Although the majority of patients with paroxysmal nocturnal hemoglobinuria (PNH) benefit from eculizumab when adhering to Dutch guidelines for treating the disease, the real-world outcomes might further be enhanced with novel therapies, according to an article recently published in the European Journal of Haematology.

For the retrospective observational multicenter cohort study, the researchers reviewed the medical records of 105 Dutch PNH patients treated with eculizumab for at least one month prior to September 23, 2021.

They analyzed the indications for treatment initiation and 5 categories of outcomes: hematological responses, effects on intravascular hemolysis and its related complications and symptoms, survival, effects on extravascular hemolysis, and pregnancy-related outcomes.

The study revealed that all patients with PNH started receiving eculizumab conforming to the indications stated by Dutch PNH guidelines. 

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According to recently published response criteria, a complete hematological response could be seen in 23.4% of participants, a good or partial response was achieved in 53.2%, and 23.4% of patients saw a minor response after 12 months of therapy.

Moreover, different response groups also had varying degrees and relevance of extravascular hemolysis. The achieved response remained stable at long-term follow-up in most patients. A total of 11 (10.5%) patients died while receiving eculizumab.

Although treatment with eculizumab resulted in improvements in EORTC-QLQC30 and FACIT-Fatigue scores, patients with PNH still reported lower scores compared with the general population.

The researchers also evaluated the effects of eculizumab on fetal development. In a total of 18 reviewed pregnancies, the medication caused no thromboembolic events or fetal or maternal deaths.

“To improve the treatment of PNH, it is important to discriminate between the different causes of residual anemia during eculizumab therapy. Patients with bone-marrow failure may require other treatments than complement inhibitors, while patients with prominent extravascular hemolysis will likely benefit more from agents affecting the complement pathway proximal of C5, such as C3, factor B, and factor D,” Schaap and colleagues wrote.

Due to the risk of life-threatening meningococcal disease, lifelong treatment duration, and high costs, strict criteria determine the initiation of eculizumab in patients with PNH.

Reference

Schaap CCM, Heubel-Moenen FCJI, Nur E, et al. Nationwide study of eculizumab in paroxysmal nocturnal hemoglobinuria: evaluation of treatment indications and outcomes. Eur J Haematol. Published online February 22, 2023. doi:10.1111/ejh.13946