of AZD2171. With the exception of dose-related changes in blood pressure at AZD2171 doses of 20 mg and higher, there were no clinically relevant trends in laboratory measures, vital signs, physical findings, or ECG measurements.
Twenty-one DLTs were reported in the study, and each occurred at AZD2171 doses of 20 mg and higher, the most common being hypertension (n = 7) and hypertensive crisis (n = 2). In the 60-mg cohort, two DLTs were reported (hypoglycemia and increased blood bilirubin), and there was an increased incidence of AEs and increases in thyroid-stimulating hormone at this dose (Table 3). Before each dose escalation in part A, the safety review committee reviewed the available safety and pharmacokinetic data to decide whether the MTD had been reached. Although the 60-mg dose did not exceed the MTD per protocol, the committee decided that the 60-mg dose was unlikely to be tolerated for long-term treatment by the majority of patients, and 45 mg was considered to be the MTD.
In the randomized phase (part B), the mean change from baseline in systolic blood pressure after 28 days dosing was 5.5 (95% CI, −1.7 to 12.8), 7.9 (95% CI, 0.6 to 15.1) and 21.6 (95% CI, 12.9 to 30.3) mmHg for 20, 30, and 45 mg AZD2171, respectively. The relationship between systolic blood pressure and dose was shown to be statistically significant at the two-sided 5% level in the dose range 20 to 45 mg (overall P = .02; 45 mg v 30 mg, P = .02; 45 mg v 20 mg, P < .01; 30 mg v 20 mg, P = .64).
After a single dose of AZD2171, maximal plasma concentrations were measured from 1 to 8 hours postdosing with an overall median value of 3.0 hours (Table 5; Fig A2A, online only). After attaining maximum serum concentration (Cmax), the plasma concentration declined in an apparent biexponential manner with a terminal half-life ranging from 12.4 to 35.7 hours, with an overall arithmetic mean of approximately 22 hours (± 6.5 hours). The apparent oral clearance ranged from 2.52 to 61.0 L/h (overall arithmetic mean, 28.2 L/h; standard deviation [SD], 15.1 L/h).
After multiple dosing of AZD2171 (parts A and B combined), maximal plasma concentrations were measured from 1.0 to 6.4 hours postdosing with an overall median value of 2.1 (Table 6; Fig A2B). On the basis of the overall arithmetic mean accumulation ratio (Rac) value of 1.61, accumulation is consistent with the terminal half-life observed after single doses. Steady-state plasma concentrations were attained after approximately 7 days of repeated once-daily oral dosing. The grand arithmetic mean temporal change parameter (TCP) value of 0.988 supports no time-dependent changes in pharmacokinetics, which is consistent with no autoinduction or autoinhibition of AZD2171 metabolism after multiple doses. After multiple oral dosing of AZD2171 from 0.5 to 60 mg, the interpatient variability in Css,max and AUCss, expressed as the coefficient of variation percentage (CV%), ranged from 20.7% to 87.6% and appeared to be dose dependent.
Dose-proportional increases in AUCss and Css,max were observed over the dose range 0.5 to 60 mg. For a two-fold difference in dose, the corresponding fold-change in AUCss was estimated as 1.93 (90% CI, 1.80 to 2.07) and for Css,max as 1.95 (90% CI, 1.82 to 2.08). For both parameters, the corresponding CI includes 2.0, thus supporting dose proportionality. The evidence for dose proportionality was weaker over the dose range 20 to 45 mg when only data from part B were examined. For a two-fold difference in dose, the ratio of AUCss was estimated as 1.33 (90% CI, 0.85 to 2.10) and Css,max as 1.09 (90% CI, 0.70 to 1.72).
A review of the DCE-MRI data from the initial cohorts in part A found that iAUC60 was less variable than Ktrans, and iAUC60 was selected as the primary DCE-MRI measure for this trial (data not shown). The relationship between iAUC60 and AUCss, Css,max, and Css,min obtained from multiple doses ranging from 0.5 to 60 mg from parts A and B is presented in Figure 1. The results of the statistical modeling showed that the pharmacokinetic parameters appear to be major determinants of the decrease in tumor vascular permeability as described by the DCE-MRI variable of iAUC60 (R2 range, 0.33 to 0.49) with all of the relationships being significant (two-sided P < .01). However, when the dose range was restricted to the doses explored in the randomly assigned part B (20, 30, and 45 mg), the pharmacokinetic parameters were not a major determinant (R2 range, 0.12 to 0.35; data not shown). Furthermore, this can also be seen from statistical analysis of doses evaluated in randomly assigned part B (20, 30, and 45 mg). Similar pharmacokinetic/pharmacodynamic relationships were observed for Ktrans as for iAUC60 (data not shown). Other pharmacokinetic/pharmacodynamic models, including nonlinear models, were utilized to explore these relationships, but on the basis of model differentiation criteria and using the rule of parsimony, the linear regression model was optimal.
In comparison, the relationship between percentage change in iAUC60, at the same time point used for the pharmacokinetic/pharmacodynamic modeling, and dose first received (0.5 to 60 mg) was not a major determinant of the decreases in tumor vascular permeability as described by iAUC60 (R2 = 0.07), with the relationship being nonsignificant (P = .12). Because of the large proportion of patients in the 20- to 45-mg range, analysis was heavily influenced by the relationship in this range. Analyses that attempted to correct for the disproportionate number of patients in each dose group were conducted; these exhibited a trend of larger decreases in iAUC60 with increasing dose, but this did not reach statistical significance.
Statistical analyses revealed significant average reductions from baseline in iAUC60 for all three doses in part B; however, there was no evidence of a dose effect within this range (Fig 2A). The average reduction in iAUC60 from baseline was similar for each dose, and the magnitude of the reduction on day 2 was less compared with the reductions on days 28 and 56. Example DCE-MRI scans from a patient with a reduction in tumor iAUC60 after single and multiple dosing with AZD2171 and corresponding MRI scans are shown in Figure 3. Findings from the statistical analysis of Ktrans were consistent with those for iAUC60 (data not shown).
After once-daily dosing of AZD2171, time- and dose-dependent reductions in soluble VEGFR-2 levels were demonstrated from day 1 (Fig 2B). Increases in VEGF and PlGF were detected after dosing, but there was no suggestion of a dose relationship. No clear trends in levels of b-FGF, VEGFR-1, TIE-2, E-selectin, or IL-8 levels were observed.
The objective tumor responses from parts A and B combined are summarized in Figure A3 (online only). There were two confirmed partial responses; one in a patient with prostate cancer in the 45-mg cohort and one in a patient with renal cancer in the 60-mg cohort. In addition, 22 patients had stable disease comprising colorectal (n = 7), lung (n = 3), liver (n = 2), breast (n = 2), skin/soft tissue (n = 2), and stomach, head and neck, ovarian, biliary duct, thyroid, and pancreatic (n = 1 each) tumor types; these included two patients with an unconfirmed partial response and seven patients with a confirmed minor response (10% to 30% reduction). Minor responses were observed in patients with the following tumor types: breast (n = 2) and colorectal, lung, head and neck, liver and skin/soft tissue (n = 1 each). There was encouraging evidence of dose-related control of tumor growth. Dose-related increases in the percentage of patients with stable disease and dose-related reductions in the percentage of patients with progressive disease were observed (Fig A3). Furthermore, dose-related increases in the proportion of patients alive and progression free after 12 weeks of treatment were seen: AZD2171 10 mg or less, one (6%) of six; 20 mg, two (11%) of 19; 30 mg, two (10%) of 21; 45 mg, four (21%) of 19; and 60 mg, three (38%) of eight.
Figure 2C shows the smallest postdose measurement of the liver target lesion size for each patient obtained from scans conducted throughout the study. Analysis of the size of the single metastatic liver lesion for patients randomly assigned to doses in part B did not show a statistically significant dose effect within this range, but demonstrated a trend for a dose-related effect on change in tumor size (Fig A4, online only).
In this phase I study of patients with advanced solid tumors with liver lesions, AZD2171 was generally well tolerated at doses of 45 mg or less. The most common dose-related AEs reported were hypertension, diarrhea, and dysphonia. Hypertension did not occur below 20 mg, and dose-related changes in blood pressure were observed at AZD2171 doses of 20 mg and higher. The increased incidence of dose-related hypertension seen in this study is most likely a result of the potent inhibitory effect of AZD2171 on VEGF signaling, and an increased incidence of hypertension has been reported in clinical investigations with other small-molecule VEGF tyrosine kinase inhibitors,20-22 as well as with the anti–VEGF-A monoclonal antibody bevacizumab.11,12 VEGF has vasodilatory activity, and agents that inhibit VEGF/VEGFR signaling may indirectly cause vasoconstriction by removing a single factor contributing to overall vasodilatory tone. In this study, hypertension was manageable by standard hypertension therapy (the most commonly prescribed antihypertensive agents were calcium channel antagonists). A hypertension management protocol, based on international guidelines,23 has been developed for use in all future studies. It incorporates a standard, stepwise approach to the addition of antihypertension agents and clear guidelines for a temporary dose interruption or reduction. A randomized, double-blind phase II study to further investigate the management of hypertension at AZD2171 30 and 45 mg is currently ongoing in patients with advanced solid tumors.24
After multiple oral doses of AZD2171 20 mg, the unbound Css,min was 4.86 times higher than the human umbilical vein endothelial cell proliferation IC50, consistent with inhibition of target enzyme throughout the 24-hour dosing interval.16 This supports a once-daily oral dosing schedule for AZD2171. The interpatient variability in Css,max and AUCss is comparable with phase I data for other oral agents evaluated for the treatment of solid tumors.25-28 Dose proportional increases in Css,max and AUCss were observed for multiple doses ranging from 0.5 to 60 mg. However, when data from part B were examined, this showed weak evidence to support dose proportionality with two-fold changes in dose resulting in less than two-fold changes in the pharmacokinetic parameters. It is likely that this analysis has been confounded by a disproportionate number of dose reductions in the higher doses; patients at the 30- and 45-mg dose who experience a higher than average exposure may have been more likely to undergo dose reduction, underestimating the true level of exposure at these doses and hence leading to less than proportional increases in exposure being obtained from the statistical analysis. Additional evaluation will be required to make a definitive statement about pharmacokinetic linearity.
Evaluation of novel targeted agents, such as VEGF signaling inhibitors, may be supported by the identification of suitable markers of biologic activity. These include measures of vascular density and permeability, as assessed using DCE-MRI.29-31 The reduction in iAUC60 on day 2 observed in this study suggests a reduction in vascular permeability, whereas the sustained effects on days 28 and 56 are likely to reflect changes in blood flow. Overall, the findings from the DCE-MRI investigation demonstrated that AZD2171 modulates tumor vascular physiology and reduces tumor blood flow and vascular permeability. Evaluation of an additional biologic marker, soluble VEGFR-2, showed dose- and time-dependent decreases at doses of 20 mg and lower. Although there was no evidence of a dose-response relationship for soluble VEGFR-2 levels at doses greater than 20 mg, the decrease was time dependent. The decreased levels of VEGFR-2 and increased levels of VEGF and PlGF in this clinical investigation of AZD2171 may be related to its highly potent antiangiogenic activity previously demonstrated in preclinical studies.16 In summary, the pharmacodynamic changes observed in the present study are consistent with inhibition of VEGF/VEGFR-dependent signaling with a dose/pharmacokinetic relationship, and similar findings have been reported for other agents.15,30-32
There is encouraging evidence of dose-related control of tumor growth in this population of patients with advanced, treatment-refractory tumors. Dose-related increases in the percentage of patients with stable disease were observed, and there was evidence of dose-related reductions in the percentage of patients with progressive disease. These preliminary response data, in combination with the observed dose-related decreases in tumor size and the proportion of patients alive and progression free at week 12, suggest that AZD2171 monotherapy has activity in a range of tumor types, including those refractory to previous treatment. The preliminary evaluation of biologic activity of AZD2171 in this study using a combination of suitable markers and disease stabilization data demonstrate that it is biologically active at doses of 20 mg and higher, with a suggested MTD of 45 mg. As with all investigational compounds of this class, monitoring for signs of hypertension is advisable. AZD2171 (20, 30, and 45 mg) is currently being investigated in a range of tumor types, and recruitment to a series of randomized, double-blind phase II and phase II/III trials is ongoing.
Although all authors completed the disclosure declaration, the following authors or their immediate family members indicated a financial interest. No conflict exists for drugs or devices used in a study if they are not being evaluated as part of the investigation. For a detailed description of the disclosure categories, or for more information about ASCO's conflict of interest policy, please refer to the Author Disclosure Declaration and the Disclosures of Potential Conflicts of Interest section in Information for Contributors.
Employment: Jane Robertson, AstraZeneca; Juliane M. Jürgensmeier, AstraZeneca; Thomas A. Puchalski, AstraZeneca; Helen Young, AstraZeneca; Owain Saunders, AstraZeneca Leadership: N/A Consultant: N/A Stock: Jane Robertson, AstraZeneca; Juliane M. Jürgensmeier, AstraZeneca; Thomas A. Puchalski, AstraZeneca; Owain Saunders, AstraZeneca Honoraria: N/A Research Funds: Klaus Mross, Funds, AstraZeneca Germany Testimony: N/A Other: N/A
Conception and design: Joachim Drevs, Jane Robertson, Juliane M. Jürgensmeier, Thomas A. Puchalski, Helen Young, Owain Saunders
Administrative support: Klaus Mross
Provision of study materials or patients: Klaus Mross, Jane Robertson
Collection and assembly of data: Joachim Drevs, Patrizia Siegert, Michael Medinger, Klaus Mross, Ralph Strecker, Ute Zirrgiebel, Jan Harder, Hubert Blum, Clemens Unger
Data analysis and interpretation: Joachim Drevs, Patrizia Siegert, Michael Medinger, Klaus Mross, Ralph Strecker, Ute Zirrgiebel, Jan Harder, Hubert Blum, Jane Robertson, Juliane M. Jürgensmeier, Thomas A. Puchalski, Helen Young, Owain Saunders, Clemens Unger
Manuscript writing: Joachim Drevs, Patrizia Siegert, Ralph Strecker, Ute Zirrgiebel, Jan Harder, Hubert Blum, Jane Robertson, Thomas A. Puchalski, Helen Young, Clemens Unger
Final approval of manuscript: Joachim Drevs, Jane Robertson, Juliane M. Jürgensmeier, Thomas A. Puchalski, Helen Young, Owain Saunders, Clemens Unger
Measurements were made after the patient has been resting supine for at least 5 minutes. Two or more readings were taken at 2-minute intervals and averaged. If the first two diastolic readings differed by more than 5 mmHg, an additional reading was obtained and averaged.
Twelve-lead ECGs were obtained after the patient has been lying down for 5 minutes. Two copies of ECG traces were recorded using the same ECG machine set at 25 and 50 mm/sec. Each study day, a physician reviewed the paper copies of each ECG. Heart rate; P and QRS duration; R-R, PQ, QT, and QTc intervals (ms); and height of the ST-segment and T-wave (mV) and T-wave morphology were determined by an external cardiologist.
The plasma pharmacokinetics of AZD2171 were characterized following both single dose (part A) and multiple doses (parts A and B). To estimate the single-dose pharmacokinetic profile of AZD2171 blood samples were obtained: 0 (pre), 1, 2, 3, 4, 6, 8, 12, 24, 36, 48, 72, 96, 120, and 144 hours postdose. For four patients in the 60-mg cohort, blood samples were obtained only up to 48 hours postdosing. To estimate the multiple-dose pharmacokinetic profile of AZD2171, blood samples were obtained before dosing on days 8, 15, 22, and 28 and at 1, 2, 3, 4, 6, 8, 12, and 24 hours after dosing on day 28. To be eligible for steady-state pharmacokinetic assessments, patients must have received once-daily oral administration for 7 consecutive days at the same dose before pharmacokinetic sampling on day 28.
Plasma concentrations of AZD2171 were determined by solid-phase extraction followed by reverse-phase liquid chromatography and detection by tandem mass spectrometry. The method was validated to cover the concentration range of 0.1 to 500 ng/mL, with 0.1 ng/mL adopted as the lower limit of quantification.
Single- and multiple-dose pharmacokinetic parameters of AZD2171 were determined by noncompartmental methods using the WINNonlin Professional Version software package (Scientific Consulting, Apex, NC). Cmax, Css,max, Css,min, and time to reach peak or maximum concentration or maximum response after drug administration (tmax) were determined by visual inspection of the individual plasma concentration-time profiles. The half-life associated with terminal slope of a semilogarithmic concentration-time curve (t1/2λz) was determined by log-linear regression of those plasma time-concentrations considered to be in the terminal phase of drug disposition. The area under the plasma concentration-time curve from 0 to 24 hours after a single dose (AUC0-24) and the area under the plasma concentration time curve from time zero to infinity (AUC) were estimated by the linear trapezoidal algorithm with extrapolation to time infinity for AUC using the slope of the terminal log concentration versus time data (-λz). The apparent oral clearance (CL/F) was calculated as Dose/AUC. The AUCss was estimated by linear trapezoidal algorithm to the last data point of the 24-hour dosing interval. The TCP was calculated as the ratio of day-28 AUCss to AUC, and the Rac was calculated as the ratio of AUCss to AUC0-24.
Because some patients underwent dose reduction and/or took breaks in continuous dosing, it was necessary to present concentration and pharmacokinetic parameter data according to dose actually received to better understand the underlying pharmacokinetic properties of AZD2171. The dose received during the 7 days before pharmacokinetic sampling on day 28 of multiple dosing was the dose allocated for summarizing pharmacokinetic data. Pharmacokinetic sampling was not obtained before those scheduled on day 28 in patients who had their dose reduced during the first 28 days of repeated multiple doses.
Soluble markers of angiogenesis (VEGF, b-FGF, VEGFR-1, VEGFR-2, PlGF, TIE-2, E-selectin, and IL-8 levels) were measured in serum and plasma samples. VEGF and bFGF were measured in EDTA-plasma samples, with the remaining markers measured in serum. In part A, assessments were performed at screening and up to 36 hours after the first dose of AZD2171. Additional assessments were performed after 15 and 28 days of multiple dosing and every 28 days thereafter. In part B, assessments were performed at screening, 8 hours post–first dose, after 8 and 28 days of multiple dosing, and every 28 days thereafter.
Parameters were determined using the sandwich enzyme-linked immunosorbent assay (ELISA) technique with a specific capture antibody covering the bottom of the microtiter plate and a specific detection antibody recognizing the bound antigen. The resulting optical density values were translated into concentration by calibration against a standard curve obtained with the respective recombinant protein. With the exception of IL-8 (Bender MedSystems, Burlingame, CA), all ELISA sets were obtained from R&D Systems (Minneapolis, MN).
The parameter ELISA set included the following: VEGF, Quantikine Human VEGF immunoassay; bFGF, Quantikine HS Human FGF basic immunoassay; VEGFR-1, Quantikine Human Soluble VEGF R1/FLT-1 immunoassay; sVEGFR-2, Quantikine Human Soluble VEGFR-2 immunoassay; sTIE-2, Quantikine Human Tie-2 immunoassay; IL-8, Bender MedSystems human IL-8 immunoassay; and sE-Selectin, Parameter Human sE-Selectin immunoassay.
Analysis of covariance (ANCOVA) models were used to assess the dose response of AZD2171 on tumor size, blood pressure, and the DCE-MRI parameter of iAUC60 for data from the randomly assigned part B. Models contained a factor for dose (20, 30, or 45 mg) and a continuous baseline covariate. Tumor size was log transformed before analysis because it was found that this end point was multiplicative in nature. A statistically significant dose effect was declared if the corresponding test was significant at the two-sided 5% level. If this test was significant, P values associated with the pair-wise comparisons are presented. From the fitted models, adjusted means and associated 95% CIs were calculated for change from baseline at each dose level (20, 30, and 45 mg).
A preliminary assessment of dose proportionality was performed for the multiple-dose parameters of Css,max and AUCss. Dose proportionality was assessed using a power model [parameter = α × doseβ] where α is the intercept and β is the slope, measuring the extent of dose proportionality. Dose proportionality implies that a two-fold change in dose would result in a two-fold change in the pharmacokinetic parameter of interest (ie, β = 1). Because of variability in the estimation of β, dose proportionality was concluded if the range of the 90% CI for a two-fold change in dose contained 2 (ie, the range of the 90% CI for β contained 1).
Linear models were used to explore the relationship between percentage change from baseline in iAUC60 and the multiple-dose pharmacokinetic parameters of AUCss, Css,max, and Css,min. Models had baseline iAUC60 fitted as a continuous covariate in the model. Statistical significance was concluded if the P value of the regression coefficient associated with the multiple-dose pharmacokinetic parameter was significant at the two-sided 5% level. In an attempt to better examine the pharmacokinetic/pharmacodynamic relationships, nonlinear models with various weighting schemes were also utilized, with the results compared to the linear model using penalized sums of squares. Furthermore, to assess whether the effect on iAUC60 was best associated with the multiple-dose pharmacokinetic parameters or dose, percentage change from baseline in iAUC60 was regressed against dose (0.5 to 60 mg). The dose used in this analysis was that first received, irrespective of dose reductions or delays.S
|Characteristic||Tumor Type||Metastatic Disease Sites (outside the liver)*|
|Initial dose of AZD2171, mg|
|0.5 (n = 3)||Colorectal (n = 3)||Lung (n = 2)|
|1.0 (n = 3)||Colorectal (n = 2); breast (n = 1)||Lymph nodes (n = 2)|
|2.5 (n = 3)||Colorectal (n = 1); small bowel (n = 1); other† (n = 1)||Lymph nodes (n = 1); lung (n = 1); other‡ (n = 1)|
|5 (n = 3)||Skin/soft tissue (n = 1); lung (n = 1); liver (n = 1)||Lymph nodes (n = 1); bone (n = 1)|
|10 (n = 4)||Colorectal (n = 2); breast (n = 2)||Bone (n = 2); lung (n = 2); other† (n = 2)|
|20 (n = 3)||Colorectal (n = 1); skin/soft tissue (n = 1); other† (n = 1)||Lung (n = 2); lymph nodes (n = 1); pleural (n = 1); bone (n = 1); other‡ (n = 1)|
|30 (n = 5)||Colorectal (n = 2); breast (n = 1); prostate (n = 1); other† (n = 1)||Bone (n = 2); lymph nodes (n = 2); lung (n = 2); pleural (n = 1); other‡ (n = 2)|
|45 (n = 4)||Colorectal (n = 1); stomach (n = 1); other† (n = 2)||Lung (n = 2); bone (n = 1); other‡ (n = 1)|
|60 (n = 8)||Renal (n = 3); colorectal (n = 2); skin/soft tissue (n = 1); other† (n = 2)||Lymph nodes (n = 1); bone (n = 1); skin/soft tissue (n = 1); other‡ (n = 4)|
*Not all patients had a site of metastatic disease outside the liver; some patients had more than one site of metastatic disease outside the liver.
†Other tumor types included: cancer of the pancreas/gallbladder; ovary; cervix; skin/soft tissue; thyroid; choroid melanoma.
‡Other sites of metastatic disease included: peritoneal carcinomatosis of the adrenal gland; bone marrow; pancreas; pleural/peritoneal region of the abdominal wall, liver, pancreas, spleen, or kidney; spleen; thyroid gland.
|Characteristic||Tumor Type||Metastatic Disease Sites (outside the liver)*|
|Initial dose of AZD2171, mg|
|20 (n = 16)||Colorectal (n = 4); breast (n = 4); lungs (n = 2); renal (n = 1); skin/soft tissue (n = 1); other† (n = 4)||Lung (n = 4); bone (n = 4); Ascites (n = 3); skin/soft tissue (n = 3); lymph nodes (n = 3); pleural (n = 3); other‡ (n = 8)|
|30 (n = 16)||Breast (n = 4); colorectal (n = 3); lungs (n = 2); stomach (n = 2); esophagus (n = 2); liver (n = 1); other† (n = 2)||Lymph nodes (n = 5); lung (n = 4); pleural (n = 4); ascites (n = 2); other‡ (n = 1)|
|45 (n = 15)||Breast (n = 3); liver (n = 2); lungs (n = 1); prostate (n = 1); stomach (n = 1); colorectal (n = 1); head and neck (n = 1); other† (n = 5)||Lymph nodes (n = 3); bone (n = 2); lung (n = 2); skin/soft tissue (n = 2); pleural (n = 1); other‡ (n = 2)|
*Not all patients had a site of metastatic disease outside the liver; some patients had more than one site of metastatic disease outside the liver.
†Other tumor types included: cancer of the pancreas/gallbladder; ovary; cervix; cancer of unknown primary site.
‡Other sites of metastatic disease included: abdominal wall; adrenal gland; peritoneal carcinomatosis; pancreas; pleural/peritoneal region of the abdominal wall, liver, pancreas, spleen, or kidney; spleen; thoracic wall.
|MedDRA-Preferred Term||AZD2171 Dose (mg)|
|≤ 10 (n = 16)||20||30||45||60 (n = 8)||All (N = 83)|
|A (n = 3)||B (n = 16)||A (n = 5)||B (n = 16)||A (n = 4)||B (n = 15)|
Abbreviation: PPE, palmar-plantar erythrodysesthesia syndrome (hand-foot syndrome).
|MedDRA-Preferred Term||CTC Grade†||AZD2171 Dose (mg)|
|20 (n = 19)||30 (n = 21)||45 (n = 19)||60 (n = 8)||All (n = 83)|
NOTE. Adverse events occurring at both grades 3 and 4 in the same patient have been counted only once. Adverse event occurring in only one patient were (grade 3 unless stated) as follows: 60 mg—blood bilirubin increased, hypoglycemia (grade 4; both were considered to be dose-limiting toxicities); 45 mg—aphasia (grade 4), cerebrovascular accident (grade 4), dyspnea exacerbated, fatigue, transient ischemic attack; 30 mg—deep vein thrombosis, muscular weakness; 20 mg—alanine aminotransferase increased, dizziness, duodenal ulcer, headache, hepatic enzyme increased, hepatic hemorrhage.
Abbreviations: GGT, gamma-glutamyl transferase; PPE, palmar-plantar erythrodysesthesia (hand-foot syndrome); CTC, Common Toxicity Criteria version 2.0.
*The investigator considered there was a reasonable possibility that the event may have been caused by the study treatment or procedure.
†No drug-related CTC grade 3 or 4 adverse events were reported at doses ≤ 10 mg.
|Parameter||AZD2171 Dose (mg)|
|0.5 (n = 3)||1.0 (n = 3)||2.5 (n = 3)||5.0 (n = 3)||10 (n = 4)||20 (n = 3)||30 (n = 5)||45 (n = 4)||60 (n = 8)|
|AUC, ng · hour/mL|
Abbreviations: Cmax, maximum plasma (peak) drug concentration after single-dose administration; CV, coefficient of variation; tmax, time to reach peak or maximum concentration or maximum response after drug administration; t1/2λz, half-life associated with terminal slope of a semilogarithmic concentration-time curve; SD, standard deviation; NC, not calculated; AUC, area under plasma concentration-time curve from zero to infinity; CL/F, apparent oral clearance.
*Arithmetic mean calculated from untransformed data.
|Parameter||AZD2171 Dose (mg)|
|0.5 (n = 3)||1.0 (n = 2)||2.5 (n = 1)||5.0 (n = 2)||10 (n = 1)||20 (n = 11)||30 (n = 12)||45 (n = 6)||60 (n = 4)|
|AUCss, ng · hour/mL|
NOTE. TCP and Rac are the data from Part A only while the others are from Parts A and B. Patients receiving consecutive daily dosing at the same dose for seven days prior to pharmacokinetic sampling on day 28 were assessable for derivation of pharmacokinetic parameters.
Abbreviations: Css,min, minimum steady-state drug concentration in plasma during dosing interval; CV, coefficient of variation; NC, not calculated; Css,max, maximum steady-state drug concentration in plasma during dosing interval; tmax, time to reach peak or maximum concentration or maximum response following drug administration; AUCss, area under plasma concentration-time curve during any dosing interval at steady state; TCP, temporal change parameter; SD, standard deviation; Rac, accumulation ratio index.
*Arithmetic mean and SD calculated from untransformed data.
Presented in part at the Gastrointestinal Cancers Symposium, San Francisco, CA, January 26-28, 2006; at the 40th Annual Meeting of the American Society of Clinical Oncology, New Orleans, LA, June 5-8, 2004; and at the 41st Annual Meeting of the American Society of Clinical Oncology, May 13-17, 2005, Orlando, FL.
Authors’ disclosures of potential conflicts of interest and author contributions are found at the end of this article.
We thank the members of the clinical study team at AstraZeneca and at the study site in Freiburg. We also thank Dr Jen Jackson, from Mudskipper Bioscience, who provided medical writing support funded by AstraZeneca.
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