A clinical trial to evaluate the safety and effectiveness of the drug sildenafil on pregnant women was halted this week after Amsterdam University Medical Center confirmed the death of 11 babies whose mothers were all part of the study.
Sildenafil, better known as Viagra, was being tested as a treatment for unborn babies who had severe growth limitations and were at significant risk of being stillborn or dying after birth. The drug, which increases blood flow, was given in hopes that more blood driven to the placenta would help with growth. Instead, it might have contributed to damaging the babies' lungs.
Dutch researchers stopped the trial immediately, according to a statement from the medical center, after multiple babies developed a blood vessel disease in the lungs—a type of high blood pressure that increases the risk of death after birth.
The study, which included 183 pregnant women at 11 different locations throughout the Netherlands, began in 2015 as a follow-up to previous research that reportedly showed that sildenafil could stimulate the growth of the unborn child. BBC News, however, stated that earlier trials in the U.K., Australia and New Zealand found no benefit.
"We need to be careful at this point to find out more,” said professor Zarcko Alfirevic from the University of Liverpool, who led part of the previous U.K. research that found no benefit.
"It needs a thorough investigation because the complications were not seen in the two other, similar trials that have already been done in the U.K. and Australia and New Zealand."
We need to be careful at this point to find out more.
Regardless, the results from the current study have proven to be fatal.
In total, about half of the participants (93 women) were treated with the drug sildenafil. The remaining 90 were given a placebo, or sugar pill. None of the mothers involved were informed which treatment they were receiving, which is standard in clinical trials.
In the end, 19 babies born to women who were treated with the drug sildenafil died, with 11 of the deaths possibly due to the lung disease. Six of the babies born with the lung disorder survived.
The heartbreaking announcement also mentions the other children, those whose moms were taking sugar pills. Based on their findings, nine of the babies born to women treated with the placebo (none of whom showed signs of the lung disease) died. Three of the babies were born with the lung disorder, but survived.
According to The Guardian, between 10 and 15 women are still waiting to find out if their child has been affected by the drug. The article also shared a statement from Wessel Ganzevoort, lead investigator in the study, who reportedly told Dutch daily newspaper De Volkskrant, "We wanted to show that this is an effective way to promote the growth of the baby. But the opposite happened. I am shocked. The last thing you want is to harm patients."
Amsterdam UMC says that, although the research has been stopped as a precaution, scientists will continue to extensively analyze available data and closely monitor the development of the children.