Gefitinib is one of the small molecule inhibitors of epidermal growth factor receptor tyrosine kinase (EGFR TKIs). Clinical trials have demonstrated it is effective for treatment of a subset of patients with advanced non-small cell lung cancer (NSCLC). Gefitinib has been generally considered to be a relatively safe agent. Besides a small proportion of fatal interstitial pneumonia, the common adverse drug reactions of gefitinib include diarrhea and skin rash, which are generally mild and reversible. Herein, we report the first two cases of brain metastasis hemorrhage that might be involved with the use of gefitinib.
Two patients with brain metastasis from NSCLC developed brain hemorrhage after gefitinib therapy. The hemorrhage in one case occurred one month after gefitinib combined with whole brain radiation therapy (WBRT), and in the another case hemorrhage developed slowly within brain metastases eight months post gefitinib monotherapy for diffuse pulmonary metastasis from a lung cancer undergone surgical removal previously.
We speculate brain hemorrhage could be one of the adverse drug reactions of gefitinib treatment for NSCLC and suggest clinicians be aware of this possible rare entity. More data are needed to confirm our findings, especially when gefitinib is used in the settings of brain metastases from NSCLC or other origins.
Patients with advanced or metastatic non-small cell lung cancer (NSCLC) can develop acquired resistance to epidermal growth factor receptor tyrosine kinase inhibitors (TKIs) erlotinib and gefitinib. Here, we report the successful treatment with alternating chemotherapy and TKIs of two cases of advanced NSCLC who developed resistance to TKI.
Two patients with advanced or metastatic NSCLC were treated with palliative chemotherapy followed by erlotinib/gefitinib. When TKI therapy failed, two cycles of chemotherapy were provided, which were followed by re-challenge with erlotinib or gefitinib.
NSCLC patients with acquired TKI resistance should be managed aggressively whenever possible. Subsequent chemotherapy and target treatment is one of the reasonable choices for those with an initial dramatic clinical response with erlotinib/gefitinib treatment. Further studies are warranted to substantiate the association of erlotinib /gefitinib treatment with the efficacy of NSCLC patients with acquired TKI failure.
Gefitinib has come to be the most widely used epidermal growth factor receptor-tyrosine kinase inhibitor in the treatment of advanced non-small cell lung cancer (NSCLC) in Asian patients. Common side effects include mild to moderate skin rash and diarrhea, however, drug-induced liver injury of varying severity is overlooked in long-term gefitinib administration and rarely reported. The current case report presents a female Chinese NSCLC patient who developed severe gefitinib-induced hepatotoxicity and was rechallenged with gefitinib following a 3-month break. The patient achieved partial clinical remission but developed drug-induced grade 4 hepatotoxicity following gefitinib administration for 14 months. As an alternative, 4 cycles of chemotherapy were administered to control tumor progression. Following restoration of the patient’s liver function, gefitinib was rechallenged together with active hepatoprotective therapy. The patient presented good disease control and maintained normal liver function for >6 months. Thus, sequential chemotherapy and gefitinib rechallenge with hepatoprotective therapy may be a potential new treatment strategy for gefitinib-induced hepatotoxicity.
hepatotoxicity; epidermal growth factor; tyrosine kinase inhibitor; adverse drug reactions
Gefitinib, an oral agent of epidermal growth factor receptor tyrosine kinase inhibitor, has a certain efficacy against non-small cell lung cancer (NSCLC). Several predictive factors of gefitinib sensitivity have been well described. However, few studies have investigated the clinical features of gefitinib-responders. In the present study, we analyzed the response and disease progression of primary and metastatic lesions to gefitinib in responders and the results of gefitinib readministration following temporary cessation of gefitinib upon progression of initial gefitinib treatment and other treatments.
We retrospectively evaluated the clinical courses of 27 NSCLC patients who received gefitinib and achieved either a complete or partial response.
The best-response rate and disease-control rate against the initial chemotherapy for the gefitinib-responders were 27.3% and 77.3%, respectively. Favorable efficacy was observed in the primary lesion and metastases to the lung, liver and brain, while there was no obvious effect on bone metastasis. The primary lesion and intrapulmonary metastasis were the sites of major recurrence. Median progression-free survival was 13.8 months, median duration of gefitinib treatment was 17.0 months and median overall survival was 29.2 months. Some of the patients who experienced disease progression after responding to gefitinib were again sensitive to readministration of gefitinib following temporary cessation of gefitinib and other treatments.
Patients may still be expected to have prolonged survival if they once responded to gefitinib and then underwent various subsequent treatments followed by readministration of gefitinib. These findings might provide valuable information for the management of gefitinib-responders.
Phase III trials evaluating the efficacy of gefitinib (IRESSA) in non-small cell lung cancer (NSCLC) lend support to the need for improved patient selection in terms of gefitinib use. Mutation of the epidermal growth factor receptor (EGFR) gene is reported to be associated with clinical responsiveness to gefitinib. However, gefitinib-sensitive and prolonged stable-disease-defined tumors without EGFR gene mutation have also been reported.
To identify other key factors involved in gefitinib sensitivity, we analyzed the protein expression of molecules within the EGFR family, PI3K-Akt and Ras/MEK/Erk pathways and examined the sensitivity to gefitinib using the MTT cell proliferation assay in 23 lung cancer cell lines.
We identified one highly sensitive cell line (PC9), eight cell lines displaying intermediate-sensitivity, and 14 resistant cell lines. Only PC9 and PC14 (intermediate-sensitivity) displayed an EGFR gene mutation including amplification. Eight out of the nine cell lines showing sensitivity had Akt phosphorylation without ligand stimulation, while only three out of the 14 resistant lines displayed this characteristic (P = 0.0059). Furthermore, the ratio of phosphor-Akt/total Akt in sensitive cells was higher than that observed in resistant cells (P = 0.0016). Akt phosphorylation was partially inhibited by gefitinib in all sensitive cell lines.
These results suggest that Akt phosphorylation without ligand stimulation may play a key signaling role in gefitinib sensitivity, especially intermediate-sensitivity. In addition, expression analyses of the EGFR family, EGFR gene mutation, and FISH (fluorescence in situ hybridization) analyses showed that the phosphorylated state of EGFR and Akt might be a useful clinical marker of Akt activation without ligand stimulation, in addition to EGFR gene mutation and amplification, particularly in adenocarcinomas.
Gefitinib was the first epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) approved for the treatment of advanced non-small cell lung cancer (NSCLC). Few treatment options are available for NSCLC patients who have responded to gefitinib treatment and demonstrated tumor progression. The present study was conducted to evaluate the efficacy and toxicity of the 2nd EGFR-TKI administration.
We retrospectively analyzed 11 patients who had obtained a partial response (PR) or stable disease (SD) with gefitinib treatment and were re-treated with EGFR-TKI after failure of the initial gefitinib treatment.
Three patients (27%) were treated with gefitinib as the 2nd EGFR-TKI, and 8 patients (73%) received erlotinib. Only one patient (9%) showed PR, 7 (64%) achieved SD, and 3 (27%) had progressive disease. The disease control rate was 73% (95% CI, 43% - 91%) and the median progression-free survival was 3.4 months (95% CI, 2 - 5.2). The median overall survival from the beginning of the 2nd EGFR-TKI and from diagnosis were 7.3 months (95% CI, 2.7 - 13) and 36.7 months (95% CI, 23.6 - 43.9), respectively. No statistical differences in PFS or OS were observed between gefitinib and erlotinib as the 2nd EGFR-TKI (PFS, P = 0.23 and OS, P = 0.052). The toxicities associated with the 2nd EGFR-TKI were generally acceptable and comparable to those observed for the initial gefitinib therapy.
Our results indicate that a 2nd EGFR-TKI treatment can be an effective treatment option for gefitinib responders.
Gefitinib (IRESSA), an epidermal growth factor receptor (EGFR) tyrosine kinase (TK) inhibitor, has antitumour activity in the advanced non-small-cell lung cancer (NSCLC) setting. However, in chemotherapy-naïve patients with advanced NSCLC, the addition of gefitinib to standard chemotherapy regimens failed to increase survival. These results suggest the need for improved patient selection and combination rationales for targeted therapies. We have identified subpopulations of an adenocarcinoma cell line that are naturally resistant to gefitinib, and have analysed the cDNA expression profiles, genomic status of EGFR gene and the effect of gefitinib on signalling pathways in these cell lines in order to identify key mechanisms for naturally acquired resistance to gefitinib. Gefitinib-resistant subpopulations demonstrated increased Akt phosphorylation (not inhibited by gefitinib), reduced PTEN protein expression and loss of the EGFR gene mutation when compared with parental cell lines. These differences in Akt and PTEN protein expression were not evident from the cDNA array profiles. These data suggests that (1) the EGFR gene mutation may be possibly lost in some cancer cells with other additional mechanisms for activating Akt, (2) reintroduction of PTEN or pharmacological downregulation of the constitutive PI3K–Akt-pathway activity may be an attractive therapeutic strategy in cancers with gefitinib resistance.
gefitinib; PTEN; Akt; epidermal growth factor receptor(EGFR) gene; mutation; natural resistance
Gefitinib is a tyrosine kinase inhibitor (TKI) of the epidermal growth factor receptor (EGFR) especially effective in tumors with activating EGFR gene mutations while EGFR wild-type non small cell lung cancer (NSCLC) patients at present do not benefit from this treatment.
The primary site of gefitinib metabolism is the liver, nevertheless tumor cell metabolism can significantly affect treatment effectiveness.
In this study, we investigated the intracellular metabolism of gefitinib in a panel of EGFR wild-type gefitinib-sensitive and -resistant NSCLC cell lines, assessing the role of cytochrome P450 1A1 (CYP1A1) inhibition on gefitinib efficacy. Our results indicate that there is a significant difference in drug metabolism between gefitinib-sensitive and -resistant cell lines. Unexpectedly, only sensitive cells metabolized gefitinib, producing metabolites which were detected both inside and outside the cells. As a consequence of gefitinib metabolism, the intracellular level of gefitinib was markedly reduced after 12-24 h of treatment. Consistent with this observation, RT-PCR analysis and EROD assay showed that mRNA and activity of CYP1A1 were present at significant levels and were induced by gefitinib only in sensitive cells. Gefitinib metabolism was elevated in crowded cells, stimulated by exposure to cigarette smoke extract and prevented by hypoxic condition. It is worth noting that the metabolism of gefitinib in the sensitive cells is a consequence and not the cause of drug responsiveness, indeed treatment with a CYP1A1 inhibitor increased the efficacy of the drug because it prevented the fall in intracellular gefitinib level and significantly enhanced the inhibition of EGFR autophosphorylation, MAPK and PI3K/AKT/mTOR signalling pathways and cell proliferation.
Our findings suggest that gefitinib metabolism in lung cancer cells, elicited by CYP1A1 activity, might represent an early assessment of gefitinib responsiveness in NSCLC cells lacking activating mutations. On the other hand, in metabolizing cells, the inhibition of CYP1A1 might lead to increased local exposure to the active drug and thus increase gefitinib potency.
Lung cancer; EGFR; gefitinib; metabolism; CYP1A1
Currently, no effective treatments exist for non-small cell lung cancer (NSCLC) after failure of gefitinib therapy. Pre-clinical studies have demonstrated that gefitinib-resistant NSCLC cells are more sensitive to irinotecan than parental cells, and that combined administration of irinotecan and gefitinib has a synergistic additive effect. We conducted a phase I study to evaluate the combination of irinotecan and gefitinib as a therapeutic option for NSCLC patients with progressive disease (PD) after initial gefitinib treatment.
Eligibility criteria included histologically confirmed NSCLC, age range of 20–74 years, refractory to or relapsed after gefitinib treatment, one or more previous chemotherapy regimens, Eastern Cooperative Oncology Group performance status 0–2, adequate organ function, and informed consent. Patients were treated with irinotecan on days 1 and 15, and treated daily with gefitinib from day 2 every 4 weeks. The treatment was continued until disease progression. The gefitinib dose was fixed at 250 mg. Irinotecan dosing started at 50 mg m−2 and was escalated in patients by 25 mg m−2 increments up to a maximum dose of 150 mg m−2.
Twenty-seven patients were enrolled: male/female=14/13; median age=60 (45–75); histology, adenocarcinoma/non-adenocarcinoma=25/2; performance status 0–1/2=19/8; previous response to gefitinib, partial response/stable disease/PD=21/2/4. Dose-limiting toxicities were observed in 2 patients at level 3. Maximum tolerated dose was not determined, and the full dose of irinotecan could be combined with the full dose of gefitinib. The disease control rate (DCR) and response rate (RR) were 69.2 and 26.9%, respectively. For 12 patients at level 5 (the recommended phase II dose), the DCR and RR were 75.0% and 41.7%, respectively. The median treatment cycles were 4; median time to treatment failure, 57 days (95% confidence interval (CI), 32–82 days); median overall survival, 244 days (95% CI, 185–303 days); and 1-year survival rate, 32.6%.
The combination of irinotecan and gefitinib was well tolerated and potentially beneficial for NSCLC patients failing initial gefitinib monotherapy.
gefitinib; resistance; irinotecan; non-small cell lung cancer
Lung cancer is the leading cause of cancer-related deaths worldwide. Non-small-cell lung cancer (NSCLC) cases comprise approximately 85% of the lung cancer cases. Before the era of target therapy, platinum-based doublet chemotherapy only led to a median survival of 8–9 months and a one-year survival of 30%–40% in patients with advanced NSCLC. In July 2002, gefitinib, a small-molecule epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI), was approved for the treatment of patients with advanced NSCLC in Japan. After the widespread use of gefitinib in the treatment of NSCLC, there have been many new studies regarding the association between the clinical anticancer efficacy of gefitinib and the somatic EGFR mutation status in patients with NSCLC. This article summarizes the role of EGFR mutations in lung cancer and the use of EGFR antagonists in the treatment of lung cancer and its associated adverse effects.
epidermal growth factor receptor; tyrosine kinase inhibitors; gefitinib; erlotinib
Gefitinib, an inhibitor of the epidermal growth factor receptor (EGFR, HER1/ErbB1) tyrosine kinase, has been shown to have clinical activity against non-small-cell lung cancers (NSCLCs), especially in women nonsmokers with adenocarcinomas. The aim of the present study was to clarify the relationship between androgen levels and gefitinib treatment in patients with advanced NSCLCs. Sera from 67 cases (36 men and 31 women) were obtained pretreatment and during treatment with gefitinib monotherapy (days 14–18) for examination of testosterone, dehydroepiandrosterone sulphate (DHEA), and dehydroepiandrosterone sulphate (DHEAS) levels. Testosterone and DHEA during treatment were significantly lower than the pretreatment values in both women and men, and the DHEAS levels during treatment were also significantly lowered in women. Gefitinib treatment significantly suppressed androgen levels, especially in women who had no smoking history. In addition, hormone levels in women responding to gefitinib were significantly lower during the treatment than in women who did not respond. Gefitinib-associated decrease in serum androgen levels may play a role in its clinical efficacy.
sex hormone; epidermal growth factor receptor; tyrosine kinase inhibitor
Lung cancer is a malignant carcinoma which has the highest morbidity and mortality in Chinese population. Gefitinib, a tyrosine kinase (TK) inhibitor of epidermal growth factor receptor (EGFR), displays anti-tumor activity. The present data regarding first-line treatment with single agent gefitinib against non-small-cell lung cancer (NSCLC) in Chinese population are not sufficient.
To assess the efficacy and toxicity of gefitinib in Chinese patients with advanced non-small-cell lung cancer (NSCLC), a study of single agent treatment with gefitinib in Chinese patients was conducted.
45 patients with advanced NSCLC were treated with gefitinib (250 mg daily) until the disease progression or intolerable toxicity.
Among the 45 patients, 15 patients achieved partial response (PR), 17 patients experienced stable disease (SD), and 13 patients developed progression disease (PD). None of the patients achieved complete response (CR). The tumor response rate and disease control rate was 33% and 71.1%, respectively. Symptom remission rate was 72.5%, and median remission time was 8 days. Median overall survival and median progression-free survival was 15.3 months and 6.0 months, respectively. The main induced toxicities by gefitinib were skin rash and diarrhea (53.3% and 33.3%, respectively). The minor induced toxicities included dehydration and pruritus of skin (26.7% and 22.2%, respectively). In addition, hepatic toxicity and oral ulceration occurred in few patients (6.7% and 4.4%2, respectively).
Single agent treatment with gefitinib is effective and well tolerated in Chinese patients with advanced NSCLC.
Gefitinib—a specific inhibitor of epidermal growth factor receptor (EGFR)-associated tyrosine kinase—has demonstrated efficacy in a subgroup of patients with non-small-cell lung carcinoma (NSCLC) who fail conventional chemotherapy. It is also reported to have an antitumor effect in brain metastases from NSCLC. Additionally, EGFR mutations have shown a strong association with gefitinib sensitivity for NSCLC. Here, we assessed the efficacy of gefitinib in brain metastases from NSCLC and evaluated the association of this efficacy with EGFR mutations. We retrospectively reviewed eight cases in which patients were suffering from brain metastases before the initiation of gefitinib treatment. Brain tumor response could be evaluated by MRI in these patients; EGFR gene analyses were also available. We evaluated whether objective tumor response was observed after gefitinib treatment and assessed the efficacy of gefitinib as effective, noneffective, or not assessable in consideration of the influence of previous radiotherapy. Of the eight patients, the efficacy of gefitinib was assessed as effective in three and as noneffective in three. All three patients demonstrating effective efficacy had EGFR mutations in the tyrosine kinase domain (deletion mutation in two patients and point mutation in one patients), whereas none of the three patients demonstrating noneffective efficacy had EGFR mutations. Gefitinib appears to be effective in treating brain metastases in a subgroup of patients. Our data suggested a possible association between the efficacy of gefitinib in the treatment of brain metastases and EGFR mutations.
brain metastases; EGFR; gefitinib; mutation
Gefitinib is a new molecular-targeted agent for the treatment of patients with advanced non-small cell lung cancer that fail to respond to conventional chemotherapy. Gefitinib is considered to be well tolerated and less toxic compared with conventional cytotoxic drugs. However, interstitial lung disease (ILD) has been reported as a serious adverse effect. The precise management of a gefitinib responder having severe adverse events remains unknown.
We report the case of gefitinib readministration in a patient with lung adenocarcinoma who had once responded but in whom treatment had to be discontinued owing to gefinitib-related ILD. A dramatic response was achieved both at the time of initial treatment (250 mg/day) and at readministration of gefitinib (125 mg/day). The effectiveness of gefitinib therapy in our patient could be explained in part by the presence of an activating mutation of epidermal growth factor receptor (EGFR) gene, L858R in exon 21, which was identified in the primary tumor.
A reduced dose of gefitinib might be sufficient for patients having tumors with EGFR gene mutations, and that the currently approved dose may be excessively potent in some of these patients, thus resulting in the onset of adverse events.
The treatment of carcinomatous meningitis in patients with non-small cell lung cancer is unsatisfactory with a median survival ranging from 4 to 6 weeks without treatment. This report presents a rare case of a long-term survivor with carcinomatous meningitis which was revealed during gefitinib therapy, and was treated with erlotinib. A 55-year-old female never-smoker was diagnosed with adenocarcinoma of the lung and underwent a right upper lobectomy. Four years had passed since surgery, she started gefitinib therapy for recurrent lung cancer. During gefitinib therapy, she presented with headache and was diagnosed with caricinomatous meningitis. After changing her treatment to erlotinib, her symptoms temporarily improved and she remained alive for 10 months. Erlotinib therapy may represent a candidate treatment option for carcinomatous meningitis after gefitinib therapy.
Gefitinib, an epidermal growth factor receptor-tyrosine kinase inhibitor, represents a new treatment option for patients with advanced non-small-cell lung cancer (NSCLC). We analyzed the data of patients who received Gefitinib for NSCLC in a tertiary care center in South India.
Materials and Methods:
Sixty-three patients with advanced NSCLC who had received Gefitinib either after failure of conventional chemotherapy or were previously not treated as they were unfit or unwilling for conventional treatment were included in the analysis.
The median follow-up for the cohort was 311 days (range 11-1544 days). Median time to progression was 161 (range 9-883) days. Complete and partial remission was seen in 1 (2%) and 6 (9%) patients, respectively, with overall response rate of 11%. Twenty-four (38%) patients had stable disease. Gefitinib was well tolerated with no significant side effects.
Gefitinib shows anti-tumor activity in pretreated or previously untreated patients with advanced NSCLC. It has a favorable toxicity profile and is well tolerated. Gefitinib should be considered as a viable therapy in patients with NSCLC.
Epidermal growth factor-tyrosine kinase inhibitor; Gefitinib; Non-small-cell lung cancer
Most patients with non-small-cell lung cancer (NSCLC) present with advanced disease and their long-term prognosis remains poor. Epidermal growth factor receptor (EGFR)-targeted therapies, such as gefitinib, have been subjected to comprehensive clinical development. Several phase II and III trials evaluated the clinical efficacy of gefitinib as monotherapy in pretreated patients with advanced NSCLC, as well as both monotherapy and combined with chemotherapy in chemotherapy-naive patients. A phase III trial (ISEL) in heavily pretreated advanced NSCLC patients demonstrated some improvement in survival with gefitinib compared with placebo; however, the difference was not statistically significant within the overall population. A large phase III trial in pretreated patients (INTEREST) demonstrated the non-inferiority of gefitinib in comparison with docetaxel for overall survival, together with an improved quality of life and tolerability profiles. In a large phase III trial (IPASS) in Asian chemotherapy-naive, never or former light-smoker patients with adenocarcinoma, gefitinib was more effective than carboplatin–paclitaxel in prolonging progression-free survival, particularly in patients harboring EGFR gene mutations. Gefitinib was a generally well tolerated treatment, with skin rash and diarrhea being the most common treatment adverse events. As a result, gefitinib is expected to have a large impact on the management of patients with advanced NSCLC, in particular in EGFR mutated patients.
non-small-cell lung cancer; gefitinib; EGFR
Gefitinib was introduced in 2002 for treatment of non-small cell lung cancer (NSCLC); however, it is not clear whether its use in daily practice has changed the outcome of patients. The purpose of this study is to evaluate the question of how molecular understanding regarding gefitinib and epidermal growth factor receptor (EGFR) mutation affect the prescribing patterns and clinical outcomes of treatment with gefitinib in NSCLC, in a real practical field.
Materials and Methods
We conducted a retrospective analysis of the consecutive database of NSCLC patients who were treated with gefitinib at Seoul National University Hospital between January 2002 and December 2011. Prescribing patterns and clinical outcomes were analyzed by year.
A total of 1,115 NSCLC patients, who received gefitinib at recurred or metastatic setting, were included in this study. Proportion of patients receiving gefitinib, for the first line, showed a gradual increase, from 5.2% in 2002-2003 to 30.6% in 2010-2011. Proportion of patients who underwent EGFR mutation testing showed a rapid increase, from 0.6% in 2004-2005 to 73.5% in 2010-2011. The response rate also showed a gradual increase, from 17.2% in 2002-2003 to 57.1% in 2010-2011 (p<0.001). The median progression-free survival of gefitinib was increased with statistical significance from 2.8 months in 2002-2003 to 9.1 months in 2010-2011 (p<0.001).
We demonstrated that molecular understanding and practical use of EGFR mutation testing have resulted in a change in the prescription patterns of gefitinib. Use of an enrichment strategy can lead to improvement in the efficacy of gefitinib in real practice.
Gefitinib; EGFR mutation; Trend; Lung neoplasms
Few treatment options are available for advanced non-small cell lung cancer (NSCLC) patients who have failed of gefitinib or erlotinib treatment in second/third-line treatment. The aim of this study was to investigate the efficacy of re-administration of the same TKI after failure of gefitinib or erlotinib.
Patients and methods
The clinical data of 33 patients with advanced NSCLC were retrospectively analyzed. All of the patients were given the same TKI treatment after the failure of gefitinib or erlotinib. Survival analysis was evaluated by Kaplan-Meier method.
Twenty patients (60.6%) were re-administration with gefitinib as the 2nd EGFR-TKI, and thirteen patients (39.4%) received erlotinib. One patient (3.0%) showed partial response (PR), 14 (42.4%) achieved stable disease (SD), and 18 (54.5%) had progressive disease (PD). The disease control rate was 45.5% and the median progression-free survival was 1.5 months (95% CI: 0.6-2.3 months). The PFS in patients who got disease control in the prior TKI was 2.2 and 1.2 months in the progression disease cases (P=0.29), the DCR was 54.5% and 27.3% in two group, respectively (P=0.26).
Re-administration of TKI seems to be a potential therapeutic option for treatment of selected advanced NSCLC patients after failure of geﬁtinib or erlotinib, especially for the patients with NSCLC who once responded from the prior TKI treatment.
Non-small cell lung cancer (NSCLC); erlotinib; gefitinib; retreatment; efficacy
Lung cancer has a high mortality rate and is often diagnosed at the metastatic stage. Recently, gefitinib, a molecule target therapeutic drug, has offered a new approach for patients with non-small-cell lung cancer (NSCLC). This report describes the effects of gefitinib on bone metastases in two patients with NSCLC. The pain induced by a bone metastasis was relieved after the administration of gefitinib. Furthermore, the radiographs and CT findings showed sclerotic changes that matched those of the metastatic bone tumor after gefitinib administration in both patients. It is believed that gefitinib inhibited tumor cell proliferation and induced normal bone formation. In patients with NSCLC, gefitinib may be effective in the treatment of bone metastases.
Gefitinib; Bone metastases; Lung cancer
Gefitinib, a small molecule tyrosine kinase inhibitor, showed a substantial effect as a salvage treatment for patients with advanced non-small cell lung cancer (NSCLC) who had failed prior chemotherapy. Subsequent phase III trials in previously untreated patients have failed to demonstrate such benefit. It was later reported that gefitinib had a positive outcome when used in selected population.
The inconsistent results and the lack published meta-analysis that systematically examined the overall efficacy of gefitinib in the frontline setting in such patients, have prompted the current meta-analysis.
We selected for analysis only those randomized, peer-reviewed clinical studies where the efficacy of gefitinib-based therapy (GBT) was investigated in chemotherapy naïve patients with locally advanced or metastatic NSCLC. We also included studies where patients were randomized between gefitinib vs. placebo or none after initial chemoradiation or chemotherapy induction offered to all included patients.
We identified seven eligible studies involving 2,646 and 1,939 patients randomized to GBT and to control arms, respectively. In mostly unselected population, GBT was not associated with higher objective response rate (ORR), progression-free survival (PFS) (hazard ratio [HR] = 0.97, 95% CI: 0.78–1.20, P = 0.78), or overall survival (OS) (HR = 1.04, 95% CI: 0.95–1.13, P = 0.45) as compared with control interventions. In a fraction of patients with known EGFR mutation status, GBT showed significantly higher ORR among patients with mutant EGFR (odds ratio [OR] = 2.81, 95% CI: 1.71–4.62, P < 0.0001); however, EGFR mutation was not associated with better PFS or OS with GBT. Nevertheless, patients receiving GBT experienced significant improvement in quality of life as compared with those in the control arms.
We conclude that GBT cannot be recommended for frontline management of patients with advanced NSCLC in unselected patient population.
EGFR; gefitinib; non-small cell lung cancer
Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) such as gefitinib and erlotinib are promising therapies for patients with advanced non-small-cell lung cancer (NSCLC). Patients with somatic activating mutations in the EGFR gene have dramatic response initially, but would eventually develop resistance to these TKIs. Subsequent studies found that a secondary mutation in the EGFR gene (T790M mutation) and amplification of the MET proto-oncogene could be the main resistance mechanisms involved. The current review is focused on T790M, which is thought to cause steric hindrance and impair the binding of gefitinib/erlotinib. The T790M is present as a minor allele before TKI therapy and accounts for about half of the acquired resistant cases. Conflicting results were reported for gefitinib-resistant, T790M-acquired patients who had switched to erlotinib treatment, which was proposed to be efficacious. The switch therapy was presumed to work for EGFR wild type patients and previously gefitinib responding patients. MET amplification accounts for about 20% of TKI acquired-resistant patients by a different molecular pathway from T790M; some of these patients will also concurrently have T790M mutation and might still not respond to irreversible TKI. As for the detection of T790M, polymerase chain reaction (PCR), especially mutant-enriched PCR was found to be more sensitive than direct DNA sequencing. In addition, whole genome amplification might also be useful and can be incorporated with future noninvasive method for detecting T790M. A better understanding of the mechanisms leading to TKI resistance is crucial in the development of effective treatment and the design of future clinical studies.
T790M; lung cancer; acquired resistance; TKI
A 73-year-old Japanese man was histologically diagnosed with lung adenocarcinoma harboring an exon 19 deletion in the epidermal growth factor receptor. The patient was treated with gefitinib for 6 weeks until he developed substantially elevated hepatic enzyme levels that resulted in the discontinuation of gefitinib. Gefitinib was reintroduced with an intermittent treatment schedule after the transaminase levels normalized, but the patient's enzyme levels rose again, and the cancer progressed. Gefitinib was eventually replaced with erlotinib. There was stable disease for 7 weeks without any signs of liver toxicity. Thus, erlotinib may be a beneficial and well-tolerated treatment option for patients with gefitinib-related hepatotoxicity.
Gefitinib (Iressa) is an inhibitor of the epidermal growth factor receptor (EGFR) that has shown promising activity in the treatment of patients with non-small cell lung cancer (NSCLC). However, adverse side effects of gefitinib treatment, such as respiratory dysfunction, have limited the therapeutic benefit of this targeting strategy. The present results show that this adverse effect can be attributed to the inhibition of the novel gefitinib target GAK (Cyclin G-associated kinase), which is as potently inhibited by the drug as the tyrosine kinase activity of EGFR. Knockout mice expressing the kinase-dead form of GAK (GAK-kd) died within 30 min after birth primarily due to respiratory dysfunction. Immunohistochemical analysis revealed that surfactant protein A (SP-A) was abundant within alveolar spaces in GAK-kd+/+ mice but not in GAK-kd-/- pups. E-cadherin and phosphorylated EGFR signals were also abnormal, suggesting the presence of flat alveolar cells with thin junctions. These results suggest that inhibition of GAK by gefitinib may cause pulmonary alveolar dysfunction, and the present study may help prevent side effects associated with gefitinib therapy in NSCLC patients.
The exact influence of statins on gefitinib resistance in human non-small cell lung cancer (NSCLC) cells with KRAS mutation alone or KRAS/PIK3CA and KRAS/PTEN comutations remains unclear. This work found that transfection of mutant KRAS plasmids significantly suppressed the gefitinib cytotoxicity in Calu3 cells (wild-type KRAS). Gefitinib disrupted the Kras/PI3K and Kras/Raf complexes in Calu3 cells, whereas not in Calu3 KRAS mutant cells. These trends were corresponding to the expression of pAKT and pERK in gefitinib treatment. Atorvastatin (1 μM) plus gefitinib treatment inhibited proliferation, promoted cell apoptosis, and reduced the AKT activity in KRAS mutant NSCLC cells compared with gefitinib alone. Atorvastatin (5 μM) further enhanced the gefitinib cytotoxicity through concomitant inhibition of AKT and ERK activity. Atorvastatin could interrupt Kras/PI3K and Kras/Raf complexes, leading to suppression of AKT and ERK activity. Similar results were also obtained in comutant KRAS/PTEN or KRAS/PIK3CA NSCLC cells. Furthermore, mevalonate administration reversed the effects of atorvastatin on the Kras/Raf and Kras/PI3K complexes, as well as AKT and ERK activity in both A549 and Calu1 cells. The in vivo results were similar to those obtained in vitro. Therefore, mutant KRAS-mediated gefitinib insensitivity is mainly derived from failure to disrupt the Kras/Raf and Kras/PI3K complexes in KRAS mutant NSCLC cells. Atorvastatin overcomes gefitinib resistance in KRAS mutant NSCLC cells irrespective of PIK3CA and PTEN statuses through inhibition of HMG-CoA reductase-dependent disruption of the Kras/Raf and Kras/PI3K complexes.
gefitinib; atorvastatin; mutant KRAS; NSCLC