Interstitial lung disease in Japanese patients with non-small cell lung cancer receiving gefitinib: an analysis of risk factors and treatment outcomes in Okayama Lung Cancer Study Group

EGF receptor tyrosine kinase inhibitors diminish transforming growth factor-α-induced pulmonary fibrosis

Transforming growth factor-α (TGF-α) is a ligand for the EGF receptor (EGFR). EGFR activation is associated with fibroproliferative processes in human lung disease and animal models of pulmonary fibrosis. We determined the effects of EGFR tyrosine kinase inhibitors gefitinib (Iressa) and erlotinib (Tarceva) on the development and progression of TGF-α-induced pulmonary fibrosis. Using a doxycycline-regulatable transgenic mouse model of lung-specific TGF-α expression, we determined effects of treatment with gefitinib and erlotinib on changes in lung histology, total lung collagen, pulmonary mechanics, pulmonary hypertension, and expression of genes associated with synthesis of ECM and vascular remodeling. Induction in the lung of TGF-α caused progressive pulmonary fibrosis over an 8-wk period. Daily administration of gefitinib or erlotinib prevented development of fibrosis, reduced accumulation of total lung collagen, prevented weight loss, and prevented changes in pulmonary mechanics. Treatment of mice with gefitinib 4 wk after the induction of TGF-α prevented further increases in and partially reversed total collagen levels and changes in pulmonary mechanics and pulmonary hypertension. Increases in expression of genes associated with synthesis of ECM as well as decreases of genes associated with vascular remodeling were also prevented or partially reversed. Administration of gefitinib or erlotinib did not cause interstitial fibrosis or increases in lavage cell counts. Administration of small molecule EGFR tyrosine kinase inhibitors prevented further increases in and partially reversed pulmonary fibrosis induced directly by EGFR activation without inducing inflammatory cell influx or additional lung injury.

Interstitial lung disease in Japanese patients with lung cancer: a cohort and nested case-control study

RATIONALE

Interstitial lung disease (ILD) occurs in Japanese patients with non-small cell lung cancer (NSCLC) receiving gefitinib.

OBJECTIVES

To elucidate risk factors for ILD in Japanese patients with NSCLC during treatment with gefitinib or chemotherapy.

METHODS

In a prospective epidemiologic cohort, 3,166 Japanese patients with advanced/recurrent NSCLC were followed for 12 weeks on 250 mg gefitinib (n = 1,872 treatment periods) or chemotherapy (n = 2,551). Patients who developed acute ILD (n = 122) and randomly selected control subjects (n = 574) entered a case-control study. Adjusted incidence rate ratios were estimated from case-control data by odds ratios (ORs) with 95% confidence intervals (CIs) using logistic regression. Crude (observed) incidence rates and risks were calculated from cohort data.

MEASUREMENTS AND MAIN RESULTS

The observed (unadjusted) incidence rate over 12 weeks was 2.8 (95% CI, 2.3-3.3) per 1,000 person-weeks, 4.5 (3.5-5.4) for gefitinib versus 1.7 (1.2-2.2) for chemotherapy; the corresponding observed naive cumulative incidence rates at the end of 12-week follow-up were 4.0% (3.0-5.1%) and 2.1% (1.5-2.9%), respectively. Adjusted for imbalances in risk factors between treatments, the overall OR for gefitinib versus chemotherapy was 3.2 (1.9-5.4), elevated chiefly during the first 4 weeks (3.8 [1.9-7.7]). Other ILD risk factors in both groups included the following: older age, poor World Health Organization performance status, smoking, recent NSCLC diagnosis, reduced normal lung on computed tomography scan, preexisting chronic ILD, concurrent cardiac disease. ILD-related deaths in patients with ILD were 31.6% (gefitinib) versus 27.9% (chemotherapy); adjusted OR, 1.05 (95% CI, 0.3-3.2).

CONCLUSIONS

ILD was relatively common in these Japanese patients with NSCLC during therapy with gefitinib or chemotherapy, being higher in the older, smoking patient with preexisting ILD or poor performance status. The risk of developing ILD was higher with gefitinib than chemotherapy, mainly in the first 4 weeks.

Remarkable effect of gefitinib retreatment in a patient with nonsmall cell lung cancer who had a complete response to initial gefitinib

Gefitinib is an orally active epidermal growth factor receptor tyrosine kinase inhibitor, and it shows favorable antitumor activity against chemorefractory nonsmall cell lung cancer (NSCLC). However, patients with NSCLC have few treatment options available if they are refractory to gefitinib. We describe a 49-year-old patient with NSCLC who had a complete response to initial gefitinib that lasted for 12 months. The tumor relapsed, and the patient received cytotoxic chemotherapy. However, despite chemotherapy, the patient had radiographic progression of lung metastases and we commenced retreatment with gefitinib, showing a remarkable effect. Epidermal growth factor receptor (EGFR) gene analysis showed deletion mutations in codon 745-750 in exon 19 and EGFR gene amplification. Our case shows that after retreatment with gefitinib, patients may show a remarkable response if they showed a remarkable response to initial gefitinib administration and if a certain time has elapsed since the previous gefitinib treatment.

Clinical aspects of epidermal growth factor receptor inhibitors: benefit and risk

Gefitinib and erlotinib are small molecules that selectively inhibit epidermal growth factor receptor (EGFR) tyrosine kinase activity. Developmental studies of either drug have failed to show synergistic effects when combined with cytotoxic drugs as the first line treatment in patients with advanced non-small cell lung cancer, but erlotinib has shown survival prolongation when compared with best supportive care in patients with recurrence. Female gender, adenocarcinoma histology and lack of smoking history are considered to be clinical factors predicting response. Being positive for EGFR mutations in exons 18-24 in cancer cells has a strong correlation with response. On the other hand, preceding idiopathic pulmonary fibrosis, male gender and history of smoking appear to be risk factors for EGFR tyrosine kinase inhibitor-induced interstitial lung disease in the Japanese population. Reports on these factors predicting response or risk for interstitial lung disease have attracted great interest in the relation between cancer genetics and drugs, as well as the relation between ethnicity and genetics. In clinical practice, EGFR tyrosine kinase inhibitor should be prescribed with careful consideration and it is essential to assess benefit and risk of the drug.

Significance of an epidermal growth factor receptor mutation in cerebrospinal fluid for carcinomatous meningitis

We report a case of epidermal growth factor receptor (EGFR) inhibitor-sensitive lung adenocarcinoma with carcinomatous meningitis who showed a good response to gefitinib, an oral tyrosine kinase inhibitor of EGFR. This good response to gefitinib treatment was attributed to evidence of an EGFR mutation, L858R in exon 21, which was detected in a small amount of cerebrospinal fluid (CSF) before the positive CSF cytology. Patients with carcinomatous meningitis often have a poor performance status, and therefore diagnostic approaches and therapeutic methods are also often limited. Detection of EGFR mutations may be a useful method for non-small cell lung cancer diagnosis, and also facilitate determination of appropriate therapeutic protocols.

Epidermal growth factor receptor inhibition and non-small cell lung cancer

The majority of non-small cell (NSC) lung cancers express epidermal growth factor receptor (EGFR). Many studies have evaluated the clinical effect from targeted therapy achieved by blocking EGFR in patients with NSC lung cancer. Treatment of biologically unselected patients with NSC lung cancer with two reversible quinazole EGFR inhibitors, gefitinib and erlotinib, gave negative results in all controlled trials but one. Ten percent to 20% of patients with NSC lung cancers have somatic mutations in EGFR, and these patients have a significantly higher response rate (73%) to treatment with EGFR inhibitors than patients with wild-type EGFR (10%). Patients with Asian background, women, non-smokers, and patients with adenocarcinoma had higher response rates than other patients, and the differences may be due to an association between the clinical characteristics and EGFR mutations. Further studies are needed to fully evaluate the effect of EGFR inhibitor-treatment for subgroups of patients with NSC lung cancer with favorable biological and clinical characteristics.

A phase II study of single-agent gefitinib as first-line therapy in patients with stage IV non-small-cell lung cancer

The aim of this study was to evaluate the efficacy and tolerability of gefitinib ('IRESSA') in Japanese patients with previously untreated stage IV non-small-cell lung cancer (NSCLC). This was a multi-institutional phase II study. Thirty-four patients with previously untreated stage IV NSCLC were enrolled between May 2003 and September 2004. Gefitinib was administered orally 250 mg once a day and was continued until there was either disease progression or severe toxicity. Objective tumour response rate was 26.5% (95% confidence interval, 11.7-41.3%). Adverse events were generally mild (National Cancer Institute-Common Toxicity Criteria grade 1 or 2) and consisted mainly of skin rash, fatigue and liver dysfunction. No pulmonary toxicity was observed. The global health status revealed that there was no change in quality of life during the study. This study found that single-agent gefitinib is active and well tolerated in chemo-naive Japanese patients with advanced NSCLC.

Relationship between epidermal growth factor receptor gene mutations and the severity of adverse events by gefitinib in patients with advanced non-small cell lung cancer

PURPOSE

Recent reports have demonstrated that mutation of epidermal growth factor receptor (EGFR) gene is predictive factor for tumor responsiveness to gefitinib suggesting the importance of EGFR status for the treatment of the patients with non-small cell lung cancer (NSCLC). However, the relationship between EGFR mutation and adverse events of gefitinib is still unknown. The aim of this study was to evaluate its correlation.

PATIENTS AND METHODS

Twenty-six tumor samples from Japanese NSCLC patients who received gefitinib in Okayama University Hospital between November 2000 and October 2004 were examined exons 18-21 of EGFR using direct sequence method. We retrospectively reviewed the clinical records and compared EGFR mutation status with adverse events during gefitinib treatment.

RESULTS

Of all 26 patients, EGFR mutation (exon 19 in-frame deletion, 6; exon 21 L858R, 5), were detected in 11 patients (42.3%). The principal adverse event was skin rash (89%), diarrhea (39%), and liver injury (39%). Grade 3 or more adverse events were not common. EGFR mutation status was correlated with neither its frequency nor severity of adverse events during gefitinib treatment including skin rash, diarrhea, liver injury, and interstitial lung disease. As expected, objective response rate of those with EGFR mutations was significantly higher than those without EGFR mutations (78% versus 21%, P<0.001).

CONCLUSION

Our study did not demonstrate the presence of close relationships between EGFR mutation status and adverse events during gefitinib treatment.

A review of the benefit-risk profile of gefitinib in Asian patients with advanced non-small-cell lung cancer

BACKGROUND

Improvements in first-line therapy of advanced non-small-cell lung cancer (NSCLC) have increased the need for effective second-line treatment options. In a Phase II trial of the anticancer drug gefitinib (IRESSA), greater efficacy was observed in Japanese compared with non-Japanese patients. Furthermore, results from a placebo-controlled Phase III trial (IRESSA Survival Evaluation in Lung cancer [ISEL]) showed that treatment with gefitinib was not associated with a statistically significant improvement in survival in either the overall or adenocarcinoma co-primary populations, although there was marked heterogeneity in survival outcomes between patient groups, with patients of Asian origin achieving a significant survival benefit with gefitinib compared with placebo.

OBJECTIVE

To review the benefit:risk profile of gefitinib in Asian patients with advanced NSCLC.

RESEARCH DESIGN AND METHODS

We identified and reviewed 31 reports (each with >or= 25 patients) of clinical experience with gefitinib 250 mg/day in Asia involving a total of > 2000 patients with refractory NSCLC in Japan, China, Korea and Taiwan by searching EMBASE and Medline databases for publications between 1 January 2003 and 1 July 2005.

RESULTS AND DISCUSSION

In the majority of these reports, objective response rates of > 25% and disease control rates of > 60% have been described. Treatment with gefitinib resulted in a median time to progression of > 3 months and a median survival time of > 6 months in most studies. These 31 reports also demonstrated the efficacy of gefitinib in patients with secondary brain metastases, those with poor performance status (PS) and in patients receiving the drug as first-line treatment. Female gender, adenocarcinoma histology, non-smoking history, good PS and the presence of multiple lung metastases are associated with improved responsiveness to gefitinib. Reflecting the results of previous clinical trials, the reports indicate that gefitinib is generally well tolerated by Asian patients. The incidence of interstitial lung disease appears to be higher in Japanese than non-Japanese patients, although the reasons for this are not clear. Recent findings regarding cellular and genetic factors that may underlie the increased responsiveness to gefitinib among Asian patients are discussed.