According to ANCA Vasculitis News, the FDA recently approved Riabni (rituximab-arrx) for the treatment of adult patients with two specific subtypes of ANCA vasculitis: microscopic polyangiitis (MPA) and granulomatosis with polyangiitis (GPA). Outside of these uses, Riabni was also approved for patients with chronic lymphocytic leukemia (CLL) and non-Hodgkin’s lymphoma. If all goes well, the drug will be available for American use before the end of the month.

Riabni

Developed by biotechnology company Amgen, Riabni is a Rituxan biosimilar; in fact, it is the 3rd Rituxan biosimilar approved for vasculitis and hematological cancers. According to FDA media, a biosimilar is considered a biological agent that is:

large and generally complex molecules, produced from living organisms, [and] carefully monitored to ensure consistent quality. For approval, the structure and function of an approved biosimilar were compared to a reference product, looking at key characteristics such as purity, molecular structure, [and] bioactivity.

In 2011, Rituxan was approved for the treatment of GPA and MPA. In these conditions, or in hematological cancers, the CD20 protein is expressed on the surface of specific immune and lymphoma cells. Rituxan targets these cells and destroys them. However, Rituxan can be expensive. As a result, the biosimilar therapies are often more affordable and more accessible.

The recent approval is based on a series of data, including data sourced from the Phase 3 JASMINE clinical trial. 256 patients enrolled in the trial. Researchers determined that both Rituxan and Riabni had similar safety and response data.

Microscopic Polyangiitis (MPA)

While the cause of microscopic polyangiitis (MPA) is unknown, some consider it an immune system disorder. This condition is characterized by blood vessel inflammation, or vasculitis. In patients with MPA, the vasculitis typically occurs in small blood vessels within the lungs, nervous system, joints, skin, and kidneys. An estimated 3 in every 100,000 people has MPA. As the blood vessels remain inflamed, this condition can cause aneurysms, organ dysfunction, and even organ failure. Symptoms vary, but may include:

• Swelling of the lower extremities
• Bloody urine
• Fatigue
• Fever
• Coughing up blood
• Shortness of breath / difficulty breathing
• Muscle and joint pain
• Lowered mobility
• Nerve damage
• Skin rashes
• Kidney failure
• Unintended weight loss
• Appetite loss

Granulomatosis with Polyangiitis (GPA)

Granulomatosis with polyangiitis (GPA) occurs when blood vessel inflammation prevents cells from receiving enough oxygen. However, the cause of this inflammation is unknown. GPA affects small and medium-sized blood vessels throughout the body. It is most common in the lungs, kidneys, and sinuses. However, GPA can also affect the eyes and ears, skin, joints, and nerves. Symptoms include:

• Frequent nosebleeds
• Coughing up blood
• Shortness of breath / difficulty breathing
• Congestion
• Skin rashes
• Fever
• Joint and muscle pain or numbness
• Night sweats
• Fatigue
• Organ failure