Zaltrap OK'd for metastatic colorectal cancer

On Aug. 3, the FDA approved Zaltrap (ziv-aflibercept) for treating patients with metastatic colorectal cancer and tumors that have progressed or are resistant to oxaliplatin-containing therapies. The drug is used in combination with FOLFIRI, a standard treatment regimen for colorectal cancer containing 5-FU (fluorouracil), leucovorin and irinotecan. Zaltrap is an angiogenesis inhibitor, meaning it cuts off the tumor's blood supply, thereby inhibiting growth. While Avastin (bevacizumab), which is also approved for treating colorectal cancer, works by attaching to and disabling the vascular endothelial growth factor (VEGF) receptor, a necessary component for growing new blood vessels. Zaltrap also targets VEGF but does so through trickery and acting like the VEGF receptor, essentially setting a trap (thus the name) and preventing two proteins from starting new blood vessel growth. The approval is based on results from the phase 3 VELOUR trial, which were reported at this year's American Society of Clinical Oncology (ASCO) meeting. In the study, 1,226 patients who had previously received some combination of treatment featuring oxaliplatin were randomized to receive Zaltrap and FOLFIRI or placebo plus FOLFIRI. The patients in the Zaltrap arm had a median overall survival of 13.5 months compared with 12 months in the placebo arm. Furthermore, Zaltrap extended progression-free survival to 6.9 months compared to the 4.7 months with FOLFIRI alone. Some severe side effects were seen with Zaltrap, so the drug includes a boxed warning that it can lead to severe bleeding, particularly gastrointestinal bleeding, and holes in the gastrointestinal tract. It also might be harder for wounds to heal. Other side effects include diarrhea, fatigue, neutropenia, mouth ulcers and decreased appetite. Many see this as an excellent step forward for this hard-to-treat patient population. In an email to CURE, Fight Colorectal Cancer's President Carlea Bauman stated, "Fight Colorectal Cancer is pleased that Zaltrap has been approved for patients with metastatic colorectal cancer. There are few treatment options for late stage disease, so adding Zaltrap to the list of drugs that physicians have to treat patients is hopeful news."