Soliris Helps Prevent aHUS Relapses During Pregnancy, Case Report Suggests

Treatment with Soliris (eculizumab) during pregnancy may help prevent subsequent relapses of pregnancy-associated atypical hemolytic uremic syndrome (aHUS), according to a case report.

The report, “Eculizumab Maintenance and the Prevention of Atypical Hemolytic Uremic Syndrome Relapse During Pregnancy: A Case Report,” was published in the Journal of Medical Cases.

Although rare, pregnancy can sometimes serve as a trigger of aHUS, a disease in which the formation of blood clots in small blood vessels leads to organ damage. aHUS complicates an estimated one in every 25,000 pregnancies, and women who experience aHUS during pregnancy are thought to be at higher risk for relapse.

Soliris (marketed by Alexion) is an engineered antibody that targets C5, a protein part of the complement system (a family of immune proteins) that is over-activated in aHUS. This inhibitor is recommended as a first line treatment for aHUS since its approval by the U.S. Food and Drug Administration in 2011. Its treatment for acute aHUS during pregnancy has been shown to be effective. However, it is not clear whether continuous maintenance treatment during pregnancy is safe and efficient.

In the report, researchers describe the case of a 37-year-old woman, whose previous pregnancy had been complicated by aHUS.

At week 40 of her first pregnancy, labor was induced because of possible preeclampsia, as the patient had high blood pressure and elevated levels of protein in her urine.

There were no complications during delivery, and the patient was discharged two days postpartum. At day four postpartum, she experienced headache and general discomfort. At this point, her blood pressure was extremely elevated, and she was anemic and had thrombocytopenia (low blood platelet counts).

She first developed acute kidney injury and required dialysis, after which the patient experienced respiratory failure and had to be intubated.

These symptoms were consistent with pregnancy-associated aHUS (P-aHUS). The patient was treated with Soliris given intravenously (directly into the vein). Her treatment regimen also involved plasmapheresis, a process in which the liquid part of the blood (plasma) is separated from blood cells to be filtered and then returned back into the body.

The patient “experienced marked improvement in both clinical and laboratory parameters,” the researchers wrote.

Since her initial diagnosis, the patient was maintained on Soliris at a dose of 900 milligrams every two weeks. Although she recovered full renal function, her blood pressure remained elevated and, as such, she was kept on Coreg (carvedilol), a medication used to treat high blood pressure.

During her second pregnancy, and given her risk of relapse, the patient continued to receive Soliris infusions every two weeks and was also kept on Coreg. Her renal function and complete blood count were normal throughout this period. No complications were experienced except for gestational diabetes, which was controlled with treatment.

Labor was induced at 39 weeks, and the delivery was normal. The newborn had no evidence of infections, a possible side effect of Soliris. An extra dose of Soliris was administered 24 hours postpartum to the mother, and she then resumed infusions every two weeks.

Overall, this case report suggests that Soliris’ use during pregnancy appears to be safe and efficient.

“More data are needed to confirm the safety of [Soliris] maintenance during pregnancy for both the mother and fetus,” the researchers wrote. “However, given the life-threatening nature of P-aHUS to both mother and fetus, [Soliris] maintenance therapy during pregnancy may confer more benefit than risk.”