Live births seen in half of pregnancies exposed to belimumab

PARIS – The live birth rate among women taking belimumab for systemic lupus erythematosus is similar to the background rate for women with the disorder, a study showed.

An analysis of clinical trials found that women who were taking the drug when they became pregnant had a live birth rate of 48% – in line with studies that place the rate at 55%-88%, Dr. Marcy Powell said at the annual European Congress of Rheumatology.

Although the number of pregnancies examined in the studies was small – with 80 exposed to belimumab (Benlysta) and 6 to placebo – the results were echoed by the initial findings in a recently established belimumab pregnancy registry, said Dr. Powell, director of safety evaluation and risk management at GlaxoSmithKline, which manufactures the drug.

More than 3,000 adult patients have been treated with belimumab – many for more than 10 years, but there are scant data on pregnancy outcomes. It’s a category C drug; women are advised to avoid pregnancy while taking it and for at least 4 months after stopping it. Thus, the only available pregnancy data are from inadvertent exposures in which the drug was stopped as soon as the pregnancy was discovered.

The data were drawn from the BLISS 52 and 78 studies, which enrolled more than 1,600 patients, 94% of whom were women. At baseline, the patients’ mean age was 38 years. Other medications were common in the cohort: 86% of patients were using corticosteroids, with 58% of those taking a prednisone equivalent of more than 5.7 mg/day. More than half (65%) were using antimalarials, and 49% were taking another immunosuppressant, including azathioprine, methotrexate, or mycophenolate mofetil.

Of the six pregnancies among patients assigned to placebo, there were three elective terminations, two spontaneous miscarriages, and one stillbirth, for a total fetal loss rate of 50%. The three pregnancies with fetal loss included two women who tested positive for anticardiolipin antibodies.

Among the 80 drug-exposed pregnancies, there were 21 elective terminations as well as 20 miscarriages and 1 stillbirth, yielding a total fetal loss rate of 26%. The background miscarriage rate was 12%-22%, and the background stillbirth rate was 2%-5%, both of which are similar to rates observed in the exposed pregnancies. Overall, women tested positive for anticardiolipin antibodies in 20 pregnancies exposed to belimumab, including 21% of the live births and 38% of the fetal losses.

There were 38 live births (48%). Four neonates had a congenital anomaly:

• One with Dandy-Walker syndrome.

• One with an unbalanced translocation (11 and 13) of maternal origin, a strictly genetic anomaly.

• One born at 27 weeks’ gestation with patent ductus arteriosus.

• One with bilateral enlarged kidneys with abnormal function whose mother was receiving ambrisentan, a known teratogen, for portal hypertension. (The infant was placed on dialysis and had the right kidney removed.)

The stillbirths in the placebo and belimumab patients occurred in conjunction with severe, very early third-trimester preeclampsia, Dr. Powell said. She noted that the sample size is so small that it’s unclear whether the results can be extrapolated to larger populations.

However, the Belimumab Pregnancy Registry, established by GlaxoSmithKline, could provide more reliable data, she said. So far, the registry has enrolled nine pregnancies, seven of which have been completed. Among those, there have been six live births and one miscarriage. Three of the infants were preterm, born at 32, 35, and 36 weeks’ gestation. There was one birth defect (mild Epstein’s anomaly of the tricuspid valve).

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On Twitter @alz_gal

PARIS – The live birth rate among women taking belimumab for systemic lupus erythematosus is similar to the background rate for women with the disorder, a study showed.

An analysis of clinical trials found that women who were taking the drug when they became pregnant had a live birth rate of 48% – in line with studies that place the rate at 55%-88%, Dr. Marcy Powell said at the annual European Congress of Rheumatology.

Although the number of pregnancies examined in the studies was small – with 80 exposed to belimumab (Benlysta) and 6 to placebo – the results were echoed by the initial findings in a recently established belimumab pregnancy registry, said Dr. Powell, director of safety evaluation and risk management at GlaxoSmithKline, which manufactures the drug.

More than 3,000 adult patients have been treated with belimumab – many for more than 10 years, but there are scant data on pregnancy outcomes. It’s a category C drug; women are advised to avoid pregnancy while taking it and for at least 4 months after stopping it. Thus, the only available pregnancy data are from inadvertent exposures in which the drug was stopped as soon as the pregnancy was discovered.

The data were drawn from the BLISS 52 and 78 studies, which enrolled more than 1,600 patients, 94% of whom were women. At baseline, the patients’ mean age was 38 years. Other medications were common in the cohort: 86% of patients were using corticosteroids, with 58% of those taking a prednisone equivalent of more than 5.7 mg/day. More than half (65%) were using antimalarials, and 49% were taking another immunosuppressant, including azathioprine, methotrexate, or mycophenolate mofetil.

Of the six pregnancies among patients assigned to placebo, there were three elective terminations, two spontaneous miscarriages, and one stillbirth, for a total fetal loss rate of 50%. The three pregnancies with fetal loss included two women who tested positive for anticardiolipin antibodies.

Among the 80 drug-exposed pregnancies, there were 21 elective terminations as well as 20 miscarriages and 1 stillbirth, yielding a total fetal loss rate of 26%. The background miscarriage rate was 12%-22%, and the background stillbirth rate was 2%-5%, both of which are similar to rates observed in the exposed pregnancies. Overall, women tested positive for anticardiolipin antibodies in 20 pregnancies exposed to belimumab, including 21% of the live births and 38% of the fetal losses.

There were 38 live births (48%). Four neonates had a congenital anomaly:

• One with Dandy-Walker syndrome.

• One with an unbalanced translocation (11 and 13) of maternal origin, a strictly genetic anomaly.

• One born at 27 weeks’ gestation with patent ductus arteriosus.

• One with bilateral enlarged kidneys with abnormal function whose mother was receiving ambrisentan, a known teratogen, for portal hypertension. (The infant was placed on dialysis and had the right kidney removed.)

The stillbirths in the placebo and belimumab patients occurred in conjunction with severe, very early third-trimester preeclampsia, Dr. Powell said. She noted that the sample size is so small that it’s unclear whether the results can be extrapolated to larger populations.

However, the Belimumab Pregnancy Registry, established by GlaxoSmithKline, could provide more reliable data, she said. So far, the registry has enrolled nine pregnancies, seven of which have been completed. Among those, there have been six live births and one miscarriage. Three of the infants were preterm, born at 32, 35, and 36 weeks’ gestation. There was one birth defect (mild Epstein’s anomaly of the tricuspid valve).

[email protected]

On Twitter @alz_gal

PARIS – The live birth rate among women taking belimumab for systemic lupus erythematosus is similar to the background rate for women with the disorder, a study showed.

An analysis of clinical trials found that women who were taking the drug when they became pregnant had a live birth rate of 48% – in line with studies that place the rate at 55%-88%, Dr. Marcy Powell said at the annual European Congress of Rheumatology.

Although the number of pregnancies examined in the studies was small – with 80 exposed to belimumab (Benlysta) and 6 to placebo – the results were echoed by the initial findings in a recently established belimumab pregnancy registry, said Dr. Powell, director of safety evaluation and risk management at GlaxoSmithKline, which manufactures the drug.

More than 3,000 adult patients have been treated with belimumab – many for more than 10 years, but there are scant data on pregnancy outcomes. It’s a category C drug; women are advised to avoid pregnancy while taking it and for at least 4 months after stopping it. Thus, the only available pregnancy data are from inadvertent exposures in which the drug was stopped as soon as the pregnancy was discovered.

The data were drawn from the BLISS 52 and 78 studies, which enrolled more than 1,600 patients, 94% of whom were women. At baseline, the patients’ mean age was 38 years. Other medications were common in the cohort: 86% of patients were using corticosteroids, with 58% of those taking a prednisone equivalent of more than 5.7 mg/day. More than half (65%) were using antimalarials, and 49% were taking another immunosuppressant, including azathioprine, methotrexate, or mycophenolate mofetil.

Of the six pregnancies among patients assigned to placebo, there were three elective terminations, two spontaneous miscarriages, and one stillbirth, for a total fetal loss rate of 50%. The three pregnancies with fetal loss included two women who tested positive for anticardiolipin antibodies.

Among the 80 drug-exposed pregnancies, there were 21 elective terminations as well as 20 miscarriages and 1 stillbirth, yielding a total fetal loss rate of 26%. The background miscarriage rate was 12%-22%, and the background stillbirth rate was 2%-5%, both of which are similar to rates observed in the exposed pregnancies. Overall, women tested positive for anticardiolipin antibodies in 20 pregnancies exposed to belimumab, including 21% of the live births and 38% of the fetal losses.

There were 38 live births (48%). Four neonates had a congenital anomaly:

• One with Dandy-Walker syndrome.

• One with an unbalanced translocation (11 and 13) of maternal origin, a strictly genetic anomaly.

• One born at 27 weeks’ gestation with patent ductus arteriosus.

• One with bilateral enlarged kidneys with abnormal function whose mother was receiving ambrisentan, a known teratogen, for portal hypertension. (The infant was placed on dialysis and had the right kidney removed.)

The stillbirths in the placebo and belimumab patients occurred in conjunction with severe, very early third-trimester preeclampsia, Dr. Powell said. She noted that the sample size is so small that it’s unclear whether the results can be extrapolated to larger populations.

However, the Belimumab Pregnancy Registry, established by GlaxoSmithKline, could provide more reliable data, she said. So far, the registry has enrolled nine pregnancies, seven of which have been completed. Among those, there have been six live births and one miscarriage. Three of the infants were preterm, born at 32, 35, and 36 weeks’ gestation. There was one birth defect (mild Epstein’s anomaly of the tricuspid valve).

[email protected]

On Twitter @alz_gal