Pitt professor's gene therapy trial holds promise for Parkinson's patients

Dr. Mark Richardson performs an MRI-guided brain surgery that uses techniques similar to those that will be used to infuse the experimental gene therapy for Parkinson’s disease.

BY BEN SCHMITT  | Monday, Feb. 29, 2016, 9:00 p.m.

How Parkinson's gene therapy works: 

• Surgeons make one small hole in each side of a patient's skull and use MRI to insert a thin tube into the brain with pinpoint precision. 

• Surgeons deliver a gene known as AADC through this tube, carried by a harmless virus, into the brain. 

• The gene is designed to increase production of an enzyme that helps convert the levodopa drug into dopamine. 

• After infusing the genes, doctors remove the tube and repair the skull. 

Richardson and other researchers are looking for Parkinson's patients between ages 40 and 70 who have been on levodopa for at least three years to participate in the trial. 

The symptoms crept up on Cecilia Alsina as she entered her early 30s: slurred speech, loss of muscle control and excruciating forearm muscle spasms in the middle of the night. 

Tasks like cutting a piece of meat or buttoning a shirt became drawn-out chores. Her handwriting mysteriously shrank to half its size. 

When a doctor uttered the words “Parkinson's disease,” Alsina was six months pregnant and living with her husband in Rochester, N.Y. 

“I definitely had more of a sense of frustration than fear,” she recalled in a telephone interview with the Tribune-Review. “It's hard because your mind is not really affected, particularly in young-onset patients with an active life. Sometimes, you want to do things, and you just can't.” 

She joyously delivered a healthy baby boy, Marc, in 1991, but her Parkinson's symptoms continued to worsen. 

Alsina started experiencing tremendous cramps in her feet that struck unexpectedly when her medications started to wear off. She would drop to her knees until they passed. 

“My feet would twist and turn in such a way that made it impossible to walk,” she said. “It was really difficult to predict when it would happen.” 

A series of events that began with a friend spotting a newspaper article connected Alsina, now 60, to UPMC's Dr. Mark Richardson in Pittsburgh. On April 19, 2014, Richardson, assistant professor of neurological surgery at the University of Pittsburgh School of Medicine, operated on Alsina by implanting thin wires, or electrodes, deep into her brain. He connected the wires to a tiny circuit-like device implanted in her skin below the collarbone. The procedure is known as deep brain stimulation, or DBS. 

The surgery changed Alsina's life and piqued her interest in Richardson's latest venture in the fight against Parkinson's: He's leading a clinical trial to determine if gene therapy can permanently curb tremors, stiffness, mobility impairment and other debilitating symptoms associated with the disease. Richardson is conducting the research along with experts from the University of California at San Francisco on 20 study participants. 

Alsina and the estimated 7 million to 10 million people worldwide who have Parkinson's disease have impaired neurons in their brains that do not produce enough of a chemical known as dopamine. The lack of dopamine causes movement disorders associated with Parkinson's. 

Many patients, like Alsina, take a drug called levodopa as a way to replace dopamine and stave off tremors and other symptoms. But the drug eventually loses effectiveness, and high doses cause other unwanted side effects. 

Before her surgery, Alsina took levodopa every two hours just to get by. But the pills came with side effects: She could not sit still, and her head involuntarily moved constantly. 

“Cecilia's symptoms were like a roller coaster throughout the day,” Richardson said. “Her motor fluctuations were up and down, up and down.” 

The deep brain stimulation, a common therapy to treat Parkinson's, calmed everything. The electrical pulse generator under her collarbone sends signals to her brain to control abnormal movements. It allowed doctors to cut her levodopa dosage by two-thirds. 

“Five minutes after the doctors turned on the device, I was walking around the office without any problems,” she said. “It was very emotional. I was speechless. It was awesome.” 

Still, the device only cancels out abnormal brain activity when turned on. Richardson's hope is that the gene therapy ultimately replaces DBS by making permanent changes in the brain that would wipe out her symptoms completely. 

“I think there's a good chance that, in the next decade, gene therapy will be a viable treatment option for Parkinson's,” he said. 

Alsina is well-aware that the clinical trial could take years. 

“The new work he is doing is going to eventually solve Parkinson's,” she said. “I truly believe that.” 

Cecilia Alsina  

Ben Schmitt is a Tribune-Review staff writer. Reach him at 412-320-7991 or bschmitt@tribweb.com.

http://triblive.com/news/healthnews/10039028-74/parkinson-gene-therapy