Jiří Tomášek

Biomarker analyses in REGARD gastric/GEJ carcinoma patients treated with VEGFR2-targeted antibody ramucirumab

Background:Angiogenesis inhibition is an important strategy for cancer treatment. Ramucirumab, a human IgG1 monoclonal antibody that targets VEGF receptor 2 (VEGFR2), inhibits VEGF-A, -C, -D binding and endothelial cell proliferation. To attempt to identify prognostic and predictive biomarkers, retrospective analyses were used to assess tumour (HER2, VEGFR2) and serum (VEGF-C and -D, and soluble (s) VEGFR1 and 3) biomarkers in phase 3 REGARD patients with metastatic gastric/gastroesophageal junction carcinoma.Methods:A total of 152 out of 355 (43%) patients randomised to ramucirumab or placebo had ⩾1 evaluable biomarker result using VEGFR2 immunohistochemistry or HER2, immunohistochemistry or FISH, of blinded baseline tumour tissue samples. Serum samples (32 patients, 9%) were assayed for VEGF-C and -D, and sVEGFR1 and 3.Results:None of the biomarkers tested were associated with ramucirumab efficacy at a level of statistical significance. High VEGFR2 endothelial expression was associated with a non-significant prognostic trend toward shorter progression-free survival (high vs low HR=1.65, 95% CI=0.84,3.23). Treatment with ramucirumab was associated with a trend toward improved survival in both high (HR=0.69, 95% CI=0.38, 1.22) and low (HR=0.73, 95% CI=0.42, 1.26) VEGFR2 subgroups. The benefit associated with ramucirumab did not appear to differ by tumoural HER2 expression.Conclusions:REGARD exploratory analyses did not identify a strong potentially predictive biomarker of ramucirumab efficacy; however, statistical power was limited.

Clinical relevance of uPA, uPAR, PAI 1 and PAI 2 tissue expression and plasma PAI 1 level in colorectal carcinoma patients.

BACKGROUND/AIMS Urokinase (uPA) is a serine protease, which together with uPAR, tPA, PAI 1 and PAI 2 forms the plasminogen activator system, a component of metastatic cascade contributing to the invasive growth and angiogenesis of malignant tumours. METHODOLOGY Both preceding therapy and after 6-8 weeks of the treatment, plasma PAI 1 levels (photometric microplate method on the ELISA) and uPA, uPAR, PAI 1 and PAI 2 tissue expression (immunohistochemical reaction) were analysed from 80 colorectal carcinoma patients. RESULTS Analysis showed higher pre-treatment plasma levels of PAI 1 in patients with advanced tumours, which decreased after surgery or the start of therapy (p=0.004); Patients with higher plasma level PAI 1 before (0.013) and after therapy (0.004) had significantly shorter survival. There was a higher expression of uPA (p<0.001), uPAR (p<0.001), PAI 1 (p=0.042) and PAI 2 (p<0.001) in advanced colorectal carcinoma. A relationship between PAI 2 (p=0.010) and uPAR (p=0.019) expression and survival was demonstrated. There is a correlation between pre-treatment plasma PAI 1 levels and PAI 2 (p=0.028) and uPAR (p=0.043) expression. CONCLUSIONS Immunohistochemical analysis of PAS in tumour tissue and plasma PAI 1 levels was found to be a useful prognostic factor in colorectal carcinoma patients. Plasma PAI 1 could be advantageous in evaluating the effectiveness of a mode of treatment.

Panitumumab Use in Metastatic Colorectal Cancer and Patterns of KRAS Testing: Results from a Europe-Wide Physician Survey and Medical Records Review.

Background From 2008–2013, the European indication for panitumumab required that patients’ tumor KRAS exon 2 mutation status was known prior to starting treatment. To evaluate physician awareness of panitumumab prescribing information and how physicians prescribe panitumumab in patients with metastatic colorectal cancer (mCRC), two European multi-country, cross-sectional, observational studies were initiated in 2012: a physician survey and a medical records review. The first two out of three planned rounds for each study are reported. Methods The primary objective in the physician survey was to estimate the prevalence of KRAS testing, and in the medical records review, it was to evaluate the effect of test results on patterns of panitumumab use. The medical records review study also included a pathologists’ survey. Results In the physician survey, nearly all oncologists (299/301) were aware of the correct panitumumab indication and the need to test patients’ tumor KRAS status before treatment with panitumumab. Nearly all oncologists (283/301) had in the past 6 months of clinical practice administered panitumumab correctly to mCRC patients with wild-type KRAS status. In the medical records review, 97.5% of participating oncologists (77/79) conducted a KRAS test for all of their patients prior to prescribing panitumumab. Four patients (1.3%) did not have tumor KRAS mutation status tested prior to starting panitumumab treatment. Approximately one-quarter of patients (85/306) were treated with panitumumab and concurrent oxaliplatin-containing chemotherapy; of these, 83/85 had confirmed wild-type KRAS status prior to starting panitumumab treatment. All 56 referred laboratories that participated used a Conformité Européenne-marked or otherwise validated KRAS detection method, and nearly all (55/56) participated in a quality assurance scheme. Conclusions There was a high level of knowledge amongst oncologists around panitumumab prescribing information and the need to test and confirm patients’ tumors as being wild-type KRAS prior to treatment with panitumumab, with or without concurrent oxaliplatin-containing therapy.

Immunotherapy of Colorectal and Anal Carcinoma

BACKGROUND The lower part of the digestive tract includes the large intestine, rectum and anus. Treatment algorithms of cancers in these localities have significant differences in both early and advanced stages. The vast majority of metastatic cases are incurable. A few years ago, it was generally accepted that gastrointestinal tumors are poorly immunogenic and modern immunotherapy would not work in gastrointestinal cancers. The breakthrough has become the recognition of the mismatch repair system (MMR) that affects the microsatellite instability (MSI) and its role in the development of colorectal carcinoma (CRC). Metastatic colorectal carcinoma (mCRC) with defect MMR (dMMR) and MSI-H, resp. is immunogenic and can be a target of modern imunotherapy directed on the PD1/PD-L1 axis. Such a treatment can improve prognosis and life quality od patients with mCRC MSI-H. Immunotherapy effectiveness was shown also in a subgroup of patients with a BRAF mutation where the effectiveness of existing systemic treatment is low. The proven predictive factor is dMMR/MSI-H. PD-1 expression does not have this significance. Results of clinical studies with nivolumab and pembrolizumab result in the inclusion of these drugs in mCRC treatment algorithms. Phase II study shows nivolumab effectiveness also in pretreated metastatic anal cancer. PURPOSE An overview of basic information on the possibilities of immunotherapy in CRC and anal cancers.Key words: cancer immunotherapy - checkpoint inhibitors - colorectal cancer - anal cancer - nivolumab - pembrolizumab Supported by MH CZ - DRO (MMCI, 00209805) I declare that, in connection with the abovementioned contribution, which I am an author, I have a conflict of interest with the following companies: BMS, Roche, Merck, Amgem and Bayer. The author declares he has no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers.Submitted: 7. 9. 2017Accepted: 5. 11. 2017.