FDA Approves New Biosimilar to Etanercept
The US Food and Drug Administration (FDA) recently approved etanercept-szzs (Erelzi, Sandoz), a drug designed to mirror the benefits of name-brand etanercept (Enbrel, Amgen). Considered a biosimilar to etanercept, etanercept-szzs could be a new, cost-effective treatment option for patients suffering from rheumatoid arthritis (RA) and other inflammatory conditions.
Etanercept-szzs is a tumor necrosis factor blocker administered subcutaneously for the same conditions, which include:
- Moderate-to-severe rheumatoid arthritis: Could be used as either a standalone therapy or used in conjunction with methotrexate
- Active psoriatic arthritis: Could be used in combination with methotrexate for psoriatic arthritis patients unresponsive to methotrexate alone
- Moderate-to-severe polyarticular juvenile idiopathic arthritis for patients aged 2 years or older
- Active ankylosing spondylitis
- Chronic, moderate-to-severe plaque psoriasis in patients who are aged 18 years or older and are candidates for systemic therapy or phototherapy
According to the FDA, the most common adverse events associated with etanercept-szzs are infections and injection-site reactions. Other serious adverse events could include neurologic events, congestive heart failure, and hematologic events. Etanercept-szzs should not be administered to patients with sepsis.
In recent years, the market for biologics has widened considerably, taking up about 20% of the pharmaceutical marketplace.1 Many of these products, like etanercept, can be effective but also have high price tags. The current name-brand version of etanercept, marketed as Enbrel by Amgen, is reported to cost in the range of $2,000 dollars for a supply of 4 kits to a cash-paying customer.
Biosimilar drugs are considered generic, cost-effective versions of existing biologic products. Since the signing of The Biologics Price Competition and Innovation Act (BPCIA) back in 2010, companies have had a window of opportunity to develop and potentially market more cost-effective alternatives to existing biologics.
“The biosimilar pathway is an important mechanism to improve access to treatment for patients with rheumatic and autoimmune diseases,” said Janet Woodcock, MD, director of the FDA’s Center for Drug Evaluation and Research. “We carefully evaluate the structural and functional characteristics of these complex molecules. Patients and providers can have confidence that there are no clinically meaningful differences in safety and efficacy from the reference product.”
But biosimilars still are far more common outside the US, as pharmaceutical companies have posted much resistance to the commercialization of these potentially competing products. Earlier this year, Amgen filed suit against Sandoz, the makers of etanercept-szzs, on the grounds of patent infringement.
A current preliminary injunction effectively bars the manufacture or distribution of etanercept-szzs, so it is difficult to say when the drug actually will come out.
How Similar are Biosimilars?
The concern with biosimilar products is they may not have the same efficacy or safety as the name-brand products they serve to emulate.
Biosimilars are not exactly the same as name-brand products, given the complexities of the manufacturing process that goes into making biologic drugs.2-3 Indeed, the FDA has an entirely separate distinction for products considered “interchangeable” with reference products.
In a statement to Practical Pain Management, Janssen Pharmaceutica, the makers of the biologic infliximab (Remicade) described this, stating:
“For the FDA to determine a biosimilar is interchangeable with its reference product, a manufacturer must demonstrate that the biosimilar is expected to produce the same clinical result as the reference product in any given patient. In addition, the manufacturer must demonstrate the risk of alternating or switching between the reference product and biosimilar is no greater than the risk of using the reference product,” the company stated.
However, recent retrospective evidence suggests biosimilars have negligible differences to their reference counterparts.4 The review, published in the Annals of Internal Medicine, looked at thousands of existing abstracts to find robust data comparing biosimilars against biologics. Most Phase III trials showed similar treatment and safety outcomes.
Indeed, Erelzi safety indications is comparable to other approved tumor necrosis factor inhibitors currently on the market. Erelzi contains a boxed warning for alerting patients and doctors about the increased risk of serious infections that could lead to hospitalization or death, including tuberculosis, invasive fungal infections (such as histoplasmosis) and others.
“The Boxed Warning also notes that lymphoma and other malignancies, some fatal, have been reported in children and adolescent patients treated with tumor necrosis factor blockers, including etanercept products,” the FDA said in its announcement.
The product also will be required to include a patient medication guide for describing important information to users about the drug’s indications and risks.