Emerging Insights into Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis Induced by Immune Checkpoint Inhibitor and Tumor-Targeted Therapy

Objective

Anticancer drugs have revolutionized tumor therapy, with cutaneous toxicities such as Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) being common immune-related adverse events. The debate over the efficacy of systemic corticosteroids in treating these conditions persists, while tumor necrosis factor (TNF)-alpha inhibitors show promise. This study aims to evaluate the effectiveness and safety of combination therapy involving the TNF-α inhibitor adalimumab for SJS/TEN induced by anticancer drugs.

Methods

A literature review of SJS/TEN cases induced by anticancer drugs from 1992 to 2023 was conducted, alongside an analysis of patients admitted to the First Affiliated Hospital of Fujian Medical University during the same period. Clinical characteristics, skin healing time, mortality, and adverse events were evaluated in two treatment groups: SJS/TEN patients treated with targeted anticancer therapies and immunotherapies.

Results

Among the 27 patients studied (18 with SJS or SJS-TEN overlapping and 9 with TEN), combination therapy with adalimumab significantly reduced mucocutaneous reepithelization time and healing duration compared to corticosteroid monotherapy. Patients receiving adalimumab combined with corticosteroids had lower actual mortality rates than those on corticosteroid monotherapy. The combination therapy also showed a trend towards reducing standardized mortality rates based on the Score of Toxic Epidermal Necrolysis (SCORTEN).

Conclusion

The findings suggest that adalimumab in combination with corticosteroids provides significant clinical benefits and is safer than corticosteroids alone for treating SJS/TEN induced by targeted anticancer therapies and immunotherapies. This study contributes valuable insights into potential treatment strategies for severe cutaneous adverse reactions to anticancer drugs, highlighting the importance of exploring alternative therapies such as TNF-α inhibitors in managing these conditions effectively.

Cutaneous adverse reactions resulting from targeted cancer therapies: histopathologic and clinical findings

Targeted cancer treatments-designed to interfere with specific molecular signals responsible for tumor survival and progression-have shown benefit over conventional chemotherapies but may lead to diverse cutaneous adverse effects. This review highlights clinically significant dermatologic toxicities and their associated histopathologic findings, resulting from various targeted cancer drugs. Case reports and series, clinical trials, reviews, and meta-analyses are included for analysis and summarized herein. Cutaneous side effects resulting from targeted cancer therapies were reported with incidences as high as 90% for certain medications, and reactions are often predictable based on mechanism(s) of action of a given drug. Common and important reaction patterns included: acneiform eruptions, neutrophilic dermatoses, hand-foot skin reaction, secondary cutaneous malignancies, and alopecia. Clinical and histopathologic recognition of these toxicities remains impactful for patient care.

Evaluation of Delayed-Type Hypersensitivity to Antineoplastic Drugs-An Overview

Nowadays, clinical practice encounters the problem of delayed-type hypersensitivity (DTH) induced by several drugs. Antineoplastic treatments are among the drugs which show an elevated proportion of DHT reactions, leading to the worsening of patients' quality of life. The range of symptoms in DHT reactions can vary from mild, such as self-limiting maculopapular eruptions, to severe, such as Stevens-Johnson Syndrome. The development of these reactions supposes a negative impact, not only by limiting patients' quality of life, but also leading to economic loss due to market withdrawal of the affected drugs and high hospitalization costs. However, despite this problem, there are no available standard in vitro or in vivo methods that allow for the evaluation of the sensitizing potential of drugs in the preclinical phase. Therefore, the aim of this review is to summarize the skin reactions caused by the different antineoplastic families, followed by a comprehensive evaluation of the in vitro and in vivo methods used to detect DTHs and that could be suitable to test antineoplastic hypersensitivity reactions.

The diverse landscape of dermatologic toxicities of non-immune checkpoint inhibitor monoclonal antibody-based cancer therapy

BACKGROUND

Since their first approval 25 years ago, monoclonal antibodies (mAbs) have become important targeted cancer therapeutics. However, dermatologic toxicities associated with non-immune checkpoint inhibitor (non-ICI) mAbs may complicate the course of cancer treatment. Data on the incidence and types of these reactions are limited.

METHODS

A comprehensive review was conducted on dermatologic toxicities associated with different classes of non-ICI mAbs approved for treatment of solid tumors and hematologic malignancies. The review included prospective Phase 1, 2, and 3 clinical trials; retrospective literature reviews; systematic reviews/meta-analyses; and case series/reports.

RESULTS

Dermatologic toxicities were associated with several types of non-ICI mAbs. Inflammatory reactions were the most common dermatologic toxicities, manifesting as maculopapular, urticarial, papulopustular/acneiform, and lichenoid/interface cutaneous adverse events (cAEs) with non-ICI mAbs. Immunobullous reactions were rare and a subset of non-ICI mAbs were associated with the development of vitiligo cAEs.

CONCLUSION

Dermatologic toxicities of non-ICI mAbs are diverse and mostly limited to inflammatory reactions. Awareness of the spectrum of the histopathologic patterns of cAE from non-ICI mAbs therapy is critical in the era of oncodermatology and oncodermatopathology.

Hypersensitivity reactions to biologics in children

INTRODUCTION

Hypersensitivity reactions (HSRs) have been observed with the use of biologics in children. The management of HSRs in children is mainly based on experiences from the adult population. Recently, data from different centers experienced in managing these reactions, including desensitization in children, have been published, allowing clinicians to have an appropriate global overview and compare results.

AREAS COVERED

This review highlights the published data on hypersensitivity reactions to biologics in children and drug desensitization protocols adapted to the pediatric population.

EXPERT OPINION

With regard to HSRs to biologics in children, few data are available. Compared with the adult population, there is a lack of knowledge in the endophenotypes, management and the standardization of protocols including premedication regimens in children. An international consensus is needed to provide clinicians with new insight on how to apply personalized management and to perform tailored desensitization protocols in pediatric populations. Various specialists including allergists, pediatricians, oncologists, hematologists, rheumatologists, and pharmacists, should build a multidisciplinary management team to keep pediatric patients on their best treatment options in the safest manner.

Mechanism of Lethal Skin Toxicities Induced by Epidermal Growth Factor Receptor Inhibitors and Related Treatment Strategies

Epidermal growth factor receptor (EGFR) inhibitors are widely used to treat various types of cancers such as non-small cell lung cancer, head and neck cancer, breast cancer, pancreatic cancer. Adverse reactions such as skin toxicity, interstitial lung disease, hepatotoxicity, ocular toxicity, hypomagnesemia, stomatitis, and diarrhea may occur during treatment. Because the EGFR signaling pathway is important for maintaining normal physiological skin function. Adverse skin reactions occurred in up to 90% of cancer patients treated with EGFR inhibitors, including common skin toxicities (such as papulopustular exanthemas, paronychia, hair changes) and rare fatal skin toxicities (e.g., Stevens–Johnson syndrome, toxic epidermal necrolysis, acute generalized exanthematous pustulosis). This has led to the dose reduction or discontinuation of EGFR inhibitors in the treatment of cancer. Recently, progress has been made about research on the skin toxicity of EGFR inhibitors. Here, we summarize the mechanism of skin toxicity caused by EGFR inhibitors, measures to prevent severe fatal skin toxicity, and provide reference for medical staff how to give care and treatment after adverse skin reactions.

Adverse Reactions to Biologic Medications Used in Allergy and Immunology Diseases

PURPOSE OF REVIEW

The use of biologic therapies has risen exponentially over recent years, allowing for unprecedented disease control within numerous areas of Allergy/Immunology. With this expanded use, awareness and understanding of adverse reactions to biologic agents have also increased.

RECENT FINDINGS

Multiple biologic adverse reaction phenotypes have been described, but significant overlap in clinical features across phenotypes exists. Given considerable phenotypic overlap, a targeted testing approach may not always be clear, and more recent classifications focus on management decision making using tools of diagnostic challenges and rapid drug desensitizations, guiding clinicians in developing a management plan when the exact underlying mechanism is not clearly known. With increased clinical experience with omalizumab, mepolizumab, reslizumab, benralizumab, dupilumab, tezepelumab, rituximab, and TNF-inhibitors, there is a growing appreciation to the spectrum and particularities of adverse reactions to these agents which are outlined in this review. Our understanding of the clinical presentation and management of adverse reactions to biologic medications encountered in Allergy/Immunology has grown. Opportunities remain to further define optimal diagnostic and management strategies for these reactions.

Drug eruptions with novel targeted therapies - immune checkpoint and EGFR inhibitors

Given the increasing use of novel targeted therapies, dermatologists are constantly confronted with novel cutaneous side effects of these agents. A rapid diagnosis and appropriate management of these side effects are crucial to prevent impairment of the patients' quality of life and interruptions of essential cancer treatments. Immune checkpoint and EGFR inhibitors are frequently used targeted therapies for various malignancies and are associated with a distinct spectrum of cutaneous adverse events. Exanthematous drug eruptions represent a particular diagnostic challenge in these patients. Immune checkpoint inhibitors can elicit a plethora of immune-related exanthemas, most commonly maculopapular, lichenoid, and psoriasiform eruptions. Additionally, autoimmune bullous dermatoses and exanthemas associated with connective tissue diseases may arise. In cases of severe, atypical or therapy-resistant presentations an extensive dermatological investigation including a skin biopsy is recommended. Topical and systemic steroids are the mainstay of treatment. Papulopustular eruptions represent the major cutaneous adverse effect of EGFR inhibitor therapy, occurring in up to 90 % of patients within the first two weeks of therapy, depending on the agent. Besides topical antibiotics and steroids, oral tetracyclines are the first choice in systemic treatment and can also be used as prophylaxis.

Potentially life‑threatening severe cutaneous adverse reactions associated with tyrosine kinase inhibitors (Review)

Tyrosine kinase inhibitors (TKIs) have emerged as a new frontier of cancer therapy. These agents include inhibitors of epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER2), BRAF, mitogen‑activated protein kinase kinase (also referred to as MEK), bcr‑abl, c‑KIT, platelet‑derived growth factor (PDGFR), fibroblast growth factor receptor (FGFR), anaplastic lymphoma kinase (ALK) and vascular endothelial growth factor (VEGF). Along with the evolving applications of TKIs, there has been an increased recognition of the breadth of potential cutaneous toxicities to these agents. In this review, we provide an overview of potentially life‑threatening severe cutaneous adverse reactions (SCARs) that may occur during therapy with TKIs. These toxicities include Stevens‑Johnson Syndrome (SJS), toxic epidermal necrolysis (TEN), drug reaction with eosinophilia and systemic symptoms (DRESS), and acute generalized exanthematous pustulosis (AGEP).

Critical Care Management of Toxicities Associated With Targeted Agents and Immunotherapies for Cancer

OBJECTIVES

To describe the most common serious adverse effects and organ toxicities associated with emerging therapies for cancer that may necessitate admission to the ICU.

DATA SOURCES AND STUDY SELECTION

PubMed and Medline search of relevant articles in English on the management of adverse effects of immunotherapy for cancer.

DATA EXTRACTION AND DATA SYNTHESIS

Targeted therapies including tyrosine kinase inhibitors, monoclonal antibodies, checkpoint inhibitors, and immune effector cell therapy have improved the outcome and quality of life of patients with cancer. However, severe and life-threatening side effects can occur. These toxicities include infusion or hypersensitivity reactions, cytokine release syndrome, pulmonary, cardiac, renal, hepatic, and neurologic toxicities, hemophagocytic lymphohistiocytosis, opportunistic infections, and endocrinopathies. Cytokine release syndrome is the most common serious toxicity after administration of monoclonal antibodies and immune effector cell therapies. Most of the adverse events from immunotherapy results from an exaggerated T-cell response directed against normal tissue, resulting in the generation of high levels of proinflammatory cytokines. Toxicities from targeted therapies are usually secondary to "on target toxicities." Management is largely supportive and may include discontinuation of the specific agent, corticosteroids, and other immune suppressing agents for severe (grade 3 or 4) immune-related adverse events like neurotoxicity and pneumonitis.

CONCLUSIONS

The complexity of toxicities associated with modern targeted and immunotherapeutic agents for cancer require a multidisciplinary approach among ICU staff, oncologists, and organ specialists and adoption of standardized treatment protocols to ensure the best possible patient outcomes.

Current Perspectives on Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are considered a delayed-type hypersensitivity reaction to drugs. They represent true medical emergencies and an early recognition and appropriate management is decisive for the survival. SJS/TEN manifest with an "influenza-like" prodromal phase (malaise, fever), followed by painful cutaneous and mucous membrane (ocular, oral, and genital) lesions, and other systemic symptoms. The difference between SJS, SJS/TEN overlap, and TEN is defined by the degree of skin detachment: SJS is defined as skin involvement of < 10%, TEN is defined as skin involvement of > 30%, and SJS/TEN overlap as 10-30% skin involvement. The diagnosis of different degrees of epidermal necrolysis is based on the clinical assessment in conjunction with the corresponding histopathology. The mortality rates for SJS and TEN have decreased in the last decades. Today, the severity-of-illness score for toxic epidermal necrolysis (SCORTEN) is available for SJS/TEN severity assessment. Drugs with a high risk of causing SJS/TEN are anti-infective sulfonamides, anti-epileptic drugs, non-steroidal anti-inflammatory drugs of the oxicam type, allopurinol, nevirapine, and chlormezanone. Besides conventional drugs, herbal remedies and new biologicals should be considered as causative agents. The increased risk of hypersensitivity reactions to certain drugs may be linked to specific HLA antigens. Our understanding of the pathogenesis of SJS/TEN has improved: drug-specific T cell-mediated cytotoxicity, genetic linkage with HLA- and non-HLA-genes, TCR restriction, and cytotoxicity mechanisms were clarified. However, many factors contributing to epidermal necrolysis still have to be identified, especially in virus-induced and autoimmune forms of epidermal necrolysis not related to drugs. In SJS/TEN, the most common complications are ocular, cutaneous, or renal. Nasopharyngeal, esophageal, and genital mucosal involvement with blisters, erosions as well as secondary development of strictures also play a role. However, in the acute phase, septicemia is a leading cause of morbidity and fatality. Pulmonary and hepatic involvement is frequent. The acute management of SJS/TEN requires a multidisciplinary approach. Immediate withdrawal of potentially causative drugs is mandatory. Prompt referral to an appropriate medical center for specific supportive treatment is of utmost importance. The most frequently used treatments for SJS/TEN are systemic corticosteroids, immunoglobulins, and cyclosporine A.

Severe cutaneous adverse reactions induced by targeted anticancer therapies and immunotherapies

With the increasing use of targeted anticancer drugs and immunotherapies, there have been a substantial number of reports concerning life-threatening severe cutaneous adverse reactions (SCARs), including Stevens–Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), drug rash with eosinophilia and systemic symptoms, drug-induced hypersensitivity syndrome, and acute generalized exanthematous pustulosis. Although the potential risks and characteristics for targeted anticancer agent- and immunotherapy-induced SCAR were not well understood, these serious adverse reactions usually result in morbidity and sequela. As a treatment guideline for this devastating condition is still unavailable, prompt withdrawal of causative drugs is believed to be a priority of patient management. In this review, we outline distinct types of SCARs caused by targeted anticancer therapies and immunotherapies. Also, we discuss the clinical course, latency, concomitant medication, tolerability of rechallenge or alternatives, tumor response, and mortality associated with these devastating conditions. Imatinib, vemurafenib, and rituximab were the top three offending medications that most commonly caused SJS/TEN, while EGFR inhibitors were the group of drugs that most frequently induced SJS/TEN. For drug rash with eosinophilia and systemic symptoms/drug-induced hypersensitivity syndrome and acute generalized exanthematous pustulosis, imatinib was also the most common offending drug. Additionally, we delineated 10 SCAR cases related to innovative immunotherapies, including PD1 and CTLA4 inhibitors. There was a wide range of latency periods: 5.5–91 days (median). Only eight of 16 reported patients with SCAR showed clinical responses. Targeted anticancer drugs and immunotherapies can lead to lethal SCAR (14 deceased patients were identified as suffering from SJS/TEN). The mortality rate of TEN was high: up to 52.4%. The information compiled herein will serve as a solid foundation to formulate ideas for early recognition of SCAR and to discontinue offending drugs for better management.

Anticancer Drugs Induced Severe Adverse Cutaneous Drug Reactions: An Updated Review on the Risks Associated with Anticancer Targeted Therapy or Immunotherapies

Cutaneous adverse drug reactions are commonly seen in patients with anticancer drug treatment. Anticancer drugs, including chemotherapy, target therapy, and recent immunotherapy causing skin reactions ranging from mild skin rash to life-threatening severe cutaneous adverse reactions (SCARs), such as Stevens-Johnson syndrome (SJS) and toxic epidermal necrosis (TEN) with increase morbidity and mortality while they are receiving cancer treatments, have been proposed to be a result of direct skin toxicity or drug hypersensitivity reactions (these are proposed mechanism, not definite). Differentiating SCARs from other more commonly seen reactions with a better outcome help prevent discontinuation of therapy and inappropriate use of systemic immunosuppressants for presumable allergic reactions, of which will affect the clinical outcome. In this article, we have reviewed published articles from 1950 to August 2017 for SJS/TEN associated with anticancer drugs, including chemotherapy, targeted therapy, and immunotherapy. We aimed to provide an overview of SJS/TEN associated with anticancer drugs to increase clinician recognition and accelerate future studies on the pathomechanism and managements.

Afatinib-associated Stevens-Johnson syndrome in an EGFR-mutated lung cancer patient

INTRODUCTION

Afatinib is a tyrosine kinase inhibitor (TKI), that has been approved for treating patients with epidermal growth factor receptor (EGFR) mutated advanced non-small-cell lung cancer (NSCLC). Stevens-Johnson syndrome (SJS) related to EGFR directed TKIs is a rare adverse event.

CASE PRESENTATION

We report a case of a 79-year-old white female with EGFR-mutated, metastatic non-small-cell lung cancer treated with afatinib as first-line palliative treatment, who developed a SJS after two months of treatment. Discontinuation of the TKI and systemic glucocorticoid treatment led to improvement of symptoms and recovery.

CONCLUSION

Severe adverse cutaneous drug reactions that predominantly involve the skin and mucous membranes during treatment with afatinib should alert clinicians to suspect SJS and react appropriately.

Life-threatening dermatologic adverse events in oncology

The incidences of life-threatening toxicities such as Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are inconsistently reported. The potential association of anticancer agents with SJS or TEN has not been systematically investigated. We searched the literature (Ovid: 1950 to June 2013 and PubMed: 1948 to June 2013) using terms for SJS/TEN and anticancer therapies. Primary case reports, case series, and clinical trials were included. In addition, MedWatch, the Food and Drug Administration Adverse Event Reporting System (FAERS), was searched (1968 to August 2012) for SJS/TEN reports associated with anticancer therapies. Proportional reporting ratios (PRR>2, N>3), empirical Bayes geometric mean (EBGM>2, N>3), and lower 95% confidence interval (EBGM0.05>2) were used as thresholds to constitute a signal of association between SJS/TEN and anticancer drugs. There were 46 SJS and 37 TEN cases associated with 18 and 22 anticancer drugs in the literature, respectively. Among cases in the FAERS, significant signals were associated with SJS for bendamustine and with TEN for bendamustine, busulfan, chlorambucil, fludarabine, lomustine, and procarbazine. Several drugs reported in the published literature to be associated with SJS/TEN were not found to have significant signals in FAERS. Proactive pharmacovigilance to detect and define safety signals serves to aid oncology practitioners in the recognition of possible, yet uncommon, serious, and/or life-threatening skin reactions.

Stevens-Johnson syndrome and toxic epidermal necrolysis overlap in a patient receiving cetuximab and radiotherapy for head and neck cancer

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are severe and life-threatening adverse drug reactions. Herein we report about a patient with head and neck cancer, who developed SJS-TEN overlap after having received cetuximab and radiotherapy. To date, there are only two reports of TEN associated with cetuximab therapy in patients with cancer. Every skin condition in a patient with cancer leading to extensive exfoliation of the skin should alert the oncologist of a possibility of drug-induced SJS or TEN.

Autoimmunity associated with immunotherapy of cancer

In this age of promise of new therapies for cancer, immunotherapy is emerging as an exciting treatment option for patients. Vaccines and cytokines are being tested extensively in clinical trials, and strategies using monoclonal antibodies and cell transfer are mediating dramatic regression of tumors in patients with certain malignancies. However, although initially advocated as being more specific for cancer and having fewer side effects than conventional therapies, it is becoming increasingly clear that many immunotherapies can lead to immune reactions against normal tissues. Immunotoxicities resulting from treatment can range from relatively minor conditions, such as skin depigmentation, to severe toxicities against crucial organ systems, such as liver, bowel, and lung. Treatment-related toxicity has correlated with better responses in some cases, and it is probable that serious adverse events from immune-mediated reactions will increase in frequency and severity as immunotherapeutic approaches become more effective. This review introduces immunotherapeutic approaches to cancer treatment, provides details of toxicities arising from therapy, and discusses future potential ways to avoid or circumvent these side effects.

Toxic epidermal necrolysis associated with TS-1 in a patient with gastric cancer

A 64-year-old female who has undergone D2 total gastrectomy was started on adjuvant treatment with TS-1. Four weeks after initiation of TS-1, the patient developed a rare complication of life-threatening toxic epidermal necrolysis. TS-1 was discontinued and the patient received treatment with intravenous immunoglobulin and supportive care with resolution of toxic epidermal necrolysis. TS-1 has been used for the treatment of gastric cancer, both in the adjuvant and metastatic setting, and is increasingly being used in other malignancies such as colon, pancreatic and non-small cell lung cancer. TS-1 is generally well tolerated. To our knowledge, this is the first reported case of toxic epidermal necrolysis associated with the usage of TS-1.

Density of Demodex folliculorum in patients receiving epidermal growth factor receptor inhibitors

BACKGROUND

Rosacea-like papulopustular eruptions (rash) are considered the most frequent toxicities associated with the use of inhibitors of the epidermal growth factor receptor (EGFR). Recently, evidence has been accumulating of infectious complications in patients suffering from these adverse effects.

OBJECTIVE

We sought to analyze the density of Demodex folliculorum (DF) in cutaneous lesions of patients presenting with EGFR-inhibitor (EGFRI)-induced rashes.

METHODS

This is a retrospective study of 19 adult patients presenting with EGFRI rashes. Patients were reviewed for the density of DF (Demodex density, Dd; mites per square centimeter) by standardized skin surface biopsy.

RESULTS

In our patient collective the mean Dd of 4.7/cm² significantly exceeded the mean Dd reported for the healthy adult population (Dd = 0.7/cm²).

LIMITATIONS

The retrospective nature of the study.

CONCLUSIONS

EGFRI patients have an increased susceptibility to DF colonization or infection, respectively. Our results support the recent concept that EGFRI may induce an impairment of antimicrobial defense mechanisms.

Interdisciplinary management of EGFR-inhibitor-induced skin reactions: a German expert opinion

BACKGROUND

Anti-epidermal growth factor receptor treatment strategies, i.e. monoclonal antibodies such as cetuximab and panitumumab, or epidermal growth factor receptor (EGFR) small molecule tyrosine kinase inhibitors, such as erlotinib and gefitinib, have expanded the treatment options for different tumor types. Dermatologic toxic effects are the most common side-effects of EGFR inhibitor therapy. They can profoundly affect the patient's quality of life.

PURPOSE

The aim of this study was to provide interdisciplinary expert recommendations on how to treat patients with skin reactions undergoing anti-EGFR treatment.

MATERIAL AND METHODS

An expert panel from Germany with expertise in medical oncology, dermatology or clinical pharmacology was convened to develop expert recommendations based on published peer-reviewed literature.

RESULTS

The expert recommendations for the state-of-the-art treatment of skin reactions induced by EGFR inhibitor therapy include recommendations for diagnostics and grading as well as grade-specific and stage-adapted treatment approaches and preventive measures. It was concluded that EGFR-inhibitor-related dermatologic reactions should always be treated combining basic care of the skin and a specific therapy adapted to stage and grade of skin reaction. For grade 2 and above, specific treatment recommendations for early- and later-stage skin reactions induced by EGFR-inhibitor therapy were proposed.

CONCLUSION

This paper presents a German national expert opinion for the treatment of skin reactions in patients receiving EGFR inhibitor therapy.

Toxic epidermal necrolysis caused by cetuximab plus minocycline in head and neck cancer

We present a unique case of toxic epidermal necrolysis (TEN) caused by cetuximab plus minocycline during chemoradiation for recurrent squamous cell carcinoma of the head and neck (SCCHN). In April 2008, a 49-year-old man was diagnosed with recurrent SCCHN. He received surgery and postoperative adjuvant therapy with cetuximab plus chemoradiation. Because of exacerbation of acneform rash by cetuximab, minocycline was added thereafter. However, TEN appeared after the fifth course of weekly cetuximab, and cetuximab plus minocycline was assumed to be the cause. Cetuximab plus minocycline carries a risk of evoking TEN, and the side effects of chemoradiation for SCCHN mask some early signs of TEN. Noticing the transformation of skin lesions makes early diagnosis possible, and prompt cessation of the causative agent is essential for patients with TEN. We review the literature on cetuximab, minocycline, and TEN and discuss the impact of TEN on cancer therapy.

The complex clinical picture of side effects to biologicals

Biologicals are proteins used as drugs. Biologicals target clearly defined molecular structures, being part of established pathogenetic pathways. Therefore, their focused mode of action seems to render them superior to classic small molecular drugs regarding "off-target" adverse drug reactions (ADR). Nevertheless, the increasing use of biologicals for the treatment of different diseases has revealed partially unexpected adverse reactions. The often direct interaction of a biological with the immune system provides a clue to most side effects, which have consequently been subclassified, based on pathogenetic principles, into 5 subtypes named alpha, beta, gamma, delta, and epsilon, reflecting overstimulation (high cytokine values, type alpha), hypersensitivity (type beta), immune deviation (including immunodeficiency, type gamma), cross-reactivity (type delta), and nonimmune mediated side effects (type epsilon). This article presents typical clinical manifestations of these subtypes of ADR to biologicals, proposes general rules for treating them, and provides a scheme for a thorough allergological workup. This approach should help in future handling of these often very efficient drugs.

Adverse drug reactions to biologics

The use of biologics has rapidly expanded since the introduction of the first diagnostic antibodies; they are now widely employed in oncology, autoimmune disorders, inflammatory diseases and transplantation medicine. Their widespread use has resulted in an increase in adverse drug reactions. Adverse effects result from both direct pharmacological actions and immunological actions, as well as through induction of a specific immune response. The nomenclature, particularly of the monoclonal antibodies, identifies the target structure and organ as well as the species of origin, which then helps predict their effects and antigenic properties. Depending on the extent of foreign protein, anti-allotypic or anti-idiotypic antibodies with or without neutralizing properties may be induced. Adverse drug reactions from biologics often depend on the target and may be explained by activation or inhibition of particular cytokine pathways. Adverse drug reactions are classified by their pathomechanism, which enhances understanding of the pathogenesis and facilitates both allergologic diagnostic measures and planning of premedication in future treatments. This review emphasizes immunostimulatory and hypersensitivity reactions.