Degranulation assay to evaluate NK cell natural and antibody-dependent cell-mediated cytotoxicity against A549 tumor spheroids.

Adoptive natural killer (NK) cell-based immunotherapy is a promising treatment approach in cancer that is showing notable efficacy against hematological malignancies. However, the success of NK cell immunotherapy in patients with solid tumors is limited due to several barriers, which include the immunosuppressive tumor microenvironment (TME), heterogeneity of tumor cells and poor NK cell infiltration into the tumor. Advances in 3D in vitro culture technologies have opened new avenues for the development of more physiological human cancer models that mimic important tumor features which are absent in traditional 2D studies and may be essential for the improvement of immunotherapies against solid tumors. Here, we describe a comprehensive protocol to generate tumor spheroids from the A549 lung carcinoma cell line, then establish co-cultures with NK cells to, ultimately, determine NK cell functional response with a degranulation assay, a surrogate of NK cell cytotoxicity against tumor spheroids. Additionally, we studied degranulation by stimulating NK cell antibody-dependent cell-mediated cytotoxicity (ADCC) with cetuximab, an IgG1 monoclonal antibody used in cancer therapy. Likewise, other monoclonal antibodies or combination treatments could also be studied in this 3D co-culture system, providing very valuable information to define effective combinations of therapeutic agents able to generate NK cells with high cytotoxic potential that could lead to more successful adoptive NK cell-based therapies for the treatment of solid tumors.

Efficacy and Safety of Anti-EGFR Therapy Rechallenge in Metastatic Colorectal Cancer: A Systematic Review and Meta-Analysis.

BACKGROUND: Colorectal cancer (CRC) represents the second leading cause of cancer-related mortality worldwide, with a significant portion of patients presenting with metastatic disease at diagnosis. Resistance to initial anti-EGFR therapy, a key treatment for RAS wild-type metastatic CRC, remains a major challenge. This study aimed to assess the efficacy and safety of rechallenge with anti-EGFR therapy in patients with metastatic CRC who have progressed after prior treatments. METHODS: A systematic search was conducted across PubMed, Web of Science, Cochrane, and Scopus. Studies were included if they were randomized controlled trials (RCTs) or observational studies involving patients with EGFR-mutated metastatic CRC who received anti-EGFR therapy as a rechallenge. Endpoints included objective response rate (ORR), disease control rate (DCR), and the incidence of adverse events. Statistical analyses were performed using the DerSimonian/Laird random effect model, with heterogeneity assessed via I2 statistics. R, version 4.2.3, was used for statistical analyses. RESULTS: Fourteen studies were included with 520 patients; 50.3% were male, and the median age was 63 years old. The median progression-free survival (mPFS) ranged between 2.4 and 4.9 months, while the median overall survival (mOS) ranged from 5 to 17.8 months. Our pooled analysis demonstrated an objective response rate (ORR) of 17.70% (95% CI, 8.58-26.82%) and a disease control rate (DCR) of 61.72% (95% CI, 53.32-70.11%), both with significant heterogeneity (I2, 84% and 80%, respectively; p < 0.01). In the subgroup analysis, cetuximab showed an ORR of 18.31% (95% CI, 4.67-31.94%), and panitumumab an ORR of 10.9% (95% CI, 0.00-26.82%), while the combination of both resulted in an ORR of 29.24% (95% CI, 0.00-65.84%). For DCR, cetuximab resulted in 62.1% (95% CI, 49.32-74.87%), panitumumab in 63.05% (95% CI, 52.13-73.97%), and the combination in 60.34% (95% CI, 31.92-88.77%), all with significant heterogeneity. Adverse events included anemia (15.39%), diarrhea (4.20%), hypomagnesemia (6.40%), neutropenia (22.57%), and skin rash (13.22%). CONCLUSIONS: Rechallenge with anti-EGFR therapy in metastatic CRC patients shows moderate efficacy with manageable safety profiles. These findings highlight the need for careful patient selection and monitoring to optimize outcomes. Further studies are warranted to refine strategies for maximizing the therapeutic benefits of anti-EGFR rechallenge.

Prognostic factors and risk-stratification model of recurrent or metastatic head and neck squamous cell carcinoma treated with cetuximab containing regimen.

BACKGROUND: In recent years, the addition of cetuximab to chemotherapy has improved treatment outcomes for patients with recurrent/metastatic head and neck squamous cell carcinoma (R/M HNSCC). In this study, we present the real-world survival data of R/M HNSCC patients who received cetuximab-containing regimens from thirteen medical centers in Taiwan, as well as a three-level risk stratification model for this patient population. METHODS: This study enrolled R/M HNSCC patients from thirteen medical centers in Taiwan who received cetuximab-containing regimens from January 1, 2017 to June 6, 2022. The cases were divided into a training cohort and a validation cohort based on the start of treatment. Overall survival (OS) was evaluated in both cohorts and exploratory analysis was performed to identify associated adverse clinical and laboratory factors. The results of the exploratory analysis were used to construct a three-level risk stratification prediction model for OS. RESULTS: A total of 1434 patients with R/M HNSCC were enrolled in this study and received cetuximab-containing regimens. The overall population had a median OS of 8.57 months (95% CI: 8.07 - 9.08). Multivariate analysis of the training cohort identified poor ECOG performance status, heavy alcohol consumption, and prior adjuvant CCRT or lack of prior RT as adverse prognostic factors. Comparison of laboratory data between patients with OS≦6 and OS > 6 also revealed unfavorable factors, including increased white blood cell count, decreased hemoglobin level, increased platelet count, increased absolute neutrophil count, decreased absolute lymphocyte count, and increased neutrophil-to-lymphocyte ratio. Using forward prediction, a three-level risk stratification prediction model was constructed using the variables of ECOG performance status, alcohol consumption, skin metastasis, modality of radiation therapy, hemoglobin level, and neutrophil-to-lymphocyte ratio. The median OS in the low-risk, intermediate-risk, and high-risk groups were 12.02 months (95% CI 10.44-13.61), 7.5 months (95% CI 7.33-8.17), and 4.01 months (95% CI 3.94-4.08), respectively, with a log-rank test p-value < 0.001. CONCLUSION: This study presents a three-level risk stratification model with strong prediction ability for OS in R/M HNSCC patients who received cetuximab-containing regimens. The results are based on real-world data and may provide valuable information for clinicians in treatment planning and future drug development.

Cetuximab-conjugated sodium selenite nanoparticles for doxorubicin targeted delivery against MCF-7 breast cancer cells.

Aim: To develop and characterize doxorubicin-loaded sodium selenite nanoparticles (SSNP-DOX) and their surface attachment with cetuximab (mAb-SSNP-DOX).Methods: SSNP-DOX was formulated by gelation and then conjugated with cetuximab to form mAb-SSNP-DOX. Characterization included DLS, SEM, TEM, DSC, Raman spectroscopy and XRD. In vitro, the kinetics of doxorubicin release and cytotoxicity in MCF-7 breast cancer cells were investigated.Results: The zeta potential for SSNP-DOX and mAb-SSNP-DOX was -14.4 ± 10.1 mV and -27.5 ± 7.28 mV, with particle sizes of 181.3 nm and 227.5 nm, respectively. The formulation intensity was 89.7% for SSNP-DOX and 100% for mAb-SSNP-DOX, with PDI values of 0.419 and 0.251, respectively. SEM and TEM showed that mAb-SSNP-DOX was smooth and spherical. The DSC analysis revealed exothermic peaks at 102.44°C for SSNP-DOX and 144.21°C for mAb-SSNP-DOX, along with endothermic peaks at 269.19°C and 241.6°C, respectively. Raman spectroscopy showed a higher intensity for mAb-SSNP-DOX. The XRD study showed different peaks for each formulation. Both followed zero order kinetics for doxorubicin release. Cytotoxicity studies showed significant effects and high apoptosis in MCF-7 cells for both formulations.Conclusion: The mAb-SSNP-DOX showed promising properties, more effective doxorubicin release and higher cytotoxicity against breast cancer cells compared with SSNP-DOX.

[Box: see text].

Successful administration of cetuximab using dose escalation method: a case report.

INTRODUCTION: Cetuximab, used to treat head and neck squamous cell carcinoma and metastatic colorectal cancer, can cause severe infusion reactions. CASE PRESENTATION: We report an 87-year-old East Asian woman with stage IV ileocecal signet ring cell carcinoma who experienced severe allergic reactions to cetuximab despite pre-treatment. A dose escalation method, involving weekly incremental doses with comprehensive pre-treatment and close monitoring, was employed, successfully reducing allergic reactions and allowing safe administration. CONCLUSION: This approach demonstrates a viable alternative for patients with hypersensitivity to cetuximab, warranting further research for personalized treatment optimization.

Modified FOLFOX6 with Cetuximab versus with Radiotherapy in Neoadjuvant Treatment of Locally Advanced Rectal Cancer: A Single-Center, Prospective, Randomized Controlled Trial.

In this trial, the feasibility and efficacy of neoadjuvant chemotherapy with targeted agents in the treatment of patients with locally advanced rectal cancer were evaluated. In this single-center, prospective, randomized controlled trial, we randomly assigned (1 : 1) patients with locally advanced rectal cancer with wild-type RAS/BRAF gene to two groups: 5 cycles of modified leucovorin calcium (folinic acid), fluorouracil, and oxaliplatin combination regimen (modified FOLFOX6, mFOLFOX6) concurrent with 25 times radiotherapy or 5 cycles of mFOLFOX6 plus cetuximab, all with subsequent total mesorectal excision (TME) resection and adjuvant chemotherapy. We performed a random assignment by a computer-generated random number sequence. The primary end point was the R0 resection rate. The secondary end points were rates of pathologic complete response, downstaging, adverse events, postoperative complications, preventive enterostomy and low anterior resection syndrome. From January 6, 2020 to October 28, 2022, 80 patients were assigned and evaluated. In the mFOLFOX6-RT and mFOLFOX6-Cet groups, the rate of R0 resection was 96.7 and 96.9% (p = 1.000); the rate of pathological complete response (pCR) was 23.3 and 21.9% (p = 0.891); and the rate of downstaging (ypStage 0 to 1) was 53.3 and 53.1% (p = 1.000), respectively. No statistical differences between the two groups were observed in the incidence of adverse events and postoperative complications. Additionally, lower rates of preventive enterostomy and low anterior resection syndrome were shown in the mFOLFOX6-Cet group compared to the mFOLFOX6-RT group. The neoadjuvant treatment strategy of mFOLFOX6 with cetuximab is feasible and promising for patients with locally advanced rectal cancer, even superior to mFOLFOX6 with radiotherapy.

EGFR-Targeted and NIR-Triggered Lipid-Polymer Hybrid Nanoparticles for Chemo-Photothermal Colorectal Tumor Therapy.

Background: Epidermal growth factor receptor (EGFR) is a major target for the treatment of colorectal cancer. Thus, anti-EGFR antibody conjugated lipid-polymer hybrid nanoparticles can offer a potential means of enhancing the efficacy of chemotherapeutics in EGFR overexpressing cancers. In addition, the combination of chemotherapy and photothermal therapy is a promising strategy for cancer treatment. Hence, it is highly desirable to develop a safe and effective delivery system for colorectal tumor therapy. Methods: In this study, EGFR-targeted and NIR-triggered lipid-polymer hybrid nanoparticles (abbreviated as Cet-Iri-NPs) were prepared with copolymer PPG-PEG, lipids DSPE-PEG-Mal and lecithin as carriers, CPT-11 as an anticancer chemotherapeutic agent, indocyanine green (ICG) as a photothermal agent, and cetuximab as a surface-targeting ligand. Results: In vitro analyses revealed that Cet-Iri-NPs were spherical with size of 99.88 nm, charge of 29.17 mV, drug entrapment efficiency of 51.72%, and antibody conjugation efficiency of 41.70%. Meanwhile, Cet-Iri-NPs exhibited a remarkable photothermal effect, and pH/NIR-triggered faster release of CPT-11 with near infrared (NIR) laser irradiation, which induced enhanced cytotoxicity against SW480 cells. Furthermore, the promoted tumor-growth suppression effect of Cet-Iri-NPs on SW480 tumor xenograft nude mice was achieved under NIR laser irradiation. Conclusion: These results indicate that the well-defined Cet-Iri-NPs are a promising platform for targeted colorectal cancer treatment with chemo-photothermal therapy.

Honokiol enhances the sensitivity of cetuximab in KRASG13D mutant colorectal cancer through destroying SNX3-retromer complex.

Rationale : the proto-oncogene KRAS is frequently mutated in colorectal cancer (CRC), leading to inherent resistance against monoclonal antibodies targeting the epidermal growth factor receptor (EGFR), such as cetuximab. Therefore, addressing the primary resistance and expanding the indications for target therapy have become critical challenges. Methods : the screening of a natural product library against KRAS mutant CRC cells was conducted, leading to the discovery of a small molecule compound that sensitive to the KRASG13D mutation site. The anti-tumor activity of this small molecule compound in combination with cetuximab was evaluated using the KRASG13D mutant CRC models both in vivo and in vitro. This evaluation includes an examination of its effects on cell proliferation, viability, apoptosis, cell cycle progression, and tumor growth. Furthermore, RNA sequencing, western blot analysis, immunofluorescence, real-time quantitative PCR, and pull-down assays were employed to explore the molecular mechanisms underlying the synergistic anti-tumor effect of this small molecule compound in combination with cetuximab. Results : our study screened 882 compounds in KRAS mutant CRC cells and identified honokiol, a small molecule compound that exhibits specific sensitivity to KRASG13D mutant CRC cells. Furthermore, we revealed that the synergistic augmentation of cetuximab's sensitivity in vivo and in vitro models of KRASG13D mutant CRC in combination with honokiol. Mechanistically, honokiol suppresses SNX3-retromer mediated trafficking, thereby impeding lysosomal proteolytic capacity and inhibiting autophagy and macropinocytosis fluxes. Moreover, honokiol inhibits the conversion of RAS GDP to RAS GTP, heightening the susceptibility of KRASG13D CRC mutant cells to cetuximab. Conclusions : honokiol enhances the sensitivity of cetuximab by destroying SNX3 retromer in KRASG13D mutant CRC preclinical model. These findings present a promising strategy for expanding the indications of target therapy in KRAS mutant colorectal cancer patients.

Efficacy and safety of the combination of encorafenib/cetuximab with or without binimetinib in patients with BRAF V600E-mutated metastatic colorectal cancer: an AGEO real-world multicenter study.

BACKGROUND: The combination of encorafenib with cetuximab has become the standard of care in patients with BRAF V600E-mutated metastatic colorectal cancer (mCRC) after a prior systemic therapy. This study aims to describe the efficacy and safety of encorafenib/cetuximab +/- binimetinib in patients with BRAF V600E-mutated mCRC in a real-world setting. PATIENTS AND METHODS: This retrospective study included patients with BRAF V600E-mutated mCRC who received this combination from January 2020 to June 2022 in 30 centers. RESULTS: A total of 201 patients were included, with 55% of women, a median age of 62 years, and an Eastern Cooperative Oncology Group performance status (ECOG-PS) >1 in 20% of cases. The main tumor characteristics were 60% of right-sided primary tumor, 11% of microsatellite instability/mismatch repair deficient phenotype, and liver and peritoneum being the two main metastatic sites (57% and 51%). Encorafenib/cetuximab +/- binimetinib was prescribed in the first, second, third, and beyond third line in 4%, 56%, 29%, and 11%, respectively, of cases, with the encorafenib/cetuximab/binimetinib combination for 21 patients (10%). With encorafenib/cetuximab treatment, 21% of patients experienced grade ≥3 adverse events (AEs), with each type of grade ≥3 AE observed in <5% of patients. The objective response rate was 32.2% and the disease control rate (DCR) was 71.2%. The median progression-free survival (PFS) was 4.5 months [95% confidence interval (CI) 3.9-5.4 months] and the median overall survival (OS) was 9.2 months (95% CI 7.8-10.8 months). In multivariable analysis, factors associated with a shorter PFS were synchronous metastases [hazard ratio (HR) 1.66, P = 0.04] and ECOG-PS >1 (HR 1.88, P = 0.007), and those associated with a shorter OS were the same factors (HR 1.71, P = 0.03 and HR 2.36, P < 0.001, respectively) in addition to treatment beyond the second line (HR 1.74, P = 0.003) and high carcinoembryonic antigen level (HR 1.72, P = 0.003). CONCLUSION: This real-world study showed that in patients with BRAF V600E-mutated mCRC treated with encorafenib/cetuximab +/- binimetinib, efficacy and safety data confirm those reported in the BEACON registration trial. The main poor prognostic factors for this treatment are synchronous metastases and ECOG-PS >1.

Confined copper depletion via a hydrogel platform for reversing dabrafenib/cetuximab resistance in BRAFV600E-mutant colorectal cancer.

BRAFV600E-mutant colorectal cancer (CRC) is resistant to most first-line therapeutics, including the BRAF inhibitor dabrafenib and epidermal growth factor receptor (EGFR) inhibitor cetuximab. Although copper depletion shows promise in reversing dabrafenib/cetuximab resistance in BRAFV600E-mutant CRC, its application is limited by the potential for excessive copper depletion in non-tumor objects. In this study, we have developed a hydrogel platform for confined copper depletion in BRAFV600E-mutant CRC cells, which effectively reverses dabrafenib/cetuximab resistance and enhancing therapeutic efficiency. The hydrogel platform enables precise intracellular copper depletion through localized administration, acidity-triggered drug release, and oxidized activation of a copper prochelator. The dosage of this prochelator is 37.5 µg/kg in mouse models, which is significantly lower than the commonly used tetrathiomolybdate. Furthermore, both dabrafenib and the prochelator are preloaded into acid-responsive nanoparticles before being embedded in the hydrogel matrix to facilitate efficient endocytosis and acid-activatable drug release. Confined copper depletion inhibits MEK1 signaling and suppresses the MAPK signaling pathway when combined with BRAF and EGFR inhibitors. Moreover, the hydrogel platform inhibits tumor growth and prolongs survival in subcutaneous and postsurgical models of BRAFV600E-mutant CRC. This study provides an innovative strategy for overcoming dabrafenib/cetuximab resistance in BRAFV600E-mutant CRC through precise intracellular copper depletion.

EGFR-targeting oxygen-saturated nanophotosensitizers for orchestrating multifaceted antitumor responses by counteracting immunosuppressive milieu.

High Epidermal growth factor receptor (EGFR) in Cutaneous Squamous Cell Carcinoma (cSCC) is associated with poor prognosis and advanced metastatic stages, severely impeding the efficacy of EGFR-targeting immunotherapy. This is commonly attributed to the combinatory outcomes of hypoxic tumor microenvironment (TME) and immunosuppressive effector cells together. Herein, a novel paradigm of EGFR-targeting oxygen-saturated nanophotosensitizers, designated as CHPFN-O2, has been specifically tailored to mitigate tumor hypoxia in EGFR-positive cSCC and achieve Cetuximab (CTX)-mediated immunotherapy (CIT). The conjugated CTX in CHPFN-O2 serves to initiate immune responses by recruiting Fc receptor (FcR)-expressing immune effector cells towards tumor cells, thereby eliciting antibody-dependent cellular phagocytosis (ADCP), antibody-dependent cellular trogocytosis (ADCT) and antibody-dependent cellular cytotoxicity (ADCC). Besides, CHPFN-O2 can engender a shift from a tumor-friendly to a tumor-hostile one through improved tumor oxygenation, contributing to oxygen-elevated photodynamic therapy (oxPDT). Notably, the combination of oxPDT and CIT eventually promotes T-cell-mediated antitumor activity and successfully inhibits the growth of EGFR-expressing cSCC with good safety profiles. This comprehensive oxPDT/CIT integration aims not only to enhance therapeutic efficacy against EGFRhigh cSCC but also to extend its applicability to other EGFRhigh malignancies, thus delineating a new avenue for the highly efficient synergistic treatment of EGFR-expressing malignancies.

Consensus molecular subtyping of metastatic colorectal cancer expands biomarker-directed therapeutic benefit for patients with CMS1 and CMS2 tumors.

BACKGROUND: We developed a whole transcriptome sequencing (WTS)-based Consensus Molecular Subtypes (CMS) classifier using FFPE tissue and investigated its prognostic and predictive utility in a large clinico-genomic database of CRC patients (n = 24,939). METHODS: The classifier was trained against the original CMS datasets using an SVM model and validated in an independent blinded TCGA dataset (88.0% accuracy). Kaplan-Meier estimates of overall survival (OS) and time-on-treatment (TOT) were calculated for each CMS (p < 0.05 considered significant). RESULTS: CMS2 tumors were enriched on left-side of colon and conferred the longest median OS. In RAS-wildtype mCRC, left-sided tumors and CMS2 classification were associated with longer TOT with anti-EGFR antibodies (cetuximab and panitumumab). When restricting to only CMS2, there was no significant difference in TOT between right- versus left-sided tumors. CMS1 tumors were associated with a longer median TOT with pembrolizumab relative to other CMS groups, even when analyzing only microsatellite stable (MSS) tumors. DISCUSSION: A WTS-based CMS classifier allowed investigation of a large multi-institutional clinico-genomic mCRC cohort, suggesting anti-EGFR therapy benefit for right-sided RAS-WT CMS2 tumors and immune checkpoint inhibitor benefit for MSS CMS1. Routine CMS classification of CRC provides important treatment associations that should be further investigated.

Natural killer cells: a future star for immunotherapy of head and neck squamous cell carcinoma.

The interplay between immune components and the epithelium plays a crucial role in the development and progression of head and neck squamous cell carcinoma (HNSCC). Natural killer (NK) cells, one of the main tumor-killing immune cell populations, have received increasing attention in HNSCC immunotherapy. In this review, we explore the mechanism underlying the interplay between NK cells and HNSCC. A series of immune evasion strategies utilized by cancer cells restrict HNSCC infiltration of NK cells. Overcoming these limitations can fully exploit the antineoplastic potential of NK cells. We also investigated the tumor-killing efficacy of NK cell-based immunotherapies, immunotherapeutic strategies, and new results from clinical trials. Notably, cetuximab, the most essential component of NK cell-based immunotherapy, inhibits the epidermal growth factor receptor (EGFR) signaling pathway and activates the immune system in conjunction with NK cells, inducing innate effector functions and improving patient prognosis. In addition, we compiled information on other areas for the improvement of patient prognosis using anti-EGFR receptor-based monoclonal antibody drugs and the underlying mechanisms and prognoses of new immunotherapeutic strategies for the treatment of HNSCC.

Study protocol for Near-infrared molecular imaging for lung cancer detection and treatment during mini-invasive surgery (phase II Trial) - (the RECOGNISE study).

INTRODUCTION: To date, radical surgery remains the best curative option in patients with early-stage lung cancer. In patients with small lung lesions, video-assisted thoracic surgery (VATS) should be increasingly chosen as a fundamental alternative to thoracotomy as it is associated with less postoperative pain and better quality of life. This scenario necessarily increases the need for thoracic surgeons to implement new localization techniques. The conventional near-infrared (NIR) indocyanine green (ICG) method demonstrated a significant limitation in deep cancer recognition, principally due to its intrinsic low-depth tissue penetration. Similarly, the lymph-node sentinel approach conducted by the ICG method was demonstrated to be inefficient, mainly due to the non-specificity of the tracker and the irregular pathway of pulmonary lymph node drainage. Our study aims to evaluate the effectiveness of Cetuximab- IRDye800CW in marking lung nodules and mediastinal lymph nodes. METHODS AND ANALYSIS: This study is defined as an open-label, single-arm, single-stage phase II trial evaluating the effectiveness of Cetuximab-IRDye800CW in detecting tumors and lymph-node metastases in patients with lung cancer who are undergoing video-assisted thoracic surgery (VATS). Cetuximab is a monoclonal antibody that binds, inhibits, and degrade the EGFR. The IRDye® 800CW, an indocyanine-type NIR fluorophore, demonstrated enhanced tissue penetration compared to other NIR dyes. The combination with the clinical approved monoclonal antibody anti-epidermal growth factor EGFR Cetuximab (Cetuximab-IRDye800) has shown promising results as a specific tracker in different cancer types (i.e., brain, pancreas, head, and neck). The study's primary outcome is focused on the proportion of patients with lung nodules detected during surgery using an NIR camera. The secondary outcomes include a broad spectrum of items, including the proportion of patients with detection of unexpected cancer localization during surgery by NIR camera and the proportion of patients with negative surgical margins, the evaluation of the time spawns between the insertion of the NIR camera and the visualization of the nodule and the possible morbidity of the drug assessed during and after the drug infusion. ETHICS AND DISSEMINATION: This trial has been approved by the Ethical Committee of Azienda Ospedaliera Universitaria Città della Salute e della Scienza di Torino (Torino, Italy) and by the Italian Medicines Agency (AIFA). Findings will be written as methodology papers for conference presentations and published in peer-reviewed journals. The Azienda Ospedaliera Universitaria Città della Salute e della Scienza di Torino, the University of Torino, and the AIRC Public Engagement Divisions will help identify how best to publicize the findings.Trial registration EudraCT 202,100,645,430. CLINICALTRIALS: gov NCT06101394 (October 23, 2023).

Discovery of potent allosteric antibodies inhibiting EGFR.

In this work, we report the discovery of potent anti-epidermal growth factor receptor (EGFR) allosteric heavy-chain antibodies by combining camelid immunization and fluorescence-activated cell sorting (FACS). After immunization and yeast surface display library construction, allosteric clones were obtained by introducing the labeled EGF Fc fusion protein as an additional criterion for FACS. This sorting method enabled the identification of 11 heavy-chain antibodies that did not compete with the orthosteric ligand EGF for the binding to EGFR. These antibodies bind to a triple-negative breast cancer cell line expressing EGFR with affinities in the picomolar to nanomolar range. Those camelid-derived antibodies also exhibit interesting properties by modulating EGFR affinity for EGF. Moreover, they are also able to inhibit EGF-induced downstream signaling pathways. In particular, we identified one clone that is more potent than the approved blocking antibody cetuximab in inhibiting both PI3K/AKT and MAPK/ERK pathways. Our results suggest that allosteric antibodies may be potential new modalities for therapeutics.

Ag2S quantum dot-based magnetic resonance/fluorescence dual-mode imaging nanoprobes for tumor diagnosis.

Accurate tumor detection is crucial for the early discovery and subsequent treatment of small neoplastic foci. Molecular imaging, which combines non-invasiveness, high specificity, and strong sensitivity, excels in diagnosing early tumors and stands out among tumor diagnosis methods. Here, we introduced a dual-modal imaging probe capable of actively targeting tumor cells, suitable for both near-infrared (NIR) fluorescence and magnetic resonance imaging (MRI). Dendritic mesoporous silica was used as a carrier for the probe, encapsulating Ag2S quantum dots (QDs) for NIR fluorescence imaging. Additionally, the probe conjugated the MRI contrast agent Gd-DOTA and cetuximab, which targeted EGFR on the tumor cell membrane surface, to achieve dual-modal imaging in the tumor area. This strategy provided a methodology for the accurate diagnosis of early-stage tumor lesions and guides precise lesion resection during surgery, offering significant potential for clinical application.

Analysis of translesion polymerases in colorectal cancer cells following cetuximab treatment: A network perspective.

INTRODUCTION: Adaptive mutagenesis observed in colorectal cancer (CRC) cells upon exposure to EGFR inhibitors contributes to the development of resistance and recurrence. Multiple investigations have indicated a parallel between cancer cells and bacteria in terms of exhibiting adaptive mutagenesis. This phenomenon entails a transient and coordinated escalation of error-prone translesion synthesis polymerases (TLS polymerases), resulting in mutagenesis of a magnitude sufficient to drive the selection of resistant phenotypes. METHODS: In this study, we conducted a comprehensive pan-transcriptome analysis of the regulatory framework within CRC cells, with the objective of identifying potential transcriptome modules encompassing certain translesion polymerases and the associated transcription factors (TFs) that govern them. Our sampling strategy involved the collection of transcriptomic data from tumors treated with cetuximab, an EGFR inhibitor, untreated CRC tumors, and colorectal-derived cell lines, resulting in a diverse dataset. Subsequently, we identified co-regulated modules using weighted correlation network analysis with a minKMEtostay threshold set at 0.5 to minimize false-positive module identifications and mapped the modules to STRING annotations. Furthermore, we explored the putative TFs influencing these modules using KBoost, a kernel PCA regression model. RESULTS: Our analysis did not reveal a distinct transcriptional profile specific to cetuximab treatment. Moreover, we elucidated co-expression modules housing genes, for example, POLK, POLI, POLQ, REV1, POLN, and POLM. Specifically, POLK, POLI, and POLQ were assigned to the "blue" module, which also encompassed critical DNA damage response enzymes, for example. BRCA1, BRCA2, MSH6, and MSH2. To delineate the transcriptional control of this module, we investigated associated TFs, highlighting the roles of prominent cancer-associated TFs, such as CENPA, HNF1A, and E2F7. CONCLUSION: We found that translesion polymerases are co-regulated with DNA mismatch repair and cell cycle-associated factors. We did not, however, identified any networks specific to cetuximab treatment indicating that the response to EGFR inhibitors relates to a general stress response mechanism.

Real-world treatment costs of first-line treatment for metastatic colorectal cancer: a survey of the JCOG colorectal cancer study group.

BACKGROUND: Although treatment outcomes for metastatic colorectal cancer (mCRC) have dramatically improved over the past few decades, drug costs have also significantly increased. This study aimed to investigate which first-line treatment regimens for mCRC are actually used (frequency) in Japanese practice and at what cost. METHODS: We collected data on patients with mCRC who received first-line treatment at 37 institutions of the Japan Clinical Oncology Group Colorectal Cancer Study Group from July 2021 to June 2022, and calculated the cost of regimens. The cost per month of each regimen was estimated based on standard usage, assuming a patient with a weight of 70 kg and a body surface area of 1.8 m2. We categorized the regimens into very high-cost (≥1 000 000 Japanese yen [JPY]/month), high-cost (≥500 000 JPY/month), and others (<500 000 JPY/month). RESULTS: The study included 1880 participants, 24% of whom were ≥ 75 years. Molecular targeted containing regimens were received by 78% of the patients. The most frequently used regimen was the doublet regimen (fluoropyrimidine with either oxaliplatin or irinotecan) plus bevacizumab (43%), followed by doublet plus cetuximab or panitumumab (21%). The cost of molecular targeted drugs-containing regimens (ranging from 85 406 to 843 602 JPY/month) is much higher than that of only cytotoxic drug regimens (ranging from 17 672 to 51 004 JPY/month). About 16% received high-cost treatments that included panitumumab-containing regimens and pembrolizumab (17% of patients aged ≤74 years and 11% of patients aged ≥75 years). CONCLUSION: About 16% of mCRC patients received first-line treatment with regimens costing >500 000JPY/month, and molecular targeted drugs being the main drivers of cost.

In silico evaluation of the role of Fab glycosylation in cetuximab antibody dynamics.

Introduction: N-glycosylation is a post-translational modification that is highly important for the development of monoclonal antibodies (mAbs), as it regulates their biological activity, particularly in terms of immune effector functions. While typically added at the Fc level, approximately 15-25% of circulating antibodies exhibit glycosylation in the Fab domains as well. To the best of our knowledge, cetuximab (Erbitux®) is the only therapeutic antibody presenting Fab glycosylation approved world-wide targeting the epidermal growth factor receptor for the treatment of metastatic-colorectal and head and neck cancers. Additionally, it can trigger antibody-dependent cell cytotoxicity (ADCC), a response that typically is influenced by N-glycosylation at Fc level. However, the role of Fab glycosylation in cetuximab remains poorly understood. Hence, this study aims to investigate the structural role of Fab glycosylation on the conformational behavior of cetuximab. Methods: The study was performed in silico via accelerated molecular dynamics simulations. The commercial cetuximab was compared to its form without Fab glycosylation and structural descriptors were evaluated to establish conformational differences. Results: The results clearly show a correlation between the Fab glycosylation and structural descriptors that may modulate the conformational freedom of the antibody, potentially affecting Fc effector functions, and suggesting a negative role of Fab glycosylation on the interaction with FcγRIIIa. Conclusion: Fab glycosylation of cetuximab is the most critical challenge for biosimilar development, but the differences highlighted in this work with respect to its aglycosylated form can improve the knowledge and represent also a great opportunity to develop novel strategies of biotherapeutics.

Model-informed Evidence for Clinical Non-inferiority of Every-2-Weeks Versus Standard Weekly Dosing Schedule of Cetuximab in Metastatic Colorectal Cancer.

Cetuximab was initially developed and approved as a first-line treatment in patients with unresectable metastatic colorectal cancer (mCRC) for weekly administration (250 mg/m2 Q1W with 400 mg/m2 loading dose). An every-2-weeks schedule (500 mg/m2 Q2W) was approved recently by several health authorities. Being synchronized with chemotherapy, Q2W administration should improve patients' convenience and healthcare resource utilization. Herein, we present evidence of non-inferiority of Q2W cetuximab, compared with Q1W dosing using pharmacometrics modeling and clinical trial simulation (CTS). Pooled data from five phase I-III clinical trials in 852 patients with KRAS wild-type mCRC treated with Q1W or Q2W cetuximab were modeled using a population exposure-tumor size (TS) model linked to overall survival (OS); exposure was derived from a previously established population pharmacokinetic model. A semi-mechanistic TS model adapted from the Claret model incorporated killing rate proportional to cetuximab area under the concentration-time curve over 2 weeks (AUC) with Eastern Cooperative Oncology Group (ECOG) status as covariate on baseline TS. The OS was modeled with Weibull hazard using ECOG, baseline TS, primary tumor location, and predicted percent change in TS at 8 weeks as covariates. Model-based simulations revealed indistinguishable early tumor shrinkage and survival between Q2W vs. Q1W cetuximab. CTS evaluated OS non-inferiority (predefined margin of 1.25) in 1,000 trials, each with 2,000 virtual patients receiving Q2W or Q1W cetuximab (1:1), and demonstrated non-inferiority in 94% of cases. Taken together, these analyses provide model-based evidence for clinical non-inferiority of Q2W vs. Q1W cetuximab in mCRC with potential benefits to patients and healthcare providers.