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.

PRONOUNCE: randomized, open-label, phase III study of first-line pemetrexed + carboplatin followed by maintenance pemetrexed versus paclitaxel + carboplatin + bevacizumab followed by maintenance bevacizumab in patients ith advanced nonsquamous non-small-cell lung cancer.

INTRODUCTION: PRONOUNCE compared the efficacy and safety of pemetrexed+carboplatin followed by pemetrexed (Pem+Cb) with paclitaxel+carboplatin+bevacizumab followed by bevacizumab (Pac+Cb+Bev) in patients with advanced nonsquamous non-small-cell lung cancer (NSCLC). METHODS: Patients ≥18 years of age with stage IV nonsquamous NSCLC (American Joint Committee on Cancer v7.0), and Eastern Cooperative Oncology Group performance status 0/1 were randomized (1:1) to four cycles of induction Pem+Cb (pemetrexed, 500 mg/m, carboplatin, area under the curve = 6) followed by Pem maintenance or Pac+Cb+Bev (paclitaxel, 200 mg/m, carboplatin, area under the curve = 6, and bevacizumab, 15 mg/kg) followed by Bev maintenance in the absence of progressive disease or discontinuation. The primary objective was progression-free survival (PFS) without grade 4 toxicity (G4PFS). Secondary end points were PFS, overall survival (OS), overall response rate (ORR), disease control rate (DCR), and safety. Resource utilization was also assessed. RESULTS: Baseline characteristics of the patients randomized to Pem+Cb (N = 182) and Pac+Cb+Bev (N = 179) were well balanced between the arms. Median (months) G4PFS was 3.91 for Pem+Cb and 2.86 for Pac+Cb+Bev (hazard ratio = 0.85, 90% confidence interval, 0.7-1.04; p = 0.176); PFS, OS, ORR, or DCR did not differ significantly between the arms. Significantly more drug-related grade 3/4 anemia (18.7% versus 5.4%) and thrombocytopenia (24.0% versus 9.6%) were reported for Pem+Cb. Significantly more grade 3/4 neutropenia (48.8% versus 24.6%), grade 1/2 alopecia (28.3% versus 8.2%), and grade 1/2 sensory neuropathy were reported for Pac+Cb+Bev. Number of hospitalizations and overall length of stay did not differ significantly between the arms. CONCLUSIONS: Pem+Cb did not produce significantly better G4PFS compared with Pac+Cb+Bev. Pem+Cb was not superior in PFS, OS, ORR, or DCR compared with Pac+Cb+Bev. Both regimens were well tolerated, although, toxicity profiles differed.

Tumor cell expression of vascular endothelial growth factor receptor 2 is an adverse prognostic factor in patients with squamous cell carcinoma of the lung.

A robust immunohistochemical (IHC) assay for VEGFR2 was developed to investigate its utility for patient tailoring in clinical trials. The sensitivity, specificity, and selectivity of the IHC assay were established by siRNA knockdown, immunoblotting, mass spectrometry, and pre-absorption experiments. Characterization of the assay included screening a panel of multiple human cancer tissues and an independent cohort of non-small cell lung carcinoma (NSCLC, n = 118) characterized by TTF-1, p63, CK5/6, and CK7 IHC. VEGFR2 immunoreactivity was interpreted qualitatively (VEGFR2 positive/negative) in blood vessels and by semi-quantitative evaluation using H-scores in tumor cells (0-300). Associations were determined among combinations of VEGFR2 expression in blood vessels and tumor cells, and clinico-pathologic characteristics (age, sex, race, histologic subtype, disease stage) and overall survival using Kaplan-Meier analyses and appropriate statistical models. VEGFR2 expression both in blood vessels and in tumor cells in carcinomas of the lung, cervix, larynx, breast, and others was demonstrated. In the validation cohort, 99/118 (83.9%) NSCLC tissues expressed VEGFR2 in the blood vessels and 46/118 (39.0%) showed high tumor cell positivity (H-score ≥10). Vascular and tumor cell expression were inversely correlated (p = 0.0175). High tumor cell expression of VEGFR2 was associated with a 3.7-fold reduction in median overall survival in lung squamous-cell carcinoma (SCC, n = 25, p = 0.0134). The inverse correlation between vascular and tumor cell expression of VEGFR2 and the adverse prognosis associated with high VEGFR2 expression in immunohistochemically characterized pulmonary SCC are new findings with potential therapeutic implications. The robustness of this novel IHC assay will support further evaluation of its utility for patient tailoring in clinical trials of antiangiogenic agents.