Truxima vs. Rituxan

Both Truxima and Rituxan deliver rituximab—a targeted therapy with more than two decades of use in oncology and autoimmune care.

If your provider has recommended one and you’re wondering how they compare, the short answer is that clinically, they are highly similar. The more meaningful differences show up in how insurance plans handle them and what they cost.

Here’s a closer look at everything patients and caregivers need to know about the Truxima vs. Rituxan comparison: how they work, what they treat, where they differ, and how to navigate the practical side of treatment. If you’re new to specialty pharmacy support for a complex therapy like this, understanding your options is a solid first step.

Rituxan (rituximab)

Rituximab has reshaped the treatment of several difficult-to-manage conditions since it was first approved in 1997. Whether a patient receives Truxima or Rituxan, the mechanism and the goals of treatment are the same.

Acelpa Health and its affiliated specialty pharmacies—California Specialty Pharmacy (CSP), ContinuumRx (CRx), Hawaii Specialty Pharmacy (HSP), Continuum Health (CH), and Integrated Care Systems (ICS)—support patients receiving rituximab across oncology, rheumatology, and other specialty areas, coordinating benefits verification, insurance approval, and scheduling.

How Does Rituximab Work?

Rituximab is a monoclonal antibody that targets a protein called CD20 found on the surface of certain immune cells, called B cells. When rituximab binds to CD20, it signals the immune system to destroy those cells. In cancer treatment, this targets cancerous B cells directly. In autoimmune disease, it reduces inflammation and tissue damage caused by overactive B cells.

This mechanism is distinct from traditional chemotherapy, which broadly kills rapidly dividing cells, and also different from TNF antagonists, which block a specific inflammatory protein. Rituximab works by depleting a specific type of immune cell from the body.

What Conditions Does Rituximab Treat?

Rituximab is FDA-approved for several serious conditions. The common thread is that B cells play a central role in each, and reducing B-cell activity can help slow disease progression and ease symptoms.

For blood cancers, Rituximab is used to treat:

• Non-Hodgkin lymphoma (NHL): often given alongside chemotherapy
• Chronic lymphocytic leukemia (CLL): where abnormal B cells accumulate and crowd out healthy blood cells

For autoimmune conditions, it’s prescribed for:

• Rheumatoid arthritis (RA): given in combination with another drug, methotrexate, when other disease-modifying treatments haven’t worked well enough
• Granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA): inflammatory conditions that affect blood vessels
• Pemphigus vulgaris (PV): a rare autoimmune condition that causes painful skin blistering

Is Rituximab Chemotherapy or Immunotherapy?

Rituximab is classified as immunotherapy—specifically, a targeted monoclonal antibody. It is not like traditional chemotherapy drugs that kill all types of cells, it specifically targets B cells.

That said, it is frequently given in combination with chemotherapy drug regimens (such as CHOP for NHL or fludarabine and cyclophosphamide for CLL), which can sometimes create confusion about how to categorize it. On its own, it does not damage DNA or broadly target rapidly dividing cells the way chemotherapy does.

Truxima (rituximab-abbs)

Truxima (rituximab-abbs) was the first rituximab biosimilar approved by the FDA, receiving approval in November 2018. 

A biosimilar is a biologic medication that is highly similar to an original biologic medication (also called the reference product) already approved by FDA.

The “abbs” suffix in “rituximab-abbs” is a four-letter distinguisher that identifies it as a distinct biological product from the reference—standard naming practice for all biosimilars. It is manufactured by Celltrion.

The table below summarizes the key differences between the two products:

Feature	Rituxan	Truxima
Active ingredient	Rituximab	Rituximab-abbs
Product type	Reference product	FDA-approved biosimilar
FDA approval year	1997	2018
Manufacturer	Genentech/Biogen	Celltrion
Interchangeable designation	N/A	No
Typical cost	Higher	Lower

How Does the FDA Approve Biosimilars?

Biosimilar approval is a rigorous process—it is not the same as approving a generic drug. The FDA requires biosimilar applicants to demonstrate biosimilarity, which means there is no clinically meaningful difference to the reference product. 

The manufacturer does this by running a combination of analytical studies (comparing molecular structure and stability), pharmacokinetic and pharmacodynamic studies (confirming the drug behaves identically in the body), and clinical trials (confirming equivalent safety and efficacy).

Truxima completed this full pathway before approval.

What Does “Not Interchangeable” Mean?

In states where permitted by law, an “interchangeable” biosimilar designation may allow a pharmacist to substitute Renflexis for Remicade at the time of dispensing without prior prescriber authorization, subject to applicable state-specific requirements. Truxima does not hold this designation for Rituxan. In practice, this means:

• A prescriber must actively choose Truxima, and if they do not, the pharmacist must contact the prescriber to get a new prescription
• If an insurer requires step therapy or a biosimilar-first policy, the prescriber will need to write specifically for Truxima

This is not a reflection of Truxima’s effectiveness—it reflects a separate regulatory designation process.

Efficacy and Safety

Truxima and Rituxan have no clinically meaningful differences in efficacy or safety. The FDA’s biosimilar approval standard requires this level of similarity to be demonstrated before approval is granted.

Side Effects

Because Truxima and Rituxan contain the same active ingredient, they’re expected to have highly similar side effects. Common side effects include:

• Infusion reactions (fever, chills, nausea, headache, itching, rash, fatigue)
• Upper respiratory infections and sinusitis
• Urinary tract infections
• Low blood cell counts for neutrophils (a type of white blood cell) and platelets (which help clot your blood when you get injured)
• Fatigue and weakness

Serious side effects requiring prompt attention include:

• Severe infusion reactions or anaphylaxis, which requires immediate medical treatment
• Progressive multifocal leukoencephalopathy (PML), a rare but serious brain infection
• Hepatitis B reactivation in patients with chronic hepatitis B
• Serious infections due to immune suppression
• Severe skin and mouth reactions (such as Stevens-Johnson syndrome)
• Tumor lysis syndrome, a condition that some cancer patients may experience and requires immediate medical treatment
• Cardiac arrhythmias and worsening heart failure

Patients should complete a hepatitis B screening and review their infection history with their provider before starting either medication. New or worsening neurological symptoms should always be reported right away.

Infusion Reactions and Premedication

Infusion reactions are the most common side effect with both medications and are most likely to occur during the first infusion.

To reduce the risk, care teams give premedication before every infusion—typically acetaminophen and an antihistamine (such as diphenhydramine), and for some patients, a corticosteroid. Reactions that do occur are usually mild to moderate and can often be managed by slowing the infusion rate temporarily.

Cost, Insurance, and Coverage

Cost is one of the most practical reasons a patient might receive Truxima instead of Rituxan. Biosimilars are typically priced lower than their reference biologics, which can translate to meaningful savings on copays and total treatment costs depending on how insurance plans handle each product.

Insurance formulary rules often determine the answer before a patient has a chance to weigh in. Some plans prefer biosimilars and require step therapy—meaning Truxima must be tried before Rituxan is covered. Others may have preferred pricing for one product over the other. Checking with the insurance plan or a specialty pharmacy before starting treatment helps clarify what coverage looks like.

Both Genentech (Rituxan) and Celltrion (Truxima) offer patient support programs for eligible individuals. The financial coordinators at Acelpa Health’s affiliated pharmacies can help you explore manufacturer-sponsored and foundation financial assistance programs and navigate coverage in accordance with applicable state and federal guidelines. Find a location near you to get started.

Moving Forward with Rituximab Treatment

For most patients, the choice between Truxima and Rituxan won’t change how well treatment works.

The clinical evidence is consistent: they are highly similar, and the decision usually comes down to what your insurance covers and what costs less out of pocket.

Acelpa Health and its affiliated specialty pharmacies work with patients across a wide range of rituximab indications—from autoimmune conditions like RA and GPA to cancers like NHL and CLL. Our team handles insurance coordination, medication delivery, and ongoing care team communication to help take the logistical weight off you, so you can focus on your treatment.

When you’re ready to take the next step, reach out to an Acelpa Health pharmacy. We’re here to help.

Frequently Asked Questions (FAQ): 

Are Truxima and Rituxan the same thing?

Not exactly. Both contain rituximab and work the same way in the body, but Truxima (rituximab-abbs) is an FDA-approved biosimilar made by Celltrion, while Rituxan (rituximab) is the original reference biologic made by Genentech/Biogen. The FDA required Truxima to demonstrate no clinically meaningful differences from Rituxan in safety, purity, or effectiveness before approval.

Does Truxima have the same side effects as Rituxan?

Yes. Because both products contain the same active ingredient with the same mechanism of action, their side effect profiles are highly similar. This includes common effects like infusion reactions and infections, and serious but uncommon side effects like PML, hepatitis B reactivation, and severe immune reactions. Premedication protocols and monitoring requirements are also the same.

How long does a Truxima or Rituxan infusion last?

The first infusion is given slowly and typically takes four to six hours, sometimes longer. If it is well tolerated, later infusions can often be completed in three to four hours on average, depending on the condition and how the patient reacts to the infusion. Patients should plan ahead and bring items to stay comfortable during the session.

Is Truxima cheaper than Rituxan?

Generally, yes. Biosimilars are typically priced lower than their reference biologics. The actual difference in out-of-pocket cost depends on individual insurance coverage and formulary placement. Some plans require treatment with a biosimilar first, while others may cover Rituxan before biosimilars. A specialty pharmacy coordinator can help clarify what your plan covers.

Can I switch from Rituxan to Truxima mid-treatment?

Yes, switching is clinically supported and has been studied. Clinical trial data showed no meaningful difference in outcomes for patients who transitioned between the two. However, because Truxima does not hold an interchangeable designation, the switch requires explicit directions from the prescribing provider—a pharmacy cannot substitute automatically. Insurance formulary changes are one of the most common reasons a switch is initiated.

Are there other rituximab biosimilars besides Truxima?

Yes. Ruxience (rituximab-pvvr) by Pfizer and Riabni (rituximab-arrx) by Amgen are also FDA-approved rituximab biosimilars. All share the same mechanism and indications. Which product a patient receives is usually determined by their insurance plan’s formulary.