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Osimertinib is the standard of care in the initial treatment for advanced epidermal growth factor receptor (EGFR) mutation-positive lung cancer. However, clinical data and reliable prognostic biomarkers are insufficient.We performed a retrospective multicentre cohort study for 538 EGFR mutation-positive patients, who received osimertinib as the initial treatment between August 2018 and December 2019. The main outcome was progression-free survival (PFS).The median observation period was 14.7 months (interquartile range 11.4-20.0). The median PFS was 20.5 months (95% confidence interval [CI] 18.6-not reached). Multivariate analysis showed that sex (male) (hazard ratio [HR] 1.99, 95% CI 1.35-2.93, P = 0.001), malignant effusions (HR 1.51, 95% CI 1.11-2.04, P = 0.008), liver metastasis (HR 1.55, 95% CI 1.03-2.33, P = 0.037), advanced unresectable cases (HR 1.71, 95% CI, 1.04-2.82, P = 0.036), mutation type and programmed cell death-ligand 1 (PD-L1) expression were associated with PFS. The L858R (HR 1.55, 95% CI 1.01-2.38, P = 0.043) and uncommon mutations (HR 3.15, 95% CI 1.70-5.83, P 0.001) were associated with PFS. PD-L1 expression of 1-49% (HR 1.66, 95% CI 1.05-2.63, P = 0.029), ≥50% (HR 2.24, 95% CI 1.17-4.30, P = 0.015) and unknown (HR 1.53, 95% CI 1.05-2.22, P = 0.026) was associated with PFS. The main reasons for treatment discontinuation among 219 patients were disease progression (44.3%), pneumonitis (25.5%) and other adverse events (16.0%).During initial treatment with osimertinib, PD-L1 expression is significantly related to PFS. Adverse events are a noteworthy reason for discontinuation.

The recommended antibiotic for pulmonary nocardiosis (PN) is trimethoprim-sulfamethoxazole (TMP-SMZ). However, no comparative studies have assessed its efficacy and safety. We compared 180-day outcomes of first-line therapies for PN between fifty-two patients treated with TMP-SMZ (TS group [n = 18]) and with alternative antibiotics (non-TS group [n = 34]). Failure-free survival (FFS) was defined as the time from initiation to discontinuation of first-line therapy due to treatment failure including disease progression or death and adverse events. Overall survival (hazard ratio [HR] of TMP-SMZ, 2.96; p = 0.118) and the time to disease progression or death (HR of TMP-SMZ, 3.15; p = 0.136) did not differ significantly between the two groups. The incidence of adverse events was 61.1% (TS group) and 20.6% (non-TS group). The time to adverse events inducing treatment failure was significantly shorter (HR, 3.44; p = 0.021), and FFS was poorer in the TS group than in the non-TS group (HR, 3.33; p = 0.005). Multivariate Cox analysis revealed that TMP-SMZ administration was an independent predictor of treatment failure (HR, 3.16; p = 0.016). TMP-SMZ may not be an optimal antibiotic for first-line therapy for PN as it is inferior to alternative antibiotics in safety and associated with increased treatment failure.

Although osimertinib is a standard first-line treatment for patients with advanced-stage non-small cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) mutations, the incidence rate of pneumonitis associated with osimertinib is high. However, there are few reports about the safety and efficacy of osimertinib rechallenge after the development of pneumonitis.We conducted a retrospective multicentre cohort study of consecutive patients who developed pneumonitis associated with osimertinib as a first-line and received osimertinib rechallenge. The primary outcome was the incidence rate of any grade pneumonitis after osimertinib rechallenge. The secondary outcome was treatment efficacy in patients after osimertinib rechallenge.In total, 33 patients who received osimertinib rechallenge were included. Of them, 26 patients had grade 1, 6 patients had grade 2, and 1 patient had grade 3 initial pneumonitis. The median follow-up period after the osimertinib rechallenge was 16.9 months (interquartile range, 11.1-21.3 months). After the start of osimertinib rechallenge, five patients (15%) experienced mild relapsed pneumonitis. Three of the five patients had similar imaging patterns for initial and relapsed pneumonitis. No significant differences in characteristics were observed between patients with and without relapsed pneumonitis. The median progression-free survival after osimertinib rechallenge was not achieved (95% confidence interval: 10.3 months - not reached).Osimertinib rechallenge was feasible and effective for patients who developed initial pneumonitis associated with first-line osimertinib therapy. Osimertinib might be considered a treatment option even after the development of mild initial pneumonitis.

Anti-programmed cell death protein-1/ligand-1 (anti-PD-1/PD-L1) therapy is promising for patients with non-small-cell lung cancer (NSCLC); however, clinical trials have focused on patients with a performance status (PS) 0 or 1. This study aimed to evaluate the clinical outcomes and correlation between PD-L1 expression status and tumor response to anti-PD-1/PD-L1 therapy among NSCLC patients with poor PS (i.e., PS ≥ 2). In total, 130 patients with NSCLC and PS ≥ 2 treated with anti-PD-1/PD-L1 monotherapy at 12 institutions between January 2016 and August 2019 were retrospectively reviewed. PD-L1 expression status was divided into four groups

BackgroundThe increasing incidence of life-threatening Pneumocystis pneumonia (PCP) in non-HIV immunocompromised patients is a global concern. Yet, no reports have examined the prognostic significance of pre-existing interstitial lung disease (ILD) in non-HIV PCP.MethodsWe retrospectively reviewed the medical records of non-HIV PCP patients with (ILD group) or without (non-ILD group) pre-existing ILD. The clinical features and outcomes of the ILD group were compared with those of the non-ILD group. Cox regression models were constructed to identify prognostic factors.Results74 patients were enrolled in this study. The 90-day mortality was significantly higher in the ILD group than in the non-ILD group (62.5% versus 19.0%, pd-glucan were significantly reduced after treatment of PCP in both groups, whereas levels of Krebs von den Lungen-6 (KL-6) significantly increased in the ILD group. In the ILD group, the 90-day mortality of patients with increasing KL-6 levels after treatment was significantly higher than those with decreasing levels (78.9% versus 0%, p=0.019).ConclusionIn non-HIV PCP patients, pre-existing ILD is associated with a poorer prognosis. Prophylaxis for PCP is needed in patients with pre-existing ILD under immunosuppression.

Background: Based on the results of the PACIFIC study, chemoradiotherapy followed by 1-year consolidation therapy with durvalumab was established as the standard of care for unresectable, locally advanced non-small-cell lung cancer (LA-NSCLC). However, some topics not foreseen in that design can be explored, including progression-free survival (PFS) and overall survival (OS) after the start of chemoradiotherapy, the proportion of patients who proceeded to consolidation therapy with durvalumab, and the optimal chemotherapeutic regimens. In Japan, the combination regimen of S-1 + cisplatin (SP), for which the results of multiple clinical studies have suggested a good balance of efficacy and tolerability, is frequently selected in clinical settings. However, the efficacy and safety of consolidation therapy with durvalumab following this SP regimen have not been evaluated. We therefore planned a multicenter, prospective, single-arm, phase II study. Methods: In treatment-naïve LA-NSCLC, two cycles of combination chemotherapy with S-1 (80–120 mg/body, Days 1–14) + cisplatin (60 mg/m2, Day 1) will be administered at an interval of 4 weeks, with concurrent thoracic radiotherapy (60 Gy). Responders will then receive durvalumab every 2 weeks for up to 1 year. The primary endpoint is 1-year PFS rate. Discussion: Compared with the conventional standard regimen in Japan, the SP regimen is expected to be associated with lower incidences of pneumonitis, esophagitis, and febrile neutropenia, which complicate the initiation of consolidation therapy with durvalumab, and have higher antitumor efficacy during chemoradiotherapy. Therefore, SP-based chemoradiotherapy is expected to be successfully followed by consolidation therapy with durvalumab in more patients, resulting in prolonged PFS and OS. Toxicity and efficacy results of the SP regimen in this study will also provide information important to the future establishment of the concurrent combination of chemoradiotherapy and durvalumab. Trial registration: Japan Registry of Clinical Trials, jRCTs031190127, registered 1 November 2019, https://jrct.niph.go.jp/latest-detail/jRCTs031190127

Pulmonary alveolar proteinosis (PAP) is a rare disease characterized by abnormal accumulation of surfactant in the alveoli. Whole lung lavage (WLL) is the standard treatment for severe autoimmune PAP (aPAP); however, it is highly invasive. Intrapulmonary percussive ventilation (IPV) is a non‐invasive technique that delivers small bursts of high‐flow respiratory gas into the lung and mobilizes secretions. As IPV is beneficial for chronic respiratory diseases such as cystic fibrosis and bronchiectasis to reduce sputum, it was hypothesized that IPV will ameliorate aPAP by mobilizing and removing accumulated surfactant and foamy macrophages. Here, we report the case of a 52‐year‐old female with severe aPAP and progressive respiratory failure. She received intermittent IPV therapy for six months and thereby showed improvement in assessments of chest computed tomography (CT), lung function, and oxygenation. We suggest that IPV should be used as an alternative therapy for patients with aPAP and respiratory failure., We report the first case of severe autoimmune pulmonary alveolar proteinosis (aPAP) with progressive respiratory failure successfully treated by intrapulmonary percussive ventilation (IPV) therapy for six months.

Determinants of interindividual variability in erlotinib pharmacokinetics (PK) and adverse events remain to be elucidated. This study with 50 Japanese non-small-cell lung cancer patients treated with oral erlotinib at a standard dose of 150 mg aimed to investigate whether genetic polymorphisms affect erlotinib PK and adverse events. Single nucleotide polymorphisms (SNPs) in genes encoding metabolizing enzymes (CYP1A1, CYP1A2, CYP2D6, CYP3A4, CYP3A5, UGT1A1, UGT2B7, GSTM1, and GSTT1) or efflux transporters (ABCB1, and ABCG2) were analyzed as covariates in a population PK model. The ABCB1 1236C>T (rs1128503) polymorphism, not ABCB1*2 haplotype (1236TT-2677TT-3455TT, rs1128503 TT-rs2032582 TT-rs1045642 TT), was a significant covariate for the apparent clearance (CL/F), with the TT genotype showing a 29.4% decrease in CL/F as compared with the CC and the CT genotypes. A marginally higher incidence of adverse events (mainly skin rash) was observed in the TT genotype group; however, patients with high plasma erlotinib exposure did not always experience skin rash. None of the other SNPs affected PK or adverse events. The ABCB1 genotype is a potential predictor for erlotinib adverse events. Erlotinib might be used with careful monitoring of adverse events in patients with ABCB1 polymorphic variants.

Background The increasing incidence of life-threatening Pneumocystis pneumonia (PCP) in non-HIV immunocompromised patients is a global concern. Yet, no reports have examined the prognostic significance of pre-existing interstitial lung disease (ILD) in non-HIV PCP. Methods We retrospectively reviewed the medical records of non-HIV PCP patients with (ILD group) or without (non-ILD group) pre-existing ILD. The clinical features and outcomes of the ILD group were compared with those of the non-ILD group. Cox regression models were constructed to identify prognostic factors. Results 74 patients were enrolled in this study. The 90-day mortality was significantly higher in the ILD group than in the non-ILD group (62.5% versus 19.0%, p, Pre-existing interstitial lung disease (ILD) is an independent prognostic risk factor for non- HIV Pneumocystis pneumonia (PCP). Prophylaxis for PCP is needed in patients with pre-existing ILD under immunosuppression. http://bit.ly/37BGZuK

Background Acute exacerbation of interstitial lung disease (AE-ILD) is the most serious complication in lung cancer patients with pre-existing ILD receiving chemotherapy. The role of vascular endothelial growth factor (VEGF) in pathogenesis of AE-ILD is conflicting. The influence of bevacizumab (Bev), a monoclonal antibody against VEGF, on lung cancer patients with pre-existing ILD remains unclear. We examined the effect of Bev on reducing AE-ILD risk in non-squamous non-small cell lung cancer (NSCLC) patients receiving chemotherapy. Methods We analysed incidence of AE-ILD and outcomes of 48 patients with advanced non-squamous NSCLC with ILD who received first-line chemotherapy with (Bev group, n = 17) and without (non-Bev group, n = 31) Bev between July 2011 and July 2016. Gray’s test, which was competing risk analysis during the study period, was performed for both groups. Results The most common regimen used for first-line chemotherapy was the combination of carboplatin plus pemetrexed (PEM) in both groups. The incidences of chemotherapy-related AE-ILD 120 days after first-line chemotherapy initiation were significantly lower in the Bev than in the non-Bev groups (0% vs. 22.6%, p = 0.037, Gray’s test). However, there were no differences in development of progressive disease of lung cancer and other events as the competing risk factors of AE-ILD between the two groups. Only patients receiving PEM-containing regimens also showed a significant difference in the incidence of AE-ILD between the two groups (p = 0.044). The overall-cumulative incidence of AE-ILD during the first-line and subsequent chemotherapy was 29.2% (14 of the 48). The median progression-free survival was significantly longer in the Bev than in the non-Bev groups (8.0 vs. 4.3 months, p = 0.026). Conclusions The addition of Bev to chemotherapy regimens may reduce the risk of chemotherapy-related AE-ILD in patients with lung cancer. Electronic supplementary material The online version of this article (10.1186/s12890-019-0838-2) contains supplementary material, which is available to authorized users.

Evolution of tumor-immune microenviroments (TIMEs) occurs during tumor growth and dissemination. Understanding inter-site tumor-immune heterogeneity is essential to harness the immune system for cancer therapy. While the development of immunotherapy against lung cancer with driver mutations and neuroendocrine tumors is ongoing, little is known about the TIME of large cell neuroendocrine carcinoma (LCNEC) or anaplastic lymphoma kinase (ALK) rearrangement-positive lung cancer. We present a case study of a 32-year-old female patient with ALK-rearrangement-positive LCNEC, who had multiple distant metastases including mediastinal lymph-node, bilateral breasts, multiple bones, liver and brain. Multiple biopsy samples obtained from primary lung and three metastatic tumors were analyzed by fluorescent multiplex immunohistochemistry. Tissue localizations of tumor-infiltrating lymphocytes in the tumor nest and surrounding stroma were evaluated. T cell and B cell infiltrations were decreased with distance from primary lung lesion. Although each tumor displayed a unique TIME, all tumors exhibited concomitant regression after treatment with an ALK-inhibitor. This study provides the first evidence of the coexistence of distinct TIME within a single individual with ALK-rearrangement-positive LCNEC. The present study contributes to our understanding of heterogeneous TIMEs between primary and metastatic lesions and provides new insights into the complex interplay between host-immunity and cancer cells in primary and metastatic lesions.

Erythrocyte pyruvate kinase (PK) deficiency is an inherited glycolytic erythroenzymopathy caused by mutations of the PKLR gene. A causative mutation of the feline PKLR gene was originally identified in Abyssinian and Somali cats in the U.S.A. In the present study, a TaqMan probe-based real-time PCR genotyping assay was developed and evaluated for rapid genotyping and large-scale screening for this mutation. Furthermore, a genotyping survey was carried out in a population of four popular purebred cats in Japan to determine the current mutant allele frequency. The assay clearly displayed all genotypes of feline PK deficiency, indicating its suitability for large-scale survey as well as diagnosis. The survey demonstrated that the mutant allele frequency in Abyssinian and Somali cats was high enough to warrant measures to control and prevent the disease. The mutant allele frequency was relatively low in Bengal and American Shorthair cats; however, the testing should still be carried out to prevent the spread of the disease. In addition, PK deficiency should always be considered in the differential diagnosis of anemia in purebred cats in Japan as well as worldwide.

Aims: We analyzed the association of ABCB1 polymorphisms with erlotinib-induced toxicity and the pharmacokinetics in patients with non-small-cell lung cancer. Materials & methods: After erlotinib 150 mg was administered to 50 patients, ABCB1 polymorphisms were analyzed via either TaqMan® assays or direct nucleotide sequencing. Plasma concentrations were measured by HPLC. Results: The trough concentration at steady state in patients with the ABCB1 1236TT–2677TT–3435TT genotype was higher compared with others groups (p = 0.021) and patients carrying this genotype had a higher risk of developing higher grade 2 toxicity (p = 0.012). Conclusion: The present study suggested that the ABCB1 1236TT–2677TT–3435TT genotype was associated with higher plasma concentration and the risk of developing higher toxicity in patients treated with erlotinib. Original submitted 5 August 2011; Revision submitted 30 November 2011

背景．胸壁に悪性リンパ腫が発生することは非常に稀である．症例．62歳男性．他疾患加療中に撮影されたCTにおいて，偶然1.5 cm程の右胸壁腫瘍と4 cm大の肝腫瘍を発見された．悪性肝腫瘍を疑われ肝生検を含めた精査が行われたが確定診断に至らず経過観察されていた．両腫瘍はMRI所見が酷似しており，同一疾患の多臓器発生，または転移性腫瘍の可能性があった．1年後に胸壁腫瘍が増大したため胸腔鏡下腫瘍切除術を施行し，切除標本から節外性辺縁帯B細胞リンパ腫と診断された．後日，肝腫瘍は再検査により，B細胞性悪性リンパ腫と診断された．結論．極めて稀な，胸壁に生じた節外性辺縁帯B細胞リンパ腫の1例を報告した．同時性異所性病変の診断に，MRIが有用であった．

e20559 Background: Biomarkers predicting the efficacy and toxicity of bevacizumab (Bev) have not yet been established. Therefore we conducted this pharmacokinetic study to elucidate the role of plasma concentration of Bev as a biomarker to predict outcome in the treatment of patients with lung cancer. Methods: This multicenter prospective pharmacokinetic study was conducted among nine centers in Kumamoto Prefecture, Japan. Patients with non-squamous non-small cell lung cancer who were treated using tri-weekly Bev (15mg/kg) with platinum-doublet chemotherapy were enrolled. Plasma samples were collected from all patients before the administration of every dose of Bev until disease progression or treatment discontinuation owing to toxicity. Plasma concentrations of Bev were analyzed via nano-surface and molecular-orientation limited proteolysis coupled with liquid chromatography-mass spectrometry. Results: Between July 2010 and May 2014, 30 patients were enrolled in this study. Majority of the patients received pemetrexed with cisplatin or carboplatin (24 patients, 80%) and others received paclitaxel with carboplatin. The trough concentrations of Bev after first administration (day 22) were 63.19 ± 19.57 μg/mL. Trough concentrations gradually increased until the six cycle of Bev and reached a steady state. Plasma concentrations of Bev did not decrease until disease progression in patients with a long treatment period. Higher mean plasma concentrations of Bev correlated with female sex (p = 0.034) and high serum albumin levels (p = 0.034). Patients who received pemetrexed had higher mean concentrations of Bev (p = 0.038) than those who received paclitaxel. The response rate and progression-free survival did not correlate with the plasma concentration of Bev. Proteinuria (≥Grade 2) correlated with higher concentrations of Bev. Conclusions: Our study demonstrated that various types of chemotherapy influenced the concentrations of Bev, and a higher concentration of Bev may predict the incidence of proteinuria. In addition, clearance of Bev did not change after long treatment period until disease progression. Clinical trial information: 000007630.

To the Editor, Among nodular manifestations in rheumatoid arthritis (RA), rheumatoid nodule is the most widely recognized lesion [1]. However, those are not diagnostic for RA and can occur in other...

A 67-year-old man was admitted to our hospital because of a cough and hemoptysis. Chest CT and bronchoscopy demonstrated a polypoid tumor in the truncus intermedius. The pathological diagnosis of the biopsy specimens was glomus tumor, which is an extremely rare tumor of the respiratory tract. We performed a successful bronchoscopic removal of the tumor using a high-frequency-wave snare and microwave coagulation. After one year of follow-up, there was no recurrence. To the best of our knowledge, this is only the 24th report of a tracheobronchial glomus tumor.

An 83-year-old man was found to have multiple pulmonary nodules and ground-glass opacities after a left upper lobectomy for non-small-cell lung cancer. After bronchoalveolar lavage and transbronchial lung biopsy, he was put on a regimen of steroids for a tentative diagnosis of organizing pneumonia. Over the course of 3 months, the radiographic findings improved; however, they progressively deteriorated during the steroid tapering period and new skin lesions also appeared. Skin biopsy specimens showed lymphohistiocytic infiltration in which the atypical lymphocytes were positive for EBV encoding small RNAs by in situ hybridization; we therefore diagnosed lymphomatoid granulomatosis. The pulmonary and cutaneous lesions responded to steroid and cyclophosphamide therapy, but the patient died unexpectedly due to a rapid onset of massive pulmonary thromboembolism.

Introduction: Erlotinib is an epidermal growth factor receptor (EGFR) tyrosine-kinase inhibitor, a 150 mg daily dose of which has been shown to be effective for improving overall survival in non-small-cell lung cancer (NSCLC) patients who had failed at least 1 prior chemotherapy regimen. Furthermore, erlotinib demonstrated significant prolongation of progression-free survival versus standard chemotherapy in EGFR mutation positive NSCLC patients. However, skin rash and diarrhea often occurs, and these toxicities lead to discontinuation of therapy or dose reduction in many patients. Several population pharmacokinetics (PK) analyses have reported large interindividual variabilities in erlotinib blood exposure and its toxicities. However, none of those analyses clearly explains the determinants of these large interindividual variabilities. Here, aiming to develop a dose regimen that would maintain the clinical benefits of erlotinib while minimizing its adverse effects, we analyzed single nucleotide polymorphisms (SNPs) of PK-related genes and investigated the relationships between genotypes and interindividual variabilities in the PK and adverse effects. Methods: We performed a multicenter study of 50 patients treated with 150 mg erlotinib as a second-line or later treatment. PK and toxicity were assessed. For PK analyses, blood samples were collected from 28 patients at 5 to 18 time points, and trough blood samples were collected from 20 patients at 1 time point. SNPs in genes encoding metabolizing enzymes or efflux transporters (CYP1A1, CYP1A2, CYP2D6, CYP3A4, CYP3A5, UGT1A1, UGT2B7, GSTM1, GSTT1, ABCB1, and ABCG2) were analyzed. Population PK analyses were carried out using NONMEM. SNPs were tested as covariates in a population PK model. The effects of these SNPs and erlotinib exposure on toxicity were evaluated. Results and Discussion: A 2-compartment model with first order absorption and linear elimination described the erlotinib PK. Only the ABCB1 1236C>T polymorphism was a statically significant covariate for CL/F, showing a 29.4% decrease in CL/F for the TT genotype as compared with the CC and the CT genotypes. The interindividual variability in CL/F decreased by 10.6% after inclusion of the TT genotype as a covariate in the model. This result indicates that a dose reduction to 100 mg for the TT genotype group could equalize the erlotinib exposure between each genotype group. A higher incidence of adverse effects (mainly diarrhea) was observed in the TT genotype group. Conclusions: Of the 20 SNPs that are related to erlotinib PK, only ABCB1 1236C>T influenced the exposure of erlotinib. This SNP was suggested to be related to the risk of adverse events. Individual dosing based on ABCB1 genotype might reduce the adverse effects. Further clinical trials are needed to investigate the toxicity and the clinical outcome of this dose regimen. Citation Format: Chihiro Endo-Tsukude, Ji-ichiro Sasaki, Sho Saeki, Norihiro Iwamoto, Megumi Inaba, Sunao Ushijima, Hiroto Kishi, Shinji Fujii, Hiroshi Semba, Kosuke Kashiwabara, Yukari Tsubata, Yuki Kai, Hideyuki Saito, Takeshi Isobe, Hirotsugu Kohrogi, Akinobu Hamada. Effect of genetic polymorphisms on erlotinib pharmacokinetics and toxicity in Japanese patients with non-small-cell lung cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5481. doi:10.1158/1538-7445.AM2015-5481

2593 Background: Erlotinib is an orally available, selective inhibitor of EGFR tyrosine kinase activity used in the treatment of patients with non-small cell lung cancer (NSCLC), and skin rash is a...

Background: Erlotinib is a selective inhibitor of EGFR tyrosine kinase activity used for the treatment of patients with NSCLC. It has been reported that ABCB1 polymorphisms affect pharmacokinetics and adverse events of erlotinib in Japanese patients (Hamada A, 2009 AACR meeting). Erlotinib is metabolized by CYP3A4, CYP3A5, CYP1A1, and CYP1A2. The purpose of this study was to investigate the association of CYP1A1 and CYP1A5 single nucleotide polymorphisms (SNPs) with inter-individual variability of erlotinib pharmacokinetics. Methods: Patients with NSCLC were treated with single-agent oral erlotinib 150 mg/day. Plasma levels of erlotinib were measured by high-performance liquid chromatography on days 1 and at steady state (>day 8). DNA was obtained from whole blood, and genotyping was carried out using an Applied Biosystems TaqMan SNP Genotyping Assay on an ABI PRISM® 7900HT system. Results: Fifty patients (mean age, 67 years) were enrolled in the study. Histological classifications were: adenocarcinoma (n=41), squamous cell carcinoma (n=7), and unknown (n=2). Smoking history was indicated as: never smoker (n=23), former smoker (n=24), and current smoker (n=3). For the CYP3A5 6986A>G polymorphism, the frequencies of wild-type (AA), heterozygote (GA), and homozygote (GG) were 6%, 34%, and 60%, respectively. For the CYP1A1 2455A>G polymorphism, the frequencies of wild-type (AA), heterozygote (GA), and homozygote (GG) were 64%, 24%, and 12%, respectively. The mean (±SD) maximum concentrations (Cmax), trough concentrations (Ctrough) on day 1, and steady-state trough concentrations (Css) on >day 8 were 1.66±0.73 μg/mL, 0.77±0.5 μg/mL, and 1.5±0.8 μg/mL, respectively. Lower exposure levels of erlotinib were observed in patients carrying the CYP3A5 6986AA allele than in patients carrying one or two G alleles (GA, GG). The Cmax on day 1 in patients carrying the CYP3A5 AA and GA/GG alleles were 0.76±0.27 μg/mL and 1.78±0.69 μg/mL, respectively. (p=0.0198) On the other hand, patients carrying the CYP1A1 2455GG allele had higher Css than in patients carrying the CYP1A1 2455AA or the CYP1A1 2455GA alleles (2.3±1.16 μg/mL vs. 1.4±0.69 μg/mL, p=0.0161) Conclusion: These results suggested that the CYP3A5 6986A>G and CYP1A1 2455A>G polymorphisms affect the pharmacokinetics of erlotinib in Japanese patients. Further studies involving a larger sample size will be required to evaluate whether measurement of the CYP3A5 and the CYP1A1 polymorphisms may help to optimize erlotinib treatment in individual patients. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 5459. doi:10.1158/1538-7445.AM2011-5459

e18115 Background: Erlotinib demonstrates individual differences in toxicity and efficacy. Last year we reported that patients with homozygous and heterozygous variant for ABCB1 1236C>T, 2766G>(T/A...

2506 Background: Erlotinib demonstrates substantial inter-individual differences in response and the development of skin rash (grade≥2) was correlated with efficacy. Erlotinib interacts with its target EGFR and the efflux transporter ABCB1 and ABCG2. EGFR CA repeat is associated with incidence of skin rash. A 421C>A SNP in ABCG2 and 1236C>T, 2677 G>(T/A), and 3435C>T SNPs in ABCB1 are associated with reduced protein expression. The aim of this study was to evaluate the effects of these variants and pharmacokinetics of erlotinib on toxicity grade in Japanese patients treating single agent erlotinib. Methods: Twenty-two patients with NSCLC received erlotinib orally at 150 mg/day and plasma levels of erlotinib were measured on days 1(D1), 8(D8), and stable phase (>day 14) by high-performance liquid chromatography. DNA from plasma was screened for SNPs in the EGFR, ABCB1, and ABCG2 genes using direct nucleotide sequencing or TaqMan assay. Eligibility criteria included: performance status (PS) < 3, age < 75, stage IIIB-IV, and written informed consent. Results: The mean Cmax (±SD) of D1 and D8 were 1.8 ± 1.0 and 3.1 ± 1.4 μg/ml, respectively. Trough concentration (Cmin) at D1 and steady state were 0.9 and 1.7 μg/ml, respectively. Grade 1–2 skin rash or diarrhea occurred in 95% of patients. One patient (Cmax at D1, 3.0 μg/ml) developed interstitial lung disease after continuous treatment with erlotinib for 3 days. The area under curves and Cmax on D1 were correlated with the severity of skin rash (p=0.05 and 0.01), however, Cmin were not correlated. Patients with homozygous variant and heterozygous for ABCB1 1236C>T, 2677 G>(T/A), and 3435C>T genotype as compared to patients carrying the wild-type were associated with higher Cmin at steady state (2.4 vs 1.2 μg/ml, p=0.01). EGFR CA repeat and AGCG2 421C>A genotype were not associated with any pharmacokinetic parameters. All Patients (n=4) with homozygous variant for ABCB1 1236TT- 2677TT/TA/AA-3435TT developed grade≥2 skin rash or diarrhea. Conclusions: The present study suggests that ABCB1 gene polymorphism is associated with the variable toxicity and pharmacokinetics to erlotinib treatment. No significant financial relationships to disclose.