FDA Approval Gives New Hope to Patients With Rare Genetic Disease

By Pat Anson, PNN Editor

Lisa Kehrberg was once frightened about her future. For years the retired family practice doctor and mother of two would suffer severe bouts of unexplained abdominal pain, headaches and nausea that would leave her hospitalized for weeks at a time.

“I was doubled over, rocking, vomiting and crying with the worst pain of my life. Worse than labor, appendicitis, or anything else I'd experienced. It was a hot, burning pressure that was like lava and hot razor blades filling up my abdomen,” Lisa recalled.

She was eventually diagnosed with a rare genetic disease called acute intermittent porphyria, which causes toxic molecules to build up in the body. The same disease killed Lisa’s brother in 2011. And she thought the same fate awaited her.

“One of the most common causes of death from porphyria is suicide. This isn't surprising. I always wonder how people who are sick like me keep surviving. To live in continuous excruciating pain every minute of every day with no end in sight is quite the challenge,” Lisa wrote in a 2016 column for PNN.

It was about that time that Lisa entered a clinical trial program. Every four weeks she’d travel to Houston from her home near Chicago for injections of an experimental drug. Over time, her symptoms began to improve and the porphyria attacks that used to occur monthly became less frequent.

LISA KEHRBERG, MD

Like other participants in clinical studies, Lisa wasn’t allowed to talk publicly about the drug she was getting – until now.  

The Food and Drug Administration has just approved the use of Givlaari (givosiran) for the treatment of adult patients with acute hepatic porphyria (AHP). Approval was granted based on results from placebo controlled trials involving 94 porphyria patients. Those who received Givlaari experienced 70% fewer porphyria attacks compared to patients receiving a placebo.  

“Prior to getting givosiran I was bed-bound for close to 6 months straight from severe muscle weakness and paralysis issues. I no longer have paralysis and most of the muscle weakness has resolved,” Lisa said in an email. “The rate of new attacks has decreased greatly, finally giving my nerves a chance to heal after 22 years of attacks and 6 years of back-to-back attacks.”

“These attacks occur suddenly and can produce permanent neurological damage and death,” Richard Pazdur, MD, director of the FDA’s Oncology Center of Excellence, said in a statement Wednesday. “Prior to today’s approval, treatment options have only provided partial relief from the intense unremitting pain that characterizes these attacks. The drug approved today can treat this disease by helping to reduce the number of attacks that disrupt the lives of patients.”

The FDA approved Givlaari under its breakthrough therapy, priority review and orphan drug designations, which provide incentives to companies in the development of drugs for rare diseases. Approval was granted to Alnylam Pharmaceuticals, which expects Givlaari to be available to healthcare providers by the end of the year.

There are about 3,000 people diagnosed with active porphyria in the U.S. and Europe. Due the wide array of symptoms the disease has, it can take years before an accurate diagnosis is made.

“The FDA approval of Givlaari is an important milestone for our community, as we now have a new treatment option for adults living with acute hepatic porphyria,” said Kristen Wheeden, Executive Director of the American Porphyria Foundation.

Image courtesy of Alnylam Pharmaceuticals

“AHP can have a profound impact on the lives of patients and their families. Porphyria attacks are associated with severe, incapacitating pain, often requiring hospitalization for management. In addition, many patients struggle on a daily basis with chronic symptoms related to their disease. The approval of Givlaari is exciting for our community.”

Lisa Kehrberg isn’t out of the woods just yet. She has permanent nerve damage from years of porphyria attacks. But her future is a lot brighter than it was.  

“For newly diagnosed patients, I strongly believe this treatment has the ability to stop the progression of the disease and will allow patients to lead a normal, functional life,” she says.