The plasma and cerebrospinal fluid pharmacokinetics of erlotinib and its active metabolite (OSI-420) after intravenous administration of erlotinib in non-human primates

Heterogeneity and Clinical Effect of Epidermal Growth Factor Receptor in Primary Lung and Brain Metastases of Nonsmall Cell Lung Cancer

INTRODUCTION

This study aimed to analyze the heterogeneity in epidermal growth factor receptor (EGFR) gene mutation and its impact on clinical outcomes in primary tumor and corresponding brain metastasis (BM) in nonsmall cell lung cancer (NSCLC).

MATERIALS AND METHODS

Primary pulmonary tumors and paired BMs of 27 NSCLC patients were surgically removed. All brain lesions were histologically confirmed as metastatic NSCLC. EGFR gene mutation status was detected by using amplification refraction mutation system. McNemar test was performed to compare EGFR mutation status between lung primary tumors and metastatic brain tumors and Kappa test was performed to quantify the agreement between the two.

RESULTS

Of the 27 patients, nine cases were found to have EGFR mutations in BMs and 10 had a positive EGFR mutation status in primary lung tumor tissue. The rate of consistency of the matched tumor was 24/27 (88.9%). Among the three cases presenting EGFR mutational heterogeneity, two patients harbored an EGFR mutation in the primary tumor but not in the BMs; meanwhile, the last patient demonstrated the opposite pattern. Compared to patients with consistent EGFR mutations, patients with inconsistent mutations showed better outcomes. Further analysis revealed that the two patients whose EGFR mutant-type primary tumor progressed to wild-type cerebral metastatic tumor had longer overall survival than the patient whose EGFR wild-type primary tumor progressed to mutant-type brain metastatic tumor.

CONCLUSIONS

Heterogeneity of EGFR mutation status was observed between primary NSCLC and paired BM. Patients possessing a wild-type EGFR mutation in BM might have better outcomes, especially those with transition from mutant to wild-type.

Biological Treatments of Neurofibromatosis Type 2 and Other Skull Base Disorders

Studies of genomic alterations that occur in skull base tumors have provided information regarding biological aberrations that are necessary for the growth and maintenance of these tumors. This has led to the development and initiation of clinical trials incorporating biological treatments for many skull base tumors. The exciting developments of molecularly targeted therapy for the treatment of skull base tumors may provide noninvasive therapeutic options for patients that can be used either alone or in combination with surgery and/or radiation therapy. Future analysis and continued scientific discovery of treatments for skull base tumors can lead to improved outcomes in patients.

Durable response to pulsatile icotinib for central nervous system metastases from EGFR-mutated non-small cell lung cancer: A case report

BACKGROUND

Central nervous system (CNS) metastases are a catastrophic complication of non-small cell lung cancer (NSCLC), including brain and leptomeningeal carcinomatosis, and are always accompanied by a poor prognosis. Despite the continuous development of existing treatments, the therapy of CNS metastases remains challenging.

CASE SUMMARY

We report a patient who was definitively diagnosed with brain and leptomeningeal metastases from NSCLC with a targeted mutation in epidermal growth factor receptor (EGFR). A standard dosage of icotinib (125 mg three times daily) was implemented but ineffective. CNS lesions developed despite stable systemic control, so pulsatile icotinib (1125 mg every 3 d) was administered. This new strategy for administration has lasted 25 mo so far, and resulted in complete remission of neurological symptoms, almost vanished lesions, and longer survival with no notable side effects.

CONCLUSION

This is the first successful example of pulsatile icotinib for treating isolated CNS progression from EGFR mutation-positive NSCLC, providing a new alternative for the local treatment of CNS metastases.

Biodistribution of TAT or QLPVM coupled to receptor targeted liposomes for delivery of anticancer therapeutics to brain in vitro and in vivo

Combination therapy has emerged as an efficient way to deliver chemotherapeutics for treatment of glioblastoma. It provides collaborative approach of targeting cancer cells by acting via multiple mechanisms, thereby reducing drug resistance. However, the presence of impermeable blood brain barrier (BBB) restricts the delivery of chemotherapeutic drugs into the brain. To overcome this limitation, we designed a dual functionalized liposomes by modifying their surface with transferrin (Tf) and a cell penetrating peptide (CPP) for receptor and adsorptive mediated transcytosis, respectively. In this study, we used two different CPPs (based on physicochemical properties) and investigated the influence of insertion of CPP to Tf-liposomes on biocompatibility, cellular uptake, and transport across the BBB both in vitro and in vivo. The biodistribution profile of Tf-CPP liposomes showed more than 10 and 2.7 fold increase in doxorubicin and erlotinib accumulation in mice brain, respectively as compared to free drugs with no signs of toxicity.

EGFR-TKIs in non-small-cell lung cancer: focus on clinical pharmacology and mechanisms of resistance

The clinical introduction of EGFR-TKIs within the oncologic armamentarium has changed the therapeutic landscape of non-small-cell lung cancer (NSCLC) creating widespread expectations both in patients and clinicians. However, several gaps in current understanding leave open important questions regarding the use of these drugs in clinical practice. For instance, there is uncertainty in regard to which EGFR-TKI should be given first in naive patients with EGFR-driven malignancies since different generations of drugs are available with different pharmacological profiles. Furthermore, acquired drug resistance may limit the therapeutic potential of EGFR-TKIs and the choice of the best treatment strategy after first-line treatment failure is still debated. This review article is aimed at describing the pharmacological properties of EGFR-TKIs and the current treatment options for NSCLC patients who develop acquired resistance. This information might be useful to design new rational and more effective pharmacological strategies in patients with EGFR-mutant NSCLC.

The association between clinical prognostic factors and epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) efficacy in advanced non-small-cell lung cancer patients: a retrospective assessment of 94 cases with EGFR mutations

Objective

This study aimed to examine the association of clinical prognostic factors with epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) efficacy in advanced non-small-cell lung cancer (NSCLC) patients.

Methods

The demographic and clinical characteristics of 94 patients with stage IV NSCLC were retrospectively reviewed, and the association between clinical factors and EGFR-TKIs efficacy was evaluated.

Results

Of the 94 stage IV NSCLC patients enrolled in this study, a 74.5% objective response rate (ORR) and 97.9% disease control rate (DCR) were observed for EGFR-TKIs treatment, and a higher ORR was seen in patients with 0 and 1 ECOG scores than those with 2 or greater scores (P = 0.049). The subjects had a median PFS of 11 months and a median OS of 31 months after EGFR-TKIs treatment. ECOG score and timing of targeted therapy were factors affecting PFS, and ECOG score, smoking status and brain metastasis were factors affecting OS. In addition, ECOG score was an independent prognostic factor for PFS in stage IV NSCLC patients, and the patients with EGFR 19del mutation had a longer PFS than those with exon 21 L855R mutation (P = 0.003), while ECOG score and brain metastasis were independent prognostic factors for OS.

Conclusions

The results of this study demonstrate that EGFR-TKI therapy results in survival benefits for EGFR-mutant advanced NSCLC patients, regardless of gender, smoking history, pathologic type, type of EGFR mutations, brain metastasis and timing of targeted therapy. ECOG score is an independent prognostic factor for PFS, and ECOG score and brain metastasis are independent prognostic factors for OS in advanced NSCLC patients.

Assessing the selective therapeutic efficacy of superparamagnetic erlotinib nanoparticles in lung cancer by using quantitative magnetic resonance imaging and a nuclear factor kappa-B reporter gene system

Non-small-cell lung cancer (NSCLC) is the most common type of lung cancer. Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors are commonly used as the first-line treatment for advanced NSCLC; however, the efficacy of drug delivery remains unknown. Hence, we successfully developed erlotinib-conjugated iron oxide nanoparticles (FeDC-E NPs) as theranostic probe that can potentially provide a new avenue for monitoring drug delivering through noninvasive magnetic resonance imaging. MRI ΔR2* relaxivity measurements offer an opportunity to quantitatively evaluate the uptake of FeDC-E NPs at cellular and tumoral levels. Additionally, NF-κB reporter gene system provides NF-κB activation status monitoring to validate the therapeutic efficiency of FeDC-E NPs. FeDC-E NPs not only inhibit the tumor growth and NF-κB-modulated antiapoptotic mechanism but also trigger extrinsic and intrinsic apoptotic pathways. Taken together, dual functional FeDC-E NPs offer diagnostic and therapeutic benefits against lung cancers, indicating that our presented probe could be applied in clinical.

Pulsatile Erlotinib in EGFR-Positive Non-Small-Cell Lung Cancer Patients With Leptomeningeal and Brain Metastases: Review of the Literature

Patients with epidermal growth factor receptor (EGFR)-positive (EGFR⁺) non-small-cell lung cancer (NSCLC) show improved response rates when treated with tyrosine kinase inhibitors (TKIs) such as erlotinib. However, standard daily dosing of erlotinib often does not reach therapeutic concentrations within the cerebrospinal fluid (CSF), resulting in progression of central nervous system (CNS) disease. Intermittent, high-dose administration of erlotinib reaches therapeutic concentrations within the CSF and is well tolerated in patients. Experience with "pulsatile" dosing, however, is limited. We review the literature on the pharmacology and clinical outcomes of pulsatile erlotinib in the treatment of EGFR⁺ NSCLC with brain and leptomeningeal metastases, and include available data on the use of next-generation TKIs in CNS progression. We also provide our institution's experience with patients treated with pulsatile erlotinib for CNS metastasis, and propose clinical criteria for its use. Pulsatile erlotinib is a reasonable alternative in EGFR⁺ patients with new or worsening CNS disease, without evidence of systemic progression, and without confirmed T790M resistance mutations within the CNS.

Erlotinib-Conjugated Iron Oxide Nanoparticles as a Smart Cancer-Targeted Theranostic Probe for MRI

We designed and synthesized novel theranostic nanoparticles that showed the considerable potential for clinical use in targeted therapy, and non-invasive real-time monitoring of tumors by MRI. Our nanoparticles were ultra-small with superparamagnetic iron oxide cores, conjugated to erlotinib (FeDC-E NPs). Such smart targeted nanoparticles have the preference to release the drug intracellularly rather than into the bloodstream, and specifically recognize and kill cancer cells that overexpress EGFR while being non-toxic to EGFR-negative cells. MRI, transmission electron microscopy and Prussian blue staining results indicated that cellular uptake and intracellular accumulation of FeDC-E NPs in the EGFR overexpressing cells was significantly higher than those of the non-erlotinib-conjugated nanoparticles. FeDC-E NPs inhibited the EGFR-ERK-NF-κB signaling pathways, and subsequently suppressed the migration and invasion capabilities of the highly invasive and migrative CL1-5-F4 cancer cells. In vivo tumor xenograft experiments using BALB/c nude mice showed that FeDC-E NPs could effectively inhibit the growth of tumors. T₂-weighted MRI images of the mice showed significant decrease in the normalized signal within the tumor post-treatment with FeDC-E NPs compared to the non-targeted control iron oxide nanoparticles. This is the first study to use erlotinib as a small-molecule targeting agent for nanoparticles.

Risk of brain metastasis reduced after erlotinib treatment in advanced pulmonary adenocarcinoma patients with sensitive EGFR mutation

Purpose

Brain metastasis (BM) is associated with impaired quality of life and increased mortality. The study aimed to compare BM risk after erlotinib administration and chemotherapy in stage IIIB/IV pulmonary adenocarcinoma patients harboring epidermal growth factor receptor (EGFR) mutation.

Patients and methods

Eligible patients underwent match pair process with matching factors, including age, sex, performance status score, first-line or second-line treatment, first-line chemotherapy regimen (for the second-line treatment subgroup), stage IIIB or IV, and genotypes of EGFR mutation. BM and mortality risk of both groups were recorded and compared.

Results

In total 129 matched pairs were included for analysis. During a median follow-up of 21.5 months, time to BM risk was longer and incidences of BM within 2 years were lower in patients who received erlotinib than chemotherapy in total population, as well as subgroups of first-line treatment, second-line treatment, stage IIIB, stage IV, exon 19 deletion mutation, and exon 21 L858R mutation. Similar overall survival time and 2-year survival rates were seen in two groups totally or in any subgroup. Multivariate analysis showed that BM was retarded in patients who received erlotinib administration (hazard ratio, 1.695; P=0.001) and in patients who were in stage IIIB (hazard ratio, 1.751; P=0.001).

Conclusion

Erlotinib administration decreases BM risk in advanced pulmonary adenocarcinoma patients harboring sensitive EGFR mutations.

Experience with erlotinib in the treatment of non-small cell lung cancer

Non-small cell lung cancer (NSCLC) remains the leading cause of cancer-related deaths. In the last decade, the epidermal growth factor receptor (EGFR) signalling pathway has emerged as one of the most important molecular aberrations, representing an attractive therapeutic target in NSCLC. Drugs interfering with the tyrosine kinase domain of the EGFR (EGFR TKIs), such as erlotinib and gefitinib, have demonstrated efficacy in patients with advanced NSCLC irrespective of therapy line and particularly in patients harbouring activating mutations in the EGFR gene (EGFR(mut+)). Results of large phase III randomized trials clearly established that EGFR TKIs are superior to chemotherapy as frontline treatment in patients with EGFR(mut+), whereas in the EGFR wild-type (EGFR(WT)) or EGFR unknown population, platinum-based chemotherapy remains the standard of care, with no consistent benefit produced by the addition of EGFR TKI. In pretreated NSCLC, EGFR TKIs are considered more effective than standard monotherapy with cytotoxics in the presence of classical EGFR mutations, whereas in the EGFR(WT) population, a similar efficacy to docetaxel or pemetrexed in terms of survival has been demonstrated. Unfortunately, patients who initially responded to EGFR TKIs invariably develop acquired resistance. For such patients there is an urgent need for more effective strategies able to delay or possibly overcome resistance. In the present review we analysed the available data on erlotinib in the treatment of advanced NSCLC.

Erlotinib in the first-line treatment of non-small-cell lung cancer

Non-small-cell lung cancer (NSCLC) is the leading cause of cancer-related deaths. In the last decade the EGF receptor (EGFR) signaling pathway has emerged as one of the most important molecular aberrations in NSCLC. Drugs interfering with the tyrosine kinase domain of the EGFR (EGFR-TKI), such as erlotinib or gefitinib, demonstrated efficacy in patients with advanced NSCLC irrespective of therapy line and particularly in patients harboring activating mutations of the EGFR gene. Results of large Phase III randomized trials clearly demonstrated that an EGFR-TKI is the best front-line option for patients with classical EGFR mutations, while in the EGFR wild-type or EGFR unknown population platinum-based chemotherapy remains the gold standard. In pretreated patients, EGFR-TKIs are considered more effective than standard chemotherapy in the EGFR-mutated population, with no difference in EGFR wild-type NSCLC. Although EGFR-TKIs are certainly particularly effective in patients with EGFR mutations, at present no biomarker, including KRAS mutations, can be recommended in clinical practice for precluding the therapy to any pretreated patient. In this article, the authors analyzed data of erlotinib in NSCLC, focusing on its role in front-line therapy.

Clinical outcomes with erlotinib in patients with epidermal growth factor receptor mutation

The epidermal growth factor receptor (EGFR) mutation is the first recognized molecular target in non-small cell lung cancer that makes personalized therapy feasible. This molecular alteration has been demonstrated to be more frequent in Asians, non-smokers and patients with adenocarcinoma histology. Several retrospective and subgroup analyses of phase III trials have shown the single agent, erlotinib, to be associated with higher response rates and longer progression-free survival in patients harbouring an EGFR mutation. Two prospective randomized phase III studies from China and Europe have confirmed the role of first-line erlotinib in patients with the mutations. Erlotinib has also been evaluated in combination with chemotherapy in either a concurrent or intercalated regimen. Earlier trials were limited by little information on the EGFR mutational status of the enrolled patients, and an ongoing phase III trial with translational biomarker analysis will provide more comprehensive data on the combination.

Development and validation of a spectrofluorimetric method for the determination of erlotinib in spiked human plasma

A rapid and sensitive spectrofluorimetric method was developed and validated for the determination of erlotinib (ETB), a potent anticancer drug, in spiked human plasma without any derivatization. The described method was validated and the analytical parameters of linearity, accuracy, precision (intra- and inter-day), limit of detection (LOD), and limit of quantification (LOQ) were evaluated. The relation between the fluorescence intensity and concentration was found to be linear (r(2) 0.9998) over the range 125 to 1000 ng/mL with the detection limit of 15 ng/mL. A simple liquid-liquid extraction method was followed in order to extract the drug from spiked plasma. The mean absolute recoveries of ETB were 85.59 % (±0.57), 86.91 % (±1.77) and 89.31 % (±3.01) at spiked plasma ETB concentration of 5000, 3750 and 2500 ng/mL, respectively. The spectrofluorimetric method presented here is a rapid, simple, specific, and reproducible method and can be used to characterize the plasma pharmacokinetics of ETB.

Simultaneous Determination of Celecoxib, Erlotinib, and its Metabolite Desmethyl-Erlotinib (OSI-420) in Rat Plasma by Liquid chromatography/Tandem Mass Spectrometry with Positive/Negative Ion-Switching Electrospray Ionisation

A new method for the simultaneous determination of celecoxib, erlotinib, and its active metabolite desmethyl-erlotinib (OSI-420) in rat plasma, by liquid chromatography/tandem mass spectrometry with positive/negative ion-switching electrospray ionization mode, was developed and validated. Protein precipitation with methanol was selected as the method for preparing the samples. The analytes were separated on a reverse-phase C₁₈ column (50mm×4.6mm i.d., 3μ) using methanol: 2 mM ammonium acetate buffer, and pH 4.0 as the mobile phase at a flow rate 0.8 mL/min. Sitagliptin and Efervirenz were used as the internal standards for quantification. The determination was carried out on a Theremo Finnigan Quantam ultra triple-quadrupole mass spectrometer, operated in selected reaction monitoring (SRM) mode using the following transitions monitored simultaneously: positive m/z 394.5→278.1 for erlotinib, m/z 380.3→278.1 for desmethyl erlotinib (OSI-420), and negative m/z −380.1→ −316.3 for celecoxib. The limits of quantification (LOQs) were 1.5 ng/mL for Celecoxib, erlotinib, and OSI-420. Within- and between-day accuracy and precision of the validated method were within the acceptable limits of < 15% at all concentrations. The quantitation method was successfully applied for the simultaneous estimation of celecoxib, erlotinib, and desmethyl erlotinib in a pharmacokinetic study in Wistar rats.

[Inhibitors of the epidermal growth factor receptor (EGFR) tyrosine kinase: similarity and differences]

Tyrosine kinase inhibitors (TKI) of EGFR are used in advanced non-small cell lung cancer (NSCLC) in 2(nd) and 3(rd) line, and for gefitinib in first line in case of EGFR mutations. These drugs are particularly active in presence of these mutations, with response rate around 60-70%. Pharmacological data suggest an equivalent effect of erlotinib and gefitinib. One phase II study has directly compared the two drugs in 2(nd) line, with a non significant advantage for gefitinib in term of response and progression-free survival. However, skin tolerance profile was statistically better with gefitinib. Indirect comparisons between erlotinib and gefitinib in the phase III trials vs chemotherapy 1(st) line have to be interpreted, with caution and take under consideration the impact of the chemotherapy arm on the Hazard Ratio for Progression-free and overall survival. However, response rates seem to be equivalent. Cohort and phase IV studies have shown no significant difference for response and survival, and a similar tolerance profile.

Erlotinib for progressive vestibular schwannoma in neurofibromatosis 2 patients

OBJECTIVE

In vitro treatment of Nf2-deficient cells with epidermal growth factor receptor (EGFR) inhibitors can reduce cellular proliferation. We sought to determine the activity of erlotinib for progressive vestibular schwannoma (VS) associated with neurofibromatosis 2 (NF2).

STUDY DESIGN

Retrospective case review.

SETTING

Tertiary referral center.

PATIENTS

Eleven NF2 patients with progressive VS who were poor candidates for standard therapy.

INTERVENTION

Erlotinib 150 mg daily.

MAIN OUTCOME MEASURES

A radiographic response was defined as >or= 20% decrease in tumor volume compared with baseline. A hearing response was defined as a statistically significant increase in word recognition score (WRS) compared with baseline; a minor hearing response was defined as a 10 dB improvement in pure-tone average with stable WRS.

RESULTS

: Before treatment, the median and mean annual volumetric growth rate for 11 index VS were 26% and 46%, respectively. Among 10 evaluable patients, the median time-to-tumor progression was 9.2 months. Three patients with stable disease experienced maximum tumor shrinkage of 4%, 13%, and 14%. Nine patients underwent audiologic evaluations. One experienced a transient hearing response, 2 experienced minor hearing responses, 3 remained stable, and 2 developed progressive hearing loss. The median time-to-progressive hearing loss was 9.2 months and to either tumor growth or progressive hearing loss was 7.1 months. Adverse treatment effects included mild-to-moderate rash, diarrhea, and hair thinning, with 2 episodes of grade 3 toxicity.

CONCLUSION

Erlotinib treatment was not associated with radiographic or hearing responses in NF2 patients with progressive VS. Because a subset of patients experienced prolonged stable disease, time-to-progression may be more appropriate than radiographic or hearing response for anti-EGFR agents in NF2-associated VS.

Role of ATP-binding cassette and solute carrier transporters in erlotinib CNS penetration and intracellular accumulation

PURPOSE

To study the role of drug transporters in central nervous system (CNS) penetration and cellular accumulation of erlotinib and its metabolite, OSI-420.

EXPERIMENTAL DESIGN

After oral erlotinib administration to wild-type and ATP-binding cassette (ABC) transporter-knockout mice (Mdr1a/b(-/-), Abcg2(-/-), Mdr1a/b(-/-)Abcg2(-/-), and Abcc4(-/-)), plasma was collected and brain extracellular fluid (ECF) was sampled using intracerebral microdialysis. A pharmacokinetic model was fit to erlotinib and OSI-420 concentration-time data, and brain penetration (P(Brain)) was estimated by the ratio of ECF-to-unbound plasma area under concentration-time curves. Intracellular accumulation of erlotinib was assessed in cells overexpressing human ABC transporters or SLC22A solute carriers.

RESULTS

P(Brain) in wild-type mice was 0.27 ± 0.11 and 0.07 ± 0.02 (mean ± SD) for erlotinib and OSI-420, respectively. Erlotinib and OSI-420 P(Brain) in Abcg2(-/-) and Mdr1a/b(-/-)Abcg2(-/-) mice were significantly higher than in wild-type mice. Mdr1a/b(-/-) mice showed similar brain ECF penetration as wild-type mice (0.49 ± 0.37 and 0.04 ± 0.02 for erlotinib and OSI-420, respectively). In vitro, erlotinib and OSI-420 accumulation was significantly lower in cells overexpressing breast cancer resistance protein (BCRP) than in control cells. Only OSI-420, not erlotinib, showed lower accumulation in cells overexpressing P-glycoprotein (P-gp) than in control cells. The P-gp/BCRP inhibitor elacridar increased erlotinib and OSI-420 accumulation in BCRP-overexpressing cells. Erlotinib uptake was higher in OAT3- and OCT2-transfected cells than in empty vector control cells.

CONCLUSION

Abcg2 is the main efflux transporter preventing erlotinib and OSI-420 penetration in mouse brain. Erlotinib and OSI-420 are substrates for SLC22A family members OAT3 and OCT2. Our findings provide a mechanistic basis for erlotinib CNS penetration, cellular uptake, and efflux mechanisms.

Innovative Therapies for Children with Cancer pediatric phase I study of erlotinib in brainstem glioma and relapsing/refractory brain tumors

This multicenter phase I study aimed to establish the recommended dose (RD) of the epidermal growth factor receptor (EGFR) inhibitor erlotinib, given as monotherapy or with radiotherapy to children with malignant brain tumors. Group 1 included patients with refractory or relapsing brain tumors receiving erlotinib alone, and group 2 included newly diagnosed patients with brainstem gliomas receiving radiotherapy and erlotinib. A conventional 3 + 3 dose escalation and a continual reassessment method, respectively, were utilized in 4 dose levels: 75, 100, 125, and 150 mg/m² per day. Fifty-one children were enrolled (30 and 21, respectively); 50 received treatment. The RD of erlotinib was 125 mg/m² per day as monotherapy or in combination with radiotherapy. Overall, 230 adverse events in 44 patients were possibly treatment related (216, grades 1 and 2; 9, grade 3; 1, grade 4; 4, grade 5). Dermatologic and neurologic symptoms were common; intratumoral hemorrhage was confirmed in 3 patients. In group 1, 8 of 29 patients (28%) had stable disease with tumor regression approaching 50% in a malignant glioma and an anaplastic oligoastrocytoma. In group 2, overall survival was 12.0 months. EGFR overexpression by immunohistochemistry was found in 17 of 38 (45%) tumor samples analyzed, with a partial gain of 7p11.2 in 1 glioblastoma; phosphate and tensin homolog loss was frequent in brainstem glioma (15 of 19). Mean (95% CI) apparent clearance and volume of distribution for erlotinib were 4.0 L/h (3.4-4.5 L/h) and 98.6 L (69.8-127.0 L), respectively, and were independent of the dose level; mean half-life was 16.6 hours. Thus, erlotinib 125 mg/m² per day has an acceptable tolerability profile in pediatric patients with brain tumors and can be combined with radiotherapy.

The serum and cerebrospinal fluid pharmacokinetics of anakinra after intravenous administration to non-human primates

Anakinra improves the central nervous system manifestations of neonatal-onset multisystem inflammatory disease, which is mediated by IL-1beta oversecretion. The cerebrospinal fluid (CSF) penetration of the IL-1 receptor antagonist anakinra was studied in rhesus monkeys after intravenous doses of 3 and 10 mg/kg. Drug exposure (area under concentration-time curve) in CSF was 0.28% of that in serum. The average CSF concentration at 3 mg/kg was 1.8 ng/mL, which is 30-fold higher than endogenous CSF levels of IL-1Ra. The CSF penetration was not dose-dependent, indicating that the CSF penetration was not saturated in the 3 to 10 mg/kg dose range.

Good Clinical Response to Erlotinib in a Non-Small Cell Lung Cancer Patient Harboring Multiple Brain Metastases and a Double Active Somatic Epidermal Growth Factor Gene Mutation

Recently, 2 small molecule kinase inhibitors (TKIs), targeting epidermal growth factor receptor (EGFR), have proven effective in the treatment of non-small cell lung cancer. However, it is unknown whether the EGFR double activating mutation of L858R in exon 21 and the in-frame deletion in exon 19 is a predictor of the effectiveness of EGFR-TKIs. We report for the first time a case of non-small cell lung cancer with central nervous system metastases harboring a rare EGFR double activating mutation who showed a good clinical response to erlotinib, regardless of his poor performance status, as swallowing is not possible. Therefore, we suggest that erlotinib may become a therapeutic choice in cases of central nervous system metastases even with poor performance status.

A phase II trial of erlotinib in patients with recurrent malignant gliomas and nonprogressive glioblastoma multiforme postradiation therapy

Patients with (a) recurrent malignant glioma (MG): glioblastoma (GBM) or recurrent anaplastic glioma (AG), and (b) nonprogressive (NP) GBM following radiation therapy (RT) were eligible. Primary objective for recurrent MG was progression-free survival at 6 months (PFS-6) and overall survival at 12 months for NP GBM post-RT. Secondary objectives for recurrent MGs were response, survival, assessment of toxicity, and pharmacokinetics (PKs). Treatment with enzyme-inducing antiepileptic drugs was not allowed. Patients received 150 mg/day erlotinib. Patients requiring surgery were treated 7 days prior to tumor removal for PK analysis and effects of erlotinib on epidermal growth factor receptor (EGFR) and intracellular signaling pathways. Ninety-six patients were evaluable (53 recurrent MG and 43 NP GBM); 5 patients were not evaluable for response. PFS-6 in recurrent GBM was 3% with a median PFS of 2 months; PFS-6 in recurrent AG was 27% with a median PFS of 2 months. Twelve-month survival was 57% in NP GBMs post-RT. Primary toxicity was dermatologic. The tissue-to-plasma ratio normalized to nanograms per gram dry weight for erlotinib and OSI-420 ranged from 25% to 44% and 30% to 59%, respectively, for pretreated surgical patients. No effect on EGFR or intratumoral signaling was seen. Patients with NP GBM post-RT who developed rash in cycle 1 had improved survival (P < .001). Single-agent activity of erlotinib is minimal for recurrent MGs and marginally beneficial following RT for NP GBM patients. Development of rash in cycle 1 correlates with survival in patients with NP GBM after RT.

Extracellular fluid concentrations of cisplatin, carboplatin, and oxaliplatin in brain, muscle, and blood measured using microdialysis in nonhuman primates

PURPOSE

Cisplatin, carboplatin, and oxaliplatin are chemically reactive anticancer drugs with modest activity in brain tumors. Previously, we have demonstrated that drug exposure in cerebrospinal fluid (CSF) for these platinum analogs is <5% of the plasma ultrafiltrate (UF) drug exposure in nonhuman primates. Microdialysis is a minimally invasive in vivo method for sampling small molecules in the blood and tissue extracellular fluid (ECF). The purpose of this study was to estimate the penetration of platinum analogs into the brain ECF.

METHODS

We measured free concentrations of cisplatin, carboplatin, and oxaliplatin in ECF of brain, muscle, and blood of nonhuman primates using microdialysis and compared ECF platinum concentrations in blood and brain to plasma UF and CSF concentrations obtained using conventional sampling methods.

RESULTS

For all three platinum analogs, AUC(0-4h) for microdialysis sampling from the vein was similar to standard plasma UF sampling. The median AUC(0-4h) ratio for vein to plasma UF was 1.1 (range, 0.9-1.4). The platinum analogs had limited distribution (<5%) to the CSF and brain ECF. CSF penetration predicts for the limited penetration of the platinum analogs into brain ECF, but concordance between CSF and brain ECF measurements was poor. CSF oxaliplatin concentrations (AUC(0-4h), 0.4-0.9 microM h) were substantially lower than brain ECF concentrations (AUC(0-4h), 2.0-8.6 microM h).

CONCLUSIONS

The penetration of platinum analogs into CSF and brain is limited. The differences in the CNS penetrations among the three platinum analogs are not clinically significant. For cisplatin and carboplatin, CSF penetration appears to be a surrogate for brain extracellular free drug exposure.