anti-EGFR Monoclonal Antibody Research Articles

Circulating tumour DNA analysis and new uses of anti-EGFR monoclonal antibodies in patients with metastatic colorectal cancer

Currently, tumour tissue biopsy to determine RAS/BRAF gene alterations, assess microsatellite instability status, and determine HER‑2/neu gene amplification/hyperexpression is the gold standard of diagnosis and allows the selection of optimal molecularly targeted therapy when considering treatment strategies for patients with metastatic colorectal cancer. However, biopsy does not fully reflect the existing intratumoural heterogeneity and clonal evolution of tumour cells, which can often be the cause of therapeutic failures. In recent years, liquid biopsy has attracted increasing attention as an additional and potentially alternative non-invasive tool for molecular tumour profiling. Assessment of circulating tumour DNA allows changes in the genetic status of the tumour to be monitored and the «burden» of disease to be measured dynamically in real time. Advances in liquid biopsy technology have led to promising new strategies for the management of patients with metastatic colorectal cancer in late-line therapy. The standard drug arsenal in this group of patients is limited to either repeat administration of previously effective therapy or regorafenib and the combination of trifluridine/tipiracil with bevacizumab, which are characterized by limited clinical activity. However, thanks to the discovery of the NeoRAS wild-type phenomenon and the rechallenge strategy of anti-EGFR monoclonal antibodies based on the study of clonal selection and evolution of tumour cells, the administration of epidermal growth factor inhibitors in a molecularly selected by liquid biopsy population is accompanied by good tolerability and efficacy. Numerous clinical studies are ongoing to further understand the mechanisms of tumour resistance and to develop new evidence-based treatment approaches in order to realise the concept of personalised medicine.

Chinese expert consensus on maintenance treatment with anti-EGFR monoclonal antibody for RAS wild-type metastatic colorectal cancer (2024 edition)

For patients with metastatic colorectal cancer (mCRC) who achieve disease control during first-line standard therapy, post-induction strategies should emphasize on quality of life improvement while maintaining disease control. Chemotherapy combined with anti-epidermal growth factor receptor (EGFR) monoclonal antibody is the standard first-line treatment for RAS wild-type mCRC patients. After anti-EGFR-based first-line induction therapy achieves at least stable disease, anti-EGFR-based maintenance treatment could maintain disease control while keeping a good safety profile. Based on research evidence and clinical practice, the Chinese expert consensus on anti-EGFR-based maintenance strategy for RAS wild-type mCRC aims to futher clarify the treatment timing, regimen options, adverse reaction management and follow-up strategy, providing standardized guidance to maximize the clinical benefit in RAS wild-type mCRC.

Cancer therapy related cardiac dysfunction as a result of Panitumumab

Panitumumab is a human immunoglobulin monoclonal antibody designed to target the epidermal growth factor receptor (EGFR) which is used in the treatment of metastatic colorectal cancer alone or in combination with chemotherapy. In this report, we present a case of new onset heart failure with reduced ejection fraction in a patient following panitumumab therapy. A 73-year-old gentleman with metastatic rectal adenocarcinoma presented to his local hospital with increased shortness of breath, two months after his first and only dose of panitumumab. A transthoracic echocardiogram demonstrated dilated left ventricle with global hypokinesis and an estimated left ventricular ejection fraction of 25%. Our patient underwent a comprehensive diagnostic assessment at his presentation, including ECG, transthoracic echocardiogram, cardiac magnetic resonance, computed tomography coronary angiography (CTCA), invasive coronary angiogram and 18F-FDG PET-CT. These investigations revealed no evidence of ischemic events or inflammatory processes that could account for the severe left ventricular dysfunction. To our knowledge, this is the first reported case of heart failure with reduced ejection fraction linked to panitumumab with subsequent deep phenotyping. The current guidelines do not recommend specific cardiovascular monitoring protocols for patients receiving anti-EGFR monoclonal antibodies. Until more data are available, it would be prudent to implement the same cardiovascular surveillance measures outlined for individuals receiving osimertinib, which is an EGFR tyrosine kinase inhibitor.

Abstract CT216: Anti-EGFR in combination with paclitaxel as second-line therapy for gastric cancer with EGFR overexpression

Abstract Background: We and other investigators reported that EGFR gene is amplified in 2-4% of gastric cancer with protein overexpression (Gastroenterology 2017 Aug;153(2):536-549; Cancer Cell 2019 Jan 14; 35:1:111:E10), but EGFR-targeted therapy has not entered into clinic. Patients and Methods: As a subprotocol of the investigator-initated of umbrella trial, patients with metastatic gastric cancer received weekly anti-EGFR monoclonal antibody (GC-1118 (GC Biopharma), 2.5mg/kg) in combination with paclitaxel 80mg/m2 (D1, D8, D15) every 4 weeks as a second-line therapy, if the gastric cancer tissue sample revealed EGFR protein overexpression (NCT04077255). Projected accrual was 19 based on minimax two-stage design (P1=45%; P0=15%; alpha and beta errors, 0.05 and 0.1, respectively). Results: Among 19 evaluable patients, 6 patients had objective clinical response (RR, 31.6%). Median progression-free survival was 4.7 months (95% CI, 1.8-5.1). Median overall survival was 7.6 months (95% CI, 4.2-11.1). Predictive biomarkers were explored by post hoc correlative analyses. Conclusion: EGFR inhibition, in combination with paclitaxel, demonstrated modest activity for gastric cancer refractory to first-line 5-FU/platinum-based chemotherapy. (This study was supported by a grant from the National R&D Program for Cancer Control, Ministry of Health & Welfare, Republic of Korea (HA22C0056.)) Citation Format: Dong-Hoe Koo, Jin-Young Kim, Jae-Joon Kim, Sung Y. Oh, Min-Hee Ryu, Dae Y. Zang, Hark K. Kim. Anti-EGFR in combination with paclitaxel as second-line therapy for gastric cancer with EGFR overexpression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT216.

Remediating Desmoplasia using Targeted Photo-nanomedicines: Improving Surgical and Survival Outcomes

SignificanceIn recent years, a deeper understanding of the sub-therapeutic photodynamic priming (PDP) effects of photodynamic therapy is being gained. Here we show that PDP can remediate desmoplasia in pancreatic and head and neck tumors, improving both surgical and survival outcomes. ApproachOrthotopic FaDu head and neck tumors and MIA-PaCa-2 pancreatic tumors were used. PDP is facilitated by various nanoconstructs containing benzoporphyrin derivative and its lipidated variants, in addition to molecular targeting provided by conjugates of Cetuximab (anti-EGFR monoclonal antibody). ResultsPDP improved the tumor delivery and diagnostic accuracy of the clinical fluorescence image-guided surgery probe Cetuximab-IRDye800CW by 264.2%. Time-to-surgery is reduced from 25.7 h to 2.5 h. PDP also reduced the density (>90%) and alignment (>103-fold) of collagen in pancreatic tumors. PDP induced 90% tumor growth inhibition at 8.1% of the clinical chemotherapy dose and doubled overall survival. ConclusionsThis study demonstrates how remediating desmoplasia using PDP plays a versatile role in cancer management, from improving image guided surgery to potentiating chemotherapy.

Abstract 925: Continuing anti-EGFR treatment prolonged survival in mCRC patients receiving conversion liver resection

Abstract Introduction: Anti-EGFR monoclonal antibody plus doublet chemotherapy is the mainstay of first-line treatment of RAS/BRAF wild-type metastatic colorectal cancer (mCRC) patients. Some of these patients might undergo secondary resection. However, there is no standardized suggestion on whether colorectal cancer liver metastasis patients should keep target therapy after secondary resection. NCCN guidelines suggest chemotherapy only in patients receiving primary liver resection. Whether we could spare the use of target therapy after secondary resection is the main aim of our study. Methods: Using Taiwan's National Health Insurance Research Database, we established a cohort of KRAS wild-type mCRC patients treated with first-line anti-EGFR therapy plus doublet chemotherapy between 2013 and 2018. Secondary surgery was defined as either resection of liver metastases or radiofrequency ablation. Results: 5694 stage IV mCRC patients received anti-EGFR MAb plus doublet chemotherapy as a first-line treatment between 2013 and 2018. 174 patients were enrolled in the final analysis, with 153 continuing anti-EGFR MAb after secondary resection and 21 patients without anti-EGFR MAb. Compared with those who without anti-EGFR therapy after secondary resection, patients who continued anti-EGFR MAb exhibited significantly longer overall survival (OS; median, 43.8 vs. 31.9 months, p = 0.031) but not in time to treatment failure (TTF; median, 22.2 vs. 26.6 months, p = 0.841). The OS benefits of continuing anti-EGFR MAb remained regardless of left-sided or right-sided primary tumors (40.9 vs. 43.0 months, p = 0.980). The patient cohort from 2016 to 2018 showed more prolonged survival than from 2012 to 2015 (not reached vs. 40.450, p = 0.0305). TTF has no statistical difference when considering patient cohort or primary tumor location. In multivariate analyses, continuing first-line anti-EGFR MAb therapy after secondary resection remained an independent predictor of longer OS. Conclusion: For mCRC patients who received secondary resection after first-line anti-EGFR and doublet chemotherapy, continuing anti-EGFR MAb after resection was associated with significantly longer OS regardless of primary tumor sidedness. Citation Format: Yao-Yu Hsieh, Chin-Wen Tsai, T-CARE Group, Yi-Hsieh Liang. Continuing anti-EGFR treatment prolonged survival in mCRC patients receiving conversion liver resection [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 925.

Abstract 6027: 89Zr-matuzumab and 225Ac-matuzumab as a theranostic for epidermal growth factor receptor-positive KRAS wild-type colorectal and breast cancer xenografts

Abstract Background: About 80% of colorectal cancer (CRC) and 50 % of Triple-Negative breast cancer (TNBC) patients overexpress epidermal growth factor receptor (EGFR). Mutations in the KRAS oncogene (present in 40% of mCRC) lead to constitutive over-activation of EGFR and drive de novo resistance to anti-EGFR drugs. Here, we propose to target KRAS-mutant/BRAF mutant EGFR positive mCRC and TNBC using 225Ac-labeled matuzumab, a humanized anti-EGFR monoclonal antibody. Methods: p- -SCN-macropa was used to conjugate matuzumab for radiolabeling with 225Ac and SCN-deferoxamine was used to conjugate matuzumab for labelling with 89Zr. The radioimmunoconjugates were characterized by flow cytometry, HPLC and iTLC. in vitro cytotoxicity was evaluated in EGFR-positive mCRC, TNBC cell lines and 3D spheroids with different levels of EGFR density. Tumor growth was monitored using digital caliper. Mice were treated with either 10 MBq of 89Zr-matuzumab for imaging or three doses of 13 KBq/dose administered of 225Ac-matuzumab 10 days apart. In vivo study endpoint was tumor volume greater than or equal to 1500 mm3. Results: Flow cytometry showed about 95% binding to the cells in all EGFR-positive colorectal cell lines (DLD-1, SW620, SNU-C2B, HT-29) and breast cancer cell lines (MDA-MB-468, MDA-MB-231). in vitro studies showed enhanced cytotoxicity of 225Ac-matuzumab compared with matuzumab. IC50 in the MDA-MB-468 cell line for 225Ac-matuzumab (1.86 ± nM) was 35 times more effective than matuzumab (65.25± 7 nM). Similar trends were observed in the other KRAS-mutant mCRC cell lines and breast cancer cell lines. In 3D spheroid models, the IC50 of 225Ac-matuzumab (3.0 ± 2 nM) in MDA-MB-468, was 20.79 times more effective than matuzumab (62.3 ± 1.38 nM). Similar trends were observed for all the other spheroid models as well. High uptake of 89Zr-matuzumab was observed in both mCRC and TNBC xenografts. 225Ac-matuzumab slowed tumor growth rate in MDA-MB-468 and MDA-MB-231 tumors models compared with control antibody or non-treated controls for 30 days. This study is still ongoing and will last for 2 more months. Conclusion: 225Ac-matuzumab shows very promising outcomes in KRAS-mutant mCRC models and breast cancer models and warrants further investigation. Citation Format: Florence Anjong Tikum, Humphrey Fonge, Fabrice Njotu, Hanan Babeker, Jessica K. Pougoue, Nikita Henning, Alireza Doroudi. 89Zr-matuzumab and 225Ac-matuzumab as a theranostic for epidermal growth factor receptor-positive KRAS wild-type colorectal and breast cancer xenografts [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6027.

Safety and efficacy of SNK01 (autologous natural killer cells) in combination with cytotoxic chemotherapy and/or cetuximab after failure of prior tyrosine kinase inhibitor in non-small cell lung cancer: non-clinical mouse model and phase I/IIa clinical study

BackgroundChoosing treatments for epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NSCLC) patients with osimertinib resistance is challenging. We evaluated the safety and efficacy of SNK01 (autologous natural killer...

Molecular screening with liquid biopsy for anti-EGFR retreatment in metastatic colorectal cancer: preliminary data from the randomized phase 2 PARERE trial.

Retreatment with anti-EGFR monoclonal antibodies is a promising strategy in patients with RAS/BRAF wild-type (wt) metastatic colorectal cancer (mCRC) who achieved benefit from previous anti-EGFR exposure upon exclusion of mutations in RAS/BRAF genes according to circulating tumor DNA (ctDNA) analysis by means of liquid biopsy (LB). This treatment approach is now being investigated in the randomized phase II trial PARERE (NCT04787341). We here present preliminary findings of molecular screening. Patients with RAS/BRAFV600E wt mCRC according to tissue genotyping who benefited from previous anti-EGFR-based treatment (fluoropyrimidines, oxaliplatin, irinotecan, and antiangiogenics) and then experienced disease progression to EGFR targeting were eligible for screening in the PARERE trial. The next-generation sequencing (NGS) panel Oncomine™ was employed for ctDNA testing. A total of 218 patients underwent LB, and ctDNA sequencing was successful in 201 of them (92%). RAS/BRAFV600E mutations were found in 68 (34%) patients and were mainly subclonal (median variant allele fraction [VAF] for KRAS, NRAS, and BRAF mutant clones: 0.52%, 0.62%, and 0.12%, respectively; p = 0.01), with KRASQ61H being the most frequently detected (31%). Anti-EGFR-free intervals did not predict ctDNA molecular status (p = 0.12). Among the 133 patients with RAS/BRAFV600E wt tumors according to LB, 40 (30%) harbored a mutation in at least another gene potentially implied in anti-EGFR resistance, mainly with subclonal expression (median VAF, 0.56%). In detail, alterations in PIK3CA, FBXW7, GNAS, MAP2K, ERBB2, BRAF (class I and II non-BRAFV600E), SMAD, EGFR, AKT1, and CTNNB1 occurred in 13%, 8%, 7%, 3%, 2%, 2%, 1%, 1%, 1%, and 1% cases, respectively. Co-mutations were detected in 13 (33%) out of 40 patients. This is the largest prospective cohort of mCRC patients screened with LB for anti-EGFR retreatment in a randomized study. ctDNA genotyping reveals that at least one out of three patients candidate for retreatment should be excluded from this therapy, and other potential drivers of anti-EGFR resistance are found in approximately one out of three patients with RAS/BRAFV600E wt ctDNA.

Impact of acquired RAS, BRAF and PIK3CA mutation at 8 weeks on the efficacy of anti-EGFR monoclonal antibodies in metastatic colorectal cancer.

193 Background: Recent studies indicate that the emergence of RAS/BRAF mutation sometimes occurs during initial anti-EGFR monoclonal antibody (mAb)-based treatment in metastatic colorectal cancer (mCRC). However, limited data was available regarding the timing and frequency of the emergence of RAS/BRAF mutation, and its impact on the efficacy of anti-EGFR mAb. With this background, we conducted an observational study to monitor RAS, BRAF, and PIK3CA mutation status by ctDNA in RAS/BRAF wt mCRC. Methods: RAS-trace is a pilot study to monitor RAS, BRAF, and PIK3CA mutation status by ctDNA, using NGS-based Plasma-Safe-SeqS technology for RAS/BRAF wt (diagnosed from tissue samples) mCRC treated with anti-EGFR mAb as a first-line chemotherapy. ctDNA- RAS/BRAF/PIK3CA status evaluated at baseline, 8, 12, 16, 20, 24, 36, 48 weeks and disease progression. The primary endpoint was the time to the acquired RAS mutations. The results of ctDNA at baseline and 8 weeks are presented. Results: Forty-two patients were enrolled, and 40 and 39 were used in the analysis of ctDNA at baseline and 8 weeks, respectively. All patients received mFOLFOX6 plus cetuximab (N=32) or panitumumab (N=8). At baseline, RAS, BRAF, and PIK3CA mutations were detected in 3, 3, and 1 of the 40 patients, respectively. One patient had both KRAS and BRAF mutations. Baseline ctDNA mutations were not associated with the presence of liver metastases, tumor sidedness, early tumor shrinkage, depth of response or skin rash ≥Grade 2. At 8 weeks, RAS, BRAF, and PIK3CA mutations were detected in 3, 2, and 0 among the 39 patients, respectively. One patient had both KRAS and BRAF mutations. ctDNA mutations at 8 weeks were not associated with the presence of liver metastases, tumor sidedness, or early tumor shrinkage, however, they were associated with depth of response and had a tendency of skin rashes ≥ Grade 2 (Table). Conclusions: Emergence of RAS/BRAF/PIK3CA mutations at 8 weeks may be related to the response of anti-EGFR mAb. The association of ctDNA status with survival outcomes will be presented in 2025. Clinical trial information: jRCT1050210160 . [Table: see text]

Amivantamab monotherapy in relapsed/refractory metastatic colorectal cancer: OrigAMI-1, an open-label, phase 1b/2 study.

135 Background: Amivantamab (ami), an EGFR-MET bispecific antibody with immune cell-directing activity, has shown preclinical activity in colorectal cancer (CRC) models. MET amplification is implicated in driving resistance to anti-EGFR therapies in metastatic CRC (mCRC). We hypothesize that dual, co-inhibition of EGFR and MET with ami could improve outcomes in relapsed/refractory mCRC. Methods: OrigAMI-1 (NCT05379595) is assessing the safety and efficacy of ami as monotherapy in patients (pts) with refractory mCRC in 3 separate cohorts (Table). Eligible pts were wild-type for KRAS, NRAS, BRAF, and EGFR ectodomain by ctDNA testing, without ERBB2/ HER2 amplification. Cohorts A and B included pts with left-sided mCRC without/with prior exposure to anti-EGFR monoclonal antibodies, respectively, and cohort C included pts with right-sided mCRC. Safety population included all pts receiving the recommended phase 2 dose (RP2D; 1050 mg [1400 mg, ≥80kg]). Investigator-assessed response per RECIST v1.1 is reported for evaluable pts with post-baseline disease assessment(s) or who discontinued for any reason. Ami plus FOLFOX or FOLFIRI is being explored in additional cohorts. Results: As of September 4, 2023, 93 pts were treated at RP2D; 89 were response evaluable (median follow-up: 4.4 mo). Median age was 60 years, 66% were male, and median prior lines of therapy were 2, with 94% receiving prior bevacizumab and 69% prior anti-EGFR therapy. Best timepoint responses were: Cohort A: 7/17, 41.2%; Cohort B: 13/54, 24.1%; Cohort C: 1/18, 5.6%. Disease control rates (DCR) were 88.2%, 72.2%, and 77.8% for Cohorts A, B, and C, respectively. Median duration of response (mDoR) for confirmed responders was 7.5 and 7.4 mo for Cohorts A and B, respectively. Treatment is ongoing for the responder in Cohort C. 10/13 responders (77%) remain on treatment. Preliminary biomarker data suggest ami may be active in alterations associated with anti-EGFR antibody resistance (eg, EML4-ALK fusion, PTEN). The most frequent treatment-emergent adverse events were rash (84%) and infusion-related reactions (53%). No new safety signals were observed. Updated results will be presented at the meeting. Conclusions: Ami monotherapy demonstrated promising, durable antitumor activity in refractory mCRC, including pts treated with prior anti-EGFR therapy and pts with right-sided disease. The safety profile of ami in mCRC is manageable and consistent with prior NSCLC experience. Clinical trial information: NCT05379595 . [Table: see text]

Novel potential mechanisms of acquired resistance to anti-EGFR monoclonal antibody (mAb) therapy detected in liquid biopsies (LBx) from patients (pts) with advanced colorectal cancer (CRC).

199 Background: While several studies have explored the evolving clonal profile of mCRC under stress of anti-EGFR using circulating tumor DNA (ctDNA), heterogeneity and small cohorts limit our understanding of acquired genomic alterations (GAs) associated with EGFR resistance. Methods: CRC LBx were profiled with FoundationOne Liquid CDx, which reports GAs in 324 cancer-related genes. Foundation Medicine’s (FMI) ctDNA tumor fraction (TF) is a composite algorithm prioritizing aneuploidy at higher levels and variant allele frequency (VAF) of canonical alterations at lower levels. Variants were considered clonal at VAF/TF ≥25%, subclonal at <25%. Among 4,546 non-MSI-H LBx, 2,776 (61%) had TF ≥1% and were used in this analysis. A subset of pts had treatment data in the US-based de-identified Flatiron Health-FM real-world clinico-genomic database (CGDB), originating from ~280 US cancer clinics (01/2011–03/2023). Results: 1,349 (49%) LBx had a clonal RAS GA, 107 (3.9%) had a clonal BRAF V600E, and 1,320 (48%) had no clonal RAS pathway driver GA. GAs in EGFR and MAP2K1 were significantly (FDR<0.0001) more common in LBx with no clonal RAS GA (162, 11%; 105, 7.4%) than with one (27, 2.0%; 24, 1.8%), consistent with prior reports of these GAs appearing in the setting of acquired resistance to anti-EGFR mAb. The 362 LBx with GAs in EGFR, MAP2K1, or subclonal RAS GAs (indicators of anti-EGFR mAb exposure based on a validated exposure signature) were compared to the 1349 LBx with a clonal RAS mutation. Post anti-EGFR LBx were significantly enriched in BRAF, TP53, FGFR3, PTPN11, ERRFI1, and MLH1 GAs (FDR<0.05) and all but TP53 had median VAF/TF <25%. The majority of clonal BRAF GAs were V600E (14/19, 74%) while the majority of subclonal BRAF GAs were Class 2 (36/61, 59%). Other subclonal GAs in receptor tyrosine kinases and RAS pathway components detected in these LBx included: NF1 (26), ROS1 (9), ALK (7), MET (7), RAF1 (7), FGFR2 (6), HRAS (6), MAP2K2 (6), and RET (4). 18/362 (4.4%) of the LBx had ≥2 of these resistance GAs (up to 5 per LBx). In CGDB, 14/25 (56%) LBx collected at progression had potential resistance GAs (median 2, maximum 10). LBx collected at progression (N = 25) had higher prevalence of GA in EGFR (28% vs. 2.3%, p=0.0003), KRAS (28% vs. 0%, p<0.0001), NRAS (20% vs. 0%, p=0.0002) and MAP2K1 (20% vs. 2.3%, p=0.008) than LBx collected before therapy start (N = 87). Conclusions: This study reports on the largest set of LBx from pts likely exposed to anti-EGFR published to date. LBx can provide a more comprehensive and quantitative picture of acquired resistance to anti-EGFR in CRC than tissue biopsy, including some potential novel mechanisms identified in this study. Further investigation into whether detection of resistance can inform clinical decisions about timing of anti-EGFR mAb use and rechallenge is warranted.

Efficacy, safety and genomic analysis of SCT200, an anti-EGFR monoclonal antibody, in patients with fluorouracil, irinotecan and oxaliplatin refractory RAS and BRAF wild-type metastatic colorectal cancer: a phase Ⅱ study

Limited therapeutic options are available for metastatic colorectal cancer (mCRC) patients after failure of first- and second-line therapies, representing an unmet medical need for novel therapies. This is an open-label, single arm, multicenter, phase Ⅱ study aiming to perform the efficacy, safety and genomic analysis of SCT200, a noval fully humanized IgG1 anti-epidermal growth factor receptor (EGFR) monoclonal antibody, in patients with fluorouracil, irinotecan and oxaliplatin refractory RAS and BRAF wild-type mCRC. SCT200 (6mg/kg) was given weekly for the first six weeks, followed by a higher dose of 8mg/kg every two weeks until disease progression or unacceptable toxicity. Primary endpoint was independent review committee (IRC)-assessed objective response rate (ORR) and secondary endpoints included ORR in patients with left-sided tumor, disease control rate (DCR), duration of response (DoR), time to response (TTR), progression-free survival (PFS), overall survival (OS) and safety. From February 12, 2018 to December 1, 2019, a total of 110 patients aged between 26 and 77 years (median: 55; interquartile range [IQR]: 47-63) with fluorouracil, oxaliplatin, and irinotecan refractory RAS and BRAF wild-type mCRC were enrolled from 22 hospitals in China. As the data cut-off date on May 15, 2020, the IRC-assessed ORR and DCR was 31% (34/110, 95% confidence interval [CI] 22-40%) and 75% (82/110, 95% CI 65-82%), respectively. Thirty one percent (34/110) patients achieved confirmed partial response (PR). The median PFS and median OS were 5.1 months (95% CI 3.4-5.2) and 16.2 months (95% CI 11.1-not available [NA]), respectively. The most common≥grade 3 treatment-related adverse events (TRAEs) were hypomagnesemia (17%, 19/110) and acneiform dermatitis (11%, 12/110). No deaths occurred. Genomic analysis suggested positive association between MYC amplification and patients' response (P=0.0058). RAS/RAF mutation and MET amplification were the most frequently detected resistance mechanisms. Patients with high circulating tumor DNA (ctDNA) at baseline or without ctDNA clearance at the 7th week after the first dose of SCT200 administration before receiving SCT200 had worse PFS and OS. SCT200 exhibited promising clinical efficacy and manageable safety profiles in RAS and BRAF wild-type mCRC patients progressed on fluorouracil, irinotecan and oxaliplatin treatment. The baseline ctDNA and ctDNA clearance status at the 7th week after the first dose of SCT200 administration before receiving SCT200 could be a potential prognostic biomarker for RAS and BRAF wild-type mCRC patients with SCT200 therapy. This study was sponsored by Sinocelltech Ltd., Beijing, China and partly supported by the National Science and Technology Major Project for Key New Drug Development (2019ZX09732001-006, 2017ZX09304015).

Vaccine antibodies against a synthetic epidermal growth factor variant enhance the antitumor effects of inhibitors targeting the MAPK/ERK and PI3K/Akt pathways

BackgroundThe EGFR pathway is involved in intrinsic and acquired resistance to a wide variety of targeted therapies in cancer. Vaccination represents an alternative to the administration of anti-EGFR monoclonal antibodies, such as cetuximab or panitumumab. Here, we tested if anti-EGF antibodies generated by vaccination (anti-EGF VacAbs) could potentiate the activity of drugs targeting the ERK/MAPK and PI3K/Akt pathways. MethodsNon-small cell lung cancer (NSCLC), colorectal cancer (CRC) and melanoma cell lines harboring KRAS, NRAS, BRAF and PIK3CA mutations were used. Anti-EGF VacAbs were obtained by immunizing rabbits with a fusion protein containing a synthetic, highly mutated variant of human EGF. Cell viability was determined by MTT, total and phosphorylated proteins by Western blotting, cell cycle distribution and cell death by flow cytometry and emergence of resistance by microscopic examination in low density cultures. ResultsAnti-EGF VacAbs potentiated the antiproliferative effects of MEK, KRAS G12C, BRAF, PI3K and Akt inhibitors in KRAS, NRAS, BRAF and PIK3CA mutant cells and delayed the appearance of resistant clones in vitro. The effects of anti-EGF VacAbs were comparable or superior to those of panitumumab and cetuximab. The combination of anti-EGF VacAbs with the targeted inhibitors effectively suppressed EGFR downstream pathways and sera from patients immunized with an anti-EGF vaccine also blocked activation of EGFR effectors. ConclusionsAnti-EGF VacAbs enhance the antiproliferative effects of drugs targeting the ERK/MAPK and PIK3CA/Akt pathways. Our data provide a rationale for clinical trials testing anti-EGF vaccination combined with inhibitors selected according to the patient's genetic profile.

Design, synthesis, molecular modeling, and biological evaluations of novel chalcone based 4-Nitroacetophenone derivatives as potent anticancer agents targeting EGFR-TKD

A series of chalcone-based 4-Nitroacetophenone derivatives were designed and synthesized by the single-step condensation method. These compounds were identified by 1H NMR,13C NMR, MS, and FTIR analysis. Further, the derivatives were evaluated against four cancer cell lines H1299, MCF-7, HepG2, and K526. The IC50 value of potent compounds NCH-2, NCH-4, NCH-5, NCH-6, NCH-8, and NCH-10 was 4.5–11.4 μM in H1299, 4.3–15.7 μM in MCF-7, 2.7–4.1 μM in HepG2 and 4.9–19.7 μM in K562. To assess the toxicity against healthy cells all potent molecules were evaluated against the HEK-293T cell line, and IC50 values exhibited by NCH-2, and NCH-3 were 77.8, 74.3, and other molecules showed IC50 values > 100 μM. The EGFR expression was determined by using rabbit anti-EGFR monoclonal antibody and significant EGFR expression was knocked down observed in H1299 treated with NCH-10 as well as erlotinib. The underlying mechanism behind cell death was investigated through bioinformatics. First, the molecules were optimized and docked to the binding site of the EGFR kinase domain. The best complexes were simulated for 100-ns and compounds NCH-2, NCH-4, and NCH-10 achieved stability similar to the erlotinib bound kinase domain. The free energy binding (ΔG bind) of NCH-10 was found to be more negative −226.616 ± 2.148 kJ/mol calculated by Molecular Mechanics Poisson Boltzmann’s Surface Area (MM-PBSA) method. Both in vitro and in silico results conclude that the present class of chalcone-based 4-Nitroacetophenone derivatives are potent anti-cancer agents targeting EGFR-TKD and are 39 folds more effective against H1299, MCF-7, HepG2, and K562 carcinoma cell lines than healthy HEK-293T cell lines. Communicated by Ramaswamy H. Sarma

Biomarkers for monoclonal antibody targeting EGFR in NSCLC: Challenges, current status, and future perspectives

Targeting EGFR has a long history in the treatment of non-small cell lung cancer (NSCLC). It was around the 2000s that it was reported that EGFR protein expression increased with bronchial dysplasia in high-risk smokers and patients with lung cancer. However, EGFR inhibitors were not effective in unselected patients with advanced NSCLC. After the identification of sensitizing EGFR mutations, tyrosine kinase inhibitors became the cornerstone of treatment for patients with EGFR-mutated NSCLC. However, other drugs were developed to target EGFR in the EGFR-wild type population, such as monoclonal antibodies. Cetuximab is an anti-EGFR monoclonal antibody, and has been a focus over the past two decades. Though not approved in NSCLC due to marginal and inconsistent effects in phase 3 trials, research aimed to discover biomarkers to identify a subgroup of the population that might benefit. This includes a composite score that evaluates histology, immunohistochemistry, and gene copy amplification. This article reviews the history of the development and discontinuation of monoclonal antibodies in NSCLC and discusses the role of biomarkers in the treatment of advanced EGFR-wild type NSCLC.

Targeting KRAS-Mutated Gastrointestinal Malignancies with Small-Molecule Inhibitors: A New Generation of Breakthrough Therapies.

Kirsten rat sarcoma virus (KRAS) is one of the most important and frequently mutated oncogenes in cancer and the mutational prevalence is especially high in many gastrointestinal malignancies, including colorectal cancer and pancreatic ductal adenocarcinoma. The KRAS protein is a small GTPase that functions as an "on/off" switch to activate downstream signaling, mainly through the mitogen-activated protein kinase pathway. KRAS was previously considered undruggable because of biochemical constraints; however, recent breakthroughs have enabled the development of small-molecule inhibitors of KRAS G12C. These drugs were initially approved in lung cancer and have now shown substantial clinical activity in KRAS G12C-mutated pancreatic ductal adenocarcinoma as well as colorectal cancer when combined with anti-EGFR monoclonal antibodies. Early data are encouraging for other gastrointestinal cancers as well and many other combination strategies are being investigated. Several new KRAS G12C inhibitors and novel inhibitors of other KRAS alterations have recently entered the clinic. These molecules employ a variety of innovative mechanisms and have generated intense interest. These novel drugs are especially important as KRAS G12C is rare in gastrointestinal malignancies compared with other KRAS alterations, representing potentially groundbreaking advances. Soon, the rapidly evolving landscape of novel KRAS inhibitors may substantially shift the therapeutic landscape for gastrointestinal cancers and offer meaningful survival improvements.

Efficacy and Safety of Panitumumab in Patients With RAF/RAS-Wild-Type Glioblastoma: Results From the Drug Rediscovery Protocol.

The prognosis of malignant primary high-grade brain tumors, predominantly glioblastomas, is poor despite intensive multimodality treatment options. In more than 50% of patients with glioblastomas, potentially targetable mutations are present, including rearrangements, altered splicing, and/or focal amplifications of epidermal growth factor receptor (EGFR) by signaling through the RAF/RAS pathway. We studied whether treatment with the clinically available anti-EGFR monoclonal antibody panitumumab provides clinical benefit for patients with RAF/RAS-wild-type (wt) glioblastomas in the Drug Rediscovery Protocol (DRUP). Patients with progression of treatment refractory RAF/RASwt glioblastoma were included for treatment with panitumumab in DRUP when measurable according to RANO criteria. The primary endpoints of this study are clinical benefit (CB: defined as confirmed objective response [OR] or stable disease [SD] ≥ 16 weeks) and safety. Patients were enrolled using a Simon-like 2-stage model, with 8 patients in stage 1 and up to 24 patients in stage 2 if at least 1 in 8 patients had CB in stage 1. Between 03-2018 and 02-2022, 24 evaluable patients were treated. CB was observed in 5 patients (21%), including 2 patients with partial response (8.3%) and 3 patients with SD ≥ 16 weeks (12.5%). After median follow-up of 15 months, median progression-free survival and overall survival were 1.7 months (95% CI 1.6-2.1 months) and 4.5 months (95% CI 2.9-8.6 months), respectively. No unexpected toxicities were observed. Panitumumab treatment provides limited CB in patients with recurrent RAF/RASwt glioblastoma precluding further development of this therapeutic strategy.

Evaluation of the additional prophylactic effect of topical steroid ointment to systemic minocycline against anti-epidermal growth factor antibody-induced skin toxicities in metastatic colorectal cancer treatment.

Anti-epidermal growth factor receptor (EGFR) antibodies often cause skin toxicities. Preemptive skin treatments using systemic antibiotics with or without topical steroid are reportedly effective although the most suitable method remains unclear. This study aimed to determine whether combination prophylaxis using systemic minocycline and topical steroid is superior to minocycline alone in a real-world metastatic colorectal cancer (mCRC) treatment. Patients with mCRC (n = 87) who received anti-EGFR monoclonal antibodies were retrospectively assessed. The primary objective was to compare the incidence of grade ≥ 2 overall skin toxicities during all treatment periods between the control group receiving prophylactic minocycline 100 mg/day, and the combination prophylaxis group receiving minocycline 100 mg/day + topical steroid. The incidence of each skin symptom was also evaluated. The incidence of grade ≥ 2 overall skin toxicities was 63.6% in the control and 56.9% in the combination groups, with no significant difference (P = 0.63). Similarly, the incidence of grade ≥ 2 dry skin, fissures, paronychia, and pruritus did not significantly differ. In addition, incidence of all-grade skin toxicities was not different. However, the incidence of grade ≥ 2 papulopustular rashes was significantly lower in the combination group (23.1% vs. 50.0%, P = 0.03). Propensity score-matched analysis supported these results. Multivariate logistic regression analysis showed no significant association between combination prophylaxis and grade ≥ 2 overall skin toxicities, but it did show a reduction in grade ≥ 2 papulopustular rashes. Adding topical steroids to systemic minocycline did not mitigate grade ≥ 2 overall skin toxicities induced by anti-EGFR antibodies; however, it significantly improved papulopustular rashes.

Epidermal growth factor receptor inhibitors in advanced cutaneous squamous cell carcinoma: A systematic review and meta-analysis.

Patients with advanced cutaneous squamous cell carcinoma (cSCC) who are not eligible for or who fail to respond to anti-PD1 immunotherapy have few treatment options. Epidermal growth factor receptor (EGFR) inhibitors have been investigated as a therapeutic option for advanced cSCC; however, data are limited to small single-arm trials or retrospective studies. A systematic review and meta-analysis was conducted to PRISMA guidelines (CRD42023394300). Studies reporting on outcomes of EGFR inhibition in advanced cSCC were identified. Objective response rate (ORR), progression-free survival (PFS), overall survival (OS) and adverse event (AE) rate were pooled using a random effects model and the inverse variance method. Twelve studies (six prospective, six retrospective) were identified, representing 324 patients. Pooled ORR was 26% (95% confidence interval [CI] 18-36), median PFS was 4.8 months (95% CI 3.9-6.6) and median OS was 11.7 months (95% CI 9.2-14.1). Any grade AEs occurred in 93% of patients (95% CI 85-97) while grade 3 and higher AEs occurred in 30% (95% CI 14-54). These results were similar between anti-EGFR monoclonal antibodies (MAbs) and tyrosine kinase inhibitors (TKIs). EGFR inhibitors can be considered in patients with advanced cSCC who are contraindicated for or progress on first-line anti-PD1 immunotherapy. Future studies should evaluate their activity and safety following anti-PD1, identify predictive biomarkers for their efficacy and explore combination approaches.