KRAS Wild-type Disease Research Articles

New Therapeutic Targets in RAS Wild-type Pancreatic Cancer.

The landscape of treatment of advanced PDAC is witnessing significant changes. This is in part due to the advent of molecular profiling, which has highlighted molecularly-distinct subsets of pts, especially those with KRAS wild-type disease. We now know that these pts harbor genomic alterations that not only serve as molecular drivers but also pose as therapeutically relevant markers. In the absence of strong evidence to support the use of targeted therapy in the front-line setting, we continue to offer chemotherapy for treatment-naïve pts. However, an argument can be made for the front-line use of targeted therapy in pts who are not fit for chemotherapy or who are not interested in it. The challenge is ensuring that molecular profiling is done in a timely fashion to prevent significant delays in therapy. In our practice, we offer molecular testing to all pts with a new diagnosis of advanced PDAC. We prefer the utility of targeted therapy in the second line and beyond for pts who have an actionable target, over the use of further chemotherapy, as targeted therapy appears to confer deep and durable responses and longer survival. For pts with MSI-H or MMRd disease, the use of immunotherapy is indicated, although it has to be noted that MSI-H/MMRd PDAC performed worse that other MSI-H/MMRd cancers treated with immunotherapy. Therefore, in the presence of MSI-H/MMRd and an additional actionable target, we prefer treating with targeted therapy and reserving immunotherapy for later lines. Pt preference has to be taken into consideration at all times though.

Abstract LB_A25: Updated Phase 1 results from the PYNNACLE Phase 1/2 study of PC14586, a selective p53 reactivator, in patients with advanced solid tumors harboring a TP53 Y220C mutation

Abstract Background: Mutations in the TP53 gene leading to p53 inactivation are the most common mutational event across human cancers. PC14586 is a first-in-class p53 reactivator that selectively binds to the mutated p53 Y220C protein and restores p53 wild-type activity. Preclinical data support potential for activity of PC14586 across TP53 Y220C-bearing tumors, with enhanced activity in KRAS wild-type (WT) models, consistent with the important parallel roles for p53 inactivation and oncogenic KRAS in tumorigenesis. Preliminary analysis of Phase 1 data from the Phase 1/2 PYNNACLE trial (NCT04585750) evaluating PC14586 in patients with advanced TP53 Y220C solid tumors showed that PC14586 was well tolerated with preliminary clinical activity across multiple tumor types in the efficacious dose range (1150 mg QD to 1500 mg BID). This updated Phase 1 analysis assesses PC14586 in patients treated across the efficacious dose range. Methods: Eligible patients (≥12 years) with locally advanced or metastatic solid tumors with a TP53 Y220C mutation received increasing oral doses of PC14586 to evaluate safety, PK, and preliminary efficacy via RECIST v1.1, and to determine the Recommended Phase 2 Dose (RP2D). Tumor molecular profiling was assessed for the impact of KRAS status on response. Results: As of 1 May 2023, 61 patients were treated in the efficacious dose range (safety population): median age 63 (range 32-84) years, 62% female, and median of 3 (range 1–9) prior lines of systemic therapy. The most frequent treatment-related adverse events (TRAEs) (≥10%) were nausea (42.3%), vomiting (35.2%), diarrhea (19.7%), increased creatinine (18.3%), fatigue (14.1%), and increased AST and ALT (12.7% each); 3% of patients discontinued PC14586 due to TRAEs. Most TRAEs were grade 1 or 2; the most common grade 3 TRAEs were anemia (4.2%) and increased ALT (2.8%). PC14586 administered with food led to improvement in nausea and vomiting. Dose proportional and linear PK was observed with a median half-life of 19 hours. Among patients with measurable disease, 36 patients had KRAS WT and 15 patients had KRAS mutated tumors. A total of 12 PRs (ORR 33.3%) were observed (9 confirmed and 3 unconfirmed - pending confirmation) in patients with KRAS WT disease across multiple tumor types including ovarian, breast, prostate, small-cell lung, and endometrial cancer. The median duration of confirmed response was 7 months. In patients with a KRAS mutation, there were no confirmed responses, although clinical activity was observed. At 2000 mg QD, the ORR was 46.2% in patients with TP53 Y220C and KRAS WT tumors (n=13). A RP2D of 2000 mg QD was selected based on overall safety, PK and preliminary efficacy. Conclusions: PC14586 was well-tolerated with a favorable safety profile. Efficacy was achieved in heavily pre-treated patients across multiple tumor types. The PYNNACLE registrational Phase 2 trial will assess PC14586 as monotherapy at the RP2D of 2000 mg QD in patients with TP53 Y220C and KRAS WT advanced solid tumors. Additional/updated data will be presented at the conference. Citation Format: Alison M Schram, Geoffrey I Shapiro, Melissa L Johnson, Anthony W. Tolcher, John A Thompson, Anthony B El-Khoueiry, Andrae L Vandross, Shivaani Kummar, Aparna R Parikh, Dale R Shepard, Ursula Garczarek, Kim LeDuke, Lisa Sheehan, Marc Fellous, Leila Alland, Ecaterina E Dumbrava. Updated Phase 1 results from the PYNNACLE Phase 1/2 study of PC14586, a selective p53 reactivator, in patients with advanced solid tumors harboring a TP53 Y220C mutation [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr LB_A25.

Pathogenic genomic alterations in Chinese pancreatic cancer patients and their therapeutical implications.

Approximately 90% of pancreatic ductal adenocarcinoma (PDAC) cases are driven by the untargetable non-G12C KRAS mutations, and only a small subset of patients are eligible for FDA-approved precision therapies. The practice of precision therapy in pancreatic cancer was limited by the paucity of targetable genetic alterations, especially in the Asian population. To explore therapeutic targets in 499 Chinese PDAC patients, a deep sequencing panel (OncoPanscan™, Genetron health) was used to characterize somatic alterations including point mutations, indels, copy number alterations, gene fusions as well as pathogenic germline variants. We performed genomic profiling in 499 Chinese PDAC patients, which revealed somatic driver mutations in KRAS, TP53, CDKN2A, SMAD4, ARID1A, RNF43, and pathogenic germline variants (PGVs) in cancer predisposition genes including BRCA2, PALB2, and ATM. Overall, 20.4% of patients had targetable genomic alterations. About 8.4% of patients carried inactivating germline and somatic variants in BRCA1/2 and PALB2, which were susceptible to platinum and PARP inhibitors therapy. Patients with KRAS wild-type disease and early-onset pancreatic cancer (EOPC) harbored actionable mutations including BRAF, EGFR, ERBB2, and MAP2K1/2. Compared to PGV-negative patients, PGV-positive patients were younger and more likely to have a family history of cancer. Furthermore, PGVs in PALB2, BRCA2, and ATM were associated with high PDAC risk in the Chinese population. Our results demonstrated that a genetic screen of actionable genomic variants could facilitate precision therapy and cancer risk reduction in pancreatic cancer patients of Asian ethnicity.

Emerging Treatment Strategies in Pancreatic Cancer.

Pancreatic ductal adenocarcinoma (PDAC) is one of the main causes of cancer death in well-developed countries. Therapeutic advances in PDAC to date have been modest. Recent progress to understand the molecular landscape of the disease has opened new treatment opportunities for a small subset of patients, frequently those with KRAS wild-type disease. Novel treatment strategies in PDAC include, among others, the use of nanotechnology and metabolic reprogramming. In addition, new strategies are being investigated, which are designed to overcome the resistance to checkpoint inhibitors, targeting DNA repair pathways including mismatch repair, increasing antigen presentation through the use of vaccines, targeting various signaling pathways, and reprogramming the tumor microenvironment. Here, we review the landscape of PDAC treatment strategies and some of these new agents.

Patient demographics and management landscape of metastatic colorectal cancer in the third-line setting: Real-world data in an australian population.

Colorectal cancer is the third most common cancer and second leading cause of cancer mortality in Australia, thus carrying a significant disease burden. This analysis aims to explore real-world treatment landscape of metastatic colorectal cancer in the third-line setting. We retrospectively analysed treatment of recurrent and advanced colorectal cancer (TRACC) registry database from 2009 onwards. Patients treated with palliative intent who progressed after two lines of therapies were included. One treatment line was defined as any combination of systemic therapy given until progression. Out of 1820 patients treated palliatively, 32% (590 patients) met study criteria. Of these, 43% (254 patients) proceeded to third-line therapy, equating to 14% of all metastatic patients. In KRAS mutant or unknown tumours (97 patients), fluoropyrimidine (FP)-oxaliplatin combination was the most common choice (51%), followed by FP-irinotecan (15%), trifluridine/tipiracil (11%), mono-chemotherapy (10%), regorafenib (5%) and others (7%). Majority of FP-doublet (83%) was given as rechallenge. In 157 patients with KRAS wildtype disease, monotherapy with EGFR inhibitor was most commonly used (41%), followed by EGFR inhibitor with chemotherapy (20%), FP-doublet (18%), mono-chemotherapy (6%), trifluridine/tipiracil (6%), regorafenib (1%) and others (8%). Median overall survival was 7.1 months (range 0.4-41.2), and median time on third-line treatment was 3 months (range 0.1-40). In real-world Australian population, treatment choices differed based on KRAS status and will likely change with the availability of newer drugs on the pharmaceutical benefits scheme. Survival outcomes are comparable to newer agents in clinical trials for select patients.

Overall survival of patients with KRAS wild-type tumor treated with FOLFOX/FORFIRI±cetuximab as the first-line treatment for metastatic colorectal cancer: A meta-analysis.

The addition of cetuximab to FOLFIRI or FOLFOX as the first-line treatment for metastatic colorectal cancer (mCRC) was shown to reduce the risk of disease progression and increase the chance of response in patients with KRAS wild-type disease. An updated systematic meta-analysis was undertaken to determine the efficacy of cetuximab plus FOLFIRI or FOLFOX.Major databases were searched to identify RCTs investigating wild-type KRAS mCRC after the first-line treatment, and treatment with FOLFOX/FORFIRI ± cetuximab was compared. Data on clinical efficacy and safety were pooled and compared by ORs, HRs, and 95% CIs.Five eligible trials with 1464 patients were included in the meta-analysis. Compared to FOLFOX/FORFIRI, cetuximab as the first-line therapy has improved overall survival (OS) (hazard ratio [HR] = 0.82, 95% confidence interval [CI]: 0.72–0.93, P = 0.003), progression-free survival (PFS) (HR = 0.66, 95% CI: 0.56 –0.77, P < 0.00001), and overall response rate (ORR) (odds ratio [OR] = 2.12, 95% CI: 1.70–2.65, P < 0.00001). However, Grade 3/4 AE was increased with the OR of 2.76 (95%CI: 2.01–3.78, P < 0.00001). The most common grade 3/4 toxicity in the wild-type KRAS population was neutropenia and diarrhea. For cetuximab plus FOLFIRI, there was a higher incidence of grade 3 or 4 diarrhea (OR = 1.76, 95% CI: 1.15–2.70, P = 0.01), but there was no significant difference for neutropenia (OR = 1.35, 95% CI: 1.00–1.83, P = 0.05).The addition of cetuximab in mCRC as the first-line treatment is a potential effective approach in the improved outcomes but associated with increased toxicity.

Abstract 578: Molecular subgroup analysis of clinical outcomes in a phase 3 study of gemcitabine and oxaliplatin with or without erlotinib in advanced biliary tract cancer

Abstract BACKGROUND. We previously reported that the addition of erlotinib to gemcitabine and oxaliplatin (GEMOX) resulted in greater antitumor activity and might be a treatment option for patients with biliary tract cancers. Molecular subgroup analysis of treatment outcomes in patients who had specimens available for analysis was undertaken. METHODS. EGFR, KRAS, and PIK3CA mutations were evaluated using peptide nucleic acid-locked nucleic acid (PNA-LNA) PCR clamp reactions. Survival and response rates were analyzed according to the mutational status. 64 patients (48.1%) were available for mutational analysis in the chemotherapy alone group and 61 (45.1%) in the chemotherapy plus erlotinib group. RESULTS. 1.6% (2/116) harboured an EGFR mutation (2 patients; exon 20), 9.6% (12/121) harboured a KRAS mutation (12 patients; exon 2), and 9.6% (12/118) a PIK3CA mutation (10 patients; exon 9 and 2 patients; exon 20). The addition of erlotinib to GEMOX in patients with KRAS wild type disease (n = 109) resulted in significant improvements in overall response compared with GEMOX alone (30.2% vs. 12.5%, P = 0.024). In 95 patients with both wild type KRAS and PIK3CA, there was evidence of a benefit associated with the addition of erlotinib to GEMOX with respect to response rate (RR) as compared with GEMOX alone (P = 0.04). CONCLUSION. This study demonstrates that KRAS mutational status might be considered a predictive biomarker for the response to erlotinib in biliary tract cancers (BTCs). Additionally, the mutation status of PIK3CA may be a determinant for adding erlotinib to chemotherapy in KRAS wild type BTCs. Keywords: KRAS, PIK3CA, Erlotinib Citation Format: Seung T. Kim, Joon Park. Molecular subgroup analysis of clinical outcomes in a phase 3 study of gemcitabine and oxaliplatin with or without erlotinib in advanced biliary tract cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 578. doi:10.1158/1538-7445.AM2015-578

Molecular Subgroup Analysis of Clinical Outcomes in a Phase 3 Study of Gemcitabine and Oxaliplatin with or without Erlotinib in Advanced Biliary Tract Cancer

BACKGROUND: We previously reported that the addition of erlotinib to gemcitabine and oxaliplatin (GEMOX) resulted in greater antitumor activity and might be a treatment option for patients with biliary tract cancers (BTCs). Molecular subgroup analysis of treatment outcomes in patients who had specimens available for analysis was undertaken. METHODS: Epidermal growth factor receptor (EGFR), KRAS, and PIK3CA mutations were evaluated using peptide nucleic acid–locked nucleic acid polymerase chain reaction clamp reactions. Survival and response rates (RRs) were analyzed according to the mutational status. Sixty-four patients (48.1%) were available for mutational analysis in the chemotherapy alone group and 61 (45.1%) in the chemotherapy plus erlotinib group. RESULTS: 1.6% (2/116) harbored an EGFR mutation (2 patients; exon 20), 9.6% (12/121) harbored a KRAS mutation (12 patients; exon 2), and 9.6% (12/118) harbored a PIK3CA mutation (10 patients, exon 9 and 2 patients, exon 20). The addition of erlotinib to GEMOX in patients with KRAS wild-type disease (n = 109) resulted in significant improvements in overall response compared with GEMOX alone (30.2% vs 12.5%, P = .024). In 95 patients with both wild-type KRAS and PIK3CA, there was evidence of a benefit associated with the addition of erlotinib to GEMOX with respect to RR as compared with GEMOX alone (P = .04). CONCLUSION: This study demonstrates that KRAS mutational status might be considered a predictive biomarker for the response to erlotinib in BTCs. Additionally, the mutation status of PIK3CA may be a determinant for adding erlotinib to chemotherapy in KRAS wild-type BTCs.

722P - Molecular Subgroup Analysis of Clinical Outcomes in a Phase 3 Study of Gemcitabine and Oxaliplatin with or Without Erlotinib in Advanced Biliary Tract Cancer

ABSTRACT Aim: We previously reported that the addition of erlotinib to gemcitabine and oxaliplatin (GEMOX) resulted in greater antitumor activity and might be a treatment option for patients with biliary tract cancers. Molecular subgroup analysis of treatment outcomes in patients who had tumor specimens available for analysis was undertaken. Methods: EGFR, KRAS, and PIK3CA mutations were evaluated using peptide nucleic acid-locked nucleic acid (PNA–LNA) PCR clamp reactions. Survival and response rates were analyzed according to the mutational status. Results: 64 patients (48.1%) were available for mutational analysis in the chemotherapy alone group and 61 (45.1%) in the chemotherapy plus erlotinib group. 1.6% (2/116) harboured an EGFR mutation (2 patients; exon 20), 9.6% (12/121) harboured a KRAS mutation (12 patients; exon 2), and 9.6% (12/118) a PIK3CA mutation (10 patients; exon 9 and 2 patients; exon 20). The addition of erlotinib to GEMOX in patients with KRAS wild type disease (n = 109) resulted in significant improvements in overall response compared with GEMOX alone (30.2% vs. 12.5%, p = 0.024). In 95 patients with both wild type KRAS and PIK3CA, there was evidence of a benefit associated with the addition of erlotinib to GEMOX with respect to response rate (RR) as compared with GEMOX alone (p = 0.04). Conclusions: This study demonstrates that KRAS mutational status might be considered a predictive biomarker for the response to erlotinib in biliary tract cancers (BTCs). Additionally, the mutation status of PIK3CA may be a determinant for adding erlotinib to chemotherapy in KRAS wild type BTCs. Disclosure: All authors have declared no conflicts of interest.

Biomarker Analyses from a Randomized, Placebo-Controlled, Phase IIIb Trial Comparing Bevacizumab with or without Erlotinib as Maintenance Therapy for the Treatment of Advanced Non-Small-Cell Lung Cancer (ATLAS)

ATLAS compared bevacizumab plus erlotinib (B+E) with bevacizumab plus placebo (B+P) as maintenance therapy after first-line bevacizumab plus chemotherapy (B+C) for advanced non-small-cell lung cancer (NSCLC). Prespecified biomarkers were prospectively evaluated. Tumor samples were analyzed for: epidermal growth factor receptor (EGFR) expression (immunohistochemistry [IHC]); EGFR gene copy number (fluorescence in-situ hybridization [FISH]); EGFR mutations (exon 19 deletions/L858R mutations); and KRAS mutations (exons 2/3). Progression-free survival (PFS) and overall survival (OS) were estimated. Of 743 patients randomized to receive maintenance treatment (after four cycles of B+C without progression), 190 (B+E) and 177 (B+P) were evaluable for biomarker status. Median PFS (from randomization) was 4.4 months (B+E) versus 3.7 months (B+P; hazard ratio [HR], 0.75; 95% confidence interval [CI], 0.57-0.99), which was numerically similar to the intent-to-treat PFS. PFS benefit of B+E was observed across most biomarker subgroups. EGFR IHC, EGFR FISH, and EGFR/KRAS mutation status were not predictive of outcome. B+E-treated patients with EGFR mutation-positive NSCLC had longer PFS compared with B+P-treated patients (HR, 0.44; 95% CI, 0.22-0.86; p = 0.0139). Patients with KRAS wild-type disease had significant PFS improvements with B+E, compared with B+P (HR, 0.66; 95% CI, 0.485-0.914; p = 0.0105). No OS benefit of B+E was observed. Patients with KRAS wild-type or EGFR mutation-positive NSCLC derived PFS benefits from B+E. However, EGFR IHC, EGFR FISH, and EGFR or KRAS mutation status were not strongly predictive of survival. A larger sample size would be needed to confirm the initial trends observed in this study.

Cost-effectiveness of first-line treatments for patients with KRAS wild-type metastatic colorectal cancer.

Combinations of chemotherapy regimens and monoclonal antibodies have been demonstrated to improve clinical outcomes in patients with metastatic colorectal cancer (mcrc). Although these combination treatment strategies are safe and effective in first-line treatment for mcrc, little is known about their economic consequences and resource allocation implications. In the present study, we evaluated the cost-effectiveness of bevacizumab plus folfiri, cetuximab plus folfiri, and panitumumab plus folfiri for patients with KRAS wild-type mcrc. A Markov model simulated the lifetime patient outcomes and costs of each first-line treatment strategy and subsequent lines of treatment from the perspective of the health care payer in Ontario. The model was parameterized using data from the Ontario Cancer Registry, Ontario health administrative databases, and published randomized control trials. Patient outcomes were measured in quality-adjusted life years (qalys), and costs were measured in monetary terms. Costs and outcomes were both discounted at 5% and expressed in 2012 Canadian dollars. For mcrc patients with KRAS wild-type disease, the treatment strategy of bevacizumab plus folfiri was found to dominate the other two first-line treatment strategies. Sensitivity analyses revealed that the incremental cost-effectiveness ratio values were sensitive to the effectiveness of treatment, the costs of bevacizumab and cetuximab, and health utility values. Evidence from Ontario showed that bevacizumab plus folfiri is the cost-effective first-line treatment strategy for patients with KRAS wild-type mcrc. The panitumumab plus folfiri and cetuximab plus folfiri options were both dominated, but the cetuximab plus folfiri strategy must be further investigated given that, in the sensitivity analyses, the cost-effectiveness of that strategy was found to be superior to that of bevacizumab plus folfiri under certain ranges of parameter values.

Predictive value of epidermal growth factor receptor expression for first-line chemotherapy plus cetuximab in patients with head and neck and colorectal cancer: Analysis of data from the EXTREME and CRYSTAL studies

BackgroundThe phase III EXTREME and CRYSTAL studies demonstrated that the addition of cetuximab to chemotherapy significantly improved survival in the first-line treatment of recurrent/metastatic squamous cell carcinoma of the head and neck (SCCHN) and KRAS wild-type metastatic colorectal cancer (mCRC). In advanced non-small-cell lung cancer (NSCLC), high EGFR expression was identified as a tumour biomarker that can predict survival benefit associated with the addition of cetuximab to first-line chemotherapy. We investigated whether tumour EGFR expression level was predictive of cetuximab benefit in EXTREME and CRYSTAL study patients. MethodsProspectively collected tumour immunohistochemistry data were used to generate an EGFR immunohistochemistry score (scale 1–300) for patients in the EXTREME and CRYSTAL studies. For each study, the association between tumour immunohistochemistry score and cetuximab benefit was investigated. The EXTREME and CRYSTAL studies are registered with Clinical Trials.gov, numbers NCT00122460 and NCT00154102, respectively. FindingsTumour EGFR immunohistochemistry data were available for 411 of 442 (93%) patients from the EXTREME study intention-to-treat (ITT) population and 664 of 666 (100%) patients from the ITT population of the CRYSTAL study with EGFR-expressing, KRAS wild-type disease. The distribution of immunohistochemistry scores was similar between the treatment arms of each study, but differed between studies. A clinically relevant benefit for progression-free and overall survival associated with the addition of cetuximab to chemotherapy was seen across the full score range in EXTREME study patients. Similarly, CRYSTAL study patients derived a clinical benefit across the full score range, with no meaningful association between EGFR expression level and benefit. InterpretationThe addition of cetuximab to chemotherapy improved survival in the first-line treatment of recurrent/metastatic SCCHN and KRAS wild-type mCRC regardless of tumour EGFR expression level, indicating that in contrast to findings in NSCLC, EGFR expression level is not a clinically useful predictive biomarker in these settings.

KRAS Wild-Type Lung Cancer: A Moving Target in an Era of Genotype Migration

The development of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) for the management of advanced lung cancer ranks among one of the few most important advances in solid tumor oncology over the past decade. In recent years, much has been learned about how to most effectively use first-generation EGFR TKIs like erlotinib and gefitinib for non–small-cell lung cancer (NSCLC). We know that EGFR TKIs should be administered instead of first-line chemotherapy to patients with lung cancers carrying EGFR exon 19 or 21 mutations, because this leads to longer median progression-free survival (PFS) and improved quality of life. We know that patients with EGFR-mutant lung cancer with poor performance status should be offered treatment with EGFR TKIs, because this can lead to dramatic responses with marked and durable improvement in performance status. Furthermore, patients with KRASmutant lung cancers rarely respond to EGFR TKIs, and some investigators suspect that such patients may gain no benefit from these agents at all. We are also learning much about continuation of TKIs postprogression in some patients with EGFR-mutant lung cancers, which may prolong the duration of benefit from the drugs. One setting in which the published evidence is inadequate is in the application of predictive biomarkers to guide EGFR TKI therapy in previously treated NSCLC. The BR.21 trial resulted in the initial US Food and Drug Administration approval of erlotinib for previously treated NSCLC by showing a 2-month improvement in median survival over placebo in previously treated NSCLC. A biomarker analysis of this trial was later published, which found that only high EGFR copy number was predictive of survival benefit from erlotinib. However, retrospective EGFR genotyping could only be performed for 204 of the 731 BR.21 patients (28%), and an analysis of PFS was not performed. When one looks as a group at the biomarker analyses from several randomized trials studying erlotinib or gefitinib in previously treated NSCLC (Table 1), it is clear that patients with EGFR-mutant disease have the longest PFS and highest response rates with erlotinib and gefitinib, followed by those with KRAS wild-type disease (including EGFR-mutant disease), whereas those with KRAS-mutant and EGFR wild-type disease (including KRAS-mutant disease) do the least well. The article by Ramalingam et al in Journal of Clinical Oncology adds thought-provoking data to this discussion, with the first randomized data on irreversible EGFR TKIs in patients with lung cancer without previous TKI exposure. In this randomized phase II study for patients with NSCLC experiencing progression during chemotherapy, erlotinib was compared with dacomitinib, an irreversible inhibitor of multiple ERBB-family kinases. Although erlotinib has been found to maximally inhibit the mutant EGFR kinase, dacomitinib irreversibly inhibits EGFR, human epidermal growth factor receptor 2, and ERBB4 at nanomolar concentrations. The authors found a significant improvement in PFS with dacomitinib in the intention-to-treat population (P .012) and in patients with KRAS wild-type lung cancers (P .006). The broader inhibitory activity of dacomitinib

Cetuximab Plus Irinotecan, Fluorouracil, and Leucovorin As First-Line Treatment for Metastatic Colorectal Cancer: Updated Analysis of Overall Survival According to Tumor KRAS and BRAF Mutation Status

The addition of cetuximab to irinotecan, fluorouracil, and leucovorin (FOLFIRI) as first-line treatment for metastatic colorectal cancer (mCRC) was shown to reduce the risk of disease progression and increase the chance of response in patients with KRAS wild-type disease. An updated survival analysis, including additional patients analyzed for tumor mutation status, was undertaken. Patients were randomly assigned to receive FOLFIRI with or without cetuximab. DNA was extracted from additional slide-mounted tumor samples previously used to assess epidermal growth factor receptor expression. Clinical outcome according to the tumor mutation status of KRAS and BRAF was assessed in the expanded patient series. The ascertainment rate of patients analyzed for tumor KRAS status was increased from 45% to 89%, with mutations detected in 37% of tumors. The addition of cetuximab to FOLFIRI in patients with KRAS wild-type disease resulted in significant improvements in overall survival (median, 23.5 v 20.0 months; hazard ratio [HR], 0.796; P = .0093), progression-free survival (median, 9.9 v 8.4 months; HR, 0.696; P = .0012), and response (rate 57.3% v 39.7%; odds ratio, 2.069; P < .001) compared with FOLFIRI alone. Significant interactions between KRAS status and treatment effect were noted for all key efficacy end points. KRAS mutation status was confirmed as a powerful predictive biomarker for the efficacy of cetuximab plus FOLFIRI. BRAF tumor mutation was a strong indicator of poor prognosis. The addition of cetuximab to FOLFIRI as first-line therapy improves survival in patients with KRAS wild-type mCRC. BRAF tumor mutation is an indicator of poor prognosis.