When you are prescribed a medication to manage a chronic condition like asthma or eczema, you expect relief—not new health concerns. But for some patients taking Dupixent, an unexpected change in their blood work has raised alarm bells. Eosinophilia, a condition marked by elevated levels of certain white blood cells, has been observed in some people using this popular biologic drug. If you’ve suffered injury due to Dupixent use, our attorney can help.
What Is Eosinophilia?
Eosinophilia occurs when your blood contains an abnormally high number of eosinophils, a type of white blood cell. These cells play an important role in your immune system, helping your body fight off allergens, parasites, and fungal infections. While these cells serve a protective function, having too many of them can signal an underlying problem.
The severity of eosinophilia varies. Mild cases might result from something as simple as a drug reaction or seasonal allergies. More serious cases, however, can indicate blood disorders or other health issues. In some situations, eosinophils accumulate in tissues throughout your body, triggering inflammation that affects multiple organs.
How Dupixent Affects Eosinophil Levels
Research confirms that Dupixent can cause elevated eosinophil levels, which is actually an expected result of how the drug works. Dupixent blocks certain pathways that normally help eosinophils move from your blood into your tissues. When this migration is blocked, these cells accumulate in your bloodstream instead.
An analysis of over 6,600 patients across multiple clinical trials found that while average eosinophil levels did rise with Dupixent treatment, the most dramatic increases occurred in a relatively small group of patients. Blood eosinophil counts typically peaked around four weeks into treatment and gradually returned to baseline levels by approximately week 24.
For most patients, these elevated levels do not appear to cause clinical problems or reduce the medication’s effectiveness. However, the study did identify serious adverse events in a small number of patients, such as eosinophilic granulomatosis with polyangiitis, a serious inflammatory condition affecting the lungs and other organs. If you are taking Dupixent for asthma or sinus issues, regular blood monitoring can help your healthcare provider catch any concerning changes early.
Other Health Problems Linked to Dupixent
Beyond eosinophilia, Dupixent has been associated with another serious concern: cutaneous T-cell lymphoma (CTCL). Patients are now filing lawsuits alleging that manufacturers Regeneron Pharmaceuticals and Sanofi-Aventis failed to adequately warn about this cancer risk.
Research published in the European Respiratory Journal found that asthma patients using Dupixent had a 79% higher risk of lymphoma and a 4.5-fold increased risk of T-cell and natural killer cell lymphomas. A 2024 study found that most patients who developed CTCL were diagnosed within their first year of treatment, with a higher risk among those over 60.
Discuss Your Path Forward with Shapiro Legal Group, PLLC
Eosinophilia is just one of several serious conditions that have emerged among Dupixent users. If you or a loved one received a CTCL diagnosis following Dupixent use, the attorneys at Shapiro Legal Group, PLLC want to hear from you. Our firm is currently pursuing claims on behalf of patients who developed cutaneous T-cell lymphoma after taking Dupixent. Contact us at (800) 220-0984 to discuss your legal options at no cost.