Turkish doctors spearhead treating 'intractable' genetic diseases

By Burcu Calik Gocumlu

Doctors in Türkiye have successfully applied the world's first gene therapy for phenylketonuria, a condition that can cause permanent brain damage.

A clinical research center at the Gazi University Medical School also pioneered the first non-surgical brain gene therapy method for GM1 Gangliosidosis, which poses a life-threatening risk to children.

Dr. Fatih Ezgu, the head of the Department of Pediatric Genetics and deputy director of the clinical research center, told Anadolu that the research conducted at the center became operational approximately one year ago.

Ezgu emphasized that the center focuses on Türkiye's first advanced treatment methods and drug development studies, especially for childhood genetic diseases that require new and permanent treatments.

He mentioned that the center is currently conducting over 20 clinical trials involving various treatments.

Gene therapy applications, which can only be performed in a few qualified centers worldwide, have also been initiated in accordance with international approvals, Ezgu noted.

He highlighted three ongoing clinical trials for phenylketonuria (PKU), with the latest aiming for a "definitive, permanent" treatment via gene therapy.

- The only center in world

Ezgu emphasized the "importance" of a special diet for PKU to prevent mental retardation and permanent brain damage in children.

He mentioned that the gene therapy research for PKU, aiming for a permanent cure, has begun worldwide.

Stressing that the drug, developed in another country, has "successfully" completed the lab and animal trials, he said the human trial is the next stage.

"Our center was selected to perform the world's first gene therapy application on phenylketonuria patients due to its ability to meet the criteria established in the research," he said.

"We began this study as the only center in the world with an international status, and two to three more centers may join in the future.

"This is not only important for patients in our country but also for many patients worldwide. We have successfully applied gene therapy to two phenylketonuria patients, and the third patient will be treated soon. We will observe the results together in the coming days," he added.

He also said the Phase 1 gene therapy trials involve three patient groups receiving different doses and that international doctors will evaluate the results, guiding the next phase.

- 2 patients receive non-surgical brain gene therapy

Ezgu said they have initiated a clinical study for a treatment method, the third in the world and the first in Türkiye, for GM1 Gangliosidosis -- a type of enzyme deficiency disorder that can cause severe damage to the brain and other organs, and can result in death.

"Gene therapy has been developed by a foreign sponsor, and three centers, including ours, have been selected to apply it worldwide," he stressed.

"We administer the treatment directly into the brain, not through the vein, using a needle under tomography guidance," Ezgu added.

Ezgu noted that this method, which is very new worldwide, can only be applied by a limited number of teams.

The team at Gazi University Faculty of Medicine Hospital has received training in this area in the US.

- Local gene therapy

Ezgu highlighted two clinical studies that could offer insights into treating various genetic diseases, mentioning plans to advance a drug developed in their lab alongside those developed abroad.

He said they will commence two gene therapy studies for urea cycle disorders and lysosomal diseases.

He pointed out efforts to produce a local gene therapy drug for another disease in their laboratory, with the potential for clinical trials in the future.

Ezgu noted that Phase 1 clinical trials involve a limited number of patients initially, with more participants to be added in later stages.

For the gene therapy study, patients are accepted based on the evaluation of around 20 different criteria, including age.

He said: "Our goal is for these studies to be successful and for treatments to be developed in a way that all patients can use them. I would like to emphasize that all our patients can look to the future with hope. Of course, they will have to be patient for a while."

Ezgu noted the significant support from Türkiye's Health Ministry, the Turkish Medicines and Medical Devices Agency, as well as the country's health institutes for these studies.

He also highlighted the collaboration with various departments such as pediatric neurosurgery, anesthesia, otolaryngology, and radiology.

Ezgu added that the clinical research at the center is carried out by a professional team dedicated to ensuring that patients receive better healthcare in the future.