Clinical Utility of Epidermal Growth Factor Receptor Expression for Selecting Patients with Advanced Non-small Cell Lung Cancer for Treatment with Erlotinib:

Factors Determining Long-Term Antitumor Responses to Immune Checkpoint Blockade Therapy in Melanoma

With the increasing promise of long-term survival with immune checkpoint blockade (ICB) therapies, particularly for patients with advanced melanoma, clinicians and investigators are driven to identify prognostic and predictive factors that may help to identify individuals who are likely to experience durable benefit. Several ICB combinations are being actively developed to expand the armamentarium of treatments for patients who may not achieve long-term responses to ICB single therapies alone. Thus, negative predictive markers are also of great interest. This review seeks to deepen our understanding of the mechanisms underlying the durability of ICB treatments. We will discuss the currently available long-term data from the ICB clinical trials and real-world studies describing the survivorship of ICB-treated melanoma patients. Additionally, we explore the current treatment outcomes in patients rechallenged with ICB and the patterns of ICB resistance based on sites of disease, namely, liver or CNS metastases. Lastly, we discuss the landscape in melanoma in the context of prognostic or predictive factors as markers of long-term response to ICB.

An overview of precision oncology basket and umbrella trials for clinicians

With advancements in biomarkers and momentum in precision medicine, biomarker-guided trials such as basket trials and umbrella trials have been developed under the master protocol framework. A master protocol refers to a single, overarching design developed to evaluate multiple hypotheses with the general goal of improving the efficiency of trial evaluation. One type of master protocol is the basket trial, in which a targeted therapy is evaluated for multiple diseases that share common molecular alterations or risk factors that may help predict whether the patients will respond to the given therapy. Another variant of a master protocol is the umbrella trial, in which multiple targeted therapies are evaluated for a single disease that is stratified into multiple subgroups based on different molecular or other predictive risk factors. Both designs follow the core principle of precision medicine-to tailor intervention strategies based on the patient's risk factor(s) that can help predict whether they will respond to a specific treatment. There have been increasing numbers of basket and umbrella trials, but they are still poorly understood. This article reviews common characteristics of basket and umbrella trials, key trials and recent US Food and Drug Administration approvals for precision oncology, and important considerations for clinical readers when critically evaluating future publications on basket trials and umbrella trials and for researchers when designing these clinical trials.

Effect of a Collaboration Between a Health Plan, Oncology Practice, and Comprehensive Genomic Profiling Company from the Payer Perspective

BACKGROUND

Comprehensive genomic profiling (CGP) is a next-generation sequencing-based methodology that detects 4 classes of genomic alterations, as well as gene signature biomarkers such as microsatellite instability and tumor mutational burden. In the context of precision oncology, CGP can help to direct treatment to genomically matched therapies.

OBJECTIVE

To describe the results of a 3-year observational analysis of patients undergoing testing with CGP assays (either FoundationOne or FoundationOne Heme) at a community oncology practice after a regional health plan implemented a medical policy that enabled coverage of CGP.

METHODS

A retrospective analysis of medical records was completed at the oncology practice from November 2013 to January 2017; this date range was chosen to coincide with the regional health plan's medical policy implementation of CGP. The medical policy provided coverage of CGP for patients with advanced solid and hematologic cancers. A medical record review assessed all previous and current molecular test results, matched therapy or clinical trial enrollment, and clinical outcomes (clinical benefit or disease progression). The potential cost diversion, from payer to study sponsor, for patients who enrolled in clinical trials was explored.

RESULTS

There were 96 patients in the community oncology practice who received CGP over the 3-year period, 86 of whom had clinically relevant genomic alterations. Of the 86, 15 patients were treated with genomically matched therapy, and 6 patients enrolled in clinical trials based on CGP results. In a subset of 32 patients who previously underwent conventional testing, most (84%) had clinically relevant genomic alterations detected by CGP that conventional testing did not identify, and a portion of these patients subsequently received treatment based on the CGP results. In the separate cost diversion analysis of 20 patients who enrolled in phase 1 clinical trials, an estimated $25,000 per-patient cost-benefit may have been accrued to the payer.

CONCLUSIONS

This observational analysis characterized the use of CGP in a large community oncology practice among a group of patients insured by a regional health plan. Clinical trial enrollment was facilitated by CGP use in the community setting and may have contributed to cost diversion from the payer to study sponsors.

DISCLOSURES

No separate study-related funding was provided by or to Priority Health, Foundation Medicine, and Cancer and Hematology Centers of West Michigan. Data analysis by Reitsma was conducted as part of an internship funded by Priority Health. Reitsma and Fox are employed by Priority Health. Anhorn, Vanden Borre, Cavanaugh, Chudnovsky, and Erlich are employed by Foundation Medicine.

A model-based multithreshold method for subgroup identification

Thresholding variable plays a crucial role in subgroup identification for personalized medicine. Most existing partitioning methods split the sample based on one predictor variable. In this paper, we consider setting the splitting rule from a combination of multivariate predictors, such as the latent factors, principle components, and weighted sum of predictors. Such a subgrouping method may lead to more meaningful partitioning of the population than using a single variable. In addition, our method is based on a change point regression model and thus yields straight forward model-based prediction results. After choosing a particular thresholding variable form, we apply a two-stage multiple change point detection method to determine the subgroups and estimate the regression parameters. We show that our approach can produce two or more subgroups from the multiple change points and identify the true grouping with high probability. In addition, our estimation results enjoy oracle properties. We design a simulation study to compare performances of our proposed and existing methods and apply them to analyze data sets from a Scleroderma trial and a breast cancer study.

Inference on covariate effect types for treatment effectiveness in a randomized trial with a binary outcome

BACKGROUND/AIMS

Some randomized clinical trials seek to establish covariate effect types that indicate whether a covariate is predictive and/or prognostic, in addition to endpoint evaluation. Here, for a case with a binary outcome, we propose that the covariate effect type should be assessed in terms of four types of potential responses: activated- (always-), inert- (never-), causative-, and preventive-responder.

METHODS

We introduce a new concept of covariate effect types differing from the commonly used "prediction" and "prognosis." We summarize the covariate effect types by inspecting the proportions of subjects in each response type in two subgroups of a covariate, and indicate whether the fractions are augmented, depleted, or neutral as one changes the level of the covariate. Although these proportions cannot generally be identified, we can derive the posterior distributions of the proportions by applying a recently developed Bayesian method. On the basis of the distributions, we would say that the covariate is "augmented-causative" if the difference between the proportions of causative-responders (who would respond if they received the treatment but would not if they did not) in two subgroups is positive, rather than that it is predictive. Similarly, we would say that the covariate is "neutral-activated" if the difference in the proportion of activated-responders (who would respond regardless of their randomized treatment assignment) is close to zero, rather than saying that the covariate is not prognostic. We further describe the relationship between our approach and standard subgroup analysis.

RESULTS

We applied our approach to data from a randomized clinical trial comparing nivolumab and docetaxel for subjects with advanced nonsquamous non-small-cell lung cancer; we assessed the covariate effect type of PD-L1 status, where PD-L1 is a ligand of the programmed death 1 (PD-1) receptor expressed by activated T cells. When the endpoint was the overall response rate, the posterior distributions for the differences between the proportions of subjects in response types in the PD-L1-positive and negative subgroups yielded an expected-a-posteriori estimate of 0.243 (95% credible interval (CI): 0.094, 0.374) for causative-responders and 0.014 (95% CI: -0.087, 0.125) for activated-responders. Thus, PD-L1 status was augmented-causative for nivolumab effectiveness, to an extent of 24.3%, and was neutral-activated.

CONCLUSION

Our approach characterizes the covariate effect types in terms of the response types, and to what extent. In a randomized clinical trial with a binary outcome, our approach is a potentially valuable addition to standard subgroup or regression analysis.

Erlotinib for Patients with EGFR Wild-Type Metastatic NSCLC: a Retrospective Biomarkers Analysis

Erlotinib is approved for the treatment of patients with EGFR mutation positive, metastatic NSCLC. It is also approved as second/third line therapy for EGFR mutation negative patients, but in this setting the benefit of erlotinib is modest and there is no validated biomarker for selecting EGFR wild-type patients who may benefit the most from the treatment. We retrospectively assessed EGFR and K-RAS mutational status, and EGFR, c-MET and IGF1-R expression in tumor samples of 72 patients with metastatic NSCLC treated with erlotinib after at least one prior line of chemotherapy, from 2008 to 2012. We analyzed the association between biomarkers and outcome (RR, PFS, and OS). EGFR mutated patients achieved a better RR (56% vs 8%, p = .002), PFS (10 vs 3 months, HR 0.53, p = 0.48) and OS (20 vs 6 months, HR 0.55, p = .07), compared to EGFR wild-type patients. Among 63 EGFR wild-type patients, those with EGFR high-expression had a better outcome in terms of RR (40% vs 2%, p = .002), PFS (7.5 vs 2 months, HR 0.45, p = .007) and OS (30 vs 5 months, HR 0.34, p < .001) compared to patients with EGFR intermediate or low/negative-expression. IGF1-R expression, c-MET expression and K-RAS mutational status did not significantly affect the outcome; however, no patients with K-RAS mutation or c-MET high-expression achieved an objective response. In patients with metastatic, chemo-refractory EGFR wild-type NSCLC, EGFR high-expression may represent a positive predictor of activity for erlotinib, whereas K-RAS mutation and c-MET high-expression may predict lack of activity. These findings deserve further prospective evaluation.

Predictive and prognostic cancer biomarkers revisited

While both prognostic and predictive cancer biomarkers predict clinical outcome, the term 'predictive biomarker' is reserved for the association of a specific therapy with a specific clinical outcome. The advent of genomic signatures and next generation sequencing as candidate predictive biomarkers has led to lengthy and expensive processes for biomarker qualification. The urgency to bring novel predictive cancer biomarkers to practice faster and cheaper requires strategies to lower the bar to biomarker implementation. Three strategies are suggested: identify biomarkers closely coupled to biologic mechanism associated with the clinical endpoint and scalable from cells to humans; identify biomarkers that can be reliably detected and quantified; and assess biomarkers by capacity to reduce toxicity as well as to increase therapy efficacy. Biomarker selection directly and closely related to production of end points by biologic mechanism demonstrated by a ladder of evidence should require less burden of proof clinically than biomarkers that are merely associative.

EGFR CA repeat polymorphism predict clinical outcome in EGFR mutation positive NSCLC patients treated with erlotinib

OBJECTIVES

Somatic mutations in the epidermal growth factor receptor (EGFR) are predictors of efficacy for treatment with the EGFR tyrosine kinase inhibitor erlotinib in non-small cell lung cancer (NSCLC). A CA repeat polymorphism in intron 1 of the EGFR gene influences the transcription of the EGFR gene. This study evaluates the association between the CA repeat polymorphism and outcome in NSCLC patients treated with erlotinib.

MATERIALS AND METHODS

Number of CA repeats in the EGFR gene was evaluated with PCR-fragment length analysis by capillary electrophoresis in 432 advanced NSCLC patients treated with erlotinib irrespective of EGFR mutation status. Patients were dichotomized into harboring short allele (CA≤16 in any allele) or long alleles (CA>16 in both alleles). Number of repeats was correlated with clinical characteristic and outcome. A subgroup analysis was performed based on the somatic EGFR mutation status.

RESULTS

In EGFR mutation positive patients (N=62) we demonstrate a significantly higher median progression free survival (HR=0.39 (0.22-0.70); p=0.002) and overall survival (HR=0.43 (0.23-0.78); p=0.006) in patients also harboring a short CA repeat length vs. a long (median follow-up time of 52.2 months). The result remained highly significant in a multivariate Cox proportional hazards model. This correlation was not seen in EGFR mutation negative patients.

CONCLUSION

Our study demonstrate that in EGFR mutation positive NSCLC patients treated with erlotinib a low number of CA repeats in intron 1 of the EGFR gene is a predictor for both longer progression free survival and overall survival.

Frequent intratumoral heterogeneity of EGFR gene copy gain in non-small cell lung cancer

Next to EGFR mutation, EGFR gene copy number evaluated by fluorescence in situ hybridization (FISH) emerged as a potential predictive marker for sensitivity to EGFR tyrosine kinase inhibitors, although controversial data exist. As the diagnostic accuracy of predictive biomarkers can be substantially limited by regional differences within tumors, heterogeneity of EGFR gene copy gain in NSCLC was assessed in this study. For this purpose, a novel tissue microarray (TMA) based analysis platform was developed. TMAs were constructed containing 8 different tissue cylinders from 144 primary NSCLCs. From 62 of these patients additional nodal metastases were sampled. EGFR gene copy number and EGFR expression was analyzed by FISH and immunohistochemistry according to the suggested guidelines. 13 (9.0%) of the 144 evaluated tumors showed EGFR amplification and 37 (25.7%) tumors high polysomy in at least one tumor area. In 7 (53.8%) of 13 amplified cases the analysis of different tumor areas revealed subclones without EGFR gene copy gain next to subclones with amplification. All of the 36 evaluable tumors with high polysomy showed heterogeneity of EGFR gene copy number with areas negative for gene copy gain within the individual tumors. Heterogeneity of EGFR gene copy gain in lung cancer challenges the concept of using small biopsies for the analysis of EGFR FISH status. EGFR gene copy number is highly heterogeneous within individual NSCLCs and this finding might well be a reason for the controversial clinical data existing regarding responsiveness to anti-EGFR therapy.

Personalized medicine in breast cancer: a systematic review

The recent advent of "-omics" technologies have heralded a new era of personalized medicine. Personalized medicine is referred to as the ability to segment heterogeneous subsets of patients whose response to a therapeutic intervention within each subset is homogeneous. This new paradigm in healthcare is beginning to affect both research and clinical practice. The key to success in personalized medicine is to uncover molecular biomarkers that drive individual variability in clinical outcomes or drug responses. In this review, we begin with an overview of personalized medicine in breast cancer and illustrate the most encountered statistical approaches in the recent literature tailored for uncovering gene signatures.

Intratumor heterogeneity and chemotherapy-induced changes in EGFR status in non-small cell lung cancer

INTRODUCTION

Biomarker expression is increasingly being used to customize treatment in non-small cell lung cancer (NSCLC). The choice of systemic treatment usually depends on biomarker expression in the initial diagnostic biopsy taken before initiation of first-line treatment. Chemotherapy induces DNA damages in the tumor cells, and thus, biomarker expression in the tumor after systemic treatment might not be identical to biomarker expression in the diagnostic biopsy. NSCLC is highly heterogeneous and biomarker expression may vary in different areas within the same tumor. This review explores the tumor heterogeneity and chemotherapy-induced changes in EGFR biomarker status in NSCLC.

METHODS

A literature search was performed in August 2011 using pubmed.

RESULTS

Fifteen trials explored EGFR status in primary tumor and subsequent resected primary tumor, lymph node metastases, or organ metastases. Four papers compared EGFR status in primary tumor or metastases before and after systemic treatment. All trials included relatively few patients and used different chemotherapy regimes, biopsy locations, or time intervals between biopsies.

CONCLUSIONS

Tumor heterogeneity and probably also previous systemic treatment may be an obstacle for correct interpretation of EGFR status in NSCLC. Heterogeneity regarding EGFR mutations is probably rare and previously reported intra and intertumor heterogeneity may be due to methodological issues. In the current and future clinical scenario with many different options for systemic treatment both as 2nd line and beyond, it is increasingly important to further elucidate the role extent of chemotherapy-induced changes in biomarker expression for proper use of biomarkers in order to customize treatment and thus improve prognosis.

EGFR-mutated oncogene-addicted non-small cell lung cancer: current trends and future prospects

Non-small cell lung cancer (NSCLC) tumours with certain mutations in the epidermal growth factor receptor (EGFR) tyrosine kinase have been termed 'oncogene addicted' to reflect their dependence on EGFR-mediated pro-survival signalling and their high susceptibility to apoptosis induced by EGFR tyrosine kinase inhibitors (EGFR-TKIs, e.g. gefitinib and erlotinib). The most common mutations (L858R and exon 19 deletions) predict an improved clinical response to first-line oral EGFR-TKIs compared with standard platinum-based chemotherapy in patients with advanced NSCLC. Moreover, these mutations are also prognostic of a relatively indolent course of disease, regardless of treatment, as compared with classical NSCLC. Treatment strategies for oncogene-addicted NSCLC are therefore distinct from those for non-oncogene addicted NSCLC, and will depend on the specific genetic mutation present.

Targeted Therapies in Lung Cancer

An ongoing research and multiple clinical trials involve new targeted therapies and less aggressive treatment regimens that improve survival in patients with lung cancer. Targeted therapeutic agents are based on the concept of discovering genetic alterations and the signaling pathways altered in cancer and have added significantly to our armamentarium in order to prolong patient survival and minimizing drug toxicity. Among 34 molecularly targeted drugs approved by U.S. Food and Drug Administration (FDA) for treatment of various cancers since 1998 three targeted therapies have been approved for treatment of lung cancer (gefitinib in 2002, erlotinib in 2003, and bevacizumab in 2006).This review focuses on the targeted therapies in lung cancer, the molecular biomarkers that help identify patients that will benefit for these targeted therapies, describes the basic molecular biology principles and selected molecular diagnostic techniques and the pathological features correlated with molecular abnormalities in lung cancer. Lastly, new molecular abnormalities described in lung cancer that are predictive to novel promising targeted agents in various phases of clinical trials are discussed.

The potential clinical and economic outcomes of pharmacogenomic approaches to EGFR-tyrosine kinase inhibitor therapy in non-small-cell lung cancer

OBJECTIVES

Pharmacogenomic applications in oncology offer significant promise, but the clinical and economic implications remain unclear. The objective of this study was to evaluate the potential cost-utility of implementing epidermal growth factor receptor (EGFR) testing before initiating second-line therapy for advanced refractory non-small-cell lung cancer (NSCLC).

METHODS

We developed a decision analytic model to evaluate the cost-utility of EGFR protein expression or gene copy number testing compared to standard care with erlotinib in refractory advanced NSCLC patients. Costs and utilities were obtained from publicly available sources. We performed sensitivity analyses to evaluate uncertainty in the results.

RESULTS

The quality-adjusted life expectancies for erlotinib, EGFR protein expression testing, and gene copy number testing were: 0.44, 0.48, and 0.50 quality-adjusted life years (QALYs); and the costs were: $57,238, $63,512, and $66,447, respectively. The most cost-effective testing option, EGFR gene copy number testing, produced an incremental cost-effectiveness ratio of $162,018/QALY compared to no testing (erlotinib). The results were most sensitive to the survival estimates, health state utilities, and cost of disease progression. In the probabilistic sensitivity analyses, erlotinib without testing was the optimal treatment strategy until the $150,000/QALY willingness-to-pay threshold, after which gene copy testing was optimal. The discounted expected value of perfect information at a $100,000/QALY threshold in the USA over 5 years was $31.4 million.

CONCLUSIONS

The study results suggest that EGFR pharmacogenomic testing has the potential to improve quality-adjusted life expectancy in the treatment of refractory NSCLC by a clinically meaningful margin at a value commensurate with the approved therapies in this setting. Additional research in this area is warranted.

Phase I study of cetuximab, erlotinib, and bevacizumab in patients with advanced solid tumors

BACKGROUND

Complex interrelationships exist between the epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGF) receptor pathways. EGFR activation elicits cell proliferation and increased VEGF expression. To maximally inhibit EGFR and then downstream VEGF activity, this phase I study was initiated to determine the maximum tolerated dose (MTD) of erlotinib with fixed-dose cetuximab, and then combine with bevacizumab in patients with advanced malignancies.

PATIENTS AND METHODS

Patients with advanced malignancies likely to express EGFR were treated with a full dose of cetuximab intravenous weekly, combined with various doses of oral erlotinib daily (Part 1). Once the MTD was determined in Part 1, escalating doses of bevacizumab were administered intravenously biweekly (Part 2).

RESULTS

Forty patients were enrolled and received 155 courses over four dose levels. In Part 1, dose-limiting grade 3 rash occurred in two patients administered with erlotinib at 100 mg daily, and the MTD of erlotinib for this combination was 50 mg daily with standard-dose cetuximab (11 patients treated). Other adverse events included rash, diarrhea, fatigue, and hypomagnesemia. In Part 2, bevacizumab at 10 mg/kg intravenous every 2 weeks was safely added, with additional nondose-limiting headache, proteinuria, and hypertension. There was one partial response in a patient with renal cell carcinoma. Durable stable disease was observed in five patients for 6-11 months.

CONCLUSIONS

The MTD for Part 1 was 50 mg daily of erlotinib combined with standard cetuximab. Bevacizumab at 10 mg/kg biweekly can be safely administered with the MTD for erlotinib and cetuximab combination.

Advances in genomic and proteomic studies of non-small-cell lung cancer: clinical and translational research perspective

Recent years have brought tremendous progress in the development of genomic and proteomic platforms to study cancer biology. Tests based on these platforms are helpful in early diagnosis, prognosis, and prediction of treatment benefit. Molecular studies performed on minimally invasive material (plasma, sputum) from individuals participating in longitudinal or case-control studies have approximately 70%-90% sensitivity and specificity to detect lung cancer. In operable non-small-cell lung cancer, genomic and proteomic studies yield better prognostic information than pathologic staging. There are several examples of successful identification of predictive assays for benefit from chemotherapy (ERCC1, RRM1, p27Kip1, and p53 expression) or targeted therapies (epidermal growth factor receptor [EGFR] gene copy number, EGFR activating mutations, EGFR protein expression, serum proteomic profile). These markers should be prospectively tested in clinical studies before they can be routinely used in the clinic.

Second-line treatment of advanced non-small cell lung cancer

After failure of first-line chemotherapy for advanced non-small cell lung cancer, many patients remain candidates to receive further antitumor treatment. To guide clinical management of these patients and to suggest priorities for clinical research, an International Panel of Experts met in Naples (Italy) in April 2007. Results and evidence-based conclusions are presented in this article. Single-agent chemotherapy with docetaxel or pemetrexed is the recommended option for unselected patients with performance status 0 to 2 who are candidates for second-line chemotherapy for advanced non-small cell lung cancer. Docetaxel has demonstrated superiority compared with best supportive care. Pemetrexed has been shown to be noninferior to docetaxel, with a more favorable toxicity profile. Erlotinib is effective in pretreated patients, and can be given second-line in patients not suitable or intolerant to chemotherapy, and in all patients as third-line treatment after failure of second-line chemotherapy. Gefitinib failed to show superiority to placebo as second- or third-line treatment, but it has been shown to be noninferior to docetaxel. In selected patients such as lifetime nonsmokers or those of East-Asian ethnicity, erlotinib, or gefitinib (where licensed) may be considered as second-line treatment even if they are fit for chemotherapy. Best supportive care in addition to active treatment remains important for all patients, but may be the exclusive option for patients unsuitable for more aggressive therapy. Further research is mandatory, to find better treatments, and to identify clinical and molecular predictive markers of efficacy, both for chemotherapy and for novel biologic agents.

Epidermal growth factor receptor immunohistochemistry: comparison of antibodies and cutoff points to predict benefit from gefitinib in a phase 3 placebo-controlled study in advanced nonsmall-cell lung cancer

BACKGROUND

The ISEL (Iressa Survival Evaluation in Lung Cancer) clinical trial evaluated the efficacy of gefitinib versus placebo in pretreated nonsmall-cell lung cancer patients. Two different antibodies, scoring systems, and cutoff points of epidermal growth factor receptor (EGFR) protein expression were compared to predict response and survival of enrolled patients.

METHODS

EGFR expression was assessed in tumor samples by immunohistochemistry using the Dako EGFR pharmDx kit (scoring percent of tumor cells with positive staining) and Zymed monoclonal antibody clone 31G7 (scoring staining index derived from proportion of positive cells times staining intensity).

RESULTS

Data for EGFR expression were available for 379 patients for Dako and 357 patients for Zymed antibody (22% and 21%, respectively, of trial population). Objective response rates in gefitinib-treated EGFR-positive patients defined with various cutpoints with Dako antibody varied between 8% and 12%, and with Zymed antibody between 10% and 13%. Lower cutoff points with Dako antibody provided the best discrimination between EGFR-positive and EGFR-negative patients for survival hazard ratios comparing gefitinib to placebo, with a significant treatment/cutoff point interaction for 10% cutoff point (P = .049). A similar but less apparent trend was noted for Zymed antibody, although the discrimination between hazard ratios was not significant for any cutoff point analyzed.

CONCLUSIONS

Assessment with the Dako PharmDx kit and percentage of cells with positive staining may provide more accurate prediction of differential effect on survival with gefitinib than assessment with Zymed antibody and staining index. Using higher cutpoints to define positivity does not improve test discrimination.

Epidermal growth factor receptor inhibitor-related skin toxicity: mechanisms, treatment, and its potential role as a predictive marker

The human epidermal growth factor receptor (HER1/EGFR/ErbB1) signaling is aberrant and overexpressed in many solid malignancies making it an appealing target for biologic agents. Among the classes of drugs targeting EGFR are monoclonal antibodies and EGFR tyrosine kinase inhibitors, which have been shown effective and generally well tolerated in different clinical settings. The majority of patients treated with EGFR inhibitors (EGFRIs) develop specific dose-dependent skin toxicity. This side effect may lead to physical and psychosocial discomfort which can result in dose reduction or treatment interruption. The relationship between rash and clinical outcome has stimulated interest in this particular toxicity as a possible surrogate marker of efficacy in patients treated with targeted agents against EGFR. This review aims to summarize and update the current knowledge of the clinical presentation, predictive and prognostic value, and the management of EGFRI-related skin toxicity.