A surprising potential therapy for severe, hard-to-treat malformations of the lymphatic system is now being studied at Stanford and Lucile Packard Children's Hospital.
The malformations, called lymphangiomas, are overgrowths of the one-way lymph channels that return extra fluid from our tissues to the bloodstream. Rarely, in infants and children, these channels grow abnormally large and cause deformity or death. (The overgrowth may choke off a child's airway or interfere with other aspects of heart and lung function.) Lymphangiomas are hard to treat, since the overgrown vessels are often too tangled into vital organs to remove surgically. And the deformity tends to grow with the child, worsening over time.
But physicians at Packard Children's discovered, essentially by accident, that a common drug – sildenafil, a.k.a. Viagra – appears to shrink the overgrown vessels. A letter published today in the New England Journal of Medicine describes the first three cases the Stanford/Packard team treated, including MRI scans and photos that show dramatic before-and-after changes in the patients' malformations.
"There has been no medical treatment for lymphangiomas; now all of a sudden there may be one," Al Lane, MD, a co-author on the NEJM letter and an investigator on the lymphangioma research now underway at Packard Children's, recently told me.
The research team has a long way to go in determining if and how sildenafil should be routinely used to treat these malformations, Lane cautioned. They're now studying a handful of children using seed money provided by an Innovations in Patient Care grant from Spectrum Child Health, funds from SPARK, as well as medication provided by Pfizer, and they're applying to the U.S. Food and Drug Administration's orphan conditions program for funds to run a larger trial.
"We think this may work, but we don't know," Lane said. "We need to do a placebo-controlled trial."
However, the fact that the condition is so severe and hard to treat made the team feel that it was important to get the word out about the early findings, Lane added. "We felt like, if it really works, and we have data to suggest that it does, it wasn't fair for patients who have no other options to not at least know what we're observing," he said.
