Clinical development and evaluation of a VEGF-D assay in plasma from patients with metastatic colorectal cancer in the RAISE study

BACKGROUND

Vascular endothelial growth factor (VEGF)-D was identified as a potential predictive biomarker for ramucirumab efficacy in second-line metastatic colorectal cancer using a research use only (RUO) assay. We describe results with a new assay for detecting VEGF-D in human plasma.

METHODS

In RAISE (Clinical Trial Registration: NCT01183780), 1072 patients were randomized 1:1 to ramucirumab or placebo plus FOLFIRI. All patients were then randomized 1:2 to marker exploratory (ME) and marker confirmatory (MC) groups, and those with plasma samples were analyzed accordingly. A new assay validated for investigational use only (IUO) was used to measure VEGF-D levels in plasma, which were analyzed for correlation with overall and progression-free survival (OS/PFS). IUO assay data were compared with historical RUO assay data.

RESULTS

ME subset analyses determined the optimal cutpoint of 5.4 ng/mL for defining high/low VEGF-D subgroups. In the combined ME/MC placebo arms, OS/PFS were numerically greater for patients with low vs high VEGF-D (OS: 12.8 vs 11.1 months; PFS: 5.6 vs 4.2 months). In patients with high VEGF-D, ramucirumab vs placebo demonstrated a numerically greater improvement in OS and PFS. Differential efficacy by VEGF-D level was statistically significant for PFS, but not OS.

CONCLUSION

In patients with high VEGF-D, ramucirumab demonstrated a greater improvement in OS and PFS vs placebo; however, baseline VEGF-D level was not predictive of ramucirumab OS benefit using VEGF-D assay for IUO. The RAISE intent-to-treat results remain valid.

Subgroup analysis in RAISE: a randomized, double-blind phase III study of irinotecan, folinic acid, and 5-fluorouracil (FOLFIRI) plus ramucirumab or placebo in patients with metastatic colorectal carcinoma progression

BACKGROUND

The RAISE phase III clinical trial demonstrated that ramucirumab + FOLFIRI improved overall survival (OS) [hazard ratio (HR) = 0.844, P = 0.0219] and progression-free survival (PFS) (HR = 0.793, P < 0.0005) compared with placebo + FOLFIRI for second-line metastatic colorectal carcinoma (mCRC) patients previously treated with first-line bevacizumab, oxaliplatin, and a fluoropyrimidine. Since some patient or disease characteristics could be associated with differential efficacy or safety, prespecified subgroup analyses were undertaken. This report focuses on three of the most relevant ones: KRAS status (wild-type versus mutant), age (<65 versus ≥65 years), and time to progression (TTP) on first-line therapy (<6 versus ≥6 months).

PATIENTS AND METHODS

OS and PFS were evaluated by the Kaplan-Meier analysis, with HR determined by the Cox proportional hazards model. Treatment-by-subgroup interaction was tested to determine whether treatment effect was consistent between subgroup pairs.

RESULTS

Patients with both wild-type and mutant KRAS benefited from ramucirumab + FOLFIRI treatment over placebo + FOLFIRI (interaction P = 0.526); although numerically, wild-type KRAS patients benefited more (wild-type KRAS: median OS = 14.4 versus 11.9 months, HR = 0.82, P = 0.049; mutant KRAS: median OS = 12.7 versus 11.3 months, HR = 0.89, P = 0.263). Patients with both longer and shorter first-line TTP benefited from ramucirumab (interaction P = 0.9434), although TTP <6 months was associated with poorer OS (TTP ≥6 months: median OS = 14.3 versus 12.5 months, HR = 0.86, P = 0.061; TTP <6 months: median OS = 10.4 versus 8.0 months, HR = 0.86, P = 0.276). The subgroups of patients ≥65 versus <65 years also derived a similar ramucirumab survival benefit (interaction P = 0.9521) (≥65 years: median OS = 13.8 versus 11.7 months, HR = 0.85, P = 0.156; <65 years: median OS = 13.1 versus 11.9 months, HR = 0.86, P = 0.098). The safety profile of ramucirumab + FOLFIRI was similar across subgroups.

CONCLUSIONS

These analyses revealed similar efficacy and safety among patient subgroups with differing KRAS mutation status, longer or shorter first-line TTP, and age. Ramucirumab is a beneficial addition to second-line FOLFIRI treatment for a wide range of patients with mCRC.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT01183780.

An overview of the rangelands atmosphere-hydrosphere-biosphere interaction study experiment in northeastern Asia (RAISE)

Intensive observations, analysis and modeling within the framework of the rangelands atmosphere-hydrosphere-biosphere interaction study experiment in northeastern Asia (RAISE) project, have allowed investigations into the hydrologic cycle in the ecotone of forest-steppe, and its relation to atmosphere and ecosystem in the eastern part of Mongolia. In this region, changes in the climate have been reported and a market oriented economy was introduced recently, but their impact on the natural environment is still not well understood. In this RAISE special issue, the outcome is presented of the studies carried out by six groups within RAISE, namely: (1) Land-atmosphere interaction analysis, (2) ecosystem analysis and modeling, (3) hydrologic cycle analysis, (4) climatic modeling, (5) hydrologic modeling, and (6) integration. The results are organized in five relevant categories comprising (i) hydrologic cycle including precipitation, groundwater, and surface water, (ii) hydrologic cycle and ecosystem, (iii) surface-atmosphere interaction, (iv) effect of grazing activities on soils, plant ecosystem and surface fluxes, and (v) future prediction. Comparison with studies on rangelands in other parts of the world, and some future directions of studies still needed in this region are also summarized.