A scan of a young girl with fibrodysplasia ossificans progressiva shows inappropriate bone growth from her pelvis and an upper femur.Rare diseases often get the cold shoulder from drug developers, and fibrodysplasia ossificans progressiva , an infamous genetic condition that makes bone sprout where it shouldn’t, is one of the rarest. It can inflict terrible pain and disability and is ultimately fatal, but only affects some 8000 people around the world.
Kaplan and other researchers suggest one reason drug developers have focused on FOP is the cruelty of the disease, which is triggered by a mutation in a gene crucial to bone growth. Children with FOP usually seem fine at birth, but as they get older bone starts to form in their muscles, tendons, and ligaments. The frequent falls and bruises of childhood can spark these spates of bone development, as can surgery and even injections—forcing patients to skip vaccinations.
Not that long ago it wasn’t even clear the disease was genetic, says Eileen Shore, a geneticist and cell biologist also at UPenn, which is the epicenter for studies of the disease. “We couldn’t get pharma interested,” she recalls.in 2006, “that changed everything,” Shore says. The disease results from mutations in the gene for ALK2, a surface protein on many kinds of cells, including certain stem cells.
So far, only four countries—the U.S., Canada, Australia, and the United Arab Emirates—have approved palovarotene, which is made by the French pharma company Ipsen. “It’s exciting that there is a drug, but the reality is we can do better with targeted treatments,” says endocrinologist Marc Wein of Massachusetts General Hospital, who is not involved in developing the drug.