Dupilumab Use During Pregnancy Appeared Safe for Babies

— Prospective registry study shows no increase in birth defects

PHOENIX -- Use of dupilumab (Dupixent) in pregnancy appeared safe for the baby, a postmarketing registry study showed.

Major birth defects were not more common among babies born to women with dupilumab exposure compared with those born to non-exposed women with the same health conditions (weighted risk ratio [RR] 0.70, 95% CI 0.37-1.32) or non-exposed healthy women (weighted RR 1.06, 95% CI 0.47-2.41).

No specific birth defects stood out, and there were no spontaneous abortions or preterm deliveries with dupilumab exposure, reported Christina Chambers, PhD, MPH, of the University of California San Diego, at the CHEST annual meetingopens in a new tab or window hosted by the American College of Chest Physicians.

"While the sample size was limited, the extensive follow-up for this pregnancy cohort study yielded results that are reassuring," Chambers and colleagues concluded in their poster.

These findings are in line with the limited data that have already been published, Chambers noted.

"Like most new drugs that come on the market, most of them will be used by women of reproductive age, but almost never are pregnant women included in clinical trials in phase III," she said. "We can make some comments about animal studies that have been done, but they don't always predict what will happen in humans."

Dupilumab's indications have continued to expand since its initial approval for the treatment of eczemaopens in a new tab or window in 2017, and include asthma, chronic rhinosinusitis with nasal polypsopens in a new tab or window, chronic spontaneous urticariaopens in a new tab or window, chronic obstructive pulmonary diseaseopens in a new tab or window, and other conditionsopens in a new tab or window -- in some cases for children as young as 1 year.

Whether there's any positive impact for children with early exposure, such as decreasing the risk of developing atopic conditions, is unknown, Chambers noted.

"It's an open question, and it's a really interesting one," she told MedPage Today. "Appropriate treatment and well-controlled asthma in pregnancy is a positive thing for the mother and the baby. So outcomes of pregnancy are better if the mother is well controlled for her asthma during pregnancy."

"But to extend that to say, Does that treatment provide some protection for the child in terms of them developing allergic diseases? That question, to my knowledge, has not been addressed with any other safety study that has been done," she added. "It's a follow-on study that we're actually looking [into] doing, because we have followed the children and have captured medical records on them and have the potential to ask these moms if they would be willing to have their children followed longer term."

The prospective registry enrolled 539 pregnant women in the U.S. and Canada between 2018 and 2025. The Organization of Teratology Information Specialists' MotherToBaby Pregnancy Studies Research Center at the University of California San Diego conducted repeated telephone interviews with the mothers and looked at medical records for outcomes covering the period of pregnancy through 1 year postpartum.

Among the participants, 238 had been exposed to dupilumab, largely for treatment of asthma, atopic dermatitis, or both. The most common dose used was 300 mg twice a month (81.1%); most pregnant women who took dupilumab used it in all three trimesters (68.4%).

Another 175 women were enrolled based on having asthma or atopic dermatitis but no exposure to dupilumab at any point in pregnancy. A healthy general population comparator group of 126 women had neither condition nor dupilumab exposure.

Of the 197 evaluable users of dupilumab in the first trimester, a total of 14 women had major structural birth defects, all in live-born babies. The same number of cases occurred among the 145 evaluable disease-matched women, while nine occurred among the 109 evaluable healthy controls (all but one live-born in both groups).

Spontaneous abortion occurred in nine dupilumab-exposed pregnancies, three disease-matched pregnancies, and four healthy control pregnancies (weighted HRs 0.79, 95% CI 0.25-2.52, and 0.64, 95% CI 0.21-2.01).

Preterm delivery occurred in 18 dupilumab-exposed pregnancies, 13 disease-matched pregnancies, and five healthy control pregnancies (weighted HRs 0.79, 95% CI 0.41-1.51, and 1.97, 95% CI 0.83-4.67). "The elevated but non-significant point estimate for preterm delivery in the comparison of dupilumab-exposed to the non-diseased cohort (that was not seen in comparison to the disease-matched cohort) could be due to the contribution of the underlying maternal disease," the researchers suggested.

Rates of small-for-gestational-age births were also similar between groups. In the babies' first year of life, no differences by group were seen in postnatal growth, serious or opportunistic infections, or overall hospitalizations.