“Someday, there will be a cure!” For decades, ever since Curt Krouse was a young child with hemophilia B, those hopeful words rang out at the end of an annual fashion show that his mother, Sandy, co-hosted as part of a hard-working committee to benefit the local bleeding disorders foundation.
In October 2024, that day finally came. Krouse, now 57—with his parents by his side—was the first Penn Medicine patient to receive a new gene therapy for hemophilia B since it was approved by the FDA. It was the first FDA-approved gene therapy for the condition in adults.
Like other adults with the disorder, Krouse has a genetic mutation that makes the blood-clotting factor 9 gene nonfunctional. Through a one-time infusion, the new drug, Hemgenix, uses a harmless virus to deliver a working copy of the factor 9 gene into the liver, which then begins manufacturing the clotting factor to prevent bleeding.
When Hemgenix was approved by the Food and Drug Administration in November 2022, scientists had been working for decades to find a gene therapy to cure hemophilia. Immediately after the infusion, Krouse stopped regular prophylactic clotting factor injections.
“Living with this disease for 57 years, and then my life changes in 30 minutes. It’s hard to believe. I am grateful to have shared this experience with my family and medical team. The gene therapy injection was not just for me, but for everyone in my life that helped take care of me,” he says.
Throughout his lifetime, Krouse has seen the evolution of treatment for his severe hemophilia. As a baby, his parents would bring him to the hospital for treatment with clotting medication to stop bleeding. He, along with family members, then learned to administer at-home injections after bleeds. This meant regular prophylactic injections to maintain sufficient levels of the clotting factor to prevent bleeding.
Even with preventive injections, bleeds—both internal and external—were still possible. He wears ankle braces to control the pain from arthritis that developed after decades of internal bleeding into joints—a common problem in patients with severe hemophilia.
“It’s not only physically a huge burden—it’s also a huge burden mentally,” Krouse said. “A lot of times that’s overlooked, but you are always thinking about your disease. You must take care of yourself. It is front and center in your mind.”
Adam Cuker, director of the Penn Comprehensive Hemophilia and Thrombosis Program and Krouse’s doctor, said he hoped that in time, Krouse would learn to release those fears.
“There’s a new concept that has come with gene therapy called the ‘hemophilia-free mind.’ When you have hemophilia, even when it’s well-managed, there’s still a mental burden: the fear of bleeding, the burden of needing to do frequent IV infusions, all the hassles with insurance, the fear that your product might not be covered,” Cuker says. “You can imagine how mentally straining that is. For the first time, this is a treatment that offers an opportunity to lift that.”
This story is by Daphne Sashin. Read more at Penn Medicine News.
