BIOLOGIC DRUGS, which include some immunotherapies and targeted therapies, have become an integral part of cancer treatment. As the patents on many of these medicines expire, the door has opened for biosimilars—drugs virtually identical in terms of safety and function—to enter the market.

Since 2015, the Food and Drug Administration (FDA) has approved 26 biosimilars; 14 of these are used to treat cancer patients. Five biosimilars boost white blood cell production after chemotherapy or radiation. The other nine are used to treat cancer. Of these, five are biosimilars for Herceptin (trastuzumab), a targeted therapy used to treat breast and stomach cancers that test HER2-positive. The first of these drugs became available in July 2019, soon after the patent expired for Herceptin. The roster also includes two biosimilars for Avastin (bevacizumab) and two for Rituxan (rituximab). These biosimilars, which have become available in the past year, are approved for the same indications as the drugs they are modeled after.

“I feel very comfortable, and patients should feel very comforta​ble, knowing that these drugs work the same as​ the original ones,” says Daniel Geynisman, a medical oncologist at the Fox Chase Cancer Center in Philadelphia.

Ask Your Doctor About Biosimilars

​​Get help to decide if a biosimilar is right for you.​​

​Biosimilars are as safe and effective as their reference biologic drug, and they may have a lower cost. To find out if a biosimilar is an option for you, ask your treatment team:

  • Is there a biosimilar drug that can be used instead of the biologic drug you are prescribing?
  • Will the biosimilar lower my treatment costs?
  • Is there a patient assistance program to help pay for the biosimilar or the original biologic drug?

The biosimilar drugs approved to treat cancer patients include:

For Herceptin:

  • Herzuma (trastuzumab-pkrb)
  • Kanjinti (trastuzumab-anns)
  • Ogivri (trastuzumab-dkst)
  • Ontruzant (trastuzumab-dttb)
  • Trazimera (trastuzumab-qyyp)  

For Avastin:

  • Mvasi (bevacizumab-awwb)
  • Zirabev (bevacizumab-bvzr)

For Rituxan:

  • Ruxience (rituximab-pvvr)
  • Truxima (rituximab-abbs)

To prevent infections during chemotherapy:

  • Fulphila (pegfilgrastim-jmdb)
  • Nivestym (filgrastim-aafi)
  • Udenyca (pegfilgrastim-cbqv) 
  • Zarxio (filgrastim-sndz)
  • Ziextenzo (pegfilgrastim-bmez)

​​Chemotherapy and many targeted drugs are made from chemicals that can be produced in a lab by chemists. A generic version of a chemotherapy drug is made from the same chemical. Biologic drugs are different. They’re large molecules produced by living organisms like bacteria or yeast, and th​ey cannot be copied exactly. This means biosimilars can be close reproductions with the same function, but they cannot be exactly the same as the original drug. They also require more testing than generic drugs before they can be approved. A biosimilar manufacturer usually must present data from analytical, laboratory and clinical studies showing the biosimilar is as safe and effective as the original product in order to get FDA approval.

​​Chemotherapy and many targeted drugs are made from chemicals that can be produced in a lab by chemists. A generic version of a chemotherapy drug is made from the same chemical. Biologic drugs are different. They’re large molecules produced by living organisms like bacteria or yeast, and they cannot be copied exactly. This means biosimilars can be close reproductions with the same function, but they cannot be exactly the same as the original drug. They also require more testing than generic drugs before they can be approved. A biosimilar manufacturer usually must present data from analytical, laboratory and clinical studies showing the biosimilar is as safe and effective as the original product in order to get FDA approval.

Nearly 80 biosimilars are now in development for a range of biologics. “We anticipate approving more biosimilars to treat many different conditions, including cancer,” says rheumatologist Sarah Yim, director of the FDA Office of Therapeutic Biologics and Biosimilars in Silver Spring, Maryland.

Patients will not have access to biosimilars in the same way as generic drugs. A pharmacist can make the decision to substitute a generic drug for a brand-name drug. Or a patient can ask the pharmacist for the substitution. The same is not true for a biosimilar, says Yim. A doctor must specifically prescribe either the original drug or the biosimilar. “This does not mean it wouldn’t be safe for you and your doctor to change from the original drug to the biosimilar,” says Yim. “If we didn’t think it was going to be safe, it wouldn’t be approved.”

Biosimilars are expected to cost less than original biologics, but they may not provide the same reduction in cost as generic drugs. Generic drugs are priced up to 90% less than brand-name drugs. To date, most biosimilars have been priced between 10% and 15% lower than the biologics they mimic. A 15% decrease “is a good start,” says Geynisman, “but you may still end up with a very expensive drug at the end.” 

Cancer Tod​ay magazine is free to cancer patients, survivors and caregivers who live in the U.S. Subs​cribe here to receive four issues per year.​