The United States Food and Drug Administration (US FDA) announced its approval of Zirabev, a biosimilar to Avastin. Zirabev (bevacizumab-bvzr) is made by Pfizer and is approved for the treatment of five different cancers. These include certain types of colorectal, brain, cervical, lung, and kidney cancers. Within lung cancer, Zirabev was approved as a first-line treatment option for individuals with unresectable, locally advanced, recurrent, or metastatic non-squamous non-small cell lung cancer (NSCLC). Zirabev is intended to be used with the chemotherapy medications paclitaxel and carboplatin.
What are biosimilars?
Biosimilars are almost exact copies of other biologic medical products on the market. Since biologic therapies are made from living substances, it’s essentially impossible to exactly copy them across different laboratories and manufacturing processes. A biosimilar is basically the closest thing possible to an exact replica of another drug that is currently available and needs to be found to have no clinically significant differences from its reference product (the original therapy) before it’s approved for use.1 In this case, Zirabev is a biosimilar to the currently available treatment Avastin (bevacizumab).
How Zirabev and Avastin works
Both Zirabev and Avastin are VEGF inhibitors, which mean they block the action of a protein called vascular endothelial growth factor (VEGF). These are also sometimes referred to as anti-VEGF therapies. VEGF is responsible for the growth and development of new blood vessels in the body. This process is called angiogenesis. Tumor cells and tumors themselves can undergo angiogenesis in order to have more blood and nutrients delivered to them, allowing them to grow. By blocking VEGF and the angiogenesis process, it may be possible to stop the growth of certain tumors.
Findings from the study
Results from a clinical trial called REFLECTIONS B7391003, demonstrated that Zirabev was a biosimilar to Avastin and appropriate for clinical use. During the trial, researchers recorded the objective response rate (ORR), safety, overall survival (OS) at one year, duration of response, and progression-free survival (PFS) in individuals with advanced non-squamous NSCLC. Over 700 individuals participated in the trial, with roughly half receiving Zirabev and half receiving Avastin. Both groups also received carboplatin and paclitaxel.
The ORR, median OS, and one-year PFS were all similar Zirabev and Avastin. The median progression free survival was 9 months for those taking Zirabev versus 7.7 months for those on Avastin. Overall, these results suggest that Zirabev had no significant clinical differences from Avastin for those with advanced non-squamous NSCLC. The safety profiles of both medications were also found to be similar as well.
Reported side effects
The most commonly reported side effects of Zirabev were headache, high blood pressure, dry skin or other skin issues, back pain, runny or bloody noses, rectal bleeding, changes in taste, or changes in the way the eye makes tears. Other NSCLC-specific side effects that are rare, but may be serious, include low numbers of neutrophils (a white blood cell that helps fight infections), lung inflammation, infection, and fatigue, among others. Since Zirabev affects the way blood vessels are made, it may increase bleeding (hemorrhage) or affect how wounds heal. If you are interested in taking Zirabev, your doctor or healthcare provider will help determine what side effects you may be at risk for, and if the medication is appropriate in your situation.2,3
What is a Biosimilar? United States Food and Drug Administration. https://www.fda.gov/media/108905/download. Accessed July 2, 2019.
Pfizer Receives U.S. FDA Approval for its Oncology Biosimilar Zirabev (Bevacizumab-bvzr). Pfizer Inc. https://www.pfizer.com/news/press-release/press-release-detail/pfizer_receives_u_s_fda_approval_for_its_oncology_biosimilar_zirabev_bevacizumab_bvzr. Published June 28, 2019. Accessed July 2, 2019.
Astor L. FDA Approves Bevacizumab Biosimilar Zirabev. Targeted Oncology. https://www.targetedonc.com/news/fda-approves-bevacizumab-biosimilar-zirabev. Published June 28, 2019. Accessed July 2, 2019