On Dec. 1, 2017, the U.S. Food and Drug Administration (FDA) approved Ogivri (chemical name: trastuzumab-dkst), a biosimilar for Herceptin (chemical name: trastuzumab), to treat people with HER2-positive breast cancer or HER2-positive metastatic stomach cancer.
Ogivri was previously known as MYL-1401O and is made by Mylan-Biocon.
Herceptin (chemical name: trastuzumab) is a monoclonal antibody, a targeted therapy medicine used to treat HER2-positive breast cancers. Herceptin is what’s called a “biologic” drug. This means that it is made from living organisms, in this case a protein from a mouse cell. A monoclonal antibody is a type of protein made in the lab that can bind to substances in the body, including cancer cells. Each monoclonal antibody is made so that it binds only to one substance. Herceptin binds to the HER2 receptor proteins in cancer cells.
Because they are made from living organisms, biologic drugs are much more complex to make than conventional drugs that are made from a mixture of chemicals. The chemical structure of conventional drugs can be easily identified and duplicated, which is why there are so many generic drugs on the market.
A biosimilar is a new type of biologic drug. A biosimilar is almost identical to a biologic drug that is already approved by the FDA (or similar organizations in other countries). It can help to think of a biosimilar as a generic version of a biologic drug, though that comparison isn’t completely accurate.
The makers of biosimilars don’t have access to the original cell lines used to make the biologic drug. They also don’t have access to the exact purification process or other manufacturing steps used by the makers of the biologic drug.
Biologic drugs can be very sensitive to changes in the manufacturing process. If one small step is done differently, the biosimilar may have very different effects than the original biologic drug.
So, the FDA requires the makers of biosimilars to show that a biosimilar drug is “highly similar” to the original biologic drug and is equally safe and effective before the agency will approve the biosimilar.
The FDA’s approval of Ogivri is based on review of evidence that included extensive studies on the drug’s structure and function, animal study data, studies on how the drug is absorbed and metabolized by the human body, studies on how the drug affects people, and other clinical safety and effectiveness data that demonstrate Ogivri is biosimilar to Herceptin.
The approval is based on research showing that Ogivri is as effective and as safe as Herceptin.
Like Herceptin, Ogivri can cause side effects, some of them severe. Common side effects include:
- low white blood cell counts
- peripheral neuropathy
Less common but more severe side effects of Ogivri include heart and lung damage.
Hope Rugo, M.D., professor of medicine at the University of California, San Francisco, Helen Diller Family Comprehensive Cancer Center and member of the Breastcancer.org Professional Advisory Board, has conducted research on Ogivri. In an interview last year, she said that FDA approval of Ogivri could allow more access to treatment for women diagnosed with HER2-positive breast cancer.
“Lack of access is not a major issue in the United States,” she said, “because most patients have insurance that covers trastuzumab. I’ve not seen a situation where it wasn’t covered for a standard indication.”
Still, in other countries, cost can mean that some women don’t receive the treatment.
“It is expected that having biosimilars will reduce costs -- by some amount -- for these agents around the world,” Dr. Rugo said.
Stayed tuned to Breastcancer.org for the latest information on Ogivri and other biosimilar drugs for breast cancer.
Editor's Note: This article was updated on Sept. 27, 2019, to clarify information about biosimilars.