Cross-over response to erlotinib of brain metastatic disease from bronchial adenocarcinoma after gefitinib failure, and an unusual rash

Erlotinib usage after prior treatment with gefitinib in advanced non-small cell lung cancer: A clinical perspective and review of published literature

Erlotinib and gefitinib are among the most widely researched, used and available molecularly targeted therapies for treatment of advanced non-small cell lung cancer (NSCLC). They are both tyrosine kinase inhibitors (TKIs) of the epidermal growth factor receptor (EGFR). In the past decade, there have been reports on clinical benefit from use of erlotinib after gefitinib failure in NSCLC patients. A review of published literature on this focussed topic is provided herein. Pooled analysis of published literature shows that majority of patients were female (60.6%), non-smokers (64.5%), had adenocarcinoma histology (88.3%) and were of East Asian ethnicity (92.3%). Presence of sensitizing EGFR mutation was detected in 48.4% of subjects. Disease control rates with prior gefitinib therapy and with subsequent erlotinib treatment were 79.4% and 45.4% respectively. Based upon our review, the most important predictive factor for clinical benefit from erlotinib identified was previous response to gefitinib. The exact explanations for the potential benefit from erlotinib use in this patient population is still not known and further studies are required to determine the role of molecular mechanisms especially those related to resistance to initial EGFR TKI therapy.

Subsequent treatment choices for patients with acquired resistance to EGFR-TKIs in non-small cell lung cancer: restore after a drug holiday or switch to another EGFR-TKI?

The outcomes of first-generation EGFR-TKIs (Gefitnib and Erlotinib) have shown great advantages over traditional treatment strategies in patients with non-small cell lung cancer (NSCLC), but unfortunately we have to face the situation that most patients still fail to respond in the long term despite initially good control. Up to now, the mechanism of acquired resistance to EGFR-TKIs has not been fully clarified. Herein, we sought to compile the available clinical reports in the hope to better understanding the subsequent treatment choices, particularly on whether restoring after a drug holiday or switching to another EGFR-TKI is the better option after failure of one kind of EGFR-TKI.

Erlotinib as salvage treatment after failure to first-line gefitinib in non-small cell lung cancer

PURPOSE

Chemotherapy is the mainstay treatment for advanced non-small cell lung cancer (NSCLC). Gefitinib, an epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI), has been recently shown to be effective as a first-line treatment in Asian patients with advanced NSCLC, especially for those with favourable clinical features such as female, non-smoker and adenocarcinoma. However, resistance to gefitinib ensues invariably and there is little evidence as for the effectiveness of subsequent salvage treatment. The purpose of this study is to evaluate the efficacy of erlotinib, another EGFR-TKI, after failed first-line use of gefitinib.

METHOD

Retrospective review of NSCLC patients with favourable clinical features who received gefitinib as first-line treatment and subsequent salvage treatment with erlotinib.

RESULTS

A total of 21 patients with NSCLC were included in the study. Among them, 18 (85.7%) patients had disease control with gefitinib and 12 (57.1%) patients with salvage erlotinib. There was an association between the disease control with gefitinib and erlotinib (p = 0.031). The disease control rate of erlotinib was independent of the chemotherapy use between the two EGFR-TKIs.

CONCLUSION

For NSCLC patients with favourable clinical features, erlotinib was effective in those who had prior disease control with first-line gefitinib.

Pooled analysis of the reports of erlotinib after failure of gefitinib for non-small cell lung cancer

PURPOSE

The use of erlotinib after gefitinib failure in patients with non-small cell lung cancer (NSCLC) is not clearly clarified in clinical practice. We sought to compile the available clinical reports to better understand the effectiveness of erlotinib after failure of gefitinib.

METHODS

We searched published reports including erlotinib and gefitinib. Eleven reports were identified (published between November 2004 and December 2008). Advanced NSCLC who documented progressive disease (PD) for gefitinib 250 mg/day, received erlotinib 150 mg once daily.

RESULTS

A total of 106 patients were pooled from these studies. Asian was observed in 70.8%, women in 72.6%, adenocarcinoma in 85.1%, never smoker in 75.3%. In erlotinib therapy, there was observed in 9.9% in partial response (PR), 18.9% in stable disease (SD) and 70.8% in PD. Disease control (DC) rate for gefitinib and erlotinib was 71.7% and 29.2%, respectively. No significant difference of disease control rate (37.5% vs 21.7%, p=0.1503) and response rate (6.3% vs 8.7%, p=1.000) was observed between patients with EGFR mutations and those with wild type EGFR. The significantly different response on erlotinib therapy was observed in patients who had shown SD for gefitinib therapy (p=0.0095) and those who had a PFS of more than 6 months during gefitinib treatment (p=0.0261). The common toxicities were skin rash and diarrhea.

CONCLUSION

Erlotinib may produce clinical benefits in patients who had shown long SD on prior gefitinib therapy. Moreover, EGFR mutations were not positive predictors for erlotinib response after gefitinib failure.

Effects of erlotinib in EGFR mutated non-small cell lung cancers with resistance to gefitinib

PURPOSE

Most lung cancers with activating epidermal growth factor receptor (EGFR) mutations respond to gefitinib; however, resistance to this tyrosine kinase inhibitor (TKI) invariably ensues. The T790M mutation occurs in 50% and MET amplification in 20% of TKI-resistant tumors. Other secondary mutations (D761Y and L747S) are rare. Our goal was to determine the effects of erlotinib 150 mg/d in EGFR mutated patients resistant to gefitinib 250 mg/d, because the EGFR TKI erlotinib is given at a higher biologically active dose than gefitinib.

EXPERIMENTAL DESIGN

Retrospective review of 18 EGFR mutated (exon 19 deletions, L858R, and L861Q) patients that were given gefitinib and subsequently erlotinib. Seven patients had tumor resampling after TKI therapy and were analyzed for secondary EGFR mutations and MET amplification.

RESULTS

Most patients (14 of 18) responded to gefitinib with median progression-free survival of 11 months (95% confidence interval, 4-16). After gefitinib resistance (de novo or acquired), 78% (14 of 18) of these patients displayed progressive disease while on erlotinib with progression-free survival of 2 months (95% confidence interval, 2-3). Six of 7 resampled patients acquired the T790M mutation, and 0 of 3 had MET amplification. Only 1 gefitinib-resistant patient with the acquired L858R-L747S EGFR, which in vitro is sensitive to achievable serum concentrations of erlotinib 150 mg/d, achieved a partial response to erlotinib.

CONCLUSIONS

In EGFR mutated tumors resistant to gefitinib 250 mg/d, a switch to erlotinib 150 mg/d does not lead to responses in most patients. These findings are consistent with preclinical models, because the common mechanisms of TKI resistance (T790M and MET amplification) in vitro are not inhibited by clinically achievable doses of gefitinib or erlotinib. Alternative strategies to overcome TKI resistance must be evaluated.

Erlotinib after failure of gefitinib in patients with advanced non-small cell lung cancer previously responding to gefitinib

BACKGROUND

Gefitinib and erlotinib are two orally active epidermal growth factor receptor tyrosine kinase inhibitors used in the treatment of advanced non-small cell lung cancer (NSCLC). Gefitinib was the first one to become available in Europe in an expanded access program. When erlotinib granted approval, there were many patients who had progressed after receiving gefitinib and different lines of chemotherapy with no further treatment options; moreover, the results of clinical trials suggested possible significant differences in the mechanisms of sensitivity and in the efficacy between these two agents.

METHODS

Advanced NSCLC White patients, previously treated with almost two lines of chemotherapy and with gefitinib, obtaining a partial response or a stable disease with this agent, were treated with erlotinib after progression of disease to gefitinib. Only eight patients resulted eligible because of the unavailability of gefitinib after the closure of the expanded access program.

RESULTS

Four patients were women; histologic diagnosis was adenocarcinoma in four cases and bronchoalveolar carcinoma or unspecified NSCLC in two cases each. Median age was 70 years (range, 53-85). Seven out of eight patients had never smoked, one was a former smoker.We obtained two partial responses and three stable diseases with erlotinib with a median duration of response of 8 months. The median time to progression and overall survival were 5.9 and 14.6 months, respectively.

CONCLUSION

Erlotinib seems to be a potential therapeutic option for treatment of selected advanced NSCLC patients after failure of gefitinib. Further studies are warranted to evaluate the molecular mechanisms behind this evidence and clarify how to select patients for treatment with epidermal growth factor receptor tyrosine kinase inhibitors.

Erlotinib response of EGFR-mutant gefitinib-resistant non-small-cell lung cancer

PURPOSE

Failure to gefitinib is generally believed to be associated with cross-resistance to other epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKI). Here we report a case whose active EGFR-mutant NSCLC responded to erlotinib treatment.

PATIENT AND METHODS

Lung specimen was obtained during diagnostic procedures from a 41-year-old Taiwanese male smoker with adenocarcinoma. He received cisplatin-based chemotherapy following craniotomy to remove his brain metastasis. Tumor progressed in both lung and left adrenal gland. He underwent second-line docetaxel chemotherapy. Tumor progressed again 7 months later. He was subsequently treated with gefitinib 250mg QD. Complete regression of the lung tumor and partial response of the left adrenal gland mass was achieved. Nine months later, the left lower lobe lung tumor and left adrenal gland tumor progressed. A lung biopsy from the left lower lobe disclosed an adenocarcinoma which harbored an in-frame deletion in exon 19 (heterozygous delE746-A750) of EGFR without a second mutation such as T790M in exon 20. Subsequent erlotinib 150mg QD was administered. He experienced grade 1 skin rash, diarrhea and paronychia following erlotinib.

RESULTS

This patient achieved a partial response to erlotinib treatment. He remained on erlotinib for a total of 18 months until the left adrenal gland tumor progressed.

CONCLUSIONS

This case demonstrated that NSCLC bearing in-frame deletion in exon 19 of EGFR may respond to erlotinib treatment following gefitinib failure.