Phase I/II Trial Evaluating the Anti-Vascular Endothelial Growth Factor Monoclonal Antibody Bevacizumab in Combination With the HER-1/Epider
http://www.100md.com
《临床肿瘤学》
the Departments of Thoracic/Head & Neck Medical Oncology, Biostatistics, and Diagnostic Radiology, The University of Texas, M. D. Anderson Cancer Center, Houston, TX
Departments of Medicine and Hematology/Oncology, Vanderbilt University Medical School, The Vanderbilt-Ingram Cancer Center, Nashville, TN
Departments of Pharmacokinetic and Pharmacodynamic Sciences, BioOncology, Microbiology and Pathology, Genentech Inc, South San Francisco, CA
ABSTRACT
PURPOSE: Bevacizumab (Avastin; Genentech, South San Francisco, CA) is a recombinant, humanized anti-vascular endothelial growth factor monoclonal antibody. Erlotinib HCl (Tarceva, OSI-774; OSI Pharmaceuticals, New York, NY) is a potent, reversible, highly selective and orally available HER-1/epidermal growth factor receptor tyrosine kinase inhibitor. Preclinical data in various xenograft models produced greater growth inhibition than with either agent alone. Additionally, both agents have demonstrated benefit in patients with previously treated non–small-cell lung cancer (NSCLC).
PATIENTS AND METHODS: A phase I/II study in two centers examined erlotinib and bevacizumab (A+T) in patients with nonsquamous stage IIIB/IV NSCLC with one prior chemotherapy. In phase I, erlotinib 150 mg/day orally plus bevacizumab 15 mg/kg intravenously every 21 days was established as the phase II dose, although no dose-limiting toxicities were observed. Phase II assessed the efficacy and tolerability of A+T at this dose. Pharmacokinetic parameters were evaluated.
RESULTS: Forty patients were enrolled and treated in this study (34 patients at phase II dose); the median age was 59 years (range, 36 to 72 years), 21 were female, 30 had adenocarcinoma histology, nine were never-smokers, and 22 had two prior regimens (three patients had four prior regimens). The most common adverse events were mild to moderate rash, diarrhea, and proteinuria. Preliminary data showed no pharmacokinetic interaction between A+T. Eight patients (20.0%; 95% CI, 7.6% to 32.4%) had partial responses and 26 (65.0%; 95% CI, 50.2% to 79.8%) had stable disease as their best response. The median overall survival for the 34 patients treated at the phase II dose was 12.6 months, with progression-free survival of 6.2 months.
CONCLUSION: Encouraging antitumor activity and safety of A+T support further development of this combination for patients with advanced NSCLC and other solid tumors.
INTRODUCTION
Over the last decade, biologic agents have been developed to target molecules involved in tumor growth and progression. Potential molecular targets are cell-surface receptors and their ligands. One example is the human epidermal growth factor receptor (HER-1/EGFR). HER-1/EGFR expression has been associated with poor prognosis in some studies of patients with NSCLC.1-3 However, other studies show no correlation4-7 or that HER-1/EGFR expression is only prognostic when coexpressed with other proteins such as metalloproteinase-98 or HER-2/neu.9 Additionally, some studies show HER-1/EGFR activity10 or gene copy number11 rather than expression inversely correlates with survival in patients with NSCLC. Overproduction of HER-1/EGFR ligands such as epidermal growth factor (EGF) and transforming growth factor alpha also creates an autocrine activation loop that may promote independent tumor growth.12
Vascular endothelial growth factor (VEGF) is also a target for tumor growth inhibition, as it is a major regulator of angiogenesis.13 VEGF expression is upregulated in a range of solid tumors and is greatest in hypoxic tumor cells near necrotic areas, suggesting that hypoxia-induced VEGF is vital for the development of tumor vasculature.14 Moreover, microvessel count, which is an indication of angiogenic effect, is an independent predictor of poor prognosis in patients with NSCLC.15
HER-1/EGFR and VEGF share common downstream signaling pathways (Fig 1). They exert effects both directly and indirectly on tumor cells, and combining drugs that target these molecules may confer additional clinical benefit. HER-1/EGFR is involved in angiogenesis; it has been detected in the endothelial cells of tumor vasculature preclinically.16 Coexpression of HER-1/EGFR and transforming growth factor alpha has been correlated with increased microvessel density in invasive breast cancer.17 VEGF is also downregulated by HER-1/EGFR inhibition,18,19 and a recent study suggested that blockade of VEGF may also inhibit HER-1/EGFR autocrine signaling.20 Therefore, it is rational to suggest that dual blockade of these molecular targets may produce additive and even synergistic cytostatic effects.
Against this background, a number of preclinical studies have investigated the antitumor activity of combined anti-HER-1/EGFR and anti-VEGF agents. A combination of the HER-1/EGFR small-molecule tyrosine kinase inhibitor (TKI) erlotinib (Tarceva, OSI-774; OSI Pharmaceuticals, New York, NY) and the anti-VEGF monoclonal antibody bevacizumab (Avastin, rhuMAb-VEGF; Genentech Inc, South San Francisco, CA) delayed tumor progression in three of four human colon tumor xenograft models; the level of inhibition was much greater than with either agent alone.21 In two separate preclinical studies, both cetuximab (C225, Imclone, New York, NY; an anti-HER-1/EGFR antibody) in combination with DC101 (an anti-VEGF receptor-2 antibody) and VEGF-AS (a human VEGF antisense [AS] 21-mer phosphorothioate oligonucleotide that inhibits VEGF production in human GEO colon cancer cells) decreased tumor growth compared with controls.22,23 In the latter study, overall survival was superior in mice treated with both agents than with either agent alone (P < .001). In 10% of mice given this combination, there was no histologic evidence of GEO cancer cells 20 weeks after tumor-cell injection. In another study, treatment with cetuximab in combination with DC101 also resulted in decreased tumor vasculature and increased endothelial and tumor cell apoptosis compared with DC101 alone in nude mice injected with KM12L4 human colon cancer cells.24 Gefitinib (ZD1839, Iressa; AstraZeneca, Wilmington, DE; an anti-HER-1/EGFR TKI) given with ZD6126 (an antivascular agent) also showed greater antitumor activity than either agent alone in both human colorectal cancer and NSCLC xenograft models.25 Taken together, these data show that dual blockade of HER-1/EGFR and VEGF has additive effects in some preclinical models. These encouraging data have led to the initiation of a number of clinical studies evaluating the combination of an EGFR TKI (erlotinib) with an anti-VEGF antibody (bevacizumab) in a range of tumor types, including a phase II trial each in renal cell carcinoma26 and metastatic breast cancer,27 and a phase I trial in patients with head and neck squamous cell carcinoma.28
Clinical data show that erlotinib prolongs survival in patients with advanced non–small-cell lung cancer (NSCLC) who have relapsed following chemotherapy.29 Encouraging antitumor activity has also been observed when bevacizumab was combined with paclitaxel plus carboplatin in chemotherapy-nave patients with advanced NSCLC in a small randomized phase II trial. The Eastern Cooperative Oncology Group has recently completed a confirmatory phase III trial.
In a randomized phase II study of patients with advanced NSCLC, 99 patients with stage IIIb, stage IV, or recurrent NSCLC were randomly assigned to receive either paclitaxel/carboplatin alone or paclitaxel/carboplatin plus bevacizumab (either at 7.5 mg/kg or 15 mg/kg every 3 weeks).30 The response rate was higher with high-dose bevacizumab than with control (investigator assessment, 32% v 19%). Time to disease progression was also higher for the high-dose bevacizumab arm (investigator assessment; median 225 days v 129 days for the control).
A single-arm phase II trial of erlotinib in 57 patients with EGFR-positive, advanced, recurrent NSCLC gave encouraging results,31 providing a basis for phase III development. In this trial, the response rate was 12.3% and median survival was 8.4 months, which is comparable to other second-line therapies. The clinical benefit of erlotinib in unselected patients with advanced, recurrent NSCLC was recently confirmed in the phase III trial, BR.21. Patients treated with erlotinib had a median survival of 6.7 months, compared with 4.7 months for those receiving best supportive care (P < .001).29 These results, together with compelling preclinical data, provided a strong rationale for clinical investigation of combined anti-HER-1/EGFR and anti-VEGF agents.
The main objective of phase I of this study was to establish whether combining bevacizumab and erlotinib at their most effective single-agent doses would lead to dose-limiting toxicities (DLTs) in patients with advanced, recurrent, nonsquamous NSCLC. In the absence of DLTs, this combination would be assessed for efficacy and safety in a larger population (phase II). The pharmacokinetics (PK) of these agents in combination were also assessed.
PATIENTS AND METHODS
Patient Eligibility
Patients with histologically proven stage IIIB (with pleural effusion)/IV, recurrent, nonsquamous NSCLC, and a Karnofsky performance status of 70%, were eligible. Patients also had to have adequate hematologic, hepatic, and renal function, and have relapsed after at least one platinum-based chemotherapy regimen for recurrent or metastatic disease. Key exclusion criteria were prior anti-VEGF and/or anti-HER-1/EGFR therapy, major surgery, or radiation therapy within the last 14 and 21 days, respectively. Patients with serious infection, a history of clinically significant hemoptysis, hematemesis, coagulopathy or thrombosis, or CNS metastases were excluded. Patients with a history of uncontrolled heart disease or hypertension, or those with a recent myocardial infarction were also ineligible. Concomitant anticoagulants or other investigational drugs were not permitted. Patients gave written informed consent. The institutional review boards of each center approved the study, which was conducted in accordance with federal and institutional guidelines.
Study Design and Treatments
This was a dual-agent, open-label, phase I/II study. In phase I, eligible patients were enrolled and treated according to the schema in Figure 2, using a 3+3 design. This study had a target response rate of 15%. With 34 patients treated at the phase II dose (six patients from phase I and 28 patients from phase II), the response rate can be estimated with a standard error no greater than 0.086. Erlotinib was available in 25-, 100-, and 150-mg oral tablets. Administration via percutaneous esophago-gastroscopy or gastric tube was not permitted. Any missed or vomited doses of erlotinib were not replaced. Bevacizumab was administered over 90 minutes as an intravenous infusion on day 1 of every 21-day cycle in the first cycle. If tolerated, the bevacizumab was then administered over 60 minutes for the second infusion and, finally, over 30 minutes with each subsequent cycle. Three patients were treated per cohort for one cycle (21 days per cycle). If no DLTs were recorded, treatment continued and three patients were treated in the subsequent cohort. However, if a patient developed a DLT, another three patients were treated in this cohort for one cycle. If there were no more DLTs, dose escalation continued. If more than one of three patients developed a DLT in any cohort, another three patients were treated in the next lower dosage cohort. If no DLTs were recorded in any of the cohorts, cohort 3 was expanded to six patients. The phase II dose for this combined treatment was therefore defined as either the highest dosage cohort in which six patients had been treated and there were less than three DLTs; or erlotinib at the previously defined maximum tolerated dose as a single agent (ie, 150 mg/d)32 plus bevacizumab at the highest tolerated dose investigated in this indication (15 mg/kg every 3 weeks),30 whichever was the lower dose. A DLT was defined as grade 3 or 4 diarrhea, rash, or nonhematologic toxicity, grade 4 hematologic toxicity, or treatment-related death.
Toxicity was graded according to the National Cancer Institute Common Toxicity Criteria (NCI-CTC) version 2. Based on clinical observations from other trials involving bevacizumab, if a patient had a grade 3 or 4 hemorrhagic adverse event (AE), or grade 4 hypertension, bevacizumab was discontinued. Other grade 3 or 4 serious adverse events (SAE) relating to either study drug were managed by dose interruption and/or reduction of the associated drug. No intrapatient dose escalation was permitted.
Study Assessments
Tumor size was assessed via computed tomography, magnetic resonance imaging, or chest x-ray every 42 days. Response Evaluation Criteria in Solid Tumors (RECIST) were used to determine tumor response and disease progression33; all tumor assessments were conducted by the investigator, and all responses were independently reviewed. A confirmed response was one that persisted for two separate assessments taken at least 4 weeks apart. After two cycles, patients with either a confirmed complete response (CR) or partial response (PR), or stable disease (SD), were eligible to continue treatment until disease progression or unacceptable toxicity. Progressive disease (PD) was defined as any of the following: a 20% increase in measurable index lesions from the smallest sum observed (from baseline if no confirmed response), reappearance of any lesion that had disappeared, appearance of any new lesion/site, or worsening of any assessable disease. Patients were assessed as having SD if they had no previous confirmed CR or PR, and did not qualify for CR, PR, or PD.
Pharmacokinetics
Blood samples from consenting patients in phases I and II of this study were used for PK analyses. Samples for analysis of erlotinib (and the active metabolite, OSI-420) and bevacizumab were collected in accordance with the schedule shown in Figure 3. Samples screened for serum antibodies to rhuMAb VEGF were collected on day 1 of cycle 1 (predose) and upon study completion (or withdrawal). The plasma was collected and stored at –70°C until analysis.
Plasma samples used to evaluate erlotinib disposition in the presence of bevacizumab were collected after the first erlotinib dose. Plasma drug concentration data were analyzed by noncompartmental methods with the WinNonlin software program (Pharsight, Mountain View, CA) and PK parameters were calculated as described previously.34 Nominal doses and sample collection times were used for PK analysis. Intermittent blood samples were also collected between study days 8 and 147 to estimate minimum steady-state drug concentrations. The disposition of erlotinib in the presence of bevacizumab was compared with results from an earlier study, where erlotinib alone was given to patients with solid tumors.32
Plasma samples used to evaluate bevacizumab disposition in the presence of erlotinib were collected after the first bevacizumab dose. Intermittent peak and trough drug concentrations were measured throughout the study. Plasma drug concentration data were analyzed with a two-compartment model with first order elimination using the WinNonlin software program, and PK parameters were calculated as described previously.34 Nominal doses and sample collection times were used for PK analyses. PK parameter estimates were compared with those from a population pharmacokinetic analysis of cancer patients given bevacizumab alone, or in combination with chemotherapy.35 All bevacizumab and erlotinib samples were analyzed at Genentech Inc and MDS Pharma Services (Saint-Laurent, Quebec, Canada), respectively.
HER-1/EGFR Sequencing Tumor cells were isolated from formalin-fixed paraffin embedded tumor tissue sections by laser capture microdissection (PixCell II, Arcturus, Mountain View, CA). DNA was extracted by proteinase K digestion (PicoPure, Arcturus). Amplification of exons 19 to 21 and 23 of HER-1/EGFR was performed using nested primers. Digested DNA was added to taq/pwo reaction buffer (Expand High Fidelity polymerase chain reaction [PCR] system, Roche Molecular Biochemicals, Indianapolis, IN) containing 0.5 μM of each primer, 0.2 μM of each dNTP and 1.5 mmol/L MgCl2. PCR with the outer primers were cycled 35 times, and second-step reactions with nested primers were cycled 30 times. PCR products were sequenced using M13 sequencing primers, fluorescent dye-terminator chemistry and an ABI3730 sequencing instrument (Applied Biosystems, Foster City, CA).
RESULTS
Patient Characteristics
Forty patients were enrolled on this study. Table 1 shows selected baseline demographics and disease characteristics. Twelve patients with locally advanced or metastatic NSCLC were enrolled and treated in phase I. Three patients each were treated in cohorts 1 and 2; six patients were treated in cohort 3. In phase II, cohort 3 was expanded to include an additional 28 patients, ensuring that 34 patients were treated at the protocol-defined phase II dose established in phase I.
In the overall study population, 80% of patients (32 of 40) had stage IV disease, and 75% (30 of 40) had adenocarcinoma. More than 90% (37 of 40) of patients had a Karnofsky performance score 80 at screening. More than half of patients (22 of 40) had received two or more prior systemic chemotherapy regimens for NSCLC. Finally, nine (22.5%) patients had never smoked.
Efficacy
All patients had at least two cycles of therapy; 13 patients remained on study for more than 6 months and had at least nine cycles of therapy. All 40 patients were assessable for response following at least two cycles of therapy. Table 2 lists the observed best responses to combined erlotinib and bevacizumab, as determined by RECIST criteria. A best response of a PR was reported in eight patients (20.0%; 95% CI, 7.6% to 32.4%), and SD was reported in 26 patients (65.0%; 95% CI, 50.2% to 79.8%). There were no CRs, and six patients had PD (15.0%). The median number of cycles received for all patients treated at the phase II dose (n = 34) was four cycles.
Figure 4 shows computed tomography scans of a PR. These scans are of a 48-year-old black male diagnosed with stage IIIB adenocarcinoma with pleural effusion in July 2001. Prior therapy included two cycles of carboplatin plus paclitaxel, followed by eight cycles of docetaxel. The first image is at baseline, and the second image was taken after two cycles of therapy (100 mg erlotinib, 7.5 mg/kg bevacizumab). He remains on study after 23 cycles of therapy with a PR.
Median overall survival (OS) and progression-free survival (PFS) were analyzed for patients in phase I, phase II, and for the overall study population (Table 2). OS and PFS were also determined for all patients treated at the phase II dose (34 patients). Median OS for all patients, regardless of dosage cohort assignment, was 12.6 months (Fig 5A); median PFS was 7.0 months (Fig 5B). For the 34 patients treated at the phase II dose, the median OS was 12.6 months and the median PFS was 6.2 months. Of the eight patients with a PR, three (37.5%) were women. Two (22.2%) of the nine patients who had never smoked had a PR, compared with six (19.4%) of 31 former or current smokers. All patients with a PR had adenocarcinoma.
Pharmacokinetics
Eleven patients from phase I and 17 patients from phase II consented to PK sampling. PK parameters for 15 mg/kg bevacizumab only were calculated from data from 13 patients (one patient in cohort 2, and 12 patients in cohort 3).
Figure 6 shows the plasma erlotinib and OSI-420 concentration versus time curves following a single dose of erlotinib in the presence of bevacizumab. The PK data for erlotinib showed wide interpatient variability. PK parameter estimates are summarized in Table 3. The maximum plasma concentration (Cmax) was achieved approximately 4 hours after oral administration of both 100 and 150 mg/d erlotinib. Cmax and area under the plasma concentration versus time curve from 0 to 24 hours (AUC0–24) increased with dose. The AUC0–24 for 150 mg/d erlotinib was 26% higher than for the 100 mg/d dose (AUC0–24 150 mg = 539 ± 190 day · ng/mL; AUC0–24 100 mg = 434 ± 490 day · ng/mL). Plasma clearance values were comparable for 100 and 150 mg/d erlotinib (173 ± 200 L/d v 184 ± 130 L/d); elimination half-life (t) values were 1.25 and 0.92 days, respectively. Minimum steady-state concentration (Css min) measured from days 8 to 147 was also similar for each dose (Css min 100 mg = 1.07 ± 0.63 μg/mL; Css min 150 mg = 1.00 ± 0.67 μg/mL). The drug accumulation ratios (Rac) were 3.2 and 2.3 for the 100 and 150 mg/d doses, respectively. For the metabolite, OSI-420, plasma exposure was 7% to 10% of the parent drug.
The PK of bevacizumab showed a biphasic distribution and elimination profile following intravenous infusion (Fig 7). Pharmacokinetic parameter estimates are summarized in Table 4. The mean half-life at distribution phase (t) and mean terminal half-life (t) were 1.32 ± 1.1 days and 22.1 ± 14 days, respectively; the AUC0– was 5,040 ± 2,000 day · μg/mL. The clearance (CL), volume of distribution of the central compartment (Vc), and steady-state volume of distribution (Vss) were 3.18 ± 1.0 mL/kg/d, 36.8 ± 7.9 mL/kg, and 77.4 ± 25 mL/kg, respectively. The Cmax was 396 ± 76 μg/mL; but this increased to 517 ± 82 μg/mL on day 64 after multiple dosing.
Safety and Tolerability
Phase I AEs were recorded by highest NCI-CTC grade in each patient. No SAEs or DLTs were reported in phase I. Seven of 12 patients experienced mild (grade 1/2) proteinuria, and two had mild (grade 1) epistaxis. One patient was hospitalized for pneumonia that was believed not to be treatment related. No treatment-related grade 3 or 4 toxicities were reported. It should be noted that at the completion of the phase I portion, the study did not reach what would be considered the maximum tolerated dose of bevacizumab. As such, the phase II portion of the study proceeded with a bevacizumab dose at its highest previously utilized single-agent dose (15 mg/kg every 3 weeks).
Phase II Table 5 shows all AEs reported in greater than or equal to 10% of patients, regardless of cause, by grade of severity for the subset of patients treated at the phase II dose (n = 34). For these patients, the most common AEs were rash (85%), diarrhea (65%), infection (29%), hematuria (32%), proteinuria (9%), and epistaxis (6%). Three SAEs were reported during the phase II portion of the trial; all were pneumonia. Four patients died on study; two at 15 weeks, and one each at 22 and 27 weeks. None of the deaths were considered treatment related. Three deaths were due to progression of disease and one was secondary to complications from pneumonia.
Two patients had severe (grade 3) hypertension; both were managed using antihypertensives. In one case, bevacizumab was also discontinued (while erlotinib was maintained) leading to resolution of this event. Other grade 3/4 events reported in phase II were one case of grade 3 rash, one grade 3 pruritus, two cases of grade 3 and one case of grade 4 pneumonia. The grade 3 rash resolved to grade 1 following symptomatic treatment and erlotinib dose reduction for two cycles of therapy (bevacizumab was continued). Grade 3 pruritus resolved to below grade 3 after 2 days of treatment. Two additional cases of mild epistaxis were noted in phase II.
HER-1/EGFR Sequencing
Nine patients had sufficient paraffin-embedded tissue available for EGFR TK domain mutational analysis (exons 19, 20, 21, and 23). The patient characteristics and mutational status are shown in Table 6. These nine patients included three patients who achieved a PR as best response, three patients with SD as best response, and three patients with PD as best response. Mutations were detected in one of the three patients with a PR and one of the three patients with SD.
DISCUSSION
Lung cancer is a heterogeneous disease with multiple mutations, and it is unlikely that any one signaling pathway is driving the oncogenic behavior of all tumors. A growing body of preclinical evidence suggests that combined anti-HER-1/EGFR and anti-VEGF agents may be an effective therapeutic strategy as they target multiple cell types within a tumor. Blocking two receptors that activate a number of shared downstream signaling pathways vital for tumor cell growth and proliferation may also explain the synergistic effects seen in preclinical studies. Taken together, these data give a strong rationale for investigating the effects of this multifaceted approach to cancer therapy in the clinic.
This phase I/II trial examined the safety and efficacy of combining erlotinib and bevacizumab therapy in patients with advanced or metastatic NSCLC. No SAEs or DLTs were reported in any of the cohorts in phase I. In accordance with the study protocol, the dose defined as the phase II dose for this study and the recommended dose for future studies was erlotinib at its previously defined maximum tolerated dose as a single agent (150 mg/d)32 plus bevacizumab at the highest tolerated dose investigated in this indication (15 mg/kg).30 There was no evidence of a PK interaction between these agents, and the antitumor activity reported was very encouraging.
Baseline characteristics of the overall study population were similar. Most patients (75%) had adenocarcinoma, and 55% had received two or more prior therapies. Twenty-one (52.5%) of the 40 patients were women, and nine (22.5%) had never smoked.
Combined erlotinib and bevacizumab therapy was well tolerated in both phase I and II of this study. AEs were rarely more than mild to moderate and were easily managed, suggesting that treatment with this combination is feasible. The most common AEs were rash, diarrhea, infection, hematuria, and proteinuria.
Rash has been reported in other trials of erlotinib31,32,36 and with other HER-1/EGFR-targeted agents, and is thought to be a class effect of these drugs. Moreover, recent studies have shown a relationship between the development of rash and survival, though further studies are needed to confirm these findings.31
Bevacizumab in combination with chemotherapy has been associated with tumor bleeding, including fatal hemoptysis, hypertension, proteinuria, asthenia, headache, and nausea.37-39 In a randomized phase II trial of bevacizumab plus carboplatin and paclitaxel versus carboplatin and paclitaxel alone in previously untreated patients with advanced NSCLC, 25 cases of minor bleeding (epistaxis) and six cases of major life-threatening bleeding described as hemoptysis or hematemesis were reported.30 Pulmonary hemorrhages appeared to be associated with centrally located tumors, which are frequently squamous cell tumors, and exploratory analysis in patients with nonsquamous histology showed improved survival in the bevacizumab arms. Patients with squamous cell NSCLC were therefore excluded from this trial, and four cases of grade 1 epistaxis, and importantly, no severe hemoptysis or arterial thromboembolic events, were reported.
PK analyses suggest no interaction between erlotinib and bevacizumab. All of the PK parameters estimated for erlotinib were similar to those reported by Hidalgo et al.32 Erlotinib exposure after a single dose in the presence of bevacizumab was similar to single-agent erlotinib for both 100 mg and 150 mg.
The observed biphasic distribution of bevacizumab is consistent with data from Hsei et al,35 and probably reflects initial binding of bevacizumab to circulating and tissue-bound VEGF followed by slow elimination. The PK profile of bevacizumab was consistent with single-agent data from Hsei et al,35 suggesting that the PK of bevacizumab was not affected by coadministered erlotinib.
The lack of interaction between these agents is important, as it enables predictable dose selection without exacerbating AEs. It also suggests that any enhancement in antitumor activity compared with either agent alone is due to their complementary modes of action rather than metabolic enhancement of drug concentrations.
The antitumor activity and survival data reported in this trial were very encouraging. The disease control rate (CR + PR + SD) for the entire study population was 85%; overall response rate was 20.0% with a median response duration of > 35 weeks. Median OS and PFS for the 34 patients treated at the phase II dose were 12.6 months and 6.2 months, respectively. Similar results were noted for the entire population (n = 40), with a median OS of 12.6 months and PFS of 7.0 months.
All eight patients with a PR had adenocarcinoma. However, as patients with squamous cell histology were excluded from this study, a higher number of patients with adenocarcinoma would be expected. A randomized trial to evaluate the importance of histologic subtype would therefore be needed before we can confirm if there is a trend towards improved survival in patients with adenocarcinoma treated with this combination versus other histologies.
Three (14.3%) of the 21 women and two (22.2%) of nine patients who had never smoked had a PR. Therefore, despite previous reports that suggest an increased benefit for females and never-smokers receiving HER-1/EGFR inhibitors, the response rates were comparable for males versus females (26.3% v 14.3%) and previous/current smokers versus never smokers (19.4% v 22.2%) receiving combined erlotinib and bevacizumab. These data suggest that this combination therapy is effective in an unselected patient population, although because of low patient numbers, these figures should be treated cautiously.
These findings show that treatment with erlotinib and bevacizumab in patients with advanced or recurrent nonsquamous NSCLC is well tolerated; the lack of PK interaction suggests that this combination is feasible. These data compare favorably with those on the antitumor activity of single-agent erlotinib. In the trial by the National Cancer Institute of Canada Clinical Trials Group in unselected patients with locally advanced or metastatic NSCLC who had failed at least one chemotherapy regimen (BR.21), median survival was 6.7 months with a progression-free survival of 2.2 months.29 In addition, following the encouraging results reported by Johnson et al,30 a phase II/III trial of bevacizumab in combination with carboplatin and paclitaxel in patients with advanced, nonsquamous NSCLC is in progress, and enrollment has been completed.
Recently, a somatic mutation in the HER-1/EGFR tyrosine kinase domain was identified that correlated with tumor response to gefitinib.40,41 Although its prognostic value has yet to be fully established, diagnostic tissue from a subset of patients enrolled in this trial was tested for the presence of this mutation.
At the time of reporting, nine patients had sufficient paraffin-embedded tissue available for EGFR TKD mutational analysis (exons 19, 20, 21 and 23). The patient characteristics and mutational status are shown in Table 6. These nine patients included three patients who achieved a PR as best response, three patients with SD as best response, and three patients with PD as best response. Mutations were detected in one of the three patients with a PR and one of the three patients with SD. It is interesting that one of the wild-type (WT; exons 19-21) patients with SD was a female nonsmoker with bronchioloalveolar carcinoma, a demographic subset which has been associated with response to EGFR TKIs. While it is possible that our WT patients could have mutations in unexamined exons, these results suggest the possibility that the combination of erlotinib with bevacizumab may provide benefit to patients with a WT EGFR and is further justification for further study of this combination.
The results of this study show that this combination is well tolerated and active in NSCLC. Investigation is already ongoing in other tumor types,26,28 and further investigation into the efficacy and tolerability of combined erlotinib and bevacizumab is warranted in randomized trials.
Authors' Disclosures of Potential Conflicts of Interest
The following authors or their immediate family members have 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. Employment: Dong Xie, Genentech; David Ramies, Genentech; Sean K. Kelley, Genentech. Consultant/Advisory Role: Roy S. Herbst, Genentech; David H. Johnson, Genentech; Hai Tran, Aventis; Alan Sandler, Genentech. Stock Ownership: Dong Xie, Genentech; Sean K. Kelley, Genentech. Honoraria: Roy S. Herbst, Genentech; David P. Carbone, Genentech; Hai Tran, Aventis; Alan Sandler, Genentech. Research Funding: Roy S. Herbst, Genentech; David H. Johnson, Genentech; Edward S. Kim, AstraZeneca, Aventis; Hai Tran, Genentech, Novartis, Orphan Medical; Alan Sandler, Genentech. For a detailed description of these categories, or for more information about ASCO's conflict of interest policy, please refer to the Author Disclosure Declaration and Disclosures of Potential Conflicts of Interest found in Information for Contributors in the front of each issue.
Acknowledgment
We thank Ben Garcia and Mercedes Guerra for their contribution to this study. We also thank Thinh Pham, Jeremy Stinson, and Kanan Pujara for technical assistance.
NOTES
Supported by Genentech Inc, South San Francisco, CA
Previously presented at the 39th Annual Meeting of the American Society of Clinical Oncology (ASCO), Chicago, IL, May 31-June 3; 40th ASCO Annual Meeting, New Orleans, LA, June 5-8, 2004; and 10th World Congress on Lung Cancer, Vancouver, Canada, August 10-14, 2004.
Terms in blue are defined in the glossary, found at the end of this issue and online at www.jco.org.
Authors' disclosures of potential conflicts of interest are found at the end of this article.
REFERENCES
Veale D, Kerr N, Gibson GJ, et al: The relationship of quantitative epidermal growth factor receptor expression in non-small cell lung cancer to long term survival. Br J Cancer 68:162-165, 1993
Selvaggi G, Novello S, Torri V, et al: Epidermal growth factor receptor overexpression correlates with a poor prognosis in completely resected non-small-cell lung cancer. Ann Oncol 15:28-32, 2004
Ohsaki Y, Tanno S, Fujita Y, et al: Epidermal growth factor receptor expression correlates with poor prognosis in non-small cell lung cancer patients with p53 overexpression. Oncol Rep 7:603-607, 2000
Pfeiffer P, Clausen PP, Andersen K, et al: Lack of prognostic significance of epidermal growth factor receptor and the oncoprotein p185HER-2 in patients with systemically untreated non-small-cell lung cancer: An immunohistochemical study on cryosections. Br J Cancer 74:86-91, 1996
Pfeiffer P, Nexo E, Bentzen SM, et al: Enzyme-linked immunosorbent assay of epidermal growth factor receptor in lung cancer: Comparisons with immunohistochemistry, clinicopathological features and prognosis. Br J Cancer 78:96-99, 1998
Rusch V, Klimstra D, Venkatraman E, et al: Overexpression of the epidermal growth factor receptor and its ligand transforming growth factor alpha is frequent in resectable non-small cell lung cancer but does not predict tumor progression. Clin Cancer Res 3:515-522, 1997
Meert AP, Martin B, Delmotte P, et al: The role of EGF-R expression on patient survival in lung cancer: A systematic review with meta-analysis. Eur Respir J 20:975-981, 2002
Swinson DE, Cox G, O'Byrne KJ: Coexpression of epidermal growth factor receptor with related factors is associated with a poor prognosis in non-small-cell lung cancer. Br J Cancer 91:1301-1307, 2004
Brabender J, Danenberg KD, Metzger R, et al: Epidermal growth factor receptor and HER2-neu mRNA expression in non-small cell lung cancer is correlated with survival. Clin Cancer Res 7:1850-1855, 2001
Kanematsu T, Yano S, Uehara H, et al: Phosphorylation, but not overexpression, of epidermal growth factor receptor is associated with poor prognosis of non-small cell lung cancer patients. Oncol Res 13:289-298, 2003
Hirsch FR, Varella-Garcia M, Bunn PA, Jr., et al: Epidermal growth factor receptor in non-small-cell lung carcinomas: Correlation between gene copy number and protein expression and impact on prognosis. J Clin Oncol 21:3798-3807, 2003
Raben D, Helfrich B, Bunn PA, Jr.: Targeted therapies for non-small-cell lung cancer: Biology, rationale, and preclinical results from a radiation oncology perspective. Int J Radiat Oncol Biol Phys 59:27-38, 2004 (suppl 2)
Ferrara N: The role of vascular endothelial growth factor in pathological angiogenesis. Breast Cancer Res Treat 36:127-137, 1995
Ferrara N, Davis-Smyth T: The biology of vascular endothelial growth factor. Endocr Rev 18:4-25, 1997
Fontanini G, Lucchi M, Vignati S, et al: Angiogenesis as a prognostic indicator of survival in non-small-cell lung carcinoma: A prospective study. J Natl Cancer Inst 89:881-886, 1997
Kim SJ, Uehara H, Karashima T, et al: Blockade of epidermal growth factor receptor signaling in tumor cells and tumor-associated endothelial cells for therapy of androgen-independent human prostate cancer growing in the bone of nude mice. Clin Cancer Res 9:1200-1210, 2003
de Jong JS, van Diest PJ, van der Valk P, et al: Expression of growth factors, growth-inhibiting factors, and their receptors in invasive breast cancer. II: Correlations with proliferation and angiogenesis. J Pathol 184:53-57, 1998
Petit AM, Rak J, Hung MC, et al: Neutralizing antibodies against epidermal growth factor and ErbB2-neu receptor tyrosine kinase down-regulate vascular endothelial growth factor production by tumor cells in vitro and in vivo. Am J Pathol 151:1523-1530, 1997
Hirata A, Ogawa S, Kometani T, et al: ZD1839 (Iressa) induces antiangiogenic effects through inhibition of epidermal growth factor receptor tyrosine kinase. Cancer Res 62:2554-2560, 2002
Ciardiello F, Caputo R, Damiano V, et al: Antitumor effects of ZD6474, a small molecule vascular endothelial growth factor receptor tyrosine kinase inhibitor, with additional activity against epidermal growth factor receptor tyrosine kinase. Clin Cancer Res 9:1546-1556, 2003
Herbst RS, Mininberg E, Henderson T, et al: Phase I/II trial evaluating blockade of tumor blood supply and tumor cell proliferation with combined bevacizumab and erlotinib HCl as targeted cancer therapy in patients with recurrent non-small cell lung cancer. Eur J Cancer 1:S293, 2003
Jung YD, Mansfield PF, Akagi M, et al: Effects of combination anti-vascular endothelial growth factor receptor and anti-epidermal growth factor receptor therapies on the growth of gastric cancer in a nude mouse model. Eur J Cancer 38:1133-1140, 2002
Ciardiello F, Bianco R, Damiano V, et al: Antiangiogenic and antitumor activity of anti-epidermal growth factor receptor C225 monoclonal antibody in combination with vascular endothelial growth factor antisense oligonucleotide in human GEO colon cancer cells. Clin Cancer Res 6:3739-3747, 2000
Shaheen RM, Ahmad SA, Liu W, et al: Inhibited growth of colon cancer carcinomatosis by antibodies to vascular endothelial and epidermal growth factor receptors. Br J Cancer 85:584-589, 2001
Guy SP, Ashton S, Hughes G, et al: Gefitinib (Iressa, ZD1839) enhances the activity of the novel vascular-targeting agent ZD6126 in human colorectal cancer and non-small cell lung cancer (NSCLC) xenograft models. Clin Cancer Res 9:6142S, 2003 (abstr; suppl B13)
Hainsworth JD, Sosman JA, Spigel DR, et al: Phase II trial of bevacizumab and erlotinib in patients with metastatic renal carcinoma (RCC). Proc Am Soc Clin Oncol 23:381, 2004 (abstr 4502)
Dickler M, Rugo H, Caravelli J, et al: Phase II trial of erlotinib (OSI-774), an epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor, and bevacizumab, a recombinant humanized monoclonal antibody to vascular endothelial growth factor (VEGF), in patients (pts) with metastatic breast cancer (MBC). Proc Am Soc Clin Oncol 23:127, 2004 (abstr 2001)
Mauer AM, Cohen EEW, Wong SJ, et al: Phase I study of epidermal growth factor receptor (EGFR) inhibitor, erlotinib, and vascular endothelial growth factor monoclonal antibody, bevacizumab, in recurrent and/or metastatic squamous cell carcinoma of the head and neck (SCCHN). Proc Am Soc Clin Oncol 23:496, 2004 (abstr 5539)
Shepherd FA, Pereira J, Ciuleanu TE, et al: A randomized placebo-controlled trial of erlotinib in patients with advanced non-small cell lung cancer (NSCLC) following failure of 1st line or 2nd line chemotherapy. A National Cancer Institute of Canada Clinical Trials Group (NCIC CTG) trial. Proc Am Soc Clin Oncol 23:18, 2004 (abstr 7022)
Johnson DH, Fehrenbacher L, Novotny WF, et al: Randomized phase II trial comparing bevacizumab plus carboplatin and paclitaxel with carboplatin and paclitaxel alone in previously untreated locally advanced or metastatic non-small-cell lung cancer. J Clin Oncol 22:2184-2191, 2004
Perez-Soler R, Chachoua A, Hammond LA, et al: Determinants of tumor response and survival with erlotinib in patients with non-small-cell lung cancer. J Clin Oncol 22:3238-3247, 2004
Hidalgo M, Siu LL, Nemunaitis J, et al: Phase I and pharmacologic study of OSI-774, an epidermal growth factor receptor tyrosine kinase inhibitor, in patients with advanced solid malignancies. J Clin Oncol 19:3267-3279, 2001
Therasse P, Arbuck SG, Eisenhauer EA, et al: New guidelines to evaluate the response to treatment in solid tumors. J Natl Cancer Inst 92:205-216, 2000
Perrier D, Gibaldi M: General derivation of the equation for time to reach a certain fraction of steady state. J Pharm Sci 71:474-475, 1982
Hsei VC, Novotny WF, Margolin K, et al: Population pharmacokinetic (PK) analysis of bevacizumab (BV) in cancer subjects. Proc Am Soc Clin Oncol 20:69a, 2001 (abstr 272)
Soulieres D, Senzer NN, Vokes EE, et al: Multicenter phase II study of erlotinib, an oral epidermal growth factor receptor tyrosine kinase inhibitor, in patients with recurrent or metastatic squamous cell cancer of the head and neck. J Clin Oncol 22:77-85, 2004
Gordon MS, Margolin K, Talpaz M, et al: Phase I safety and pharmacokinetic study of recombinant human anti-vascular endothelial growth factor in patients with advanced cancer. J Clin Oncol 19:843-850, 2001
Cobleigh MA, Langmuir VK, Sledge GW, et al: A phase I/II dose-escalation trial of bevacizumab in previously treated metastatic breast cancer. Semin Oncol 30:117-124, 2003 (5 suppl 16)
Yang JC, Haworth L, Sherry RM, et al: A randomized trial of bevacizumab, an anti-vascular endothelial growth factor antibody, for metastatic renal cancer. N Engl J Med 349:427-434, 2003
Paez JG, Janne PA, Lee JC, et al: EGFR mutations in lung cancer: Correlation with clinical response to gefitinib therapy. Science 304:1497-1500, 2004
Lynch TJ, Bell DW, Sordella R, et al: Activating mutations in the epidermal growth factor receptor underlying responsiveness of non-small-cell lung cancer to gefitinib. N Engl J Med 350:2129-2139, 2004(Roy S. Herbst, David H. J)
Departments of Medicine and Hematology/Oncology, Vanderbilt University Medical School, The Vanderbilt-Ingram Cancer Center, Nashville, TN
Departments of Pharmacokinetic and Pharmacodynamic Sciences, BioOncology, Microbiology and Pathology, Genentech Inc, South San Francisco, CA
ABSTRACT
PURPOSE: Bevacizumab (Avastin; Genentech, South San Francisco, CA) is a recombinant, humanized anti-vascular endothelial growth factor monoclonal antibody. Erlotinib HCl (Tarceva, OSI-774; OSI Pharmaceuticals, New York, NY) is a potent, reversible, highly selective and orally available HER-1/epidermal growth factor receptor tyrosine kinase inhibitor. Preclinical data in various xenograft models produced greater growth inhibition than with either agent alone. Additionally, both agents have demonstrated benefit in patients with previously treated non–small-cell lung cancer (NSCLC).
PATIENTS AND METHODS: A phase I/II study in two centers examined erlotinib and bevacizumab (A+T) in patients with nonsquamous stage IIIB/IV NSCLC with one prior chemotherapy. In phase I, erlotinib 150 mg/day orally plus bevacizumab 15 mg/kg intravenously every 21 days was established as the phase II dose, although no dose-limiting toxicities were observed. Phase II assessed the efficacy and tolerability of A+T at this dose. Pharmacokinetic parameters were evaluated.
RESULTS: Forty patients were enrolled and treated in this study (34 patients at phase II dose); the median age was 59 years (range, 36 to 72 years), 21 were female, 30 had adenocarcinoma histology, nine were never-smokers, and 22 had two prior regimens (three patients had four prior regimens). The most common adverse events were mild to moderate rash, diarrhea, and proteinuria. Preliminary data showed no pharmacokinetic interaction between A+T. Eight patients (20.0%; 95% CI, 7.6% to 32.4%) had partial responses and 26 (65.0%; 95% CI, 50.2% to 79.8%) had stable disease as their best response. The median overall survival for the 34 patients treated at the phase II dose was 12.6 months, with progression-free survival of 6.2 months.
CONCLUSION: Encouraging antitumor activity and safety of A+T support further development of this combination for patients with advanced NSCLC and other solid tumors.
INTRODUCTION
Over the last decade, biologic agents have been developed to target molecules involved in tumor growth and progression. Potential molecular targets are cell-surface receptors and their ligands. One example is the human epidermal growth factor receptor (HER-1/EGFR). HER-1/EGFR expression has been associated with poor prognosis in some studies of patients with NSCLC.1-3 However, other studies show no correlation4-7 or that HER-1/EGFR expression is only prognostic when coexpressed with other proteins such as metalloproteinase-98 or HER-2/neu.9 Additionally, some studies show HER-1/EGFR activity10 or gene copy number11 rather than expression inversely correlates with survival in patients with NSCLC. Overproduction of HER-1/EGFR ligands such as epidermal growth factor (EGF) and transforming growth factor alpha also creates an autocrine activation loop that may promote independent tumor growth.12
Vascular endothelial growth factor (VEGF) is also a target for tumor growth inhibition, as it is a major regulator of angiogenesis.13 VEGF expression is upregulated in a range of solid tumors and is greatest in hypoxic tumor cells near necrotic areas, suggesting that hypoxia-induced VEGF is vital for the development of tumor vasculature.14 Moreover, microvessel count, which is an indication of angiogenic effect, is an independent predictor of poor prognosis in patients with NSCLC.15
HER-1/EGFR and VEGF share common downstream signaling pathways (Fig 1). They exert effects both directly and indirectly on tumor cells, and combining drugs that target these molecules may confer additional clinical benefit. HER-1/EGFR is involved in angiogenesis; it has been detected in the endothelial cells of tumor vasculature preclinically.16 Coexpression of HER-1/EGFR and transforming growth factor alpha has been correlated with increased microvessel density in invasive breast cancer.17 VEGF is also downregulated by HER-1/EGFR inhibition,18,19 and a recent study suggested that blockade of VEGF may also inhibit HER-1/EGFR autocrine signaling.20 Therefore, it is rational to suggest that dual blockade of these molecular targets may produce additive and even synergistic cytostatic effects.
Against this background, a number of preclinical studies have investigated the antitumor activity of combined anti-HER-1/EGFR and anti-VEGF agents. A combination of the HER-1/EGFR small-molecule tyrosine kinase inhibitor (TKI) erlotinib (Tarceva, OSI-774; OSI Pharmaceuticals, New York, NY) and the anti-VEGF monoclonal antibody bevacizumab (Avastin, rhuMAb-VEGF; Genentech Inc, South San Francisco, CA) delayed tumor progression in three of four human colon tumor xenograft models; the level of inhibition was much greater than with either agent alone.21 In two separate preclinical studies, both cetuximab (C225, Imclone, New York, NY; an anti-HER-1/EGFR antibody) in combination with DC101 (an anti-VEGF receptor-2 antibody) and VEGF-AS (a human VEGF antisense [AS] 21-mer phosphorothioate oligonucleotide that inhibits VEGF production in human GEO colon cancer cells) decreased tumor growth compared with controls.22,23 In the latter study, overall survival was superior in mice treated with both agents than with either agent alone (P < .001). In 10% of mice given this combination, there was no histologic evidence of GEO cancer cells 20 weeks after tumor-cell injection. In another study, treatment with cetuximab in combination with DC101 also resulted in decreased tumor vasculature and increased endothelial and tumor cell apoptosis compared with DC101 alone in nude mice injected with KM12L4 human colon cancer cells.24 Gefitinib (ZD1839, Iressa; AstraZeneca, Wilmington, DE; an anti-HER-1/EGFR TKI) given with ZD6126 (an antivascular agent) also showed greater antitumor activity than either agent alone in both human colorectal cancer and NSCLC xenograft models.25 Taken together, these data show that dual blockade of HER-1/EGFR and VEGF has additive effects in some preclinical models. These encouraging data have led to the initiation of a number of clinical studies evaluating the combination of an EGFR TKI (erlotinib) with an anti-VEGF antibody (bevacizumab) in a range of tumor types, including a phase II trial each in renal cell carcinoma26 and metastatic breast cancer,27 and a phase I trial in patients with head and neck squamous cell carcinoma.28
Clinical data show that erlotinib prolongs survival in patients with advanced non–small-cell lung cancer (NSCLC) who have relapsed following chemotherapy.29 Encouraging antitumor activity has also been observed when bevacizumab was combined with paclitaxel plus carboplatin in chemotherapy-nave patients with advanced NSCLC in a small randomized phase II trial. The Eastern Cooperative Oncology Group has recently completed a confirmatory phase III trial.
In a randomized phase II study of patients with advanced NSCLC, 99 patients with stage IIIb, stage IV, or recurrent NSCLC were randomly assigned to receive either paclitaxel/carboplatin alone or paclitaxel/carboplatin plus bevacizumab (either at 7.5 mg/kg or 15 mg/kg every 3 weeks).30 The response rate was higher with high-dose bevacizumab than with control (investigator assessment, 32% v 19%). Time to disease progression was also higher for the high-dose bevacizumab arm (investigator assessment; median 225 days v 129 days for the control).
A single-arm phase II trial of erlotinib in 57 patients with EGFR-positive, advanced, recurrent NSCLC gave encouraging results,31 providing a basis for phase III development. In this trial, the response rate was 12.3% and median survival was 8.4 months, which is comparable to other second-line therapies. The clinical benefit of erlotinib in unselected patients with advanced, recurrent NSCLC was recently confirmed in the phase III trial, BR.21. Patients treated with erlotinib had a median survival of 6.7 months, compared with 4.7 months for those receiving best supportive care (P < .001).29 These results, together with compelling preclinical data, provided a strong rationale for clinical investigation of combined anti-HER-1/EGFR and anti-VEGF agents.
The main objective of phase I of this study was to establish whether combining bevacizumab and erlotinib at their most effective single-agent doses would lead to dose-limiting toxicities (DLTs) in patients with advanced, recurrent, nonsquamous NSCLC. In the absence of DLTs, this combination would be assessed for efficacy and safety in a larger population (phase II). The pharmacokinetics (PK) of these agents in combination were also assessed.
PATIENTS AND METHODS
Patient Eligibility
Patients with histologically proven stage IIIB (with pleural effusion)/IV, recurrent, nonsquamous NSCLC, and a Karnofsky performance status of 70%, were eligible. Patients also had to have adequate hematologic, hepatic, and renal function, and have relapsed after at least one platinum-based chemotherapy regimen for recurrent or metastatic disease. Key exclusion criteria were prior anti-VEGF and/or anti-HER-1/EGFR therapy, major surgery, or radiation therapy within the last 14 and 21 days, respectively. Patients with serious infection, a history of clinically significant hemoptysis, hematemesis, coagulopathy or thrombosis, or CNS metastases were excluded. Patients with a history of uncontrolled heart disease or hypertension, or those with a recent myocardial infarction were also ineligible. Concomitant anticoagulants or other investigational drugs were not permitted. Patients gave written informed consent. The institutional review boards of each center approved the study, which was conducted in accordance with federal and institutional guidelines.
Study Design and Treatments
This was a dual-agent, open-label, phase I/II study. In phase I, eligible patients were enrolled and treated according to the schema in Figure 2, using a 3+3 design. This study had a target response rate of 15%. With 34 patients treated at the phase II dose (six patients from phase I and 28 patients from phase II), the response rate can be estimated with a standard error no greater than 0.086. Erlotinib was available in 25-, 100-, and 150-mg oral tablets. Administration via percutaneous esophago-gastroscopy or gastric tube was not permitted. Any missed or vomited doses of erlotinib were not replaced. Bevacizumab was administered over 90 minutes as an intravenous infusion on day 1 of every 21-day cycle in the first cycle. If tolerated, the bevacizumab was then administered over 60 minutes for the second infusion and, finally, over 30 minutes with each subsequent cycle. Three patients were treated per cohort for one cycle (21 days per cycle). If no DLTs were recorded, treatment continued and three patients were treated in the subsequent cohort. However, if a patient developed a DLT, another three patients were treated in this cohort for one cycle. If there were no more DLTs, dose escalation continued. If more than one of three patients developed a DLT in any cohort, another three patients were treated in the next lower dosage cohort. If no DLTs were recorded in any of the cohorts, cohort 3 was expanded to six patients. The phase II dose for this combined treatment was therefore defined as either the highest dosage cohort in which six patients had been treated and there were less than three DLTs; or erlotinib at the previously defined maximum tolerated dose as a single agent (ie, 150 mg/d)32 plus bevacizumab at the highest tolerated dose investigated in this indication (15 mg/kg every 3 weeks),30 whichever was the lower dose. A DLT was defined as grade 3 or 4 diarrhea, rash, or nonhematologic toxicity, grade 4 hematologic toxicity, or treatment-related death.
Toxicity was graded according to the National Cancer Institute Common Toxicity Criteria (NCI-CTC) version 2. Based on clinical observations from other trials involving bevacizumab, if a patient had a grade 3 or 4 hemorrhagic adverse event (AE), or grade 4 hypertension, bevacizumab was discontinued. Other grade 3 or 4 serious adverse events (SAE) relating to either study drug were managed by dose interruption and/or reduction of the associated drug. No intrapatient dose escalation was permitted.
Study Assessments
Tumor size was assessed via computed tomography, magnetic resonance imaging, or chest x-ray every 42 days. Response Evaluation Criteria in Solid Tumors (RECIST) were used to determine tumor response and disease progression33; all tumor assessments were conducted by the investigator, and all responses were independently reviewed. A confirmed response was one that persisted for two separate assessments taken at least 4 weeks apart. After two cycles, patients with either a confirmed complete response (CR) or partial response (PR), or stable disease (SD), were eligible to continue treatment until disease progression or unacceptable toxicity. Progressive disease (PD) was defined as any of the following: a 20% increase in measurable index lesions from the smallest sum observed (from baseline if no confirmed response), reappearance of any lesion that had disappeared, appearance of any new lesion/site, or worsening of any assessable disease. Patients were assessed as having SD if they had no previous confirmed CR or PR, and did not qualify for CR, PR, or PD.
Pharmacokinetics
Blood samples from consenting patients in phases I and II of this study were used for PK analyses. Samples for analysis of erlotinib (and the active metabolite, OSI-420) and bevacizumab were collected in accordance with the schedule shown in Figure 3. Samples screened for serum antibodies to rhuMAb VEGF were collected on day 1 of cycle 1 (predose) and upon study completion (or withdrawal). The plasma was collected and stored at –70°C until analysis.
Plasma samples used to evaluate erlotinib disposition in the presence of bevacizumab were collected after the first erlotinib dose. Plasma drug concentration data were analyzed by noncompartmental methods with the WinNonlin software program (Pharsight, Mountain View, CA) and PK parameters were calculated as described previously.34 Nominal doses and sample collection times were used for PK analysis. Intermittent blood samples were also collected between study days 8 and 147 to estimate minimum steady-state drug concentrations. The disposition of erlotinib in the presence of bevacizumab was compared with results from an earlier study, where erlotinib alone was given to patients with solid tumors.32
Plasma samples used to evaluate bevacizumab disposition in the presence of erlotinib were collected after the first bevacizumab dose. Intermittent peak and trough drug concentrations were measured throughout the study. Plasma drug concentration data were analyzed with a two-compartment model with first order elimination using the WinNonlin software program, and PK parameters were calculated as described previously.34 Nominal doses and sample collection times were used for PK analyses. PK parameter estimates were compared with those from a population pharmacokinetic analysis of cancer patients given bevacizumab alone, or in combination with chemotherapy.35 All bevacizumab and erlotinib samples were analyzed at Genentech Inc and MDS Pharma Services (Saint-Laurent, Quebec, Canada), respectively.
HER-1/EGFR Sequencing Tumor cells were isolated from formalin-fixed paraffin embedded tumor tissue sections by laser capture microdissection (PixCell II, Arcturus, Mountain View, CA). DNA was extracted by proteinase K digestion (PicoPure, Arcturus). Amplification of exons 19 to 21 and 23 of HER-1/EGFR was performed using nested primers. Digested DNA was added to taq/pwo reaction buffer (Expand High Fidelity polymerase chain reaction [PCR] system, Roche Molecular Biochemicals, Indianapolis, IN) containing 0.5 μM of each primer, 0.2 μM of each dNTP and 1.5 mmol/L MgCl2. PCR with the outer primers were cycled 35 times, and second-step reactions with nested primers were cycled 30 times. PCR products were sequenced using M13 sequencing primers, fluorescent dye-terminator chemistry and an ABI3730 sequencing instrument (Applied Biosystems, Foster City, CA).
RESULTS
Patient Characteristics
Forty patients were enrolled on this study. Table 1 shows selected baseline demographics and disease characteristics. Twelve patients with locally advanced or metastatic NSCLC were enrolled and treated in phase I. Three patients each were treated in cohorts 1 and 2; six patients were treated in cohort 3. In phase II, cohort 3 was expanded to include an additional 28 patients, ensuring that 34 patients were treated at the protocol-defined phase II dose established in phase I.
In the overall study population, 80% of patients (32 of 40) had stage IV disease, and 75% (30 of 40) had adenocarcinoma. More than 90% (37 of 40) of patients had a Karnofsky performance score 80 at screening. More than half of patients (22 of 40) had received two or more prior systemic chemotherapy regimens for NSCLC. Finally, nine (22.5%) patients had never smoked.
Efficacy
All patients had at least two cycles of therapy; 13 patients remained on study for more than 6 months and had at least nine cycles of therapy. All 40 patients were assessable for response following at least two cycles of therapy. Table 2 lists the observed best responses to combined erlotinib and bevacizumab, as determined by RECIST criteria. A best response of a PR was reported in eight patients (20.0%; 95% CI, 7.6% to 32.4%), and SD was reported in 26 patients (65.0%; 95% CI, 50.2% to 79.8%). There were no CRs, and six patients had PD (15.0%). The median number of cycles received for all patients treated at the phase II dose (n = 34) was four cycles.
Figure 4 shows computed tomography scans of a PR. These scans are of a 48-year-old black male diagnosed with stage IIIB adenocarcinoma with pleural effusion in July 2001. Prior therapy included two cycles of carboplatin plus paclitaxel, followed by eight cycles of docetaxel. The first image is at baseline, and the second image was taken after two cycles of therapy (100 mg erlotinib, 7.5 mg/kg bevacizumab). He remains on study after 23 cycles of therapy with a PR.
Median overall survival (OS) and progression-free survival (PFS) were analyzed for patients in phase I, phase II, and for the overall study population (Table 2). OS and PFS were also determined for all patients treated at the phase II dose (34 patients). Median OS for all patients, regardless of dosage cohort assignment, was 12.6 months (Fig 5A); median PFS was 7.0 months (Fig 5B). For the 34 patients treated at the phase II dose, the median OS was 12.6 months and the median PFS was 6.2 months. Of the eight patients with a PR, three (37.5%) were women. Two (22.2%) of the nine patients who had never smoked had a PR, compared with six (19.4%) of 31 former or current smokers. All patients with a PR had adenocarcinoma.
Pharmacokinetics
Eleven patients from phase I and 17 patients from phase II consented to PK sampling. PK parameters for 15 mg/kg bevacizumab only were calculated from data from 13 patients (one patient in cohort 2, and 12 patients in cohort 3).
Figure 6 shows the plasma erlotinib and OSI-420 concentration versus time curves following a single dose of erlotinib in the presence of bevacizumab. The PK data for erlotinib showed wide interpatient variability. PK parameter estimates are summarized in Table 3. The maximum plasma concentration (Cmax) was achieved approximately 4 hours after oral administration of both 100 and 150 mg/d erlotinib. Cmax and area under the plasma concentration versus time curve from 0 to 24 hours (AUC0–24) increased with dose. The AUC0–24 for 150 mg/d erlotinib was 26% higher than for the 100 mg/d dose (AUC0–24 150 mg = 539 ± 190 day · ng/mL; AUC0–24 100 mg = 434 ± 490 day · ng/mL). Plasma clearance values were comparable for 100 and 150 mg/d erlotinib (173 ± 200 L/d v 184 ± 130 L/d); elimination half-life (t) values were 1.25 and 0.92 days, respectively. Minimum steady-state concentration (Css min) measured from days 8 to 147 was also similar for each dose (Css min 100 mg = 1.07 ± 0.63 μg/mL; Css min 150 mg = 1.00 ± 0.67 μg/mL). The drug accumulation ratios (Rac) were 3.2 and 2.3 for the 100 and 150 mg/d doses, respectively. For the metabolite, OSI-420, plasma exposure was 7% to 10% of the parent drug.
The PK of bevacizumab showed a biphasic distribution and elimination profile following intravenous infusion (Fig 7). Pharmacokinetic parameter estimates are summarized in Table 4. The mean half-life at distribution phase (t) and mean terminal half-life (t) were 1.32 ± 1.1 days and 22.1 ± 14 days, respectively; the AUC0– was 5,040 ± 2,000 day · μg/mL. The clearance (CL), volume of distribution of the central compartment (Vc), and steady-state volume of distribution (Vss) were 3.18 ± 1.0 mL/kg/d, 36.8 ± 7.9 mL/kg, and 77.4 ± 25 mL/kg, respectively. The Cmax was 396 ± 76 μg/mL; but this increased to 517 ± 82 μg/mL on day 64 after multiple dosing.
Safety and Tolerability
Phase I AEs were recorded by highest NCI-CTC grade in each patient. No SAEs or DLTs were reported in phase I. Seven of 12 patients experienced mild (grade 1/2) proteinuria, and two had mild (grade 1) epistaxis. One patient was hospitalized for pneumonia that was believed not to be treatment related. No treatment-related grade 3 or 4 toxicities were reported. It should be noted that at the completion of the phase I portion, the study did not reach what would be considered the maximum tolerated dose of bevacizumab. As such, the phase II portion of the study proceeded with a bevacizumab dose at its highest previously utilized single-agent dose (15 mg/kg every 3 weeks).
Phase II Table 5 shows all AEs reported in greater than or equal to 10% of patients, regardless of cause, by grade of severity for the subset of patients treated at the phase II dose (n = 34). For these patients, the most common AEs were rash (85%), diarrhea (65%), infection (29%), hematuria (32%), proteinuria (9%), and epistaxis (6%). Three SAEs were reported during the phase II portion of the trial; all were pneumonia. Four patients died on study; two at 15 weeks, and one each at 22 and 27 weeks. None of the deaths were considered treatment related. Three deaths were due to progression of disease and one was secondary to complications from pneumonia.
Two patients had severe (grade 3) hypertension; both were managed using antihypertensives. In one case, bevacizumab was also discontinued (while erlotinib was maintained) leading to resolution of this event. Other grade 3/4 events reported in phase II were one case of grade 3 rash, one grade 3 pruritus, two cases of grade 3 and one case of grade 4 pneumonia. The grade 3 rash resolved to grade 1 following symptomatic treatment and erlotinib dose reduction for two cycles of therapy (bevacizumab was continued). Grade 3 pruritus resolved to below grade 3 after 2 days of treatment. Two additional cases of mild epistaxis were noted in phase II.
HER-1/EGFR Sequencing
Nine patients had sufficient paraffin-embedded tissue available for EGFR TK domain mutational analysis (exons 19, 20, 21, and 23). The patient characteristics and mutational status are shown in Table 6. These nine patients included three patients who achieved a PR as best response, three patients with SD as best response, and three patients with PD as best response. Mutations were detected in one of the three patients with a PR and one of the three patients with SD.
DISCUSSION
Lung cancer is a heterogeneous disease with multiple mutations, and it is unlikely that any one signaling pathway is driving the oncogenic behavior of all tumors. A growing body of preclinical evidence suggests that combined anti-HER-1/EGFR and anti-VEGF agents may be an effective therapeutic strategy as they target multiple cell types within a tumor. Blocking two receptors that activate a number of shared downstream signaling pathways vital for tumor cell growth and proliferation may also explain the synergistic effects seen in preclinical studies. Taken together, these data give a strong rationale for investigating the effects of this multifaceted approach to cancer therapy in the clinic.
This phase I/II trial examined the safety and efficacy of combining erlotinib and bevacizumab therapy in patients with advanced or metastatic NSCLC. No SAEs or DLTs were reported in any of the cohorts in phase I. In accordance with the study protocol, the dose defined as the phase II dose for this study and the recommended dose for future studies was erlotinib at its previously defined maximum tolerated dose as a single agent (150 mg/d)32 plus bevacizumab at the highest tolerated dose investigated in this indication (15 mg/kg).30 There was no evidence of a PK interaction between these agents, and the antitumor activity reported was very encouraging.
Baseline characteristics of the overall study population were similar. Most patients (75%) had adenocarcinoma, and 55% had received two or more prior therapies. Twenty-one (52.5%) of the 40 patients were women, and nine (22.5%) had never smoked.
Combined erlotinib and bevacizumab therapy was well tolerated in both phase I and II of this study. AEs were rarely more than mild to moderate and were easily managed, suggesting that treatment with this combination is feasible. The most common AEs were rash, diarrhea, infection, hematuria, and proteinuria.
Rash has been reported in other trials of erlotinib31,32,36 and with other HER-1/EGFR-targeted agents, and is thought to be a class effect of these drugs. Moreover, recent studies have shown a relationship between the development of rash and survival, though further studies are needed to confirm these findings.31
Bevacizumab in combination with chemotherapy has been associated with tumor bleeding, including fatal hemoptysis, hypertension, proteinuria, asthenia, headache, and nausea.37-39 In a randomized phase II trial of bevacizumab plus carboplatin and paclitaxel versus carboplatin and paclitaxel alone in previously untreated patients with advanced NSCLC, 25 cases of minor bleeding (epistaxis) and six cases of major life-threatening bleeding described as hemoptysis or hematemesis were reported.30 Pulmonary hemorrhages appeared to be associated with centrally located tumors, which are frequently squamous cell tumors, and exploratory analysis in patients with nonsquamous histology showed improved survival in the bevacizumab arms. Patients with squamous cell NSCLC were therefore excluded from this trial, and four cases of grade 1 epistaxis, and importantly, no severe hemoptysis or arterial thromboembolic events, were reported.
PK analyses suggest no interaction between erlotinib and bevacizumab. All of the PK parameters estimated for erlotinib were similar to those reported by Hidalgo et al.32 Erlotinib exposure after a single dose in the presence of bevacizumab was similar to single-agent erlotinib for both 100 mg and 150 mg.
The observed biphasic distribution of bevacizumab is consistent with data from Hsei et al,35 and probably reflects initial binding of bevacizumab to circulating and tissue-bound VEGF followed by slow elimination. The PK profile of bevacizumab was consistent with single-agent data from Hsei et al,35 suggesting that the PK of bevacizumab was not affected by coadministered erlotinib.
The lack of interaction between these agents is important, as it enables predictable dose selection without exacerbating AEs. It also suggests that any enhancement in antitumor activity compared with either agent alone is due to their complementary modes of action rather than metabolic enhancement of drug concentrations.
The antitumor activity and survival data reported in this trial were very encouraging. The disease control rate (CR + PR + SD) for the entire study population was 85%; overall response rate was 20.0% with a median response duration of > 35 weeks. Median OS and PFS for the 34 patients treated at the phase II dose were 12.6 months and 6.2 months, respectively. Similar results were noted for the entire population (n = 40), with a median OS of 12.6 months and PFS of 7.0 months.
All eight patients with a PR had adenocarcinoma. However, as patients with squamous cell histology were excluded from this study, a higher number of patients with adenocarcinoma would be expected. A randomized trial to evaluate the importance of histologic subtype would therefore be needed before we can confirm if there is a trend towards improved survival in patients with adenocarcinoma treated with this combination versus other histologies.
Three (14.3%) of the 21 women and two (22.2%) of nine patients who had never smoked had a PR. Therefore, despite previous reports that suggest an increased benefit for females and never-smokers receiving HER-1/EGFR inhibitors, the response rates were comparable for males versus females (26.3% v 14.3%) and previous/current smokers versus never smokers (19.4% v 22.2%) receiving combined erlotinib and bevacizumab. These data suggest that this combination therapy is effective in an unselected patient population, although because of low patient numbers, these figures should be treated cautiously.
These findings show that treatment with erlotinib and bevacizumab in patients with advanced or recurrent nonsquamous NSCLC is well tolerated; the lack of PK interaction suggests that this combination is feasible. These data compare favorably with those on the antitumor activity of single-agent erlotinib. In the trial by the National Cancer Institute of Canada Clinical Trials Group in unselected patients with locally advanced or metastatic NSCLC who had failed at least one chemotherapy regimen (BR.21), median survival was 6.7 months with a progression-free survival of 2.2 months.29 In addition, following the encouraging results reported by Johnson et al,30 a phase II/III trial of bevacizumab in combination with carboplatin and paclitaxel in patients with advanced, nonsquamous NSCLC is in progress, and enrollment has been completed.
Recently, a somatic mutation in the HER-1/EGFR tyrosine kinase domain was identified that correlated with tumor response to gefitinib.40,41 Although its prognostic value has yet to be fully established, diagnostic tissue from a subset of patients enrolled in this trial was tested for the presence of this mutation.
At the time of reporting, nine patients had sufficient paraffin-embedded tissue available for EGFR TKD mutational analysis (exons 19, 20, 21 and 23). The patient characteristics and mutational status are shown in Table 6. These nine patients included three patients who achieved a PR as best response, three patients with SD as best response, and three patients with PD as best response. Mutations were detected in one of the three patients with a PR and one of the three patients with SD. It is interesting that one of the wild-type (WT; exons 19-21) patients with SD was a female nonsmoker with bronchioloalveolar carcinoma, a demographic subset which has been associated with response to EGFR TKIs. While it is possible that our WT patients could have mutations in unexamined exons, these results suggest the possibility that the combination of erlotinib with bevacizumab may provide benefit to patients with a WT EGFR and is further justification for further study of this combination.
The results of this study show that this combination is well tolerated and active in NSCLC. Investigation is already ongoing in other tumor types,26,28 and further investigation into the efficacy and tolerability of combined erlotinib and bevacizumab is warranted in randomized trials.
Authors' Disclosures of Potential Conflicts of Interest
The following authors or their immediate family members have 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. Employment: Dong Xie, Genentech; David Ramies, Genentech; Sean K. Kelley, Genentech. Consultant/Advisory Role: Roy S. Herbst, Genentech; David H. Johnson, Genentech; Hai Tran, Aventis; Alan Sandler, Genentech. Stock Ownership: Dong Xie, Genentech; Sean K. Kelley, Genentech. Honoraria: Roy S. Herbst, Genentech; David P. Carbone, Genentech; Hai Tran, Aventis; Alan Sandler, Genentech. Research Funding: Roy S. Herbst, Genentech; David H. Johnson, Genentech; Edward S. Kim, AstraZeneca, Aventis; Hai Tran, Genentech, Novartis, Orphan Medical; Alan Sandler, Genentech. For a detailed description of these categories, or for more information about ASCO's conflict of interest policy, please refer to the Author Disclosure Declaration and Disclosures of Potential Conflicts of Interest found in Information for Contributors in the front of each issue.
Acknowledgment
We thank Ben Garcia and Mercedes Guerra for their contribution to this study. We also thank Thinh Pham, Jeremy Stinson, and Kanan Pujara for technical assistance.
NOTES
Supported by Genentech Inc, South San Francisco, CA
Previously presented at the 39th Annual Meeting of the American Society of Clinical Oncology (ASCO), Chicago, IL, May 31-June 3; 40th ASCO Annual Meeting, New Orleans, LA, June 5-8, 2004; and 10th World Congress on Lung Cancer, Vancouver, Canada, August 10-14, 2004.
Terms in blue are defined in the glossary, found at the end of this issue and online at www.jco.org.
Authors' disclosures of potential conflicts of interest are found at the end of this article.
REFERENCES
Veale D, Kerr N, Gibson GJ, et al: The relationship of quantitative epidermal growth factor receptor expression in non-small cell lung cancer to long term survival. Br J Cancer 68:162-165, 1993
Selvaggi G, Novello S, Torri V, et al: Epidermal growth factor receptor overexpression correlates with a poor prognosis in completely resected non-small-cell lung cancer. Ann Oncol 15:28-32, 2004
Ohsaki Y, Tanno S, Fujita Y, et al: Epidermal growth factor receptor expression correlates with poor prognosis in non-small cell lung cancer patients with p53 overexpression. Oncol Rep 7:603-607, 2000
Pfeiffer P, Clausen PP, Andersen K, et al: Lack of prognostic significance of epidermal growth factor receptor and the oncoprotein p185HER-2 in patients with systemically untreated non-small-cell lung cancer: An immunohistochemical study on cryosections. Br J Cancer 74:86-91, 1996
Pfeiffer P, Nexo E, Bentzen SM, et al: Enzyme-linked immunosorbent assay of epidermal growth factor receptor in lung cancer: Comparisons with immunohistochemistry, clinicopathological features and prognosis. Br J Cancer 78:96-99, 1998
Rusch V, Klimstra D, Venkatraman E, et al: Overexpression of the epidermal growth factor receptor and its ligand transforming growth factor alpha is frequent in resectable non-small cell lung cancer but does not predict tumor progression. Clin Cancer Res 3:515-522, 1997
Meert AP, Martin B, Delmotte P, et al: The role of EGF-R expression on patient survival in lung cancer: A systematic review with meta-analysis. Eur Respir J 20:975-981, 2002
Swinson DE, Cox G, O'Byrne KJ: Coexpression of epidermal growth factor receptor with related factors is associated with a poor prognosis in non-small-cell lung cancer. Br J Cancer 91:1301-1307, 2004
Brabender J, Danenberg KD, Metzger R, et al: Epidermal growth factor receptor and HER2-neu mRNA expression in non-small cell lung cancer is correlated with survival. Clin Cancer Res 7:1850-1855, 2001
Kanematsu T, Yano S, Uehara H, et al: Phosphorylation, but not overexpression, of epidermal growth factor receptor is associated with poor prognosis of non-small cell lung cancer patients. Oncol Res 13:289-298, 2003
Hirsch FR, Varella-Garcia M, Bunn PA, Jr., et al: Epidermal growth factor receptor in non-small-cell lung carcinomas: Correlation between gene copy number and protein expression and impact on prognosis. J Clin Oncol 21:3798-3807, 2003
Raben D, Helfrich B, Bunn PA, Jr.: Targeted therapies for non-small-cell lung cancer: Biology, rationale, and preclinical results from a radiation oncology perspective. Int J Radiat Oncol Biol Phys 59:27-38, 2004 (suppl 2)
Ferrara N: The role of vascular endothelial growth factor in pathological angiogenesis. Breast Cancer Res Treat 36:127-137, 1995
Ferrara N, Davis-Smyth T: The biology of vascular endothelial growth factor. Endocr Rev 18:4-25, 1997
Fontanini G, Lucchi M, Vignati S, et al: Angiogenesis as a prognostic indicator of survival in non-small-cell lung carcinoma: A prospective study. J Natl Cancer Inst 89:881-886, 1997
Kim SJ, Uehara H, Karashima T, et al: Blockade of epidermal growth factor receptor signaling in tumor cells and tumor-associated endothelial cells for therapy of androgen-independent human prostate cancer growing in the bone of nude mice. Clin Cancer Res 9:1200-1210, 2003
de Jong JS, van Diest PJ, van der Valk P, et al: Expression of growth factors, growth-inhibiting factors, and their receptors in invasive breast cancer. II: Correlations with proliferation and angiogenesis. J Pathol 184:53-57, 1998
Petit AM, Rak J, Hung MC, et al: Neutralizing antibodies against epidermal growth factor and ErbB2-neu receptor tyrosine kinase down-regulate vascular endothelial growth factor production by tumor cells in vitro and in vivo. Am J Pathol 151:1523-1530, 1997
Hirata A, Ogawa S, Kometani T, et al: ZD1839 (Iressa) induces antiangiogenic effects through inhibition of epidermal growth factor receptor tyrosine kinase. Cancer Res 62:2554-2560, 2002
Ciardiello F, Caputo R, Damiano V, et al: Antitumor effects of ZD6474, a small molecule vascular endothelial growth factor receptor tyrosine kinase inhibitor, with additional activity against epidermal growth factor receptor tyrosine kinase. Clin Cancer Res 9:1546-1556, 2003
Herbst RS, Mininberg E, Henderson T, et al: Phase I/II trial evaluating blockade of tumor blood supply and tumor cell proliferation with combined bevacizumab and erlotinib HCl as targeted cancer therapy in patients with recurrent non-small cell lung cancer. Eur J Cancer 1:S293, 2003
Jung YD, Mansfield PF, Akagi M, et al: Effects of combination anti-vascular endothelial growth factor receptor and anti-epidermal growth factor receptor therapies on the growth of gastric cancer in a nude mouse model. Eur J Cancer 38:1133-1140, 2002
Ciardiello F, Bianco R, Damiano V, et al: Antiangiogenic and antitumor activity of anti-epidermal growth factor receptor C225 monoclonal antibody in combination with vascular endothelial growth factor antisense oligonucleotide in human GEO colon cancer cells. Clin Cancer Res 6:3739-3747, 2000
Shaheen RM, Ahmad SA, Liu W, et al: Inhibited growth of colon cancer carcinomatosis by antibodies to vascular endothelial and epidermal growth factor receptors. Br J Cancer 85:584-589, 2001
Guy SP, Ashton S, Hughes G, et al: Gefitinib (Iressa, ZD1839) enhances the activity of the novel vascular-targeting agent ZD6126 in human colorectal cancer and non-small cell lung cancer (NSCLC) xenograft models. Clin Cancer Res 9:6142S, 2003 (abstr; suppl B13)
Hainsworth JD, Sosman JA, Spigel DR, et al: Phase II trial of bevacizumab and erlotinib in patients with metastatic renal carcinoma (RCC). Proc Am Soc Clin Oncol 23:381, 2004 (abstr 4502)
Dickler M, Rugo H, Caravelli J, et al: Phase II trial of erlotinib (OSI-774), an epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor, and bevacizumab, a recombinant humanized monoclonal antibody to vascular endothelial growth factor (VEGF), in patients (pts) with metastatic breast cancer (MBC). Proc Am Soc Clin Oncol 23:127, 2004 (abstr 2001)
Mauer AM, Cohen EEW, Wong SJ, et al: Phase I study of epidermal growth factor receptor (EGFR) inhibitor, erlotinib, and vascular endothelial growth factor monoclonal antibody, bevacizumab, in recurrent and/or metastatic squamous cell carcinoma of the head and neck (SCCHN). Proc Am Soc Clin Oncol 23:496, 2004 (abstr 5539)
Shepherd FA, Pereira J, Ciuleanu TE, et al: A randomized placebo-controlled trial of erlotinib in patients with advanced non-small cell lung cancer (NSCLC) following failure of 1st line or 2nd line chemotherapy. A National Cancer Institute of Canada Clinical Trials Group (NCIC CTG) trial. Proc Am Soc Clin Oncol 23:18, 2004 (abstr 7022)
Johnson DH, Fehrenbacher L, Novotny WF, et al: Randomized phase II trial comparing bevacizumab plus carboplatin and paclitaxel with carboplatin and paclitaxel alone in previously untreated locally advanced or metastatic non-small-cell lung cancer. J Clin Oncol 22:2184-2191, 2004
Perez-Soler R, Chachoua A, Hammond LA, et al: Determinants of tumor response and survival with erlotinib in patients with non-small-cell lung cancer. J Clin Oncol 22:3238-3247, 2004
Hidalgo M, Siu LL, Nemunaitis J, et al: Phase I and pharmacologic study of OSI-774, an epidermal growth factor receptor tyrosine kinase inhibitor, in patients with advanced solid malignancies. J Clin Oncol 19:3267-3279, 2001
Therasse P, Arbuck SG, Eisenhauer EA, et al: New guidelines to evaluate the response to treatment in solid tumors. J Natl Cancer Inst 92:205-216, 2000
Perrier D, Gibaldi M: General derivation of the equation for time to reach a certain fraction of steady state. J Pharm Sci 71:474-475, 1982
Hsei VC, Novotny WF, Margolin K, et al: Population pharmacokinetic (PK) analysis of bevacizumab (BV) in cancer subjects. Proc Am Soc Clin Oncol 20:69a, 2001 (abstr 272)
Soulieres D, Senzer NN, Vokes EE, et al: Multicenter phase II study of erlotinib, an oral epidermal growth factor receptor tyrosine kinase inhibitor, in patients with recurrent or metastatic squamous cell cancer of the head and neck. J Clin Oncol 22:77-85, 2004
Gordon MS, Margolin K, Talpaz M, et al: Phase I safety and pharmacokinetic study of recombinant human anti-vascular endothelial growth factor in patients with advanced cancer. J Clin Oncol 19:843-850, 2001
Cobleigh MA, Langmuir VK, Sledge GW, et al: A phase I/II dose-escalation trial of bevacizumab in previously treated metastatic breast cancer. Semin Oncol 30:117-124, 2003 (5 suppl 16)
Yang JC, Haworth L, Sherry RM, et al: A randomized trial of bevacizumab, an anti-vascular endothelial growth factor antibody, for metastatic renal cancer. N Engl J Med 349:427-434, 2003
Paez JG, Janne PA, Lee JC, et al: EGFR mutations in lung cancer: Correlation with clinical response to gefitinib therapy. Science 304:1497-1500, 2004
Lynch TJ, Bell DW, Sordella R, et al: Activating mutations in the epidermal growth factor receptor underlying responsiveness of non-small-cell lung cancer to gefitinib. N Engl J Med 350:2129-2139, 2004(Roy S. Herbst, David H. J)