Anti­epidermal growth factor receptor monoclonal antibody therapy in locally advanced head and neck cancer: A systematic review of phase III clinical trials.

The present systematic review evaluated the effectiveness of anti-EGFR therapy in combination with radiotherapy (RT) or with chemoradiation compared with the existing standard of care for the treatment of locally advanced head and neck squamous cell carcinoma (LAHNSCC). The PubMed, SCOPUS, EMBASE and COCHRANE databases were searched and 12 phase III randomized controlled trials were included. The effectiveness of the anti-EGFR monoclonal antibody cetuximab was evaluated in nine trials. Nimotuzumab (one trial), zalutumumab (one trial) and panitumumab (one trial) were the monoclonal antibodies evaluated in the remaining three trials. One study tested the effectiveness of adding cetuximab to radical RT and found that patients with LAHNSCC exhibited improvement in locoregional control (LRC), overall survival (OS) and progression-free survival (PFS) compared with those of patients treated with RT alone. A total of three studies tested the effectiveness of adding an anti-EGFR agent to chemoradiation. Of these, a single institution study in which patients received cisplatin at 30 mg/m2 weekly, instead of the standard doses of 100 mg/m2 every 3 weeks or 40 mg/m2 every week, reported significant improvement in PFS with the addition of nimotuzumab to chemoradiotherapy without an improvement in overall survival. However, the other two studies indicated that, when added to standard chemoradiation, the anti-EGFR monoclonal antibodies cetuximab or zalutumumab did not improve survival outcomes. Two phase III trials evaluated RT plus an anti-EGFR agent compared with chemoradiation alone. Of these, one study reported inferior outcomes with cetuximab-RT in terms of OS and LRC, whereas the other study with panitumumab plus RT failed to prove the non-inferiority. Two trials evaluated induction chemotherapy followed by cetuximab-RT compared with chemoradiotherapy and reported no benefits in terms of OS or PFS. Furthermore, one study evaluated induction chemotherapy followed by cetuximab-RT compared with induction chemotherapy followed by chemoradiotherapy and found no improvement in OS or PFS. Finally, three phase III trials tested the effectiveness of cetuximab plus RT in the treatment of human papillomavirus-positive oropharyngeal carcinoma, and found it to be inferior compared with cisplatin-RT in terms of OS, PFS and failure-free survival. Based on the aforementioned findings, it is difficult to conclude that anti-EGFR therapy in any form has an advantage over conventional chemoradiation in the treatment of LAHNSCC.

Panitumumab-Induced Periorbital Dermatitis: A Case Report.

Panitumumab is a recombinant, fully humanized immunoglobulin G2 monoclonal antibody targeting the epidermal growth factor receptor (EGFR). It is approved for the first- and second-line treatment of advanced wild-type KRAS colorectal cancer. Although common cutaneous side effects include acneiform dermatitis, folliculitis, and xerosis, ocular toxicities have occasionally been reported. Herein, we report the case of an 81-year-old Thai female with chemorefractory advanced stage sigmoid colon cancer who developed isolated periorbital dermatitis following treatment with panitumumab plus modified FOLFOX6. The cutaneous adverse reaction recurred after subsequent infusions; however, it was alleviated by topical therapy. To our knowledge, panitumumab-induced periorbital dermatitis is exceptionally rare. To raise awareness of potential periocular cutaneous side effects in patients taking EGFR inhibitors, the published literature regarding periorbital dermatitis induced by these agents has also been reviewed in this article. Periorbital dermatitis should be considered as a potential cutaneous reaction following panitumumab administration, and should be promptly treated.

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.

Comparative aspects of targeted sentinel lymph node mapping in veterinary and human medicine: opportunities for future research.

There is a significant overlap in the genetic, metabolic and epigenetic alterations between human and companion animal cancers, including those of the oral cavity, breast, bladder, skin, lungs and pancreas. In many cancer types, the identification and removal of affected lymph nodes are essential for accurate cancer management, including treatment and prognosis. Historically, lymphadenectomy and subsequent radical resection based on regional anatomy, palpation and lymph node aspirates were considered sufficient; however, modern approaches with sentinel lymph node mapping (SLN) mapping have increased the accuracy of surgical decision-making. Preoperative and intraoperative SLN mapping techniques in veterinary patients parallel those used in human medicine. While many of these techniques are highly successful, the main challenges with current methodologies are their sensitivity and specificity for the presence of cancer, which can be overcome via precision medicine and targeted SLN mapping agents. Given the large population of dogs and cats with cancer, the crossover of knowledge between species can help to deepen our understanding of many of these cancers and can be useful in evaluating new drugs and/or therapies. In this review, we discuss SLN mapping techniques in veterinary medicine and the concept of precision medicine as it relates to targeted SLN mapping imaging agents. The large number of companion animals affected by cancer is an underutilized resource to bridge the translational gap and we aim to provide a reference for the use of dogs and cats as a comparative model for human SLN mapping.

Clinical outcomes of intermittent panitumumab based-therapy for previously treated older patient with metastatic colorectal cancer: a case report and review of literature.

Background: Metastatic colorectal cancer is one of the most common causes of cancer death worldwide, and its incidence increases with age. Treating an older RAS and BRAF wild-type patient represents a challenge for the medical oncologist, even more so for those patients defined as "vulnerable" and undergoing at least two lines of therapy. In this context, recent evidence supports the role of retreatment with anti-EGFR inhibitors and the use of liquid biopsy. However, frequent skin toxicity constitutes a limitation of therapy, especially in older people. Since it has been described that continuous administration of these monoclonal antibodies leads to acquired resistance to anti-EGFRs, with consequent therapeutic failure, an intermittent strategy with chemotherapy plus an anti-EGFR could help maintain the efficacy of the treatment over time, delaying the resistance and improving patients' quality of life. Case presentation: In this case report, we describe the case of an older RAS and BRAF wild-type patient reporting a clinical response after first-line chemotherapy with FOLFOX + panitumumab, subsequently interrupted in the absence of disease progression. After radiological worsening and two additional lines of therapy, the reintroduction of panitumumab plus 5-fluorouracil, administered with a stop-and-go strategy, allowed the patient to benefit from the same drugs for 2 years from diagnosis, to achieve a clinical response during fourth-line treatment lasting more than 3 years, to delay resistance and to avoid unacceptable anti-EGFR skin toxicity. This patient, who died from a myocardial infarction more than 5 years after diagnosis, represents the case of a good synergy between molecular profile of disease and reintroduction of an anti-EGFR with intermittent strategy.

Anti-EGFR antibody monotherapy for colorectal cancer with severe hyperbilirubinemia: A case report.

BACKGROUND: Hyperbilirubinemia with hepatic metastases is a common complication and a poor prognostic factor for colorectal cancer (CRC). Effective drainage is often impossible before initiating systemic chemotherapy, owing to the liver's diffuse metastatic involvement. Moreover, an appropriate chemotherapeutic approach for the treatment of hyperbilirubinemia is currently unavailable. CASE SUMMARY: The patient, a man in his 50s, presented with progressive fatigue and severe jaundice. Computed tomography revealed multiple hepatic masses with thickened walls in the sigmoid colon, which was pathologically confirmed as a well-differentiated adenocarcinoma. No RAS or BRAF mutations were detected. The Eastern Cooperative Oncology Group (ECOG) performance status (PS) score was 2. Biliary drainage was impossible due to the absence of a dilated bile duct, and panitumumab monotherapy was promptly initiated. Subsequently, the bilirubin level decreased and then normalized, and the patient's PS improved to zero ECOG score after four cycles of therapy without significant adverse events. CONCLUSION: Anti-EGFR antibody monotherapy is a safe and effective treatment for RAS wild-type CRC and hepatic metastases with severe hyperbilirubinemia.

A meta-analysis of efficacy and safety data from head-to-head first-line trials of epidermal growth factor receptor inhibitors versus bevacizumab in adult patients with RAS wild-type metastatic colorectal cancer by sidedness.

The first-line treatment choice of EGFRIs plus doublet chemotherapy vs. bevacizumab plus doublet chemotherapy remains a topic of interest for patients with left-sided RAS WT mCRC. We conducted a systematic literature review and meta-analysis of clinical trial data published between 2015 and 2024. We evaluated the relative efficacy and safety of first-line EGFRIs plus doublet chemotherapy (FOLFIRI or FOLFOX) vs. bevacizumab plus doublet chemotherapy for patients with RAS WT left-sided mCRC, as well as in all- and right-sided tumors. We identified eight trials with 2624 patients. Five trials reported outcomes by tumor sidedness. In the left-sided population, overall survival (OS) (Hazard Ratio (HR) = 0.80, 95% Confidence Interval (CI): 0.71-0.90) and objective response rate (ORR) (Odds ratio [OR]=1.61, 95% CI: 1.30-1.99) favored EGFRI plus chemotherapy, while no statistically significant differences were observed for progression-free survival (PFS) (HR=0.93, 95% CI: 0.84-1.04) or resection rate (RR). Similar results were found in the all-sided population. In the right-sided population, PFS favored bevacizumab plus chemotherapy (HR=1.45, 95% CI: 1.19-1.78), while no statistically significant differences were observed for OS (HR=1.17, 95% CI: 0.95-1.44), ORR (OR=0.99, 95% CI: 0.69-1.41), and RR. Early tumor shrinkage in the all-sided population favored EGFRI plus chemotherapy (OR=1.72; 95% CI: 1.36-2.17); limited data precluded evaluation by sidedness. Safety was available in 6 trials for all-sided tumors and 1 trial for left-sided tumors, each demonstrating typical class-specific adverse events. This most comprehensive meta-analysis indicates a benefit for first-line EGFRI plus chemotherapy over bevacizumab plus chemotherapy in patients with left-sided RAS WT mCRC.

The role of anti-EGFR rechallenge in metastatic colorectal cancer, from available data to future developments: A systematic review.

Despite recent molecular and immunological advancements, prognosis of metastatic colorectal cancer (mCRC) patients remains poor. In this context, several retrospective and phase II studies suggested that after failure of an upfront anti-EGFR based regimen, a subset of patients can still benefit from further anti-EGFR blockade. Several translational studies involving circulating tumor DNA (ctDNA) analysis demonstrated that cancer clones harboring mutations driving anti-EGFR resistance, which can arise under anti-EGFR agents selective pressure, often decay after anti-EGFR discontinuation potentially restoring sensitivity to this therapeutic strategy. Accordingly, several retrospective analyses and a recent prospective trial demonstrated that ctDNA RAS and BRAF wild-type mCRC patients are those benefitting the most from anti-EGFR rechallenge. Indeed, in molecularly selected patients, anti-EGFR rechallenge strategy achieved up to 30 % response rate, with a progression free survival longer than 4 months and an overall survival longer than 1 year, which favorably compared with other standard therapeutic options available for heavily pretreated patients. Anti-EGFR is also well tolerated with no unexpected toxicities compared to the upfront setting. However, several open questions remain to be addressed towards a broader applicability of anti-EGFR strategy in the everyday clinical practice such as the identification of the best rechallenge regimen, the right placement in mCRC therapeutic algorithm, the best ctDNA screening panel. In our systematic review, we revised available data from clinical trials assessing anti-EGFR rechallenge activity in chemo-refractory mCRC patients, discussing as well potential future scenarios and development to implement this therapeutic approach. Particularly, we discussed the role of ctDNA as a safe, timely and comprehensive tool to refine patient's selection and the therapeutic index of anti-EGFR rechallenge.

Curative resection after percutaneous drainage followed by preoperative panitumumab monotherapy for locally advanced sigmoid colon cancer with intra-abdominal abscess: a case report.

BACKGROUND: The gold standard treatment for locally advanced colon cancer is curative surgery followed by adjuvant chemotherapy, although this approach is associated with serious concerns, such as high recurrence rates and occasionally unnecessary oversurgery. Neoadjuvant chemotherapy may be a promising strategy for overcoming these issues. This study reports a case of a recurrence-free patient who underwent curative resection without significant organ dysfunction after preoperative chemotherapy for locally advanced sigmoid colon cancer. The tumor coexisted with a large intra-abdominal abscess, and the patient was quite frail at the first visit. We performed percutaneous drainage followed by preoperative panitumumab monotherapy, which yielded favorable outcomes. CASE PRESENTATION: A 78-year-old frail woman was emergently transferred to our hospital with fever and abdominal pain. The diagnosis was locally advanced sigmoid colon cancer stage IIIC (T4bN2aM0) with a large intra-abdominal abscess. Immediate curative surgery was inappropriate, considering both tumor progression and the patient's frailty. We performed percutaneous drainage and colostomy construction, which was followed by seven cycles of preoperative panitumumab monotherapy without significant adverse events. After these treatments, inflammation was well controlled, and the tumor shrank remarkably. Furthermore, the patient recovered well from frailty; therefore, curative sigmoidectomy combined with resection of the left ovary and stoma closure was possible without any postoperative complications. The final pathological finding was T3N0M0, stage IIA disease. The patient was recurrence-free and had no significant organ dysfunction 21 months after the curative surgery. CONCLUSIONS: The management of intra-abdominal abscesses and tailor-made preoperative chemotherapy based on the patient's frailty may have been the key factors responsible for the favorable course of this patient. Although further research is needed on the appropriateness of percutaneous drainage for malignancies related to intra-abdominal abscesses and preoperative panitumumab use for locally advanced colon cancer, the study findings can serve as reference for managing similar cases in an aging society.

Risk Evaluation of Proton Pump Inhibitors for Panitumumab-Related Hypomagnesemia in Patients with Metastatic Colorectal Cancer.

Hypomagnesemia commonly occurs as a side effect of panitumumab treatment. In severe cases, temporary discontinuation or dose reduction of panitumumab may be necessary. Proton pump inhibitors (PPIs) are reportedly potential risk factors for hypomagnesemia. We conducted a multicenter study to assess the impact of PPIs on the risk of grade 3-4 hypomagnesemia in patients with metastatic colorectal cancer (mCRC) receiving panitumumab. We adjusted for potential bias using a propensity score-matched analysis and retrospectively reviewed the medical records of patients. Hypomagnesemia severity was graded according to the Common Terminology Criteria for Adverse Events, version 5.0. A total of 165 patients were enrolled in this study. The incidence of grade 3-4 hypomagnesemia was significantly higher in the PPI group than in the non-PPI group, both before (20.0% [30/60] vs. 8.0% [8/105], p = 0.026) and after propensity score matching (16.2% [6/37] vs. 0% [0/37], p = 0.025). In the propensity score-matched cohort, the risk of grade 3-4 hypomagnesemia was significantly higher in the PPI group (odds ratio, 2.19; 95% confidence interval, 1.69-2.84; p = 0.025). These findings suggest that concomitant use of PPIs significantly increases the risk of grade 3-4 hypomagnesemia in patients with mCRC receiving panitumumab. Therefore, close monitoring of these patients is imperative.

Anti-epidermal growth factor receptor targeted therapy-associated ulcerations.

The well-studied role of epidermal growth factor receptor (EGFR) in metastatic colorectal cancer (mCRC) and non-small cell lung cancer (NSCLC) has enabled the development of drugs that target this molecule, including panitumumab for the former and osimertinib for the latter. Oral adverse events due to those agents are rarely described in the literature and their exact characterization is hampered by inadequate reporting and/or incorrect terminology used. We report two cases of panitumumab- and osimertinib-associated oral ulcerations with emphasis on their possible pathogenesis and optimal management.

Prognostic and predictive impact of metastatic organ involvement on maintenance therapy in advanced metastatic colorectal cancer: Subgroup analysis of patients treated within the PanaMa trial (AIO KRK 0212).

Despite molecular selection, patients (pts) with RAS wildtype mCRC represent a heterogeneous population including diversity in metastatic spread. We investigated metastatic patterns for their prognostic and predictive impact on maintenance therapy with 5-fluorouracil/folinic acid ± panitumumab. The study population was stratified according to (1) number of involved metastatic sites (single vs multiple organ metastasis), liver-limited disease vs (2) liver metastasis plus one additional site, and (3) vs liver metastasis plus ≥two additional sites. Kaplan-Meier method and Cox regressions were used to correlate efficacy endpoints. Single organ metastasis was observed in 133 pts (53.6%) with 102 pts (41.1%) presenting with liver-limited disease, while multiple organ metastases were reported in 114 pts (46.0). Multiple compared to single organ metastases were associated with less favorable PFS (HR 1.48, 95% CI 1.13-1.93; P = .004) and OS (HR 1.37, 95% CI 0.98-1.93; P = .068) of maintenance therapy. While metastatic spread involving one additional extrahepatic site was not associated with clearly impaired survival compared to liver-limited disease, pts with liver metastasis plus ≥two additional sites demonstrated less favorable PFS (HR 1.92, 95% CI 1.30-2.83; P < .001), and OS (HR 2.38, 95% CI 1.51-3.76; P < .001) of maintenance therapy. Pmab-containing maintenance therapy appeared active in both pts with multiple (HR 0.58; 95% CI, 0.39-0.86; P = .006) as well as to a lesser numerical extent in pts with single organ metastasis (HR 0.83; 95% CI, 0.57-1.21; P = .332; Interaction P = .183). These data may support clinical decisions when EGFR-based maintenance therapy is considered.

Prolonging the stability of cetuximab (Erbitux®) and panitumumab (Vectibix®): An orthogonal assessment of physicochemical, biological and microbiological properties of original opened glass vials and diluted saline preparations.

The two anti-epidermal growth factor receptor monoclonal antibodies (mAbs) cetuximab and panitumumab are the pillars for the treatment of EGFR-positive, KRAS wild-type metastatic colorectal cancers. However, stability data of these mAbs are generally missing or incomplete. Here, we report for the first time an orthogonal analysis of the stability of cetuximab (Erbitux®) and panitumumab (Vectibix®), either undiluted vial leftovers or saline dilutions in polyolefin/polyamide infusion bags. All samples were stored at 2-8 °C protected from light, according to their summary of product characteristics (SmPCs). Alternatively, opened vials and preparations were maintained at 25 °C for 15 h, and then stored again at 2-8 °C protected from light to mimic a temporary interruption of the cold chain. Vial leftovers proved stable up to 180 days when stored according to their SmPCs, while compounded preparations in infusion bags maintained their physiochemical, biological and microbiological stability up to 30 days. Additionally, no changes were detected up to 30 days for the same samples undergoing a thermal excursion. Our results provide additional rationale to the SmPCs, crucial especially in the case of reassignment and pre-preparation of bags. This information will allow hospitals to achieve significant cost savings, and better organization of the entire therapeutic process.

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

BACKGROUND: 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). METHODS: 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. RESULTS: 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. CONCLUSIONS: Panitumumab treatment provides limited CB in patients with recurrent RAF/RASwt glioblastoma precluding further development of this therapeutic strategy.

Selecting Optimal First-Line Treatment for Microsatellite Stable and Non-Mutated RAS/BRAF Metastatic Colorectal Cancer.

OPINION STATEMENT: Standard frontline treatment of metastatic colorectal cancer (CRC) is cytotoxic chemotherapy plus a biologic agent such as an anti-EGFR monoclonal antibody (cetuximab or panitumumab) or anti-VEGF antibody (bevacizumab). Predictive biomarkers include mismatch repair (MMR) status, and RAS and BRAF mutation status; and important factors in treatment selection include primary tumor location, intent of therapy, and potential toxicity, as well as patient age, comorbidities, and patient preference. To date, single-, double-, or triple-agent cytotoxic chemotherapy all have important roles in appropriately selected patients, with the addition of anti-VEGF or anti-EGFR antibody therapy based on the relevant predictive biomarker. Data indicate that patients with proficient MMR, RAS/BRAF wt mCRC are candidates for an anti-EGFR antibody plus doublet chemotherapy if they have a left-sided primary tumor, or for anti-VEGF (bevacizumab) plus doublet or triplet chemotherapy if they have a right-sided primary tumor. Future studies may provide more predictive biomarkers to further personalize therapy for this heterogeneous disease.

Comparative Effectiveness of Cetuximab Versus Panitumumab in Patients With Metastatic Colorectal Cancer: A Nationwide Database Study.

BACKGROUND/AIM: The study aimed to determine the effectiveness of cetuximab and panitumumab on the survival of patients with metastatic colorectal cancer or those who had undergone conversion surgery and to identify their prognostic factors. PATIENTS AND METHODS: This retrospective cohort study used data from patients with metastatic colorectal cancer who received cetuximab or panitumumab as first-line targeted agent-based therapy. Overall survival and conversion surgery rates were evaluated, and the prognostic factors were determined. RESULTS: A total of 1,749 and 318 patients received cetuximab or panitumumab with chemotherapy, respectively. Overall survival and conversion surgery rates were similar between the cetuximab [hazard ratio (HR)=0.96] and panitumumab groups (HR=1.00). The prognostic factors associated with metastasectomy significantly lowered mortality among patients with metastatic colorectal cancer (HR=0.61). Older age (≥70 years), tumor stage 4B and 4C, right-sided tumors, mucinous adenocarcinoma, primary tumor resection, and the number of positive lymph nodes were associated with higher mortality and lower conversion surgery rates. CONCLUSION: Though panitumumab- and cetuximab-based therapies showed no differences, several factors, such as age over 70 years old, tumor stage 4B and 4C, undifferentiated carcinoma, mucinous carcinoma, right-sided tumor, number of positive lymph nodes, obstruction, and primary tumor resection increased the mortality risk of patients. This study underscores the importance of metastasectomy in current treatment guidelines and future clinical trials.

Adjuvant Auger Electron-Emitting Radioimmunotherapy with [111In]In-DOTA-Panitumumab in a Mouse Model of Local Recurrence and Metastatic Progression of Human Triple-Negative Breast Cancer.

Triple-negative breast cancer (TNBC) has a high risk for recurrence and metastasis. We studied the effectiveness of Auger electron (AE) radioimmunotherapy (RIT) with antiepidermal growth factor receptor (EGFR) panitumumab conjugated with DOTA complexed to 111In ([111In]In-DOTA-panitumumab) for preventing metastatic progression after local treatment of 231/LM2-4 Luc+ human TNBC tumors in the mammary fat pad of NRG mice. Prior to RIT, the primary tumor was resected, and tumor margins were treated with X-irradiation (XRT; 5 days × 6 Gy/d). RIT was administered 1 day post-XRT by intravenous injection of 26 MBq (15 µg) or 2 × 10 MBq (15 µg each) separated by 7 d. These treatments were compared to tumor resection with or without XRT combined with DOTA-panitumumab (15 µg) or irrelevant [111In]In-DOTA-IgG2 (24 MBq; 15 µg), and efficacy was evaluated by Kaplan-Meier survival curves. The effect of [111In]In-DOTA-panitumumab (23 MBq; 15 µg) after tumor resection without local XRT was also studied. Tumor resection followed by XRT and RIT with 26 MBq [111In]In-DOTA-panitumumab significantly increased the median survival to 35 d compared to tumor resection with or without XRT (23-24 d; P < 0.0001). Local treatment with tumor resection and XRT followed by 2 × 10 MBq of [111In]In-DOTA-panitumumab, DOTA-panitumumab, or [111In]In-DOTA-IgG2 did not significantly improve median survival (26 days for all treatments). RIT alone with [111In]In-DOTA-panitumumab postresection of the tumor without XRT increased median survival to 29 days, though this was not significant. Despite significantly improved survival in mice treated with tumor resection, XRT, and RIT with [111In]In-DOTA-panitumumab, all mice eventually succumbed to advanced metastatic disease by 45 d post-tumor resection. SPECT/CT with [111In]In-DOTA-panitumumab, PET/MRI with [64Cu]Cu-DOTA-panitumumab F(ab')2, and PET/CT with [18F]FDG were used to detect recurrent and metastatic disease. Uptake of [111In]In-DOTA-panitumumab at 4 d p.i. in the MFP tumor was 26.8 ± 9.7% ID/g and in metastatic lymph nodes (LN), lungs, and liver was 34.2 ± 26.9% ID/g, 17.5 ± 6.0% ID/g, and 9.4 ± 2.4%ID/g, respectively, while uptake in the lungs (6.0 ± 0.9% ID/g) and liver (5.2 ± 2.9% ID/g) of non-tumor-bearing NRG was significantly lower (P < 0.05). Radiation-absorbed doses in metastatic LN, lungs, and liver were 9.7 ± 6.1, 6.4 ± 2.1, and 10.9 ± 2.7 Gy, respectively. In conclusion, we demonstrated that RIT with [111In]In-DOTA-panitumumab combined with tumor resection and XRT significantly improved the survival of mice with recurrent TNBC. However, the aggressive nature of 231/LM2-4 Luc+ tumors in NRG mice may have contributed to the tumor recurrence and progression observed.

The efficacy and safety of anti-EGFR target agents in patients with potentially resectable metastatic colorectal cancer: a meta-analysis of randomized controlled trials.

BACKGROUND: Adding anti-epidermal growth factor receptor (anti-EGFR) target agents to conversion therapy may improve the resection rates and survival of patients with potentially resectable metastatic colorectal cancer (mCRC). This study aims to analyze the efficacy and safety of additional anti-EGFR target agents. METHODS: A systematic search was conducted on PubMed, Web of Science, Embase, and Cochrane Library. And all relevant studies published in English before January 2023 were collected to explore the impact of additional anti-EGFR targeted agent on the efficacy and safety of patients with potentially resectable mCRC (PROSPERO: CRD42022340523, https://www.crd.york.ac.uk/PROSPERO/ ). RESULTS: This study included a total of 8 articles, including 2618 patients. The overall response rate (ORR) and R0 resection rates of the experimental group were higher than those of the control group, while there was no significant difference in progression-free survival (PFS) and overall survival (OS) between the two groups. In RAS/KRAS wild-type patients, the ORR (RR: 1.20, 95% Cl: 1.02-1.41, p = 0.03), R0 resection rate (RR: 1.60, 95% Cl: 1.17-2.20, p = 0.003), PFS (HR: 0.80, 95% Cl: 0.68-0.93, p = 0.003), and OS (HR: 0.87, 95% Cl: 0.76-0.99, p = 0.031) of the experimental group were higher than those of the control group. While in KRAS mutant patients, there was no statistical difference between the two groups in ORR, R0 resection rate, PFS, and OS. CONCLUSION: The addition of anti-EGFR targeted agents can improve the prognosis of RAS/KRAS wild-type patients with potentially resectable mCRC, while KRAS mutant patients may not benefit. In addition, the overall safety factor was controllable.

Maintenance strategies after anti-EGFR-based induction in metastatic colorectal cancer: A systematic review and bayesian network meta-analysis.

BACKGROUND: In RAS wild type (wt) metastatic colorectal cancer (mCRC) maintenance therapy after induction with fluoropyrimidine (FP)-based cytotoxic therapy (CT) plus anti-EGFR agents is controversial. METHODS: Phase II-III randomized trials were included. Maintenance strategies considered were: observation, anti-EGFR or FP monotherapy, FP + anti-EGFR, doublet CT + anti-EGFR. RESULTS: Maintenance with FP + anti-EGFR (HR 0.56, 95% CrI 0.36-0.89) showed the greatest PFS benefit compared to observation, ranking first on SUCRA analysis (96.4%). Considering OS, doublet CT+ anti-EGFR, FP + anti-EGFR and anti-EGFR monotherapy yielded similar results. For PFS, FP + anti-EGFR confirmed to be valuable in BRAF wt patients and left sided tumors. In left sided tumors, the OS benefit of adding CT was limited. FP plus anti-EGFR showed a favourable safety profile compared to doublet CT + anti-EGFR. CONCLUSIONS: FP + anti-EGFR can be considered a valuable maintenance option in RAS wt mCRC. EGFR monotherapy can be considered, especially in left-sided tumors.