Biosimilar medicines are a type of biologic drug, and may be administered via injections of intravenous infusion. Although biosimilars are modeled after an FDA-approved biologic medicine or biologic, they undergo different approval processes. The FDA can approve a treatment as a biosimilar or an interchangeable biosimilar. FDA standards ensure that biosimilars and interchangeable biosimilars are just as safe and effective as their biologic reference product.
Relationship Between Biosimilars and Biologics
Biosimilars are highly similar to their biologic reference product. All biologics, including biosimilars:
- Target specific parts of the immune system rather than impacting the entire immune system
- Are given as an injection or IV infusion
To be approved as a biosimilar for a particular reference biologic, the biosimilar must be:
- Highly similar to the reference product and cannot have any clinically meaningful differences in terms of safety or efficacy
- Approved for the indication(s) and condition(s) for which the reference product is approved
- Be given the same form and in the same dosage as the reference product
- The same mechanism of action as the reference product, which means it works the same way in the body
An interchangeable biosimilar must meet the biosimilar standard plus an additional standard that the treatment will produce the same clinical result as the reference product in any given patient. If a biosimilar is approved as interchangeable, a pharmacist may substitute it without letting your prescribing health care provider know, in some states.
Keep in mind that biosimilars are not exact copies of their biologic reference product. Biologics are large and complex molecules from living sources that cannot be exactly copied.
Many considerations go into a treatment decision. Always speak with your health care provider about the potential risks and benefits of a treatment recommendation.
There are now three biosimilars approved for the treatment of psoriasis and PsA:
- Amjevita (adalimumab-atto) and Cyltezo (adalimumab-adbm) are biosimilar medicines to Humira (adalimumab)
- Erelzi (etanercept-szzs) is a biosimilar medicine to Enbrel (etanercept)
- Inflectra (infliximab-dyyb) and Renflexis (infliximab-abda) are biosimilar medicines to Remicade (infliximab)
Although these have been approved by the FDA, your health care provider may not be able to prescribe these treatments yet. There are other biosimilars currently being developed and tested. These may be approved and available in the future.
Who Can Take Biosimilars?
All biologics, including biosmilars, are typically prescribed for people with more advanced disease, including individuals with moderate-to-severe psoriasis and active PsA. But each of the three approved biosimilars are indicated for different groups within this population.
You should not take biosimilars if:
- Your immune system is significantly compromised
- You have an active infection
Screening for tuberculosis or other infectious diseases is required before starting treatment with all biologics, including biosimilars.
What Are the Risks of Biosimilars?
The risks and side effects of biosimilars are the same as those associated with their biologic reference product. Anyone considering taking a biosimilar should talk with their health care provider about the short- and long-term side effects and risks. It is important to weigh the risks against the benefits.
Biologics and biosimilars act on cytokines, which are specific proteins released by the immune system that can cause inflammation. Biologics suppress the function of the overactive immune system. When on a biologic or biosimilar, you may have a higher risk of infection. If you develop any signs of an infection, contact your health care provider right away.
Signs of infection include:
- Damp, sticky feeling or sweating
- Nasal (nose) or chest congestion
- Pain or burning when urinating
- Shortness of breath
- Skin redness, swelling, soreness or warmth
The impact of biologics on developing fetuses or nursing infants is not known. Biologics should only be prescribed to pregnant or nursing women if there is a clear medical need.
Common side effects for biosimilars may include:
- Abdominal pain
- Flu-like symptoms
- Injection site reactions
- Upper respiratory infections
Call your health care provider if you are experiencing any side effects with biosimilars.
Can Biosimilars Be Used With Other Treatments?
It is important to tell your health care provider about all treatments, medicines, vitamins or supplements that you are taking.
Like all biologics, biosimilars can be used with other treatment options including topicals and phototherapy. The biologics Enbrel, Humira and Remicade are shown to be safe and effective when taken with methotrexate. This means that their biosimilars, including Erelzi, Amjevita, and Inflectra, may be safe and effective when taken with methotrexate.
- With Inflectra being the biosimilar to Remicade, its use in combination with phototherapy may increase the risk for skin cancer.
- No drugs that interact with biologics should be combined with their respective biosimilars.
NPF’s medical board has issued a statement on biosimilar substitution.
From the statement:
NPF urges that the patient-provider relationship remain at the center of all treatment planning and recommends that the following minimal thresholds are met for biosimilar substitution to occur:
- the biosimilar has been designated by the FDA as interchangeable with the prescribed biologic for the specified indicated use;
- the biosimilar has a unique nonproprietary name to eliminate confusion, to allow providers to accurately track the therapeutic agent in a patient's permanent record, and to allow for the collection of adverse event information;
- the biosimilar product follows the same route of administration and dosage form as the reference product;
- the pharmacist notifies the prescriber in writing or electronic communication of the intention to substitute within 48 hours of the substitution;
- the prescribing physician has not indicated the patient must be treated with the prescribed biologic (via instruction to the pharmacist to dispense as written);
- the patient (or patient's authorized representative) must be informed and educated about a biosimilar substitution at the point of sale; and
- upon notification of a substitution, the pharmacy and the prescribing physician are to retain a permanent record in the patient's medical record of the biosimilar substitution.