All Sections

Home | Health

PKU: New drug removes threat from everyday foods

By JUSTINE GRIFFIN
Tampa Bay Times

June 18. 2018 11:30PM
Dr. Amarillis Sanchez-Valle of the USF Health Metabolic Clinic, right, examines Jennifer Mazorra, a patient in a drug trial that addresses the disease known as PKU. Mazorra, 35, says the new drug, Palynziq, has changed her life. (Fredrick J. Coleman/USF Health/TNS)



TAMPA — Jennifer Mazorra believed that childbirth was out of the question.

She had a disease known as PKU, short for Phenylketonuria, a genetic disorder that prevents the body from breaking down an amino acid found in high-protein foods and sweetened beverages. It put her at risk of developing mental and behavioral problems.

The 35-year-old nurse practitioner from Naples had lived a relatively normal life. But she had to maintain a strict, low-protein diet and get regular checkups. And if she wanted to become pregnant, her child would be at risk for several complications, from cognitive delays to congenital heart problems.

But Mazorra says a new drug tested at the University of South Florida has changed her life.

In May, the U.S. Food and Drug Administration approved Palynziq, a new injectable drug for adults with PKU that helps control concentrations of the amino acid phenylalanine in the blood.

Mazorra’s physician, Dr. Amarillis Sanchez-Valle of the USF Health Metabolic Clinic, was a lead researcher on a clinical trial that tested the drug. Patients came to the university from 14 counties across the state over the last several years.

The drug not only dropped Mazorra’s protein counts to normal levels for the first time in her life and helped her feel healthier, but it also inspired her to get pregnant.

“I was born with PKU. They test for it on newborns in the heel test. It had a real impact on my parents while I was growing up, and it’s something I’ve had to manage all my life,” she said. “I was told it was too risky to have a baby.”

The danger was not heredity. Both parents have to be carriers for the disease to be passed on, and Mazorra’s husband does not have PKU. The risks were in the powerful cravings she would have during pregancy. Those foods would be way off limits.

But her son, Sebastian, is now eight months old and healthy. And, while taking the new drug, Mazorra gets to eat foods like peanut butter, which was forbidden along with fish, meat and eggs for so many years.

PKU affects one in 10,000 to 15,000 people in the U.S., according to the FDA. If untreated, it can cause chronic intellectual, developmental and psychiatric disabilities. Until now, lifelong dietary restriction was the main way to manage the disease, said Sanchez-Valle, an associate professor of pediatrics at USF who treats children and adults with inherited metabolic disorders.

“We never thought that someone with PKU would ever have normal phenylalanine ranges,” she said. “It was mind-blowing to see that.”

‘My life is so much better’

The Palynziq drug, developed by BioMarin Pharmaceutical Inc., is an injectible shot of an enzyme similar to phenylalanine that the body can break down more easily, Sanchez-Valle said.

“It’s a long process for patients to see results,” she said. For Mazorra, it took a year and a half for her to start feeling the effects of the drug. But she said the results were significant: She feels less “brain fog” and her thoughts are more clear. Her mood is more stable. She has more energy.

Mazorra had tried another drug approved for use in PKU patients, a pill called Kuvan, which is considered a dietary supplement and can lower phenylalanine levels. However, the results vary between PKU patients. Mazorra said it didn’t have much of an effect on her.

There are some side effects associated with Palynziq. Patients reported joint pain and sensitivity to the injection site, Sanchez-Valle said. Other reactions include headaches, skin irritations, nausea, dizziness, vomiting, cough and diarrhea. The most serious side effect was allergic reaction, which occurred most often during the first year of treatment.

But Mazorra said the reactions are worth it.

“My life is so much better with this drug than it was without it,” she said.

It was Sanchez-Valle and her team at USF who were the first to tell Mazorra that it wasn’t impossible for her to carry her own children. With the careful monitoring and the help of a metabolic dietician, she could do it. So Mazorra and her husband decided to try.

She had to forgo taking Palynziq during her pregnancy and had to stick to a strict diet again, carefully weighing her food, despite the cravings that came with pregnancy.

“It wasn’t easy,” she said. But she did it.

Six weeks after giving birth, she started taking Palynziq again.

“It’s hard to know what the long-term effects of the drug could be, since it’s so new. But as of right now, it makes my life better,” she said.

Taking the drug

According to the U.S. Food and Drug Administration, to be considered for Palynziq, patients with PKU must:

• Be certified by enrolling in a restricted program under a “Risk Evaluation and Mitigation Strategy” program and complete training.

• Be prescribed auto-injectable epinephrine with Palynziq in case of allergic reaction and have it available at all times while taking the drug.

• Go to pharmacies that are certified with the program and that dispense only to patients authorized to receive Palynziq.

• Enroll in the program and be educated about the risk of anaphylaxis by a certified prescriber, and understand the risks and benefits of treatment with Palynziq.


Health

FOLLOW US
Follow us on Twitter Follow us on Facebook Follow our RSS feed
Union Leader app for Apple iPad or Android *
Click to download from Apple Apps StoreClick to download from Android Marketplace
* e-Edition subscription required