A Phase 2a study sought to compare the safety, efficacy, and tolerability of ABBV-3373, as compared to adalimumab, for patients with rheumatoid arthritis (RA). Patients involved in the study had moderate-to-severe disease presentation despite methotrexate treatment. According to an article in DocWire News, results from the study found the investigational ABBV-3373 as similarly efficacious to adalimumab after 12-weeks of treatment.

In a prior news release about ABBV-3373, drug developer AbbVie describes the treatment as:

an investigational ADC comprised of a novel glucocorticoid receptor modulator (GRM) linked to adalimumab, and aims at modulating TNF-mediated inflammatory pathways by delivering a glucocorticoid payload directly into activated immune cells expressing membrane bound TNF. This ADC was designed to potentially allow precise targeting of activated immune cells while significantly dampening inflammation and minimizing the systemic side-effects associated with glucocorticoids.

48 patients enrolled in the study, the results of which were published in Arthritis & Rheumatology. Patients received either 100mg intravenously administered ABBV-3373 (followed by a subcutaneous placebo) or 80mg subcutaneously administered adalimumab (followed by IV placebo) for 12- and 24-week periods. Study findings include:

• ABBV-3373 showed favorable improvements in disease activity compared to adalimumab, both historically and within the trial itself. 70.6% of patients maintained a lower disease activity rate from week 12 to 24. 
• ABBV-3373 was found to be relatively safe and well-tolerated. However, four serious adverse reactions did occur. These were pneumonia, anaphylactic shock, chest pain, and upper respiratory tract infection. 

The findings highlight the potential of continued ABBV-3373 development, and how that could be used to benefit this patient population.

What is Rheumatoid Arthritis (RA)? 

Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disorder that affects many joints, including those in the hands and feet. This condition occurs when the immune system mistakenly attacks the synovium, or the lining of joints. In some individuals, RA can affect multiple body systems including the eyes, skin, and blood vessels. RA is difficult to predict. While it often progresses slowly over months or years, it may plateau or come on rapidly. People with rheumatoid arthritis may experience periods of remission, where they have no symptoms. RA is 2-3x more common in females than males.

When symptoms of rheumatoid arthritis appear, they may include:

• Tender, warm, swollen, or stiff joints
• Restricted or limited mobility
• Joint, back, or muscle pain
• Fatigue and general malaise
• Fever
• Appetite loss
• Shortness of breath
• Anemia (low red blood cell count)
• Skin lumps or redness
• “Pins and needles” sensation
• Bone erosion and/or joint deformities