Mechanisms underlying skin disorders induced by EGFR inhibitors

Maximizing activity and selectivity of antibody-mediated effector functions using antibody mixtures

Fc-mediated effector functions are key for conferring potent antibody-mediated killing of cancer cells. However, it is difficult to achieve highly selective targeting of cancer cells while minimizing toxicity on healthy tissue because of the expression of most receptors, albeit at lower levels, on non-cancer cells. Previous attempts to increase the selectivity of antibody-mediated effector functions have sought to reduce binding affinity and/or increase avidity, which typically results in modest improvements in selectivity. To overcome this limitation, we report the use of mixtures of antibody variants that achieve high selectivity based on receptor level while maintaining high activity for cells with high receptor levels. We have studied mixtures of two variants of an anti-HER2 antibody (trastuzumab), one that is affinity-reduced and effector-competent and a second high-affinity variant that is effectorless. Notably, we observe that the high-affinity, effectorless antibody reduces effector function for cells with low receptor levels, including reduced antibody-dependent cellular cytotoxicity (ADCC) and phagocytosis (ADCP), while the high-avidity, effector-competent antibody mediates significant effector function for cells with high receptor levels. Moreover, replacing the effector-competent Fc region of the affinity-reduced antibody with high-affinity Fc domains that enhance effector function drives high activity while maintaining high selectivity for the antibody mixtures. These findings outline a general strategy for maximizing the therapeutic window by selectively targeting cancer cells based on receptor levels that could be applied to a wide range of applications involving antibody-mediated synapse formation, including antibody-drug conjugates and bispecific antibodies, such as T cell engagers.

Targeted Degradation of EGFR Mutations via Self-Delivery Nano-PROTACs for Boosting Tumor Synergistic Immunotherapy

Proteolysis targeting chimera (PROTAC) has recently emerged as a promising strategy to selectively degrade target proteins in the treatment of various diseases. However, it has low bioavailability due to strong hydrophobicity, poor membrane permeability, and nonspecific distribution in vivo, which greatly limits its application. In this study, self-delivery PROTAC nanoparticles (designated as CP NPs) integrating gefitinib-based PROTACs and photosensitizers were developed to efficiently degrade mutated epidermal growth factor receptor (EGFR), a crucial kinase for cell growth and survival, while simultaneously triggering photodynamic therapy and immunotherapy. The prepared NPs enhanced the tumor accumulation of PROTACs, which led to the selective degradation of EGFR mutations and a reduction in programmed cell death protein ligand 1 levels, thereby alleviating tumor immunosuppression and immune tolerance. Moreover, under laser irradiation, the coloaded photosensitizers triggered potent photodynamic therapy effects and induced immunogenic cell death, which worked synergistically with PROTACs toward eliciting a robust antitumor immune response. In a mouse model of lung cancer, primary, distant, and lung metastatic tumors were significantly suppressed. This work highlights the potential of nano-PROTACs for degrading target proteins and facilitating combination photodynamic immunotherapy toward expanding PROTAC applications in cancer therapy.

The User's Guide to Amivantamab

Targeted therapies have revolutionized treatment of non-small-cell lung cancer (NSCLC); however, epidermal growth factor receptor (EGFR) exon20ins mutations are resistant to tyrosine kinase inhibitors. Amivantamab utilizes multiple mechanisms of action to bypass the altered binding site conformation and recruits immune cells for anti-cancer activity. Amivantamab is approved in the frontline setting of EGFR exon20ins-mutated NSCLC in combination with carboplatin plus pemetrexed. Single-agent amivantamab is approved in second line or later for EGFR exon20ins. Furthermore, amivantamab with lazertinib for first line as well as amivantamab in combination with carboplatin and pemetrexed for second line after osimertinib have both been approved in the treatment of NSCLC harboring EGFR-sensitizing mutations. Now with multiple indications, we must learn how to manage the unique side effects of amivantamab to maximize treatment benefit for the patients. Side effects of amivantamab can be associated with inhibition of the EGFR and/or mesenchymal epithelial transcription factor (MET) signaling pathways. This work reviews the mechanism of action, pharmacology, clinical trial data, and covers management of toxicities. This guide is designed as a practical reference tool for clinicians, pharmacists, and basic science researchers.

Post-marketing safety surveillance of Amivantamab: a real world study based on the FDA adverse event reporting system

BACKGROUND

Amivantamab stands as the pioneering bispecific antibody that targets both EGFR and MET, utilized in the treatment of locally advanced or metastatic non-small cell lung cancer (NSCLC) harboring EGFR ex20ins mutations. Nevertheless, a thorough assessment of its safety characteristics in the real-world remains unknown.

RESEARCH DESIGN AND METHODS

The adverse event (AE) reports were collected through a search of the FDA Adverse Event Reporting System (FAERS) database spanning from 2019 Q1 to 2024 Q1, and then disproportionality analysis was utilized.

RESULTS

Totally, 9,252,269 AE reports were obtained from the FAERS database, with 893 reports of amivantamab classified as primary suspect AEs. Amivantamab-related AEs were distributed in 23 organ systems, and 87 significant preferred terms (PTs) met the reporting odds ratio criteria. Novel significant AEs were detected, and the median time to onset of amivantamab-associated AEs was 43 days. In subgroup analysis, a higher proportion of patients who were male, over 65 years, and with pneumonitis or pneumonia were reported in the death cases. We also found that AEs may vary between intravenous and subcutaneous administration.

CONCLUSIONS

This investigation offered novel prospects for monitoring and addressing undesirable medication effects associated with amivantamab, which might improve the clinical medication safety.

JAK-STAT1 as therapeutic target for EGFR deficiency-associated inflammation and scarring alopecia

The hair follicle stem cell niche is an immune-privileged microenvironment, characterized by reduced antigen presentation, thus shielding against permanent immune-mediated tissue damage. In this study, we demonstrated the protective role of hair follicle-specific epidermal growth factor receptor (EGFR) against scarring hair follicle destruction. Mechanistically, disruption of EGFR signaling generated a cell-intrinsic hypersensitivity within the JAK-STAT1 pathway, which, synergistically with interferon gamma expressing CD8 T-cell and NK-cell-mediated inflammation, compromised the stem cell niche. Hair follicle-specific genetic depletion of either JAK1/2 or STAT1 or therapeutic inhibition of JAK1/2 ameliorated the inflammation, restored skin barrier function and activated the residual stem cells to resume hair growth in mouse models of epidermal and hair follicle-specific EGFR deletion. Skin biopsies from EGFR inhibitor-treated and cicatricial alopecia patients revealed an active JAK-STAT1 signaling signature along with upregulation of antigen presentation and downregulation of key components of the EGFR pathway. Our findings offer molecular insights and highlight a mechanism-based therapeutic strategy for addressing chronic folliculitis associated with EGFR-inhibitor anti-cancer therapy and cicatricial alopecia.

Bruton's tyrosine kinase (BTK) inhibitors for the treatment of primary central nervous system lymphoma (PCNSL): current progress and latest advances

The incidence of primary central nervous system lymphoma (PCNSL) has steadily increased, particularly in elderly patients. Although highly responsive to first-line chemotherapy and radiotherapy, approximately 50% of patients relapse or become refractory within 1 year. Prognosis following relapse is dismal and no standard salvage therapy exists. Bruton's tyrosine kinase (BTK), a key regulator of the B-cell receptor (BCR) pathway, has emerged as a promising therapeutic target. The first BTK inhibitor ibrutinib has been evaluated in the relapsed/refractory PCNSL setting, with overall response rates of 51.9%-89.0% and median progression-free survival of 4.6-4.8 months. However, ibrutinib inhibits several kinases in addition to BTK, leading to off-target effects. Second-generation BTK inhibitors have since been developed, which afford greater selectivity for BTK and fewer off-target effects. We review current practices in the diagnosis and evaluation of PCNSL, as well as clinical trials of BTK inhibitors in PCNSL and future developments in PCNSL treatment.

CYpHER: Catalytic extracellular targeted protein degradation with high potency and durable effect

Many disease-causing proteins have multiple pathogenic mechanisms, and conventional inhibitors struggle to reliably disrupt more than one. Targeted protein degradation (TPD) can eliminate the protein, and thus all its functions, by directing a cell's protein turnover machinery towards it. Two established strategies either engage catalytic E3 ligases or drive uptake towards the endolysosomal pathway. Here we describe CYpHER (CatalYtic pH-dependent Endolysosomal delivery with Recycling) technology with potency and durability from a novel catalytic mechanism that shares the specificity and straightforward modular design of endolysosomal uptake. By bestowing pH-dependent release on the target engager and using the rapid-cycling transferrin receptor as the uptake receptor, CYpHER induces endolysosomal target delivery while re-using drug, potentially yielding increased potency and reduced off-target tissue exposure risks. The TfR-based approach allows targeting to tumors that overexpress this receptor and offers the potential for transport to the CNS. CYpHER function was demonstrated in vitro with EGFR and PD-L1, and in vivo with EGFR in a model of EGFR-driven non-small cell lung cancer.

Mechanism of action of adapalene for treating EGFR-TKI-induced skin disorder

BACKGROUND

Skin disorders are the most common side effect associated with epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) therapy. It is important to manage skin lesions. Adapalene has been used to treat skin lesions caused by EGFR-TKIs in some cases. The aim of this study was to investigate the functional mechanism of adapalene in erlotinib-induced skin disorder.

METHODS

To analyze the effect of adapalene on skin rash, afatinib and adapalene were administered to mice. The relationship between the concentration of adapalene and skin disorders was also examined by analyzing AQP3 expression. A skin lesion model was experimentally established in human skin keratinocytes (HaCaT) by using erlotinib with TNF-α and IL-1β. We used qRT-PCR to analyze chemokine-induced inflammation and western blotting to analyze the effects of adapalene on the NF-κB signaling pathway. Antimicrobial peptides and adhesion factors were also examined using qRT-PCR.

RESULTS

Mice administered 0.01% adapalene had less skin inflammation than mice treated with afatinib alone. The expression level of AQP3 decreased in an adapalene concentration-dependent manner. The mRNA levels of proinflammatory cytokines such as CCL2 and CCL27 in HaCaT cells were significantly reduced by adapalene. The expression of an antimicrobial peptide, hBD3, was upregulated after adapalene treatment. Adhesion factors, such as E-cadherin, were significantly downregulated by EGFR-TKI and significantly upregulated by adapalene treatment. Western blot analysis suggested that erlotinib-induced phosphorylation of p65 was decreased by adapalene.

CONCLUSION

We suggest that adapalene may be a possible treatment option for skin disorders induced by EGFR-TKIs.

A Cancer-Specific Monoclonal Antibody against Podocalyxin Exerted Antitumor Activities in Pancreatic Cancer Xenografts

Podocalyxin (PODXL) overexpression is associated with poor clinical outcomes in various tumors. PODXL is involved in tumor malignant progression through the promotion of invasiveness and metastasis. Therefore, PODXL is considered a promising target of monoclonal antibody (mAb)-based therapy. However, PODXL also plays an essential role in normal cells, such as vascular and lymphatic endothelial cells. Therefore, cancer specificity or selectivity is required to reduce adverse effects on normal cells. Here, we developed an anti-PODXL cancer-specific mAb (CasMab), PcMab-6 (IgG1, kappa), by immunizing mice with a soluble PODXL ectodomain derived from a glioblastoma LN229 cell. PcMab-6 reacted with the PODXL-positive LN229 cells but not with PODXL-knockout LN229 cells in flow cytometry. Importantly, PcMab-6 recognized pancreatic ductal adenocarcinoma (PDAC) cell lines (MIA PaCa-2, Capan-2, and PK-45H) but did not react with normal lymphatic endothelial cells (LECs). In contrast, one of the non-CasMabs, PcMab-47, showed high reactivity to both the PDAC cell lines and LECs. Next, we engineered PcMab-6 into a mouse IgG2a-type (PcMab-6-mG2a) and a humanized IgG1-type (humPcMab-6) mAb and further produced the core fucose-deficient types (PcMab-6-mG2a-f and humPcMab-6-f, respectively) to potentiate the antibody-dependent cellular cytotoxicity (ADCC). Both PcMab-6-mG2a-f and humPcMab-6-f exerted ADCC and complement-dependent cellular cytotoxicity in the presence of effector cells and complements, respectively. In the PDAC xenograft model, both PcMab-6-mG2a-f and humPcMab-6-f exhibited potent antitumor effects. These results indicated that humPcMab-6-f could apply to antibody-based therapy against PODXL-expressing pancreatic cancers.

Association of white matter hyperintensities with long-term EGFR-TKI treatment and prediction of progression risk

PURPOSE

The purpose of this study was to test the hypothesis that brain white matter hyperintensities (WMH) are more common in patients receiving epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) and identify clinical risk factors associated with WMH.

EXPERIMENTAL DESIGN

This multiple-center, prospective cohort study was conducted from March 2017 to July 2020. Two groups of patients with non-small cell lung cancer (NSCLC) who received or did not receive EGFR-TKI were included and followed up for more than 24 months. The progression of WMH was defined as an increase of ≥1 point on the Fazekas visual rating scale between the baseline and at the 2-year follow-up. A modified Poisson regression model was performed to evaluate risk factors on increased WMH load.

RESULTS

Among 286 patients with NSCLC, 194 (68%) patients with NSCLC who received EGFR-TKI and 92 (32%) patients with NSCLC without EGFR-TKI treatment were analyzed. Modified Poisson regression analysis showed that EGFR-TKI treatment was independently associated with the WMH progression (EGFR-TKI: aRR 2.72, 95% confidence interval [CI] 1.46-5.06, p = .002). Interleukin (IL)-2, IL-4, and IL-10 were associated with increased WMH in the adjusted model (IL-2: aRR 1.55 [95% CI 1.06-2.25], p = .023; IL-4: aRR 1.66 [95% CI 1.13-2.43], p = .010; IL-10: aRR 1.48 [95% CI 1.06-2.06], p = .020).

CONCLUSION

Patients with NSCLC who received EGFR-TKI may be at higher risk of developing WMH or worsening of WMH burden. The impact of increased WMH lesions in these patients is to be further assessed. IL-2, IL-4, and IL-10 may be used as potential biomarkers to monitor the risk of increased WMH burden.

Trapping all ERBB ligands decreases pancreatic lesions in a murine model of pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is among the deadliest of cancers. Attempts to develop targeted therapies still need to be established. Some oncogenic mechanisms in PDAC carcinogenesis harness the EGFR/ERBB receptor family. To explore the effects on pancreatic lesions, we attempted simultaneous blockade of all ERBB ligands in a PDAC mouse model. To this end, we engineered a molecular decoy, TRAP-FC , comprising the ligand-binding domains of both EGFR and ERBB4 and able to trap all ERBB ligands. Next, we generated a transgenic mouse model (CBATRAP/0 ) expressing TRAP-FC ubiquitously under the control of the chicken-beta-actin promoter and crossed these mice with KRASG12D/+ mice (Kras) to generate Trap/Kras mice. The resulting mice displayed decreased emergence of spontaneous pancreatic lesion areas and exhibited reduced RAS activity and decreased activities of ERBBs, with the exception of ERBB4, which showed increased activity. To identify the involved receptor(s), we employed CRISPR/Cas9 DNA editing to singly delete each ERBB receptor in the human pancreatic carcinoma cell line Panc-1. Ablation of each ERBB family member, especially the loss of EGFR or ERBB2/HER2, altered signaling downstream of the other three ERBB receptors and decreased cell proliferation, migration, and tumor growth. We conclude that simultaneously blocking the entire ERBB receptor family is therapeutically more effective than individually inhibiting only one receptor or ligand in terms of reducing pancreatic tumor burden. In summary, trapping all ERBB ligands can reduce pancreatic lesion area and RAS activity in a murine model of pancreatic adenocarcinoma; hence, it might represent a promising approach to treat PDAC in patients.

Prophylactic treatment of dacomitinib-induced skin toxicities in epidermal growth factor receptor-mutated non-small-cell lung cancer: A multicenter, Phase II trial

BACKGROUND

Dacomitinib significantly improves progression-free survival and overall survival (OS) compared with gefitinib in patients with non-small-cell lung cancer (NSCLC) harboring epidermal growth factor receptor (EGFR)-activating mutations. However, dacomitinib often causes skin toxicities, resulting in treatment discontinuation. We aimed to evaluate a prophylactic strategy for skin toxicity induced by dacomitinib.

METHODS

We performed a single-arm, prospective, open-label, multi-institutional phase II trial for comprehensive skin toxicity prophylaxis. Patients with NSCLC harboring EGFR-activating mutations were enrolled and received dacomitinib with comprehensive prophylaxis. The primary endpoint was the incidence of skin toxicity (Grade ≥2) in the initial 8 weeks.

RESULTS

In total, 41 Japanese patients participated between May 2019 and April 2021 from 14 institutions (median age 70 years; range: 32-83 years), 20 were male, and 36 had a performance status of 0-1. Nineteen patients had exon 19 deletions and L858R mutation. More than 90% of patients were perfectly compliant with prophylactic minocycline administration. Skin toxicities (Grade ≥2) occurred in 43.9% of patients (90% confidence interval [CI], 31.2%-56.7%). The most frequent skin toxicity was acneiform rash in 11 patients (26.8%), followed by paronychia in five patients (12.2%). Due to skin toxicities, eight patients (19.5%) received reduced doses of dacomitinib. The median progression-free survival was 6.8 months (95% CI, 4.0-8.6 months) and median OS was 21.6 months (95% CI, 17.0 months-not reached).

CONCLUSION

Although the prophylactic strategy was ineffective, the adherence to prophylactic medication was quite good. Patient education regarding prophylaxis is important and can lead to improved treatment continuity.

Preventing skin toxicities induced by EGFR inhibitors by topically blocking drug-receptor interactions

Epidermal growth factor receptor (EGFR) inhibitors are used to treat many advanced-stage epithelial cancers but induce severe skin toxicities in most treated patients. These side effects lead to a deterioration in the quality of life of the patients and compromise the anticancer treatment. Current treatment strategies for these skin toxicities focus on symptom reduction rather than preventing the initial trigger that causes the toxicity. In this study, we developed a compound and method for treating "on-target" skin toxicity by blocking the drug at the site of toxicity without reducing the systemic dose reaching the tumor. We first screened for small molecules that effectively blocked the binding of anti-EGFR monoclonal antibodies to EGFR and identified a potential candidate, SDT-011. In silico docking predicted that SDT-011 interacted with the same residues on EGFR found to be important for the binding of EGFR inhibitors cetuximab and panitumumab. Binding of SDT-011 to EGFR reduced the binding affinity of cetuximab to EGFR and could reactivate EGFR signaling in keratinocyte cell lines, ex vivo cetuximab-treated whole human skin, and A431-injected mice. Specific small molecules were topically applied and were delivered via a slow-release system derived from biodegradable nanoparticles that penetrate the hair follicles and sebaceous glands, within which EGFR is highly expressed. Our approach has the potential to reduce skin toxicity caused by EGFR inhibitors.

Perspectives of data science in preclinical safety assessment

The data landscape in preclinical safety assessment is fundamentally changing because of not only emerging new data types, such as human systems biology, or real-world data (RWD) from clinical trials, but also technological advancements in data-processing software and analytical tools based on deep learning approaches. The recent developments of data science are illustrated with use cases for the three factors: predictive safety (new in silico tools), insight generation (new data for outstanding questions); and reverse translation (extrapolating from clinical experience to resolve preclinical questions). Further advances in this field can be expected if companies focus on overcoming identified challenges related to a lack of platforms and data silos and assuring appropriate training of data scientists within the preclinical safety teams.

Mechanisms of ADC Toxicity and Strategies to Increase ADC Tolerability

Anti-cancer antibody-drug conjugates (ADCs) aim to expand the therapeutic index of traditional chemotherapy by employing the targeting specificity of monoclonal antibodies (mAbs) to increase the efficiency of the delivery of potent cytotoxic agents to malignant cells. In the past three years, the number of ADCs approved by the Food and Drug Administration (FDA) has tripled. Although several ADCs have demonstrated sufficient efficacy and safety to warrant FDA approval, the clinical use of all ADCs leads to substantial toxicity in treated patients, and many ADCs have failed during clinical development due to their unacceptable toxicity profiles. Analysis of the clinical data has demonstrated that dose-limiting toxicities (DLTs) are often shared by different ADCs that deliver the same cytotoxic payload, independent of the antigen that is targeted and/or the type of cancer that is treated. DLTs are commonly associated with cells and tissues that do not express the targeted antigen (i.e., off-target toxicity), and often limit ADC dosage to levels below those required for optimal anti-cancer effects. In this manuscript, we review the fundamental mechanisms contributing to ADC toxicity, we summarize common ADC treatment-related adverse events, and we discuss several approaches to mitigating ADC toxicity.

Multifunctional NK Cell–Engaging Antibodies Targeting EGFR and NKp30 Elicit Efficient Tumor Cell Killing and Proinflammatory Cytokine Release

In this work, we have generated novel Fc-comprising NK cell engagers (NKCEs) that bridge human NKp30 on NK cells to human epidermal growth factor receptor (EGFR) on tumor cells. Camelid-derived VHH single-domain Abs specific for human NKp30 and a humanized Fab derived from the EGFR-specific therapeutic Ab cetuximab were used as binding arms. By combining camelid immunization with yeast surface display, we were able to isolate a diverse panel of NKp30-specific VHHs against different epitopes on NKp30. Intriguingly, NKCEs built with VHHs that compete for binding to NKp30 with B7-H6, the natural ligand of NKp30, were significantly more potent in eliciting tumor cell lysis of EGFR-positive tumor cells than NKCEs harboring VHHs that target different epitopes on NKp30 from B7-H6. We demonstrate that the NKCEs can be further improved with respect to killing capabilities by concomitant engagement of FcγRIIIa and that soluble B7-H6 does not impede cytolytic capacities of all scrutinized NKCEs at significantly higher B7-H6 concentrations than observed in cancer patients. Moreover, we show that physiological processes requiring interactions between membrane-bound B7-H6 and NKp30 on NK cells are unaffected by noncompeting NKCEs still eliciting tumor cell killing at low picomolar concentrations. Ultimately, the NKCEs generated in this study were significantly more potent in eliciting NK cell–mediated tumor cell lysis than cetuximab and elicited a robust release of proinflammatory cytokines, both features which might be beneficial for antitumor therapy.

Composition and Bioactivity of a Modified Huang-Lian-Jie-Du Decoction

Background. Epidermal growth factor receptor inhibitors (EGFRIs) and tyrosine kinase inhibitors (TKIs) are key drugs in targeted cancer therapy. However, they may cause skin toxicity. We previously prepared a modified Huang-Lian-Jie-Du (mHLJD) decoction cream using 10 herbs, which effectively alleviated EGFRI/TKI-induced skin toxicity. In the present study, we identified the reference markers of the mHLJD decoction and investigated the anti-inflammatory and antibacterial effects of the mHLJD decoction extract. Methods. We performed high-performance liquid chromatography (HPLC) to determine the composition of the mHLJD decoction. Human epidermoid A431 cells were treated with tumor necrosis factor (TNF)-α to induce inflammation; then, the effects of the mHLJD decoction extract on the cytokine expression were determined using a cytokine array and by performing real-time quantitative polymerase chain reaction (qPCR). The antibacterial effects of the extract were examined using disk diffusion and microdilution assays. Results. HPLC results revealed that the mHLJD decoction primarily consisted of geniposide, berberine chloride, baicalin, coptisine, and palmatine. TNF-α treatment increased the expression of certain cytokines, including IL-1β, IL-8, M-CSF, and TGF-β2; however, pretreatment with the mHLJD decoction extract reduced their expression. The qPCR results demonstrated a decreased mRNA expression of IL-8, M-CSF, and TGF-β2. The antibacterial assay revealed that the extract exerted inhibitory effects on Staphylococcus aureus, forming an inhibition zone at the minimum inhibitory concentrations of 3.125 and 6.25 mg/mL; however, the extract exerted no effects on Escherichia coli and Pseudomonas aeruginosa. Conclusions. We developed an HPLC method to quantify the reference markers of the mHLJD decoction. The bioactivity analysis provided the potential mechanisms underlying the effects of the mHLJD decoction on EGFRI/TKI-induced skin toxicity.

Interplay between EGFR, E-cadherin, and PTP1B in epidermal homeostasis

Maintaining epithelial homeostasis is crucial to allow embryo development but also the protective barrier which is ensured by the epidermis. This homeostasis is regulated through the expression of several molecules among which EGFR and E-cadherin which are of major importance. Indeed, defects in the regulation of these proteins lead to abnormalities in cell adhesion, proliferation, differentiation, and migration. Hence, regulation of these two proteins is of the utmost importance as they are involved in numerous skin pathologies and cancers. In the last decades it has been described several pathways of regulation of these two proteins and notably several mechanisms of cross-regulation between these partners. In this review, we aimed to describe the current understanding of the regulation of EGFR and interactions between EGFR and E-cadherin and, in particular, the implication of these cross-regulations in epithelium homeostasis. We pay particular attention to PTP1B, a phosphatase involved in the regulation of EGFR.

A phase 2 study for evaluating doxycycline 50 mg once daily and 100 mg once daily as preemptive treatment for skin toxicity in patients with metastatic colorectal cancer treated with an anti-EGFR and chemotherapy

PURPOSE

To assess the efficacy, safety, and quality-of-life outcomes of doxycycline 50 or 100 mg once daily in the prevention of skin toxicity in patients undergoing chemotherapy plus anti-EGFR therapy as first-line treatment of metastatic colorectal cancer (mCRC).

METHODS

Phase II, multicenter, single-arm, exploratory study was conducted in 7 Spanish hospitals. The primary study outcome was the incidence of ≥ grade 2 skin toxicities during the 6-week skin treatment period. Quality of life was assessed with the Dermatology Life Quality Index (DLQI) questionnaire. Patients had to receive either doxycycline 50 mg once daily in a first stage with 10 patients, or, if more than three patients presented ≥ grade 2 skin toxicities, the next 30 patients had to receive 100 mg once daily.

RESULTS

Thirty-four patients with RAS wild-type mCRC were enrolled in the study. Ten patients were first treated with doxycycline 50 mg once daily, and the following 24 were treated with doxycycline 100 mg once daily. A total of 60.0% (95% CI 29.6-90.0) and 20.8% (95% CI 4.6-37.0) of patients who received doxycycline 50 mg/day and 100 mg/day, respectively, had at least one ≥ grade 2 skin toxicity. Patients treated with doxycycline 100 mg once daily experienced less QoL deterioration. Only 1 patient reported a mild doxycycline-related gastrointestinal adverse event.

CONCLUSION

Our results suggest that doxycycline doses as low as 100 mg once daily are efficacious and well tolerated for the prevention of skin toxicity in patients with mCRC who undergo treatment with chemotherapy plus EGFR-targeted therapies.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03448731.

Acneiform eruptions with combination targeted cancer therapy in colorectal cancer patients

PURPOSE

Epidermal growth factor receptor inhibitors (EGFRI) can be used with pathway inhibitors, including mitogen-activated protein kinase kinase inhibitors (MEKIs), BRAF inhibitors (BRAFIs), and checkpoint inhibitors such as programmed death-ligand 1 (PD-L1) and programmed cell death protein 1 (PD-1) to treat colorectal cancer. These can precipitate treatment-resistant acneiform eruptions, prompting dose modification or discontinuation. Predicting the likelihood of severe rash development and crafting effective treatments may promote adherence to life-saving chemotherapy.

METHODS

An Institutional Review Board-approved retrospective chart review of patients with colorectal cancer treated with EGFRI or MEKI in combination with HER2, BRAF, PI3K, or checkpoint inhibitors between January 1, 2016, and January 1, 2020, was performed. Surrogates for rash severity were investigated, including lower extremity involvement, utilization of oral steroids or retinoids, dose modification, and incidence of superinfection.

RESULTS

Of 122 patients treated with combination therapy, 105 developed a rash, and 87 developed an acneiform eruption. Common combinations included MEKI/PD-LI, EGFRI/MEKI, and MEKI/PD-1I. Patients treated with EGFRI/MEKI developed the most severe rashes (p = 0.02). Lower extremity involvement was more frequent with EGFRI/MEKI compared to alternative combinations (p = 0.05). Drug holiday correlated with all rash severity surrogates, including rash grade, lower extremity involvement, oral steroid or retinoid use, and incidence of superinfection. Use of oral steroids or retinoids was associated with development of superinfection (p = 0.002). Prophylactic tetracycline use did not impact rash severity or rash incidence.

CONCLUSION

This is the first descriptive analysis to characterize acneiform eruptions for patients with colorectal cancer on combination cancer therapy. Approximately 85% of patients developed a cutaneous toxicity with what appears to be synergistic effects of EGFRI and MEKI combination therapy causing the most severe eruptions. Superinfection rate correlated to systemic therapy use beyond oral tetracyclines. Further investigation into the utility of prophylactic oral tetracyclines in this population is needed.

Development of (4-Phenylamino)quinazoline Alkylthiourea Derivatives as Novel NF-κB Inhibitors

For many inflammatory diseases, new effective drugs with fewer side effects are needed. While it appears promising to target the activation of the central pro-inflammatory transcription factor NF-κB, many previously discovered agents suffered from cytotoxicity. In this study, new alkylthiourea quinazoline derivatives were developed that selectively inhibit the activation of NF-κB in macrophage-like THP−1 cells while showing low general cytotoxicity. One of the best compounds, 19, strongly inhibited the production of IL-6 (IC50 = 0.84 µM) and, less potently, of TNFα (IC50 = 4.0 µM); in comparison, the reference compound, caffeic acid phenethyl ester (CAPE), showed IC50s of 1.1 and 11.4 µM, respectively. Interestingly, 19 was found to block the translocation of the NF-κB dimer to the nucleus, although its release from the IκB complex was unaffected. Furthermore, 19 suppressed the phosphorylation of NF-κB-p65 at Ser468 but not at Ser536; however, 19 did not inhibit any kinase involved in NF-κB activation. The only partial suppression of p65 phosphorylation might be associated with fewer side effects. Since several compounds selectively induced cell death in activated macrophage-like THP−1 cells, they might be particularly effective in various inflammatory diseases that are exacerbated by excess activated macrophages, such as arteriosclerosis and autoimmune diseases.

PROPHYLACTIC EFFECT OF NITRIC OXIDE DONORS ON RAT MODELS OF EGFR INHIBITORS-INDUCED CUTANEOUS TOXICITIES

Epidermal growth factor receptor inhibitors (EGFRIs) have been established as first-line standard-of-care therapies for non-small cell lung cancer (NSCLC) but are frequently accompanied by adverse dermatological effects, in particular, acneiform rash. There is no effective clinical intervention, partially because of its poorly understood etiology. Here, we show that inhibition of EGFR initiated keratinocyte HaCaT cell cycle arrest and apoptosis, which fueled a robust secondary inflammatory response. Rats gavaged with EGFRI showed a phenotype similar to that of clinical patients, which was in line with the interrupted functions observed in HaCaT keratinocytes. We found that a nitric oxide (NO) donor, nitroglycerin (GTN), was a feasible treatment alternative for EGFRI-induced rash. Restoration of epidermal extracellular signal-regulated kinase (ERK) and a reduction in STAT3 signaling via GTN treatment rescued the cellular functions that had been damaged in vitro and further ameliorated the rash in rat models. In addition, the efficacy of GTN was superior to that of existing clinical interventions. These data highlighted the importance of epidermal EGFR signaling and led to the identification of a small-molecule NO donor as a mediator that can maintain EGFR pathway functions during anti-EGFR therapies, providing a therapeutic anchor point for adverse EGFRI-induced skin effects.

Cutaneous immune-related adverse events among Taiwanese cancer patients receiving immune checkpoint inhibitors link to a survival benefit

Cutaneous immune-related adverse events are common in cancer patients receiving immunotherapies but seldom studied in a comprehensive way of collecting all cancer types with comparisons between different immune-oncology drugs and correlation to patient survival. In this retrospective cohort study, we recruited 468 cancer patients receiving immunotherapies in a tertiary referral center in Taiwan and try to determine real-world incidence of cutaneous immune-related adverse events and their associations with the survival rates. Among them, 128 patients (27.4%) had cutaneous immune-related adverse events, with maculopapular eruption (10.6%) and pruritus (10.1%) most frequently identified in the monotherapy group. The incidence of these cutaneous immune-related adverse events was highest in patients receiving pembrolizumab (34.1%, P < .0001). Concurrent usage of molecular-targeted therapy with immunotherapy was associated with a higher incidence (57.8%, P < .0001). The Kaplan-Meier plot and log-rank test showed that patients with any type of immune-related cutaneous adverse events had longer survival time than those without (P < .0001). In conclusion, having either type of cutaneous immune-related adverse event in cancer patients receiving immunotherapies was correlated with a longer overall survival. Prompt diagnosis and suitable treatment are important.

An antibody Fc engineered for conditional antibody-dependent cellular cytotoxicity at the low tumor microenvironment pH

Despite the exquisite specificity and high affinity of antibody-based cancer therapies, treatment side effects can occur since the tumor-associated antigens targeted are also present on healthy cells. However, the low pH of the tumor microenvironment provides an opportunity to develop conditionally active antibodies with enhanced tumor specificity. Here, we engineered the human IgG1 Fc domain to enhance pH-selective binding to the receptor FcγRIIIa and subsequent antibody-dependent cellular cytotoxicity (ADCC). We displayed the Fc domain on the surface of mammalian cells and generated a site-directed library by altering Fc residues at the Fc-FcγRIIIa interface to support interactions with positively charged histidine residues. We then used a competitive staining and flow cytometric selection strategy to isolate Fc variants exhibiting reduced FcγRIIIa affinities at neutral pH, but physiological affinities at the tumor-typical pH 6.5. We demonstrate that antibodies composed of Fab arms binding the breast cell epithelial marker Her2 and the lead Fc variant, termed acid-Fc, exhibited an ∼2-fold pH-selectivity for FcγRIIIa binding based on the ratio of equilibrium dissociation constants K_d,7.4/K_d,6.5, due to a faster dissociation rate at pH 7.4. Finally, in vitro ADCC assays with human FcγRIIIa-positive natural killer and Her2-positive target cells demonstrated similar activities for anti-Her2 antibodies bearing the wild-type or acid-Fc at pH 6.5, but nearly 20-fold reduced ADCC for acid-Fc at pH 7.4, based on EC₅₀ ratios. This work shows the promise of mammalian cell display for Fc engineering and the feasibility of pH-selective Fc activation to provide a second dimension of selective tumor cell targeting.

Selective Immune Modulating Activities of Viscum album and Its Components; A Possibility of Therapeutics on Skin Rash Induced by EGFR Inhibitors

Viscum album var. coloratum (Kom.) Ohwi is a traditional herbal medicine used in East Asia to treat hypertension, skeletal muscle disorders, and cancer. The inhibitory effects of Viscum album (VA) extract on chemokines and its therapeutic potential in erlotinib-induced skin rash were investigated in this study. ELISA was used to measure the levels of chemokines, MCP-1 and RANTES, which are thought to be mediators of erlotinib-induced skin rash in RAW264.7 cells. Western blot analysis was used to look into the activation of signaling pathways like AKT, MAPK, and EGF. In order to investigate the active compounds in VA extract, solvent fractionation and preparative HPLC were performed sequentially. VA extract significantly reduced the production of TNF-α, MCP-1, and RANTES but not IL-1. Furthermore, macrophage transmigration was inhibited without causing cell toxicity. VA extract had no effect on the phosphorylation of EGF receptors stimulated by EGF or suppressed by erlotinib in both A549, a non-small cell lung cancer cells, and Hacat, a human skin keratinocyte. The isolated viscumneoside III and viscumneoside V from VA extract significantly suppressed the expression of MCP-1, according to activity guided fractionation with organic solvent fractionation and preparative HPLC. These findings suggest that VA extract and its active compounds, viscumneoside III and viscumneoside V, regulate MCP-1 production and may have the potential to suppress erlotinib-induced skin toxicity by modulating macrophage activity without neutralizing anti-cancer efficacy.

VEGF Expression, Cellular Infiltration, and Intratumoral Collagen Levels after Electroporation-Based Treatment of Dogs with Cutaneous Squamous Cell Carcinoma

Canine cutaneous squamous cell carcinoma (SCC) is the most common type of skin cancer in tropical countries and is generally associated with exposure to solar ultraviolet light. It has a low metastatic rate, and local treatments, such as electrochemotherapy (ECT), promote long-term control or even complete remission. This study aimed to evaluate pre- and post-ECT treatment expression levels of vascular endothelial growth factor (VEGF) and CD31, cellular infiltration, and intratumoral collagen levels in dogs with cutaneous SCC. A prospective nonrandomized clinical study was performed using dogs with spontaneous SCC treated with ECT. Eighteen lesions from 11 dogs were included in the study. The expression levels of VEGF and CD31; cellular infiltration; and intratumoral collagen levels, as determined by Masson's trichrome staining, were not significantly different from pre-treatment measurements on day 21 (p > 0.05). However, among cellular infiltration, the mixed subtype was correlated with better overall survival time when compared to lymphoplasmacytic and neutrophilic infiltration (p < 0.05). In conclusion, ECT had no effect on VEGF expression, cellular infiltration, or intratumoral collagen levels in dogs with cutaneous SCC at the time of evaluation, suggesting that early and late post-ECT-treatment phases should be considered.

Ex-Vivo Skin Explant Culture Is a Model for TSLP-Mediated Skin Barrier Immunity

The skin is the outermost barrier protecting the body from pathogenic invasion and environmental insults. Its breakdown initiates the start of skin inflammation. The epidermal growth factor (EGFR) on keratinocytes protects this barrier, and its dysfunction leads to atopic dermatitis-like skin disease. One of the initial cytokines expressed upon skin barrier breach and during atopic dermatitis is TSLP. Here, we describe the expression and secretion of TSLP during EGFR inhibition and present an ex-vivo model, which mimics the early events after barrier insult. Skin explants floated on culture medium at 32 °C released TSLP in parallel to the activation of the resident Langerhans cell network. We could further show the up-regulation and activation of the AP-1 family of transcription factors during atopic-like skin inflammation and its involvement in TSLP production from the skin explant cultures. Inhibition of the c-Jun N-terminal kinase pathway led to a dose-dependent blunting of TSLP release. These data indicate the involvement of AP-1 during the early stages of atopic-like skin inflammation and highlight a novel therapeutic approach by targeting it. Therefore, skin explant cultures mimic the early events during skin barrier immunity and provide a suitable model to test therapeutic intervention.

Safety of Surgery after Neoadjuvant Targeted Therapies in Non-Small Cell Lung Cancer: A Narrative Review

New drugs, including immune checkpoint inhibitors and targeted therapy, have changed the prognosis in a subset of patients with advanced lung cancer, and are now actively investigated in a number of trials with neoadjuvant and adjuvant regimens. However, no phase III randomized studies were published yet. The current narrative review proves that targeted therapies are safe in neoadjuvant approach. Unsurprisingly, administration of therapy is related to an acceptable toxicity profile. Severe adverse events’ rate that rarely compromises outcomes of patients with advanced lung cancer is not that commonly accepted in early lung cancer as it may lead to missing the chance of curative surgery. Among those complications, the most important factors that may limit the use of targeted therapies are severe respiratory adverse events precluding the resection occurring after treatment with some anaplastic lymphoma kinase and rarely after epidermal growth factor receptor tyrosine kinase inhibitors. At this point, in the presented literature assessing the feasibility of neoadjuvant therapies with anaplastic lymphoma kinase and epidermal growth factor receptor tyrosine kinase inhibitors, we did not find any unexpected intraoperative events that would be of special interest to a thoracic surgeon. Moreover, the postoperative course was associated with typical rate of complications.

Reducing Skin Toxicities from EGFR Inhibitors with Topical BRAF Inhibitor Therapy

Treatment of cancer with EGFR inhibitors is limited by on-target skin toxicities induced by inhibition of the MAPK pathway. BRAF inhibitors are known to paradoxically activate the MAPK downstream of EGFR, which we confirmed using human skin keratinocytes. We then conducted a phase I clinical trial testing the hypothesis that topical therapy with the BRAF inhibitor LUT014 could improve skin toxicities induced by EGFR inhibitors. Ten patients with metastatic colorectal cancer who had developed acneiform rash while being treated with cetuximab or panitumumab were enrolled in three cohorts. LUT014 was well tolerated, and there were no dose-limiting toxicities. The acneiform rash improved in the 6 patients who started with grade 2 rash in the low and intermediate cohorts. We conclude that topical LUT014 is safe and efficacious in improving rash from EGFR inhibitors, consistent with the mechanism of action inducting paradoxical MAPK activation. SIGNIFICANCE: BRAF inhibitor topical therapy could avoid dose reductions of EGFR inhibitors, locally treating the main dose-limiting skin toxicity of this class of agents.This article is highlighted in the In This Issue feature, p. 2113.

Preclinical evaluation of AFM24, a novel CD16A-specific innate immune cell engager targeting EGFR-positive tumors

Epidermal growth factor receptor (EGFR)-targeted cancer therapy such as anti-EGFR monoclonal antibodies and tyrosine kinase inhibitors have demonstrated clinical efficacy. However, there remains a medical need addressing limitations of these therapies, which include a narrow therapeutic window mainly due to skin and organ toxicity, and primary and secondary resistance mechanisms of the EGFR-signaling cascade (e.g., RAS-mutated colorectal cancer). Using the redirected optimized cell killing (ROCK®) antibody platform, we have developed AFM24, a novel bispecific, IgG₁-scFv fusion antibody targeting CD16A on innate immune cells, and EGFR on tumor cells. We herein demonstrate binding of AFM24 to CD16A on natural killer (NK) cells and macrophages with K_D values in the low nanomolar range and to various EGFR-expressing tumor cells. AFM24 was highly potent and effective for antibody-dependent cell-mediated cytotoxicity via NK cells, and also mediated antibody-dependent cellular phagocytosis via macrophages in vitro. Importantly, AFM24 was effective toward a variety of EGFR-expressing tumor cells, regardless of EGFR expression level and KRAS/BRAF mutational status. In vivo, AFM24 was well tolerated up to the highest dose (75 mg/kg) when administered to cynomolgus monkeys once weekly for 28 days. Notably, skin and other toxicities were not observed. A transient elevation of interleukin-6 levels was detected at all dose levels, 2-4 hours post-dose, which returned to baseline levels after 24 hours. These results emphasize the promise of bispecific innate cell engagers as an alternative cancer therapy and demonstrate the potential for AFM24 to effectively target tumors expressing varying levels of EGFR, regardless of their mutational status.Abbreviations: ADA: antidrug antibody; ADCC: antibody-dependent cell-mediated cytotoxicity; ADCP: antibody-dependent cellular phagocytosis; AUC: area under the curve; CAR: chimeric-antigen receptor; CD: Cluster of differentiation; CRC :colorectal cancer; ECD: extracellular domain; EGF: epidermal growth factorEGFR epidermal growth factor receptor; ELISA: enzyme-linked immunosorbent assay; FACS: fluorescence-activated cell sorting; Fc: fragment, crystallizableFv variable fragment; HNSCC: head and neck squamous carcinomaIL interleukinm; Ab monoclonal antibody; MOA: mechanism of action; NK :natural killer; NSCLC: non-small cell lung cancer; PBMC: peripheral blood mononuclear cell; PBS: phosphate-buffered saline; PD: pharmacodynamic; ROCK: redirected optimized cell killing; RSV: respiratory syncytial virus; SABC: specific antibody binding capacity; SD: standard deviation; TAM: tumor-associated macrophage; TKI: tyrosine kinase inhibitor; WT: wildtype.

Drug-induced Grover's disease: a case report and review of the literature

BACKGROUND

Grover's disease (GD) is a relatively rare transient dermatosis that can be idiopathic or acquired. Acquired GD may occur secondary to internal triggers such as medications and malignancies and external factors such as friction.

OBJECTIVE

The purpose of this report is to describe the clinical and histological presentation of drug-induced Grover's disease (DIGD) and discuss potential pathogenic mechanisms.

METHODS

A systemic review of the literature was performed to identify medications implicated in DIGD.

RESULTS

We identified 13 reports of patients with DIGD. Most patients presented with a papular or papulovesicular morphology involving the trunk and extremities. Pruritus was the most common symptom. The majority of the offending agents were cancer therapeutics. Discontinuation of the culprit medication was sufficient for rash clearance and symptom resolution in most cases.

CONCLUSION

The overlap in morphology and associated symptoms in DIGD and GD makes the diagnosis of DIGD challenging and has potentially led to underdiagnosis. However, in cases of more extensive involvement and treatment recalcitrance, a drug-induced eruption should be considered.

Efficacy and Safety of Modified Huang-Lian-Jie-Du Decoction Cream on Cancer Patients with Skin Side Effects Caused by EGFR Inhibition

(1) Background: The epidermal growth factor inhibitors (EGFRIs)/tyrosine kinase inhibitors (TKIs) are effective for cancer target therapy, but acneiform rashes or so-called inflammatory papulopustular exanthemas are common (50% to 90%). The conventional therapy for EGFRIs/TKIs-induced skin toxicity is steroids and antibacterial drugs, but it is still ineffective for some patients, and EGFRIs/TKIs dose reduction/interruption may be needed. In this study, a modified Chinese herbal medicine, Huang-Lian-Jie-Du decoction cream with Yin-Cold (YC) medicine characteristic, was investigated for the effect on patients suffering EGFRIs/TKIs-induced skin toxicity. (2) Methods: The modified Huang-Lian-Jie-Du (mHLJD) decoction cream was made from 10 herbal medicines, including 4 major medicines (Huanglian, Huangqin, Huangbo, and Zhizi) in traditional HLJD decoction. Patients with EGFRIs/TKIs-induced skin toxicity were enrolled. Patients were excluded if they also used other cream for skin toxicity. Skin conditions were monitored by follow up every 2 weeks. The patients’ characteristics, the skin toxicities, treatment response, and adverse events were recorded and analyzed until skin problems resolved or the study ended. (3) Results: The mHLJD decoction cream and its sub-packages were stored at 4 °C before use. Thirty-four patients who had grade 1–3 skin toxicities after receiving EGFRIs/TKIs were enrolled. Seven patients withdrew or were excluded. Finally, data from 27 patients were analyzed. The mean grade of rash acneiform was significantly decreased from 2.19 (ranged 1 to 3) to 0.88 (ranged 0 to 2) after mHLJD decoction cream treatment for 4 weeks and to 0.55 (ranged 0 to 2) after mHLJD decoction cream treatment for 8 weeks. Additionally, the mean grade of dry skin was also significantly decreased from 1.57 (ranged 1 to 2) to 0.71 (ranged 0 to 1) after mHLJD decoction cream treatment for 4 weeks. The changes of skin toxicity were significant, with no obvious adverse events. (4) Conclusions: In summary, the mHLJD decoction cream provides benefits for alleviation of EGFRIs/TKIs-induced skin rash acneiform and dry skin. Additionally, no obvious side effects were found in patients using mHLJD decoction cream.

Oxidative stress induces EGFR inhibition-related skin cell death

Cutaneous side effects are often observed in patients treated with chemotherapeutic agents, including those treated with epidermal growth factor receptor (EGFR) inhibitors. These side effects are not fatal but often require dose reduction of chemotherapies. The mechanisms of epidermal growth factor receptor inhibition-related dermatologic toxicities are unclear, and prophylactic approaches are not well-established. To explore the mechanisms of the cutaneous side effects induced by epidermal growth factor receptor inhibition, we analyzed the metabolome using human keratinocyte cells. We first demonstrated that afatinib and lapatinib induced apoptosis in HaCaT cells. Using liquid chromatography-mass spectrometry, we detected 676 and 482 metabolites and compounds in the cells and media, respectively. We observed diverse metabolic alterations, including glycolysis, TCA metabolism, and polyamine metabolism, and also found a change in glutathione metabolites after epidermal growth factor receptor inhibition, which led to the accumulation of reactive oxygen species. Supplementation of N-acetyl cysteine partly rescued the afatinib-induced apoptosis, suggesting that reactive oxygen species are involved in the cytotoxicity of skin cells. We observed epidermal growth factor receptor inhibitor-associated comprehensive metabolic changes in human keratinocyte cells, suggesting that oxidative stress evokes cutaneous side effects induced by EGFR inhibition.

The Impact of Immunological Checkpoint Inhibitors and Targeted Therapy on Chronic Pruritus in Cancer Patients

Although pruritus may sometimes be a consequential situation to neoplasms, it more frequently emerges after commencing chemotherapy. In this review, we present our analysis of the chemotherapy treatments that most often induce skin changes and itching. After discussing conventional chemotherapies capable of inducing pruritus, we present our evaluation of new drugs such as immunological checkpoint inhibitors (ICIs), tyrosine kinase inhibitors, and monoclonal antibodies. Although ICIs and targeted therapy are thought to damage tumor cells, these therapies can modify homeostatic events of the epidermis and dermis, causing the occurrence of cutaneous toxicities in treated subjects. In the face of greater efficacy, greater skin toxicity has been reported for most of these drugs. A remarkable aspect of some reports is the presence of a probable correlation between cutaneous toxicity and treatment effectiveness in tumor patients who were treated with novel drugs such as nivolumab or pembrolizumab. Findings from these experiments demonstrate that the occurrence of any grade of skin side effects can be considered as a predictor of a better outcome. In the near future, studies on the relationship between the onset of skin alterations and outcomes could open new perspectives on the treatment of neoplasms through specific target therapy.

rhEGF Treatment Improves EGFR Inhibitor-Induced Skin Barrier and Immune Defects

Simple Summary

In our prior study, we demonstrated that recombinant human epidermal growth factor (rhEGF) treatment is effective for managing epidermal growth factor receptor inhibitors (EGFRIs)-related skin toxicities and improves patients’ quality of life (QoL) compared with placebo. Nevertheless, the mechanisms of rhEGF effects are unknown yet so basic study is needed to clarify the mechanisms. In this study, we revealed that treatment of rhEGF in human epidermal keratinocytes, 3d-cultured human skin tissue and patient lesions improved EGFRIs-induced skin eruption via normalizing proliferation and differentiation of keratinocytes, reducing inflammatory cytokines expression and inducing expression of AMPs. These findings provided an evidence for the use of rhEGF as a treatment for skin side effects derived from EGFRI.

Abstract

The mechanisms of epidermal growth factor (EGF) affecting EGF receptor inhibitor (EGFRI)-related skin toxicities are as yet unknown. We investigated which mechanisms are involved in EGF’s positive effects. Two types of EGFRIs, cetuximab and gefitinib, were used to treat the cells or 3d-cultured human skin tissue with recombinant human EGF (rhEGF). As a result, rhEGF increased EGFR and pEGFR expression. Furthermore, rhEGF induces EGFR signaling by pAKT and pPI3K expression in gefitinib and rhEGF co-treated cells. In addition, rhEGF bound to EGFR after than cetuximab, but cetuximab bound to EGFR more strongly than rhEGF. Moreover, expressions of proliferation and differentiation proteins, both ki-67 and filaggrin, were decreased in EGFRI-treated tissue. However, in rhEGF and EGFRI co-treated tissue, those expressions were increased. Expression of IL-1α, IL-8, and TNF-α was increased by EGFRIs and down-regulated by rhEGF. Furthermore, hBD-2 and hBD-3 protein expressions were inhibited by cetuximab or gefitinib treatment, and those decrements were increased by rhEGF treatment. In patients’ tissue evaluation, compared with controls, patients’ Ki-67 and EGFR expression were decreased (p = 0.015, p = 0.001). Patients’ IL-17 and TNF-α expression intensity was higher than that of the control group (p = 0.038, p = 0.037). After treatment with EGF ointment, average values of Ki-67, EGFR, and Melan-A were changed to normal values. Oppositely, patients’ proportions of IL-17 and TNF-α were decreased to low stain level. In conclusion, treatment of rhEGF improved EGFRI-induced skin eruption via normalizing the proliferation and differentiation of keratinocytes, reducing inflammatory cytokines by the affected EGFRIs.

Light control of RTK activity: from technology development to translational research

Inhibition of receptor tyrosine kinases (RTKs) by small molecule inhibitors and monoclonal antibodies is used to treat cancer. Conversely, activation of RTKs with their ligands, including growth factors and insulin, is used to treat diabetes and neurodegeneration. However, conventional therapies that rely on injection of RTK inhibitors or activators do not provide spatiotemporal control over RTK signaling, which results in diminished efficiency and side effects. Recently, a number of optogenetic and optochemical approaches have been developed that allow RTK inhibition or activation in cells and in vivo with light. Light irradiation can control RTK signaling non-invasively, in a dosed manner, with high spatio-temporal precision, and without the side effects of conventional treatments. Here we provide an update on the current state of the art of optogenetic and optochemical RTK technologies and the prospects of their use in translational studies and therapy.

Entosis and apical cell extrusion constitute a tumor-suppressive mechanism downstream of Matriptase

Armistead et al. show that in a bilayered epithelium in vivo, apical cell extrusion of basal cells is achieved via their engulfment by surface cells. In zebrafish hai1a mutants, this constitutes a tumor-suppressive mechanism, revealing a double face of Matriptase.

The type II transmembrane serine protease Matriptase 1 (ST14) is commonly known as an oncogene, yet it also plays an understudied role in suppressing carcinogenesis. This double face is evident in the embryonic epidermis of zebrafish loss-of-function mutants in the cognate Matriptase inhibitor Hai1a (Spint1a). Mutant embryos display epidermal hyperplasia, but also apical cell extrusions, during which extruding outer keratinocytes carry out an entosis-like engulfment and entrainment of underlying basal cells, constituting a tumor-suppressive effect. These counteracting Matriptase effects depend on EGFR and the newly identified mediator phospholipase D (PLD), which promotes both mTORC1-dependent cell proliferation and sphingosine-1-phosphate (S1P)–dependent entosis and apical cell extrusion. Accordingly, hypomorphic hai1a mutants heal spontaneously, while otherwise lethal hai1a amorphs are efficiently rescued upon cotreatment with PLD inhibitors and S1P. Together, our data elucidate the mechanisms underlying the double face of Matriptase function in vivo and reveal the potential use of combinatorial carcinoma treatments when such double-face mechanisms are involved.

A case of unexpected peripherally inserted central catheter removal from a colorectal cancer patient with cetuximab-induced skin toxicity and contact dermatitis at the peripherally inserted central catheter insertion site: Should we recommend the patient to choose subcutaneous port preferentially?

INTRODUCTION

Obtaining central venous access is one of the most commonly performed procedures in cancer patients. However, there are very limited data to guide clinicians when selecting a device for metastatic colorectal cancer patients who received cetuximab.

CASE DESCRIPTION

A 54-year-old male patient with metastatic colorectal cancer treated with cetuximab plus FOLFIRI used peripherally inserted central catheter as intravenous pathway. After eight cycles, the patient suffered cetuximab-induced grade 2 skin toxicity and grade 3 contact dermatitis at the peripherally inserted central catheter insertion site. Finally, he removed the peripherally inserted central catheter and accepted subcutaneous port instead for 2 years without implantation cutaneous complication.

CONCLUSIONS

We suggest that metastatic colorectal cancer patients treated with cetuximab should be recommended to choose subcutaneous port preferentially to avoid potential risk of unexpected peripherally inserted central catheter removal due to cetuximab-induced skin toxicity or contact dermatitis. Further clinical practices and researches are needed for more profound evidences for better practical suggestions.

Bovine colostrum induces the differentiation of human primary keratinocytes

Bovine colostrum, the first milk secreted by the mammary glands of cows shortly after they have given birth, provides a natural source of bioactive substances helpful to promote tissue development and repair, and to maintain a healthy immune system. Owing to its properties, the use of colostrum in the treatment of human diseases is under investigation. We evaluated the biological activity of colostrum on human primary keratinocytes, focusing on its effects with regard to a proliferation/differentiation balance. Using cellular and molecular approaches, we showed that colostrum favors a cell cycle withdrawal by increasing the expression of p21/WAF1 and p27/KIP1. It also promotes the transition of keratinocytes from a proliferating to a differentiating state, as assessed by a decrease in keratin 5 and an increase in keratin 16. We demonstrated the ability of colostrum to induce the expression of early and late differentiation markers (keratin 1, involucrin, and filaggrin) and the synthesis of caspase 14 and bleomycin hydrolase, the two main enzymes involved in filaggrin maturation. Moreover, we showed that bovine colostrum is able to promote keratinocyte stratification and terminal differentiation not only in two-dimensional (2D), but also in a more physiological system of three-dimensional (3D) skin equivalents. Finally, we demonstrated that colostrum stimulates cell differentiation through the PI3K/PLC-γ1/PKCα pathways mainly associated to tyrosine kinase receptors. These results suggest the possibility to benefit from colostrum properties for the treatment of skin diseases characterized by altered differentiation and perturbed barrier function.

Purpuric drug eruptions induced by EGFR tyrosine kinase inhibitors are associated with IQGAP1-mediated increase in vascular permeability

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are used as a treatment for non-small-cell lung cancer. There have been some reports of EGFR-TKIs being associated with vascular adverse events. We found that EGFR-TKIs decreased the proliferation of HMEC-1s (immortalized human dermal microvascular endothelial cells) and HMVECs (human dermal microvascular endothelial cells), and also inhibited the phosphorylation of EGFR and ERK. We examined the mRNA expression profile of erlotinib-treated HMEC-1s and identified IQ motif containing GTPase activating protein 1 (IQGAP1) as the most consistently up-regulated transcript and protein. IQGAP1 was also overexpressed and co-localized with endothelial cells in the lesional skin. Notably, increased IQGAP1 expression was associated with decreased transendothelial electrical resistance and increased vascular permeability in vitro. Erlotinib treatment enriched the staining of IQGAP1 and reduced the intensities of α-catenin at the sites of cell-cell contact. In conclusion, erlotinib induces adherens junction dysfunction by modulating the expression of IQGAP1 in dermal endothelial cells. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Ibrutinib-Induced Vasculitis in a Patient with Metastatic Colon Cancer Treated in Combination with Cetuximab

Combination therapy with ibrutinib and cetuximab is being studied in a phase 1b/2 trial in patients with advanced gastrointestinal and genitourinary malignancies. Rash is a common cutaneous adverse effect for both medications. Ibrutinib is a Bruton's tyrosine kinase (BTK) inhibitor approved for the treatment of several hematologic malignancies. The rash can be asymptomatic, nonpalpable, mild skin eruption, or palpable purpuric rash. A rarer panniculitis form has also been reported. Cetuximab, an epidermal growth factor (EGFR) inhibitor, approved for treatment in head and neck and advanced gastrointestinal malignancies is also known to cause acneiform rash in majority of patients. The rash is due to inhibition of EGFR in the basal keratinocytes and hair follicles. In the case of ibrutinib, the off-target effects on EGFR, c-kit, and platelet-derived growth factor receptor (PDGFR) are thought to be responsible for the cutaneous eruption of various forms of rash. The combination therapy with the BTK inhibitor and a direct EGFR inhibitor may potentiate the rash inducing effects of the drugs. Here, we describe a case of vasculitis in a patient with metastatic colon cancer who received both ibrutinib and cetuximab on a phase Ib/II clinical trial.

Panitumumab Induced Forearm Panniculitis in Two Women With Metastatic Colon Cancer

BACKGROUND

Panitumumab is an EGFR inhibitor used for the treatment of metastatic colorectal cancer (mCRC), even if its use is related to skin toxicity.

CASE PRESENTATION

We report the development of forearm panniculitis in two women during the treatment with Panitumumab (6 mg/Kg intravenous every 2 weeks) + FOLFOX-6 (leucovorin, 5- fluorouracil, and oxaliplatin at higher dosage) for the treatment of mCRC.

RESULTS

In both patients, clinical, laboratory and radiological evaluation documented the presence of a local panniculitis, probably related to panitumumab (Naranjo score: 6). Panatimumab discontinuation and antimicrobial + corticosteroid treatment induced a remission of skin manifestations.

CONCLUSION

We reported for the first time the development of panniculitis during Panitumumab treatment, and we documented that the treatment with beta-lactams to either fluoroquinolones or oxazolidinone in the presence of corticosteroid improves clinical symptoms in young patients with mCRC, without the development of adverse drug reactions or drug-drug interactions.

Epidermal Growth Factor Receptor's Function in Cutaneous Squamous Cell Carcinoma and Its Role as a Therapeutic Target in the Age of Immunotherapies

OPINION STATEMENT

Recent studies have evidenced the potential of combining anti-EGFR therapies with anti-PD-1/PD-L1 checkpoint therapies. Both anti-EGFR and anti-PD-1/PD-L1 have been separately tested in the treatment of cutaneous SCC (cSCC). Here, we review recent data on EGFR in the context of cancer progression, as a prognostic and as a therapeutic target in cSCC. Anti-EGFR/checkpoint immunotherapy and other combination therapy approaches are discussed. With the advent of immunotherapy, EGFR is still a valid cSCC target.

Agonistic anti-CD148 monoclonal antibody attenuates diabetic nephropathy in mice

CD148 is a transmembrane protein tyrosine phosphatase (PTP) that is expressed in the renal vasculature, including the glomerulus. Previous studies have shown that CD148 plays a role in the negative regulation of growth factor signals (including epidermal growth factor and vascular endothelial growth factor), suppressing cell proliferation and transformation. However, the role of CD148 in kidney disease remains unknown. Here, we generated an agonistic anti-CD148 antibody and evaluated its effects in murine diabetic nephropathy (DN). Monoclonal antibodies (mAbs) against the mouse CD148 ectodomain sequence were generated by immunizing CD148 knockout (CD148KO) mice. The mAbs that increased CD148 activity were selected by biological (proliferation) and biochemical (PTP activity) assays. The mAb (18E1) that showed strong agonistic activity was injected (10 mg/kg ip) in streptozotocin-induced wild-type and CD148KO diabetic mice for 6 wk, and the renal phenotype was then assessed. The effects of 18E1 mAb in podocyte growth factor signals were also assessed in culture. Compared with control IgG, 18E1 mAb significantly decreased albuminuria and mesangial expansion without altering hyperglycemia and blood pressure in wild-type diabetic mice. Immunohistochemical evaluation showed that 18E1 mAb significantly prevented the reduction of podocyte number and nephrin expression and decreased glomerular fibronectin expression and renal macrophage infiltration. The 18E1 mAb showed no effects in CD148KO diabetic mice. Furthermore, we demonstrated that 18E1 mAb reduces podocyte epidermal growth factor receptor signals in culture and in diabetic mice. These findings suggest that agonistic anti-CD148 mAb attenuates DN in mice, in part by reducing epidermal growth factor receptor signals in podocytes. This antibody may be used for the treatment of early DN.

Current Recommendations and Novel Strategies for the Management of Skin Toxicities Related to Anti-EGFR Therapies in Patients with Metastatic Colorectal Cancer

The use of targeted therapies, when added to conventional chemotherapy, has significantly improved clinical outcomes and survival of cancer patients. While targeted therapies do not have the systemic adverse reactions of chemotherapy, they are associated with toxicities that can be severe and impair patient quality of life and adherence to anti-cancer treatment. Panitumumab and cetuximab, two monoclonal antibodies against epidermal growth factor receptor (EGFR), are recommended for the treatment of metastatic colorectal cancer (mCRC). The majority of patients with mCRC who are treated with anti-EGFR therapy develop skin toxicities, including papulopustular rash (the most common), xerosis, painful cracks and fissures on the palms and soles of the feet, paronychia, pruritus, and abnormal hair and eyelash growth; they are also more prone to skin infections. Given the involvement of EGFR in normal epidermis physiology, development and function, skin toxicities caused by anti-EGFR therapy are not unexpected. In recent years, recommendations have been formulated for the prevention and treatment of anti-EGFR therapy-related skin toxicities. Indeed, proper and timely management of these toxicities is important for ensuring uninterrupted anti-cancer treatment and optimal outcomes. Here, we review the current knowledge of anti-EGFR therapy-related skin toxicities and the latest recommendations for their management. We also present a treatment approach for papulopustular rash based on the combination of fusidic acid plus betamethasone in a lipid-enriched topical formulation. The effectiveness of this approach is documented by the presentation of five cases successfully treated in clinical practice for anti-EGFR therapy-related rash.

A Randomized Controlled Trial of Epidermal Growth Factor Ointment for Treating Epidermal Growth Factor Receptor Inhibitor-Induced Skin Toxicities

BACKGROUND

The efficacy of epidermal growth factor (EGF) receptor (EGFR) inhibitors in patients with non-small cell lung cancer (NSCLC), pancreatic cancer (PC), or colorectal cancer (CRC) has been demonstrated. However, dermatological reactions to these inhibitors can cause significant physical and psychosocial discomfort. The objective of the present study was to evaluate the efficacy of EGF ointment for EGFR inhibitor-related skin adverse events (ERSEs).

MATERIALS AND METHODS

This placebo-controlled, double-blind, multicenter, pilot phase III trial enrolled patients with NSCLC, PC, or CRC treated with EGFR inhibitors. Patients with grade ≥2 ERSEs were included. Patients were randomized to three treatment arms: arm 1, placebo; arm 2, 1 ppm of EGF ointment; and arm 3, 20 ppm of EGF ointment. Patients applied ointment to their skin lesions twice daily.

RESULTS

Efficacy evaluation was available for 80 patients (9 for PC, 28 for NSCLC, and 43 for CRC). Responses were 44.4% in arm 1, 61.5% in arm 2, and 77.8% in arm 3. There was a linear correlation between EGF concentrations and responses (p = .012). Quality of life (QoL) was assessed for 74 patients. Maximum changes in composite scores by Skindex-16 after treatment were significantly different among arms (mean ± SD: -5.2 ± 8.6 for arm 1, -11.7 ± 14.2 for arm 2, and - 18.6 ± 17.7 for arm 3; p = .008). EGF arms showed significant improvement in emotions (p = .005) and functioning (p = .044) scores over the placebo arm.

CONCLUSION

EGF ointment is effective for managing ERSEs. It can also improve patients' QoL compared with placebo. Clinical trial identification number. NCT02284139 IMPLICATIONS FOR PRACTICE: Patients with non-small cell lung cancer, pancreatic cancer, or colorectal cancer who are treated with epidermal growth factor (EGF) receptor (EGFR) inhibitors may experience dermatologic reactions to their treatment. This study investigated the benefit of an EGF ointment in the treatment of these adverse events and observed the ointment to be effective in managing EGFR inhibitor-related skin adverse events.

Molecular Profiling of EGFR Status to Identify Skin Toxicity in Colorectal Cancer: A Clinicopathological Review

Colorectal cancer (CRC) represents an important health problem, being the third most common type of cancer. In Romania, the CRC incidence has doubled over the years. Both environmental factors and genetic susceptibility are very important for the pathogenesis of CRC. The epidermal growth factor receptor (EGFR) plays an extremely important role in CRC tumorigenesis. Overexpression or dysregulation of EGFR pathway molecules are frequently associated with tumor aggressiveness and patient response to treatment. Based on these considerations, EGFR became one of the first targets of molecular therapies used in CRC. At present, cetuximab and panitumumab are considered to be essential in the treatment of patients with metastatic colorectal cancer expressing the KRAS wild-type gene and EGFR. The main adverse effect for both cetuximab and panitumumab is skin toxicity, present in approximately 80% of patients. The risk of secondary infections, in particular of bacterial infections, is also increased. Cases of staphylococcal infection associated with skin peeling, cellulite, erysipelas, and even Staphylococcus sepsis, were reported. For a long time cutaneous toxicity has been a positive predictor in the efficacy of anti-EGFR treatment, but compliance with treatment and the quality of life of patients with metastatic CRC decreases in the presence of these skin reactions. That is why we emphasize the necessity and importance of using a modern method (molecular analysis of gene polymorphisms possibly supplemented by targeted confocal laser endomicroscopy) to identify a molecular diagnosis, in order to foresee and prevent the appearance of skin reactions and to manage skin toxicity.