Is EGFR really a therapeutic target in head and neck cancers?

Epidermal growth factor receptor (EGFR) is overexpressed in 90% to 100% of squamous cell carcinoma of the head and neck (SCCHN). The overexpression of EGFR and its ligand transforming growth factor is associated with poorer survival. EGFR inhibitors such as Cetuximab (Erbitux) have shown a significant antitumoral effect in SCCHN and has improved locoregional control and as well as survival. Even though there was some success with Cetuximab, work with other EGFR inhibition has not been very fruitful and not really shown any promise. Mechanism of action of Cetuximab could be immune-mediated rather than EGFR inhibition and EGFR may not necessarily be a therapeutic target in SCCHN.     

Locoregional therapy and systemic cetuximab to treat colorectal liver metastases

AIM: To investigate efficacy and safety of second-line treatment with irinotecan-loaded drug-eluting beads (DEBIRI) and cetuximab (DEBIRITUX) of unresectable colorectal liver metastases.METHODS: Patients with the following characteristics were included in the study: unresectable hepatic metastases from colorectal carcinoma (CRC-LM), progression after first line chemotherapy (any type of chemotherapeutic drug and combination was allowed), second line treatment (mandatory), which included for each patient (unregarding the KRas status) two cycles of DEBIRI (using 100-300 μm beads loaded with irinotecan at a total dose 200 mg) followed by 12 cycles of cetuximab that was administered weekly at a first dose of 400 mg/m² and then 250 mg/m²; good performance status (0-2) and liver functionality (alanine aminotransferase and gamma-glutamyl transferase not exceeding three times the upper limit of normal, total bilirubin not exceeding 2.5 mg/mL). Data were collected retrospectively and included: tumor response (evaluated monthly for 6 mo then every 3 mo), overall response rate (ORR), KRas status, type and intensity of adverse events (G according to the Common Terminology Criteria for Adverse Events v3.0, CTCAE), overall survival (OS) and progression free survival (PFS).RESULTS: Forty consecutive cases of CRC hepatic metastases were included in the study. Median duration of DEBIRITUX was 4.4 mo (range, 4.0-6.5). Sixteen patients (40%) received the planned 2 cycles of DEBIRI and an average of 10 cetuximab cycles. ORR of the whole sample was 50%, in particular 4 patients were complete responders (10%) and 16 (40%) partial responders. The most observed side effects (G2) were: post-embolization syndrome (30%), diarrhea (25%), skin rushes (38%) and asthenia (35%). The retrospective evaluation of KRas status (24 wild type, 16 mutated) showed that the group of patients with wild type KRas had ORR significantly higher than mutant KRas. Median follow-up was 29 mo (8-48 range); median PFS was 9.8 mo and OS was 20.4 mo. Future randomized trials are required in this setting to establish a role for DEBIRITUX compared with systemic chemotherapy.CONCLUSION: DEBIRITUX seems to be efficacious after first line chemotherapy for the treatment of unresectable CRC-LM.     

Cetuximab enhances the efficiency of irinotecan through simultaneously inhibiting the MAPK signaling and ABCG2 in colorectal cancer cells

BackgroundThe present study sought to investigate the combined effects of cetuximab and irinotecan on colorectal cancer cells as well as the mechanisms underlying their anti-cancer effects.Material and methodsHigh performance liquid chromatography, Hoechst staining assay, and western blotting analysis were used to detect intracellular drug concentrations, cell apoptosis, and protein expression in the presence of cetuximab, irinotecan, and the combination of both.ResultsCetuximab was found to increase intracellular concentrations of irinotecan as well as cytotoxicity by inhibiting the epidermal growth factor receptor and, by extension, the downstream RAS-RAF-MEK-ERK signaling pathway. Cetuximab therefore induced apoptosis and improved the effect of irinotecan in colorectal cancer cells. It was also shown that cetuximab inhibited the drug efflux activity of ABCG2. In combination with irinotecan, cetuximab can both significantly induce cell apoptosis by inhibiting the RAS-RAF-MEK-ERK signaling pathway and improve the effects of irinotecan by decreasing drug efflux through the inhibition of ABCG2.ConclusionThese features contribute to its anti-cancer potential.     

Modified FOLFOXIRI With or Without Cetuximab as Conversion Therapy in Patients with RAS/BRAF Wild‐Type Unresectable Liver Metastases Colorectal Cancer: The FOCULM Multicenter Phase II Trial

PurposeThis trial evaluated the addition of cetuximab to a modified FOLFOXIRI (mFOLFOXIRI: 5‐fluorouracil/folinic acid, oxaliplatin, irinotecan) as conversion therapy in a two‐group, nonrandomized, multicenter, phase II trial in patients with initially technically unresectable colorectal liver‐limited metastases (CLM) and BRAF/RAS wild‐type.Patients and MethodsPatients were enrolled to receive cetuximab (500 mg/m²) plus mFOLFOXIRI (oxaliplatin 85 mg/m², irinotecan 165 mg/m², folinic acid 400 mg/m², 5‐fluorouracil 2,800 mg/m² 46‐hour infusion, every 2 weeks) (the cetuximab group) or the same regimen of mFOLFOXIRI alone (the control group), in a 2:1 ratio allocation. The primary endpoint was the rate of no evidence of disease (NED) achieved. Secondary endpoints included resection rate, objective response rate (ORR), survival, and safety.ResultsBetween February 2014 and July 2019, 117 patients were registered for screening at six centers in China, and 101 of these were enrolled (67 cetuximab group, 34 control group). The rate of NED achieved was 70.1% in the cetuximab group and 41.2% in the control group (difference 29.0%; 95% confidence interval [CI], 9.1%–48.8%; p = .005). Patients in the cetuximab group had improved ORR (95.5% vs. 76.5%; difference 19.1%; 95% CI, 17.4%–36.4%; p = .010) compared with those in control group. Progression‐free survival and overall survival showed the trend to favor the cetuximab group. The incidence of grade 3 and 4 adverse events was similar in the two groups.ConclusionAddition of cetuximab to mFOLFOXIRI improved the rate of NED achieved. This combination could be an option of conversion regimen for molecularly selected patients with initially technically unresectable CLM.Implications for PracticeThis trial evaluated the addition of cetuximab to a modified FOLFOXIRI as conversion therapy in a phase II trial in patients with initially technically unresectable colorectal liver‐limited metastases and BRAF/RAS wild‐type. The rate of no evidence of disease achieved was 70.1% in the cetuximab plus modified FOLFOXIRI group and 41.2% in the modified FOLFOXIRI group. Objective response rates, overall survival, and progression‐free survival were improved in the cetuximab group when compared with the modified FOLFOXIRI group. Addition of cetuximab to modified FOLFOXIRI increased the rate of no evidence of disease achieved, and this combination could be an option of conversion regimen for molecularly selected patients with initially technically unresectable colorectal liver‐limited metastasis.     

Clinical utility of KRAS status in circulating plasma DNA compared to archival tumour tissue from patients with metastatic colorectal cancer treated with anti-epidermal growth factor receptor therapy

BackgroundCirculating cell-free DNA (cfDNA) in plasma is a mixture of DNA from malignant and normal cells, and can be used as a liquid biopsy to detect and quantify tumour specific mutations e.g. KRAS. We investigated the clinical value of KRAS mutations when detected in plasma compared to tumour in patients from metastatic colorectal cancer (mCRC) prior to anti-epidermal growth factor receptor (anti-EGFR) therapy. Secondly, we investigated the concentration of total cfDNA in relation to clinical outcome.Patients and methodsPatients were resistant to 5-FU, oxaliplatin and irinotecan and treated with 3rd line irinotecan (180 mg/m²) and cetuximab (500 mg/m²) q2w in a prospective phase II trial. The study was conducted prior to implementation of KRAS as selection criteria. Plasma was obtained from a pre-treatment EDTA blood-sample, and the total cfDNA, and KRAS mutations were quantified by an in-house qPCR method. Results are presented according to REMARK.ResultsOne-hundred-and-forty patients were included. Thirty-four percent had detectable KRAS mutations in the tumour, compared to 23% in plasma. KRAS detection in archival tumour tissue showed no correlation to survival, whereas plasma KRAS status remained a strong predictive and prognostic factor in multivariate analysis (Hazard Ratio (HR) = 2.98 (95% CI 1.53–5.80, p = 0.001) and 2.84 (1.46–5.53, p = 0.002), for OS and PFS, respectively). Combining the information of total cell free DNA levels and plasma KRAS mutation status, produced an additional prognostic effect.ConclusionThe value of clinically relevant mutations could be improved by performing the analysis on circulation plasma DNA rather than archival tumour tissue.     

Phase I study of cetuximab in combination with 5-fluorouracil,mitomycin C and radiotherapy in patients with locally advanced anal cancer

Background5-fluorouracil (5FU) and mitomycin C (MMC)-based chemoradiotherapy (CRT) is standard treatment for anal squamous cell carcinoma. In this phase I study cetuximab was added and the primary aim was to determine the maximum tolerated dose (MTD) of 5FU and MMC in this combination.Methods and materialsPatients with locally advanced anal cancer, T2 (≥4 cm)–4N0–3M0, received weekly standard doses of cetuximab starting 1 week before CRT. Intensity modulated radiotherapy (IMRT) or volumetric modulated arc therapy (VMAT) with simultaneous integrated boost (SIB) was given to 57.5/54.0/48.6 Gy in 27 fractions to primary tumour/lymph node metastases/adjuvant lymph node regions. 5FU/MMC was given concomitantly on RT weeks 1 and 5 according to a predefined dose escalation schedule.ResultsThirteen patients were enrolled. Two patients discontinued cetuximab due to hypersensitivity reaction. The median age was 65 years (range 46–70), nine were females, and 85% had stage IIIB disease. Dose-limiting toxicity events (diarrheoa, febrile neutropenia and thrombocytopenia) occurred in 3 of 11 patients. The most common grade 3–4 side-effects were radiation dermatitis (63%), haematologic toxicity (54%), and diarrheoa (36%). No treatment-related deaths occurred. Three months following completion of treatment, ten patients (91%) had a local complete remission (CR), but two patients had developed liver metastases, yielding a total CR rate of 73%.ConclusionThe MTDs were determined as 5FU 800 mg/m² on RT days 1–4 and 29–32 and MMC 8 mg/m² on days 1 and 29 when combined with IMRT/VMAT with SIB and cetuximab in locally advanced anal cancer.