Dual EGFR inhibition in combination with anti-VEGF treatment: A phase I clinical trial in non-small cell lung cancer

BACKGROUND

Preclinical data indicate EGFR signals through both kinase-dependent and independent pathways and that combining a small-molecule EGFR inhibitor, EGFR antibody, and/or anti-angiogenic agent is synergistic in animal models.

METHODS

We conducted a dose-escalation, phase I study combining erlotinib, cetuximab, and bevacizumab. The subset of patients with non-small cell lung cancer (NSCLC) was analyzed for safety and response.

RESULTS

Thirty-four patients with NSCLC (median four prior therapies) received treatment on a range of dose levels. The most common treatment-related grade &ge;2 adverse events were rash (n=14, 41%), hypomagnesemia (n=9, 27%), and fatigue (n=5, 15%). Seven patients (21%) achieved stable disease (SD) &ge;6 months, two achieved a partial response (PR) (6%), and two achieved an unconfirmed partial response (uPR) (6%) (total=32%). We observed SD&ge;6 months/PR/uPR in patients who had received prior erlotinib and/or bevacizumab, those with brain metastases, smokers, and patients treated at lower dose levels. Five of 16 patients (31%) with wild-type EGFR experienced SD&ge;6 months or uPR. Correlation between grade of rash and rate of SD&ge;6 months/PR was observed (p<0.01).

CONCLUSION

The combination of erlotinib, cetuximab, and bevacizumab was well-tolerated and demonstrated antitumor activity in heavily pretreated patients with NSCLC.     

Comparison of KRAS Genotype: Therascreen Assay vs. LNA-Mediated qPCR Clamping Assay

BackgroundKirsten rat sarcoma virus (KRAS) wild-type status determined using a locked nucleic acid (LNA)-mediated quantitative polymerase chain reaction (qPCR) clamping assay (LNA assay) predicted response to therapy in the CRYSTAL (Cetuximab Combined With Irinotecan in First-Line Therapy for Metastatic Colorectal Cancer) study. A companion KRAS diagnostic tool has been developed for routine clinical use (QIAGEN therascreen kit) (QIAGEN Manchester Ltd, Manchester, UK). We wanted to assess the concordance between the validated US Food and Drug Administration (FDA)-approved therascreen assay and the LNA assay in determining the KRAS status of a subset of patients enrolled in the CRYSTAL study.Patients and MethodsDNA extracted from paraffin-embedded tumor sections was tested for KRAS status using the therascreen assay. Efficacy data from the CRYSTAL study were assessed to determine if the overall survival (OS) hazard ratio for cetuximab in patients identified as having KRAS wild-type status using the therascreen assay was equivalent to that in patients identified as KRAS wild-type using the LNA assay. This was determined by assessing if the concordance between the therascreen assay and the LNA assay met the minimum threshold (prespecified as 0.8) to achieve a significant difference in the OS hazard ratio in favor of the cetuximab + FOLFIRI (5-fluorouracil, leucovorin [folinic acid], irinotecan) arm in the KRAS wild-type population as identified using the therascreen assay.ResultsOf the 148 samples determined to be KRAS wild-type (therascreen assay), 141 (95.3%) samples were also KRAS wild-type (LNA assay) and 7 samples (4.7%) were KRAS mutant (LNA assay). The prespecified primary concordance measure p was 141/148 = 0.953 (95% confidence interval [CI], 0.905-0.981). The concordance was statistically significantly higher than the prespecified threshold of 0.8 for concordance between the therascreen assay and the LNA assay. Consistent with the concordance exceeding the prespecified threshold, the OS hazard ratio (cetuximab + FOLFIRI arm vs. FOLFIRI arm) in the KRAS wild-type population, determined by the therascreen assay, supported a significant benefit for cetuximab (ie, the 95% CI excluded 1) and was comparable to the OS hazard ratio observed in the CRYSTAL study KRAS wild-type population (LNA assay) even after adjustment for potentially confounding baseline variables.ConclusionThese results support the utility of the therascreen assay for identifying patients who may benefit from cetuximab therapy for metastatic colorectal cancer.     

结直肠癌 K-ras 基因突变检测及其意义

目的：研究结直肠癌中K-ras基因突变率及突变类型,探讨结直肠癌K-ras基因野生型及突变型与患者临床参数的关系;通过基因测序,指导临床靶向药物用药。方法随机选取哈尔滨医科大学附属第三医院结直肠外科2008年9月至2010年3月收治的100例结直肠癌患者组织标本通过手术室取材、组织标本DNA提取、逆转录PCR、凝胶电泳、胶回收、直接测序等技术筛选K-ras基因突变标本进行统计分析,从中得出突变率及突变类型。结果共筛选出了34例（34％）K-ras基因突变标本,其基因突变均发生在第一外显子的第12及第13密码子。结果表明：第一外显子的第12密码子GGT突变为GAT或GTT;第一外显子第13密码子由GGC突变为GGT。其中并未发现第二外显子第59及第61位发生突变,及第一外显子12位13位同时突变。结论 K-ras基因结直肠癌中约有34％发生突变。在K-ras基因突变类型与患者的病期、病理类型、肿瘤的浸润深度、发病部位等因素无关。     

Concurrent Cetuximab-based bioradiotherapy versus Cisplatin-based Chemoradiotherapy in the Definitive Management of Favourable Biology Human Papillomavirus-associated Oropharyngeal Squamous Cell Carcinoma: Systematic Review and Meta-analysis

Replacing cisplatin with cetuximab concurrently during radiotherapy has been one of the strategies of treatment de-escalation in human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma (OPSCC). However, until recently, there were limited data on the efficacy and safety of such an approach. A systematic search of the literature was carried out to identify prospective randomised controlled trials comparing definitive cisplatin-based chemoradiotherapy (CT-RT) versus cetuximab-based bioradiotherapy (BRT) in HPV-positive OPSCC. Overall survival and locoregional control were primary outcomes of interest; rates of acute and late toxicities (≥grade 3) were secondary end points. Outcome data were aggregated using a random-effects model as per Cochrane methodology including risk of bias assessment and expressed as hazard ratio or risk ratio as appropriate with respective 95% confidence intervals. Data from five randomised controlled trials involving 1560 patients with HPV-positive OPSCC were aggregated in the meta-analysis. Cetuximab-based BRT was associated with a significantly increased risk of death (hazard ratio = 2.83, 95% confidence interval 1.22–6.57; P = 0.02) and locoregional relapse (hazard ratio = 2.78, 95% confidence interval 1.77–4.39; P < 0.0001) compared with cisplatin-based CT-RT. Cisplatin was associated with higher rates of acute ≥grade 3 toxicity in terms of acute kidney injury, dry mouth, febrile neutropenia, hearing impairment, nausea and vomiting, whereas dermatitis and acneiform rash were more common with cetuximab. There were no significant differences in overall rates of late ≥grade 3 toxicity (risk ratio = 0.63, 95% confidence interval = 0.36–1.10; P = 0.10). In conclusion, there is moderate-certainty evidence that cetuximab-based BRT leads to inferior efficacy outcomes compared with cisplatin-based CT-RT in the definitive curative-intent management of HPV-associated OPSCC.     

Comparative analysis of binding affinities to epidermal growth factor receptor of monoclonal antibodies nimotuzumab and cetuximab using different experimental animal models

Although pharmaco/toxicological studies have always been conducted in pharmacologically relevant species in which the test material is pharmacologically active, the very specificity of many biopharmaceuticals could present challenges in the identification of a relevant species for pharmaco/toxicological studies. Alternative approaches may improve the predictive value of preclinical assessments of species-specific biopharmaceuticals. This could lead to improved decision-making, reduce the number of experimental animals by eliminating non-relevant studies, and decrease the time and cost involved in the drug development process. As an alternative to utilizing traditional animal models, this study investigated the activity of human EGF and the anti-EGF receptor monoclonal antibodies nimotuzumab and cetuximab using the placenta microsomal fraction of different experimental animals. Ligand-receptor binding curves were obtained from the different experimental animal models, and binding constants were calculated based on the Scatchard plots. The constants for human and monkey EGF receptor expressed on the placental extract showed a K_a < 10⁻⁸ M, while rabbits, mice and rats showed a K_a > 10⁻⁸ M. The K_a values obtained from animal placentas show that Macaca fascicularis and Cercopitecus aethiops monkeys are relevant species for studying the pharmaco/toxicological properties of nimotuzumab and cetuximab.     

Overcoming cetuximab resistance in HNSCC: The role of AURKB and DUSP proteins

Unraveling the underlying mechanisms of cetuximab resistance in head and neck squamous cell carcinoma (HNSCC) is of major importance as many tumors remain non-responsive or become resistant. Our microarray results suggest that “resistant” cells still exhibit RAS–MAPK pathway signaling contributing to drug resistance, as witnessed by low expression of DUSP5 and DUSP6, negative regulators of ERK1/2, and increased expression of AURKB, a key regulator of mitosis. Therefore, interrupting the RAS–MAPK pathway by an ERK1/2 inhibitor (apigenin) or an AURKB inhibitor (barasertib) might be a new strategy for overcoming cetuximab resistance in HNSCC.     

A randomised,open-label phase II trial of afatinib versus cetuximab in patients with metastatic colorectal cancer

PurposeThis randomised phase II trial aimed to compare efficacy of the irreversible ErbB family blocker, afatinib, with cetuximab in patients with KRAS wild-type metastatic colorectal adenocarcinoma (mCRC) with progression following oxaliplatin- and irinotecan-based regimens. Efficacy in patients with KRAS mutations was also evaluated.Patients and methodsPatients with KRAS wild-type tumours were randomised 2:1 to afatinib (40 mg/day, increasing to 50 mg/day if minimal toxicity) or cetuximab weekly (400 mg/m² loading dose, then 250 mg/m²/week) according to number of previous chemotherapy lines. All patients with KRAS-mutated tumours received afatinib. Primary end-points were objective response (OR) for the wild-type group and disease control for the KRAS-mutated group. Secondary end-points were progression-free survival (PFS) and overall survival (OS).ResultsPatients with KRAS wild-type tumours (n = 50) received afatinib (n = 36) or cetuximab (n = 14). Unconfirmed and confirmed ORs were 3% and 0% for afatinib versus 20% and 13% for cetuximab (odds ratio: 0.122 [P = 0.0735] and <0.001, respectively). Median PFS was 46.0 and 144.5 days for afatinib and cetuximab, respectively. Median OS was 355 days with afatinib but not reached for cetuximab. In the KRAS-mutated group (n = 41), five (12%) patients achieved confirmed disease control (stable disease; P = 0.6394 [comparison versus 10%]); no ORs were reported. Median PFS and OS were 41.0 and 173 days, respectively. Most frequent treatment-related adverse events were diarrhoea and rash across groups.ConclusionsThe efficacy of afatinib was inferior to cetuximab in patients with KRAS wild-type mCRC. In patients with KRAS-mutated tumours, disease control was modest with afatinib. Afatinib had a manageable safety profile.     

西妥昔单抗单周和双周方案治疗晚期大肠癌的对比研究

 目的　比较西妥昔单抗250 mg／m2单周方案和500 mg／m2双周方案分别联合化疗治疗晚期大肠癌的近期疗效及安全性。方法　56例晚期大肠癌患者,ECOG行为状态评分0～2分,均有可评价病灶（RECIST 2000标准）。西妥昔单抗单周方案联合化疗组30例,给药方法为400 mg／m2第1周,以后250 mg／m2每周重复应用;双周方案联合化疗组26例,给药方法为500 mg／m2第1周,以后每两周重复应用。两组均以完成8周治疗或出现疾病进展为治疗终点。结果　西妥昔单抗单周方案联合化疗组28例可评价疗效：完全缓解（CR）1例,部分缓解（PR）7例,疾病稳定（SD）11例,疾病进展（PD）9例,有效率28.6 %,疾病控制率67.9 %;双周方案联合化疗组26例可评价疗效：CR 0例,PR 8例,SD 9例,PD 9例,有效率30.8 %,疾病控制率65.4 %,两组比较差异无统计学意义（P＞0.05）。两组Ⅲ～Ⅳ度不良反应主要表现为皮疹、恶心、中性粒细胞减少及白细胞减少,两组比较差异也无统计学意义（P＞0.05）。结论　西妥昔单抗单周和双周方案分别联合化疗治疗晚期大肠癌疗效相近,不良反应均可耐受。