What Are Biosimilars?

Biosimilars are drugs that are very similar to an already-approved biologic drug. Biologics are drugs made from living cells. These cells can come from parts of the blood, proteins, viruses, or tissue. This process turns the cells into drugs that can prevent, treat, and cure disease.¹

Generic drugs have the same active ingredient and are equivalent to a brand drug. However, biosimilars are more complex to develop. They are known as “highly similar” to their original product. Biosimilars are usually less expensive than their reference medicine. They also provide another treatment option for people with certain medical conditions.¹

When comparing biosimilars to their reference biologic, biosimilars:¹

• Are made with the same kinds of natural sources
• Are given the same way
• Have the same strength and dose
• Have the same possible side effects
• Give the same treatment benefits

Biosimilars are evaluated for safety, quality, and effectiveness before they receive approval. The US Food and Drug Administration (FDA) only approves biosimilars that have no major differences from the approved reference drug.¹

Some biosimilars can be substituted for the biologic they mimic without asking the prescribing doctor. These are called interchangeable biosimilars.^2,3

The FDA-approved biosimilars for IBD are biosimilars to:⁴

• Remicade® (infliximab)
• Humira® (adalimumab)
• Stelara® (ustekinumab)

How do biosimilars work?

There are 2 different kinds of biosimilars that are approved by the FDA for IBD.^4-7

Anti-tumor necrosis factor (anti-TNF) agents

Anti-TNF agents work against small proteins that promote inflammation in the intestine. They do this by binding to these proteins or blocking them. Anti-TNF agents help reduce inflammation in the gut. They also help promote healing of tissues in the gut. But this takes time. It can take 8 weeks for people taking an anti-TNF for IBD to feel relief. But for some people, symptoms are relieved faster.⁴

Interleukin-12 and interleukin-23 antagonists

Interleukin-12 (IL-12) and interleukin-23 (IL-23) antagonists target special immune proteins called cytokines. The IL-12 and IL-23 proteins help drive inflammation. Biologic and biosimilar drugs that stop or lessen the activity of these proteins can help people with IBD.⁴

Examples of biosimilars for IBD

Anti-TNF agents biosimilars of Remicade (infliximab) that are used to treat IBD include:⁴

• • Avsola™ (infliximab-axxq)
  • Inflectra^® (infliximab-dyyb)
  • Ixifi^® (infliximab-qbtx)
  • Renflexis^® (infliximab-abda)

• • Zymfentra^® (infliximab-dyyb)

Anti-TNF agents biosimilars of Humira (adalimumab) that are used to treat IBD include:⁴

• • Abrilada^® (adalimumab-afzb)
  • Amjevita™ (adalimumab-atto)
  • Cyltezo^® (adalimumab-adbm)
  • Hadlima™ (adalimumab-bwwd)
  • Hulio^® (adalimumab-fkjp)
  • Hyrimoz^® (adalimumab-adaz)
  • Idacio^® (adalimumab-aacf)

• • Simlandi^® (adalimumab-ryvk)

• Yuflyma^® (adalimumab-aaty)
• Yusimry™ (adalimumab-aqvh)

An IL-12/IL-23 antagonist biosimilar of Stelara (ustekinumab) that is used to treat IBD includes:^4,5

• Otulfi™ (ustekinumab-aauz)
• Pyzchiva^® (ustekinumab-ttwe)
• Wezlana™(ustekinumab-auuf)

What are the possible side effects of biosimilars in IBD?

Side effects can vary depending on the specific biosimilar you are taking. But in general, side effects and safety are the same for biosimilars and their original biologic.²

The most common side effects of infliximab biosimilars include:⁶

• Upper respiratory infections
• Infusion-related allergic reactions
• Headache
• Stomach pain

The most common side effects of adalimumab biosimilars include:⁷

• Upper respiratory or sinus infections
• Headache
• Reactions around the injection site, such as redness, rash, swelling, itching, or bruising

Infliximab and adalimumab have boxed warnings, the strictest warning from the FDA. They have this warning because taking infliximab or adalimumab can increase your risk of serious viral, bacterial, and fungal infections as well as certain cancers.^6,7

The most common side effects of ustekinumab biosimilars include:⁵

• Nasal congestion, sore throat, runny nose
• Upper respiratory infections
• Fever
• Headache
• Tiredness
• Itching
• Nausea, vomiting
• Redness at the injection site
• Vaginal yeast infections
• Urinary tract infections
• Sinus infection
• Bronchitis
• Diarrhea
• Stomach pain

These are not all the possible side effects of infliximab, adalimumab, or ustekinumab biosimilars. Talk to your doctor about what to expect when taking these drugs. You also should call your doctor if you have any changes that concern you when taking a biosimilar.

Other things to know

In some cases, a single biosimilar may be used to treat different conditions. For example, Wezlana can treat both IBD and a skin condition called psoriasis.⁵

Infliximab, adalimumab, and ustekinumab biosimilars change the way the body’s immune system works. This can make you more likely to get infections and make it harder to fight them off. If you are taking an infliximab, adalimumab, or ustekinumab biosimilar, your doctor will monitor you for any signs of infection or other serious side effects during treatment.^5-7

There is not enough data to know if infliximab, adalimumab, or ustekinumab biosimilars are safe to take while pregnant or breastfeeding. Before starting IBD treatment with a biosimilar, tell your doctor if you are pregnant, planning to become pregnant, or breastfeeding.^5-7
Talk to your doctor if you are taking a biologic for IBD and want to know more about biosimilars.

Before beginning treatment for IBD, tell your doctor about all your health conditions and any other drugs, vitamins, or supplements you are taking. This includes over-the-counter drugs.