Phase II clinical and pharmacokinetic study of aflibercept in patients with previously treated metastatic colorectal cancer.

Publication/Presentation Date

11-1-2012

Abstract

PURPOSE: Aflibercept is a recombinant fusion protein of the VEGF receptor (VEGFR) 1 and VEGFR2 extracellular domains. We assessed the safety and efficacy of aflibercept in patients with metastatic colorectal cancer (MCRC) who had received at least one prior palliative regimen.

EXPERIMENTAL DESIGN: Seventy-five patients were enrolled onto this two-stage phase II trial in two cohorts, bevacizumab naïve (n = 24) and prior bevacizumab (n = 51). Aflibercept was administered at 4 mg/kg i.v. in two-week cycles. The primary endpoint was a combination of objective response rate and 16-week progression-free survival (PFS).

RESULTS: In the bevacizumab-naïve cohort (n = 24), the best response was stable disease for 16 weeks or more in five of 24 patients. In the prior bevacizumab cohort (n = 50), one patient achieved a partial response and six patients had stable disease for 16 weeks or more. The median PFS in the bevacizumab-naïve and prior bevacizumab cohorts was two months [95% confidence interval (CI): 1.7-8.6 months] and 2.4 months (95% CI: 1.9-3.7 months), respectively. Median overall survival (OS) was 10.4 months (95% CI: 7.6-15.5) and 8.5 months (95% CI: 6.2-10.6), respectively. The most common grade 3 or higher treatment-related adverse events were hypertension, proteinuria, fatigue, and headache. Ten patients discontinued study treatment due to toxicity. Mean free to VEGF-bound aflibercept ratio was 1.82, suggesting that free aflibercept was present in sufficient amount to bind endogenous VEGF.

CONCLUSION: Aflibercept showed limited single-agent activity in patients with pretreated MCRC with moderate toxicity. Further study of aflibercept with chemotherapy is ongoing.

Volume

18

Issue

21

First Page

6023

Last Page

6031

ISSN

1557-3265

Disciplines

Medicine and Health Sciences

PubMedID

22977191

Department(s)

Hematology-Medical Oncology Division

Document Type

Article

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