Adam M. Brufsky, MD, PhD
For those who might question the equivalence of biosimilars to their reference products, it is important to remember the strict guidelines in place to ensure similarity before they reach the United States market, explained Adam M. Brufsky, MD, PhD.
In December 2018, the FDA approved a second trastuzumab (Herceptin) biosimilar, CT-P6 (Herzuma; trastuzumab-pkrb). CT-P6 is indicated for patients with adjuvant HER2-overexpressing node-positive or -negative breast cancer to be used as part of a treatment regimen comprised of doxorubicin, cyclophosphamide, and either paclitaxel or docetaxel, or as part of a regimen with docetaxel and carboplatin.
The biosimilar is also indicated as a frontline treatment for patients with HER2-positive metastatic breast cancer to be used in combination with paclitaxel, or as a single agent to treat patients with HER2-positive breast cancer who received 1 or more chemotherapy regimens for metastatic disease.
The CT-P6 approval comes 1 year after the first trastuzumab biosimilar, MYL-1401O (Ogivri; trastuzumab-dkst), was granted FDA approval for the treatment of patients with HER2-positive breast cancer or metastatic gastric adenocarcinoma.
While these trastuzumab biosimilars will certainly impact the HER2-positive space when they become commercially available in the United States, Brufsky said there are other biosimilars that are also making headway in the oncology space. For example, Zarxio (filgrastim-sndz), which is the G-CSF analog of filgrastim (Neupogen), and pegfilgrastim-cbqv (CHS-1701; Udenyca), a pegfilgrastim (Neulasta) biosimilar, are already being used in practice.
As for the cost effectiveness of biosimilars, Brufsky, a professor of medicine and co-director of the Comprehensive Breast Cancer Center at the University of Pittsburgh, predicted that these products could potentially drive down the price of antineoplastics by up to 20%.
In an interview with OncLive
, Brufsky shared insight on the impact of biosimilars in the field of oncology and outlined other strategies and steps that can be taken to mitigate cost when treating patients with breast cancer.
OncLive: How will the approved trastuzumab biosimilars impact the HER2-positive landscape?
: While the trastuzumab biosimilars have been approved, they have not been marketed yet, which means that no one has actually started using them [in practice yet]. There are some biosimilars that will impact the field more quickly. For example, we have already been using the biosimilar G-CSF and there is now a pegylated biosimilar G-CSF that has been recently approved as well. Several trastuzumab biosimilars will probably receive approval in the next year or so.
When they reach market, it is important to remember that they must be similar [to trastuzumab] in terms of efficacy. If the biosimilars are superior or inferior, they [would not have been] approved. The only real difference [between biosimilars and reference products] is the cost, and what is going to happen is that the cost of care will be reduced.
This [cost reduction] is a big deal for society in general—not just in the oncology space. Everyone from our president to Congress wants to reduce drug costs. Biosimilars will go a long way, at least in the breast oncology space, particularly with the [introduction of the] trastuzumab biosimilars [into practice]. They will help reduce the cost of care by at least 15% to 20%, if not more.
What would you say to someone who is skeptical about the similarity and cost effectiveness of biosimilars?
These products have to be similar to the reference products; that is the whole idea. They must be similar in terms of biology, and there are several glycosylation assays that need to be done on the molecule to show it is almost exactly the same. The toxicity profile has to be same. Biosimilars cannot be inferior or superior; if they are, that defeats the purpose of their development and they will not be approved. There is a very specific process that the FDA has devised to determine if these drugs are the same. Therefore, to any skeptic who says that they these products are not the same: They have to be; that's number 1.