Generations of Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors: Perils and Progress

OPINION STATEMENT

Epidermal growth factor receptor (EGFR) mutations have been detected in approximately 10 % of North American patients diagnosed with non-small cell lung cancer (NSCLC). Approximately 90 % of these mutations are exon 19 deletions or exon 21 L858R point mutations. First- and second-generation EGFR tyrosine kinase inhibitors (TKIs) are approved as first-line therapy based on clinical trials demonstrating superior response rates, progression free survival (PFS), and overall survival (OS) compared to chemotherapy in patients with EGFR mutation-positive NSCLC treated with an EGFR TKI prior to chemotherapy. However, the majority of patients treated with an EGFR TKI develop resistance to therapy within about 12 months, approximately 50 % of patients due to a second site mutation, the T790M mutation occurring within exon 20. At the time of progression, the EGFR TKI is most commonly discontinued and a different systemic therapy is initiated. However, oncogene addiction persists and recent exciting data with third-generation EGFR TKIs suggests that acquired resistance may be surmountable. The newest EGFR TKIs have shown activity against EGFR-mutant NSCLC after progression on first-generation TKIs, including those with T90M, while sparing wild-type EGFR and hence appear to be both well tolerated and efficacious. At this time, it appears that third-generation EGFR TKIs are effective following first-generation therapy, and determining the most appropriate sequence to maximize overall survival is a matter of ongoing investigation. As the arsenal of active agents in EGFR mutant NSCLC grows, future research into potential combinations, optimal timing, and resistance mechanisms of these new treatments, as well as their possible role in the adjuvant, post-chemoradiation, and neoadjuvant settings holds great promise for this group of patients.

An economic model to value companion diagnostics in non-small-cell lung cancer

Aim: An economic model was used to evaluate the potential economic impact and cost–effectiveness of companion diagnostic testing for patients with non-small-cell lung cancer (NSCLC). Materials & methods: A decision analysis model examined alternative patient management strategies for patients with advanced NSCLC who were not amenable to surgical treatment. A review of the literature provided the variables used to develop a timely base case and sensitivity analysis. A potential future scenario was also modeled. The model includes three options: conventional treatment (CT), new treatment (NT) and companion diagnostic (CD) strategy. Results: In the base case analysis based upon current data, the cost per life-year saved for CT, NT option and CD was US$43,367, US$47,394 and US$47,779, respectively. The cost per life-year saved for CT, NT option and CD in a potential future scenario with more expensive, effective targeted therapy was US$47,748, US$69,255 and US$66,369, respectively. Conclusion: In the future scenario, CDs have an incremental cost–effectiveness of US$56,829 per life-year saved when compared with NT as a first-line treatment. This is one demonstration of how CDs may be a cost-effective option for the treatment of patients with advanced NSCLC when the NT is extremely expensive but the outcome is significantly improved.

Radiographic assessment and therapeutic decisions at RECIST progression in EGFR-mutant NSCLC treated with EGFR tyrosine kinase inhibitors

PURPOSE

Advanced NSCLC harboring epidermal growth factor receptor (EGFR) mutations treated with EGFR tyrosine kinase inhibitors (TKIs) typically progresses after initial response due to acquired resistance. TKIs are often continued beyond progressive disease by RECIST. We investigated the practice of continuing EGFR-TKIs after RECIST-PD via CT findings.

METHODS

Among 101 advanced NSCLC patients with sensitizing EGFR mutations treated with first-line EGFR-TKIs, 70 patients had baseline and at least one follow-up CT for retrospective radiographic assessments using RECIST1.1; 56 patients had experienced PD by the data closure date of June 2011.

RESULTS

Among 56 patients experiencing PD, 82% were female, median age was 63 years, 50% were never-smokers, 57% had distant metastasis, 57% had exon 19 deletion, and 89% were treated with erlotinib. 49 patients (88%) continued TKI therapy beyond retrospectively assessed PD. 31/32 (97%) patients who progressed by an increase in their target lesions continued TKI. 13/16 (81%) patients who progressed by appearance of a new lesion remained on TKI. 5/6 (83%) patients with both increase of target lesions and new lesion at PD continued TKI. Two patients with PD in non-target lesions discontinued therapy at PD. In 49 continuing patients, the median time from retrospectively assessed RECIST-PD to termination of TKI was 10.1 months.

CONCLUSIONS

88% of EFGR-mutant NSCLC patients who progressed on first-line TKI continued therapy beyond RECIST-PD, which is not the single determining factor for terminating TKI in EGFR-mutant NSCLC patients. Additional radiographically defined progression criteria are needed for this population.

Novel approaches of chemoradiotherapy in unresectable stage IIIA and stage IIIB non-small cell lung cancer

Approximately one third of patients with non-small cell lung cancer have unresectable stage IIIA or stage IIIB disease, and appropriate patients are candidates for chemoradiotherapy with curative intent. The optimal treatment paradigm is currently undefined. Concurrent chemoradiotherapy, compared with sequential chemotherapy and thoracic radiation therapy (TRT), results in superior overall survival outcomes as a result of better locoregional control. Recent trials have revealed efficacy for newer chemotherapy combinations similar to that of older chemotherapy combinations with concurrent TRT and a lower rate of some toxicities. Ongoing phase III trials will determine the roles of cisplatin and pemetrexed concurrent with TRT in patients with nonsquamous histology, cetuximab, and the L-BLP25 vaccine. It is unlikely that bevacizumab will have a role in stage III disease because of its toxicity. Erlotinib, gefitinib, and crizotinib have not been evaluated in stage III patients selected based on molecular characteristics. The preliminary results of a phase III trial that compared conventionally fractionated standard-dose TRT (60 Gy) with high-dose TRT (74 Gy) revealed an inferior survival outcome among patients assigned to the high-dose arm. Hyperfractionation was investigated previously with promising results, but adoption has been limited because of logistical considerations. More recent trials have investigated hypofractionated TRT in chemoradiotherapy. Advances in tumor targeting and radiation treatment planning have made this approach more feasible and reduced the risk for normal tissue toxicity. Adaptive radiotherapy uses changes in tumor volume to adjust the TRT treatment plan during therapy, and trials using this strategy are ongoing. Ongoing trials with proton therapy will provide initial efficacy and safety data.

EGFR-TKI resistant non-small cell lung cancer (NSCLC): new developments and implications for future treatment

Treatment with receptor-tyrosine kinase inhibitors (TKIs) has improved progression-free and overall survival in patients with advanced non-small cell lung cancer (NSCLC). One major target for treatment with TKI is the epidermal growth factor receptor (EGFR), particularly in patients harboring activating mutations. However, despite initial responses and long lasting remissions, the development of secondary resistance inevitably leads to treatment failure. Analyzing recent data from various phase II/III trials it seems obvious that the single mode of action of gefitinib or erlotinib can provide temporary success only. Both preclinical and clinical evidence suggest that irreversible TKIs such as afatinib or PF00299804, or combined approaches using multiple kinase inhibition (e.g. EGFR and MET) and vertical inhibition by combination of small molecules and antibodies, seem to be more promising and will be the prevailing concepts to overcome secondary EGFR-TKI resistance for the near future.

Second-generation irreversible epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs): a better mousetrap? A review of the clinical evidence

The discovery of activating epidermal growth factor receptor (EGFR) mutations in non-small cell lung cancer (NSCLC) in 2004 heralded the era of molecular targeted therapy in NSCLC. First-generation small molecule, reversible tyrosine kinase inhibitors (TKIs) of EGFR, gefitinib and erlotinib, had been approved for second- or third-line treatment of NSCLC prior to the knowledge of these mutations. However, resistance to gefitinib and erlotinib invariably develops after prolonged clinical use. Two second-generation irreversible EGFR TKIs, afatinib (BIBW 2992) and dacomitinib (PF-00299804), that can potentially overcome the majority of these resistances are in late stage clinical development. Here I will review the clinical data of EGFR TKIs and discuss the appropriate future role of afatinib and dacomitinib in NSCLC: whether as replacement of erlotinib or gefitinib or only after erlotinib or gefitinib failure and whether different subgroups would benefit from different approaches.

EGFR exon 19 insertions: a new family of sensitizing EGFR mutations in lung adenocarcinoma

PURPOSE

Epidermal growth factor receptor (EGFR) genotyping is now standard in the management of advanced lung adenocarcinoma, as this biomarker predicts marked benefit from treatment with EGFR tyrosine kinase inhibitors (TKI). EGFR exon 19 insertions are a poorly described family of EGFR mutations, and their association with EGFR-TKI sensitivity in lung adenocarcinoma is uncertain.

EXPERIMENTAL DESIGN

Patients with lung cancers harboring EGFR exon 19 insertions were studied. The predicted effects of the insertions on the structure of the EGFR protein were examined, and EGFR exon 19 insertions were introduced into Ba/F3 cells to assess oncogenicity and in vitro sensitivity to EGFR-TKIs. In patients receiving TKI, response magnitude was assessed with serial computed tomographic (CT) measurement.

RESULTS

Twelve tumors harboring EGFR exon 19 insertions were identified; patients were predominately female (92%) and never-smokers (75%). The 11 specimens available for full sequencing all showed an 18-bp insertion that resulted in the substitution of a Pro for Leu at residue 747. The mutant EGFR transformed the Ba/F3 cells, which were then sensitive to EGFR-TKI. Six patients with measurable disease received TKI and five had a response on serial CT.

CONCLUSIONS

EGFR exon 19 insertions are a newly appreciated family of EGFR-TKI-sensitizing mutations, and patients with tumors harboring these mutations should be treated with EGFR-TKI. While these mutations may be missed through the use of some mutation-specific assays, the addition of PCR product size analysis to multigene assays allows sensitive detection of both exon 19 insertion and deletion mutations.

Targeted and cytotoxic therapy in coordinated sequence (TACTICS): erlotinib, bevacizumab, and standard chemotherapy for non-small-cell lung cancer, a phase II trial

BACKGROUND

This trial focused on optimally combining existing targeted therapies and cytotoxic chemotherapy in the treatment of unselected patients with advanced non-small-cell lung cancer (NSCLC).

METHODS

Patients with previously untreated advanced-stage nonsquamous NSCLC were eligible for this trial. In module A, patients received up to 4 cycles of erlotinib 150 mg daily and bevacizumab 15 mg/kg every 3 weeks. Patients then received carboplatin (AUC = 6), paclitaxel 200 mg/m2, and bevacizumab 15 mg/kg for 4 cycles in module B. Patients who did not have progressive disease in module A received maintenance erlotinib 150 mg daily and bevacizumab 15 mg/kg every 3 weeks in module C.

RESULTS

Forty-eight patients were enrolled in this multicenter phase II trial. Most patients were male (62.5%) and white (77.1%) with stage IV disease (93.8%) and adenocarcinoma histologic type (66.7%). The overall response rate in module A was 10.4%, in module B it was 15.1%, and in module C it was 5.5%. The study achieved its primary endpoint, with a nonprogression rate of 45.8% in module A. The median overall survival (OS) was 12.6 months.

CONCLUSION

The novel systemic therapy regimen is feasible in patients with advanced NSCLC. However there is no further role for developing this regimen in unselected patients with NSCLC.

A randomized, phase II, biomarker-selected study comparing erlotinib to erlotinib intercalated with chemotherapy in first-line therapy for advanced non-small-cell lung cancer

PURPOSE

Erlotinib prolongs survival in patients with advanced non-small-cell lung cancer (NSCLC). We report the results of a randomized, phase II study of erlotinib alone or intercalated with chemotherapy (CT + erlotinib) in chemotherapy-naïve patients with advanced NSCLC who were positive for epidermal growth factor receptor (EGFR) protein expression and/or with high EGFR gene copy number.

PATIENTS AND METHODS

A total of 143 patients were randomly assigned to either erlotinib 150 mg daily orally until disease progression (PD) occurred or to chemotherapy with paclitaxel 200 mg/m(2) intravenously (IV) and carboplatin dosed by creatinine clearance (AUC 6) IV on day 1 intercalated with erlotinib 150 mg orally on days 2 through 15 every 3 weeks for four cycles followed by erlotinib 150 mg orally until PD occurred (CT + erlotinib). The primary end point was 6-month progression-free survival (PFS); secondary end points included response rate, PFS, and survival. EGFR, KRAS mutation, EGFR fluorescent in situ hybridization and immunohistochemistry, and E-cadherin and vimentin protein levels were also assessed.

RESULTS

Six-month PFS rates were 26% and 31% for the two arms (CT + erlotinib and erlotinib alone, respectively). Both were less than the historical control of 45% (P = .001 and P = .011, respectively). Median PFS times were 4.57 and 2.69 months, respectively. Patients with tumors harboring EGFR activating mutations fared better on erlotinib alone (median PFS, 18.2 months v 4.9 months for CT + erlotinib).

CONCLUSION

The feasibility of a multicenter biomarker-driven study was demonstrated, but neither treatment arms exceeded historical controls. This study does not support combined chemotherapy and erlotinib in first-line treatment of EGFR-selected advanced NSCLC, and the patients with tumors harboring EGFR mutations had a better outcome on erlotinib alone.

Problems involved in the clinical trials for non-small cell lung carcinoma

Along with changes in smoking habits, non-small cell lung carcinoma (NSCLC) has come to account for about 90% of all cases of lung cancer. For the treatment of NSCLC, cytocidal antineoplastic drugs such as pemetrexed and molecular-targeted drugs such as gefitinib, erlotinib, and bevacizumab have been approved globally and used as a part of the standard treatment. The importance of better patient selection based on the optimum indication of these drugs is attracting much attention. Additionally, timing for the use of these drugs also seems to be an important issue. The present review presents a critical discussion about the following issues based on the results of clinical studies: (1) whether or not the assessment of the EGFR mutation status in NSCLC patients is indispensable; (2) whether gefitinib and erlotinib have different effects; (3) the need to sub-classify NSCLC by histologic type; (4) significance of maintenance therapy for NSCLC; and (5) whether platinum-doublet chemotherapy plus bevacizumab is a standard treatment for non-squamous cell carcinoma.

Targeted therapy of non-small-cell lung carcinoma

The rapid expansion of novel technologies in cancer research over the past several years has led to a dramatically improved understanding of the molecular biology of lung cancer. As a consequence, novel targeted therapies are rapidly being developed. In this review, we summarize the most important molecular pathways in lung cancer and describe the clinical evidence for the development of therapies against these targets.

The role of epidermal growth factor receptor mutations and epidermal growth factor receptor-tyrosine kinase inhibitors in the treatment of 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.

[What is the best sequence of treatment for patients with EGFR mutations?]

The arrival of tyrosine kinase inhibitors (TKI) in first line of treatment for advanced non-small cell lung cancer with EGFR mutations has changed the strategy of treatment of theses patients. Indeed, response rates in these cases reach around 60 to 70%, with a progression-free survival greatly prolonged, up to 10 months. It seems that these patients with mutated tumor benefit from TKI whatever the treatment line, with the same efficacy. So, the best sequence of treatment (TKI in first line then chemotherapy in second line, or the opposite) needs still to be defined in this sub-group of NSCLC. The choice has to take in account the data of efficacy of TKIs and chemotherapy in the EGFR mutated tumors, with an anticipation of subsequent lines from the first line. Besides, data of toxicity and quality of life have also to be considered.

Incidence of EGFR exon 19 deletions and L858R in tumor specimens from men and cigarette smokers with lung adenocarcinomas

PURPOSE

EGFR mutations underlie the sensitivity of lung cancers to erlotinib and gefitinib and can occur in any patient with this illness. Here we examine the frequency of EGFR mutations in smokers and men.

METHODS

We determined the frequency of EGFR mutations and characterized their association with cigarette smoking status and male sex.

RESULTS

We tested 2,142 lung adenocarcinoma specimens for the presence of EGFR exon 19 deletions and L858R. EGFR mutations were found in 15% of tumors from former smokers (181 of 1,218; 95% CI, 13% to 17%), 6% from current smokers (20 of 344; 95% CI, 4% to 9%), and 52% from never smokers (302 of 580; 95% CI, 48% to 56%; P < .001 for ever v never smokers). EGFR mutations in former or current smokers represented 40% of all those detected (201 of 503; 95% CI, 36% to 44%). EGFR mutations were found in 19% (157 of 827; 95% CI, 16% to 22%) of tumors from men and 26% (346 of 1,315; 95% CI, 24% to 29%) of tumors from women (P < .001). EGFR mutations in men represented 31% (157 of 503; 95% CI, 27% to 35%) of all those detected.

CONCLUSION

A large number of EGFR mutations are found in adenocarcinoma tumor specimens from men and people who smoked cigarettes. If only women who were never smokers were tested, 57% of all EGFR mutations would be missed. Testing for EGFR mutations should be considered for all patients with adenocarcinoma of the lung at diagnosis, regardless of clinical characteristics. This strategy can extend the use of EGFR tyrosine kinase inhibitors to the greatest number individuals with the potential for substantial benefit.

American Society of Clinical Oncology provisional clinical opinion: epidermal growth factor receptor (EGFR) Mutation testing for patients with advanced non-small-cell lung cancer considering first-line EGFR tyrosine kinase inhibitor therapy

PURPOSE

An American Society of Clinical Oncology (ASCO) provisional clinical opinion (PCO) offers timely clinical direction to ASCO's membership following publication or presentation of potentially practice-changing data from major studies. This PCO addresses the clinical utility of using epidermal growth factor receptor (EGFR) mutation testing for patients with advanced non-small-cell lung cancer (NSCLC) to predict the benefit of taking a first-line EGFR tyrosine kinase inhibitor (TKI).

CLINICAL CONTEXT

Patients with EGFR-mutated NSCLC have a significantly higher rate of partial responses to the EGFR TKIs gefitinib and erlotinib. In the United States, approximately 15% of patients with adenocarcinoma of the lung harbor activating EGFR mutations. EGFR mutation testing is widespread at academic medical centers and in some locales in community practice. As of yet, there is no evidence of an overall survival (OS) benefit from selecting treatment based on performing this testing.

RECENT DATA

One large phase III trial (the Iressa Pan-Asia Study [IPASS] trial), three smaller phase III randomized controlled trials using progression-free survival as the primary end point, and one small phase III trial with OS as the primary end point, all involving first-line EGFR TKIs and chemotherapy doublets, form the basis of this PCO.

PROVISIONAL CLINICAL OPINION

On the basis of the results of five phase III randomized controlled trials, patients with NSCLC who are being considered for first-line therapy with an EGFR TKI (patients who have not previously received chemotherapy or an EGFR TKI) should have their tumor tested for EGFR mutations to determine whether an EGFR TKI or chemotherapy is the appropriate first-line therapy. NOTE. ASCO's provisional clinical opinions (PCOs) reflect expert consensus based on clinical evidence and literature available at the time they are written and are intended to assist physicians in clinical decision making and identify questions and settings for further research. Because of the rapid flow of scientific information in oncology, new evidence may have emerged since the time a PCO was submitted for publication. PCOs are not continually updated and may not reflect the most recent evidence. PCOs cannot account for individual variation among patients and cannot be considered inclusive of all proper methods of care or exclusive of other treatments. It is the responsibility of the treating physician or other health care provider, relying on independent experience and knowledge of the patient, to determine the best course of treatment for the patient. Accordingly, adherence to any PCO is voluntary, with the ultimate determination regarding its application to be made by the physician in light of each patient's individual circumstances. ASCO PCOs describe the use of procedures and therapies in clinical practice and cannot be assumed to apply to the use of these interventions in the context of clinical trials. ASCO assumes no responsibility for any injury or damage to persons or property arising out of or related to any use of ASCO's PCOs, or for any errors or omissions.

Lung cancer: New biological insights and recent therapeutic advances

Approximately 1.6 million new cases of lung cancer are diagnosed each year throughout the world. In many countries, the mortality related to lung cancer continues to rise. The outcomes for patients with all stages of lung cancer have improved in recent years. The use of systemic therapy in conjunction with local therapy has led to improved cure rates in both resectable and unresectable patient groups. For patients with advanced stage disease, modest but real improvements in overall survival and quality of life have been achieved with systemic chemotherapy. A major focus of research has been the development of molecularly targeted agents and the identification of biomarkers for patient selection. Patients with non-small cell lung cancer with mutations in the epidermal growth factor receptor (EGFR) tyrosine kinase domain achieve response rates of greater than 70% and superior progression-free survival when treated with an EGFR tyrosine kinase inhibitor compared with standard chemotherapy. This has now emerged as the preferred therapeutic approach for the subset of patients with a mutation in exons 19 or 21 of the EGFR. Another promising targeted approach involves the use of an anaplastic lymphoma kinase (ALK) inhibitor in patients with a translocation involving the echinoderm microtubule-associated protein-like 4 (EML4) and -ALK genes. Finally, a paradigm shift in favor of maintenance therapy for patients with advanced stage disease has gained strength from recent data. All of these advances have been made possible by developing a greater understanding of the biology, the discovery of novel anticancer agents, and improved supportive care measures. This article reviews the major strides made in the treatment of lung cancer in the recent past.

Rebiopsy of lung cancer patients with acquired resistance to EGFR inhibitors and enhanced detection of the T790M mutation using a locked nucleic acid-based assay

BACKGROUND

The epidermal growth factor receptor (EGFR) mutation T790M is reported in approximately 50% of lung cancers with acquired resistance to EGFR inhibitors and is a potential prognostic and predictive biomarker. Its assessment can be challenging due to limited tissue availability and underdetection at low mutant allele levels. Here, we sought to determine the feasibility of tumor rebiopsy and to more accurately assess the prevalence of the T790M using a highly sensitive locked nucleic acid (LNA) PCR/sequencing assay. MET amplification was also analyzed.

METHODS

Patients with acquired resistance were rebiopsied and samples were studied for sensitizing EGFR mutations. Positive cases were evaluated for T790M using standard PCR-based methods and a subset were re-evaluated with an LNA-PCR/sequencing method with an analytical sensitivity of approximately 0.1%. MET amplification was assessed by FISH.

RESULTS

Of 121 patients undergoing tissue sampling, 104 (86%) were successfully analyzed for sensitizing EGFR mutations. Most failures were related to low tumor content. All patients (61/61) with matched pretreatment and resistance specimens showed concordance for the original sensitizing EGFR mutation. Standard T790M mutation analysis on 99 patients detected 51(51%) mutants. Retesting of 30 negative patients by the LNA-based method detected 11 additional mutants for an estimated prevalence of 68%. MET was amplified in 11% of cases (4/37).

CONCLUSIONS

The re-biopsy of lung cancer patients with acquired resistance is feasible and provides sufficient material for mutation analysis in most patients. Using high sensitivity methods, the T790M is detected in up to 68% of these patients.

Phase I/II trial of cetuximab and erlotinib in patients with lung adenocarcinoma and acquired resistance to erlotinib

PURPOSE

In patients with epidermal growth factor receptor (EGFR) mutant lung adenocarcinoma, treatment with erlotinib or gefitinib is associated with a 75% radiographic response rate and progression-free survival of approximately 12 months. The most common mechanism of acquired resistance to erlotinib is development of a secondary mutation in EGFR, suggesting that these tumors continue to depend on EGFR signaling. We hypothesized that combined EGFR blockade would overcome acquired resistance to erlotinib in patients with lung adenocarcinoma. To evaluate the toxicity and efficacy of cetuximab and erlotinib in patients with acquired resistance to erlotinib, we conducted this phase I/II clinical trial.

EXPERIMENTAL DESIGN

Patients with lung adenocarcinoma and clinically defined acquired resistance to erlotinib were treated with erlotinib 100 mg daily, along with cetuximab every 2 weeks in three escalating dose cohorts (250 mg/m(2), 375 mg/m(2), and 500 mg/m(2)). The recommended phase II dose was then evaluated in a two-stage trial, with a primary end point of objective response rate.

RESULTS

A total of 19 patients were enrolled. The most common toxicities for the combination of cetuximab and erlotinib were rash, fatigue, and hypomagnesemia. The recommended phase II dose identified was cetuximab 500 mg/m(2) every 2 weeks and erlotinib 100 mg daily. At this dose and schedule, no radiographic responses were seen (0 of 13, 0%, 95% CI, 0-25).

CONCLUSIONS

Combined EGFR inhibition, with cetuximab 500 mg/m(2) every 2 weeks and erlotinib 100 mg daily, had no significant activity in patients with acquired resistance to erlotinib.

Summary of presentations from the 46th Annual Meeting of the American Society of Clinical Oncology: focus on non-small cell lung cancer (2010)

The promising results of crizotinib in molecularly selected patients with advanced non-small cell lung cancer (NSCLC) whose tumor cells had a novel fusion protein involving anaplastic lymphoma kinase presented at the 2010 American Society of Clinical Oncology reinforce once again the importance of understanding molecular heterogeneity of lung cancer and careful patient selection. Several other important issues were the subject of presentations related to lung cancer at the recently concluded American Society of Clinical Oncology annual meeting. The articles covered a wide variety of topics including optimal staging techniques to detect mediastinal nodal involvement, the role of platinum-based doublet chemotherapy in the management of elderly patients with advanced NSCLC, use of maintenance therapy with gemcitabine, and the impact of early introduction of organized palliative care in improving the quality of life of patients with advanced NSCLC. This report provides a brief overview of the presentations related to lung cancer that are relevant to clinical practice and future research.

Development of central nervous system metastases in patients with advanced non-small cell lung cancer and somatic EGFR mutations treated with gefitinib or erlotinib

PURPOSE

Gefitinib and erlotinib can penetrate into the central nervous system (CNS) and elicit responses in patients with brain metastases (BM) from non-small cell lung cancer (NSCLC). However, there are incomplete data about their impact on the development and control of CNS metastases.

EXPERIMENTAL DESIGN

Patients with stage IIIB/IV NSCLC with somatic EGFR mutations initially treated with gefitinib or erlotinib were identified. The cumulative risk of CNS progression was calculated using death as a competing risk.

RESULTS

Of the 100 patients, 19 had BM at the time of diagnosis of advanced NSCLC; 17 of them received CNS therapy before initiating gefitinib or erlotinib. Eighty-four patients progressed after a median potential follow-up of 42.2 months. The median time to progression was 13.1 months. Twenty-eight patients developed CNS progression, 8 of whom had previously treated BM. The 1- and 2-year actuarial risk of CNS progression was 7% and 19%, respectively. Patient age and EGFR mutation genotype were significant predictors of the development of CNS progression. The median overall survival for the entire cohort was 33.1 months.

CONCLUSIONS

Our data suggest a lower risk of CNS progression in patients with advanced NSCLC and somatic EGFR mutations initially treated with gefitinib or erlotinib than published rates of 40% in historical series of advanced NSCLC patients. Further research is needed to distinguish between the underlying rates of developing CNS metastases between NSCLC with and without EGFR mutations and the impact of gefitinib and erlotinib versus chemotherapy on CNS failure patterns in these patients.