Ongoing Clinical Trials for Mitochondrial DNA Depletion
There is currently 1 ongoing clinical trial for mitochondrial DNA depletion, specifically focusing on Thymidine Kinase 2 (TK2) Deficiency. This trial is investigating a combination treatment of doxecitine and doxribtimine oral solution for patients who have previously received nucleoside therapy. The study is being conducted in Spain and aims to evaluate the safety and effectiveness of continued treatment with these investigational medications.
Clinical trial locations
Study of Doxecitine and Doxribtimine Oral Solution for Treatment of Patients with Thymidine Kinase 2 (TK2) Deficiency Who Have Previously Received Treatment
This clinical trial is designed for patients with Thymidine Kinase 2 Deficiency, a rare genetic condition that affects how the body produces energy in cells. TK2 deficiency causes problems with an enzyme called thymidine kinase 2, which is essential for creating DNA building blocks in mitochondria, the powerhouses of cells. This condition primarily impacts muscle tissues, leading to progressive muscle weakness that affects movement, breathing, and swallowing.
Main inclusion criteria:
- Patients must have confirmed genetic mutations in the TK2 gene
- Must be currently receiving nucleoside treatment for TK2 deficiency
- For female participants aged 10 years or older, a negative pregnancy test is required
- Participants must be willing to maintain their current treatment and exercise routines throughout the study
- Both patients and their parents or legal guardians must sign informed consent forms
- Female participants of childbearing age must use effective birth control during the study and for 30 days after, and male participants must use condoms during the same period
Main exclusion criteria:
- Patients who have not previously received treatment with specific nucleoside medications such as dC/dT, dCMP/dTMP, or doxecitine and doxribtimine
- Individuals unable to comply with study procedures and follow-up visits
- Patients with known allergies or severe reactions to the study medications
- Those participating in other clinical trials at the same time
- Patients with severe liver or kidney problems
- Pregnant women, women planning to become pregnant, or breastfeeding mothers
- Patients who have had major surgery within 30 days before starting the study
- Individuals with serious medical conditions that could interfere with study participation
Focus and goal of the trial:
The primary goal of this study is to evaluate how safe and effective continued treatment with doxecitine and doxribtimine is for patients who have previously received similar treatments for their TK2 deficiency. The medications are given as an oral solution, with doses calculated based on the patient’s weight up to a maximum of 800 milligrams per kilogram per day.
During the study, which may last up to 72 months (running from September 2019 to June 2025), participants will continue their current treatment while researchers closely monitor their health. The trial includes comprehensive monitoring through regular blood tests, heart monitoring using electrocardiograms, and tracking of any side effects. Researchers will also conduct movement ability tests, breathing tests to check lung function, feeding status monitoring, and quality of life questionnaires. For participants under 18 years of age, growth will also be tracked. Additionally, blood samples will be taken to measure drug levels and other important markers, and the medication’s taste will be assessed using a simple rating scale.
Investigational drugs:
The study investigates a combination of doxecitine and doxribtimine, which are pyrimidine nucleosides that help replace missing components in cells affected by TK2 deficiency. These medications work together to support proper cellular function by providing essential building blocks for mitochondrial DNA synthesis, helping to compensate for the defective TK2 enzyme and improve cellular energy production.
The trial also references other similar formulations, including dCMP/dTMP and dC/dT, which are combination pyrimidine nucleoside therapies that work in a similar manner to restore normal cellular processes in patients with this genetic condition. These medications all aim to provide the body with important cellular building blocks that are lacking due to the genetic defect.
Summary
Currently, there is one active clinical trial addressing mitochondrial DNA depletion, specifically targeting Thymidine Kinase 2 Deficiency. This trial is being conducted exclusively in Spain and represents an important continuation study for patients who have already received nucleoside therapy. The focus on combination therapy with doxecitine and doxribtimine reflects an ongoing effort to optimize treatment for this rare genetic condition. The extended study duration of up to 72 months demonstrates a commitment to long-term safety and efficacy monitoring. This trial is particularly significant as it serves patients who have already begun treatment, providing valuable data on sustained therapy outcomes for this challenging condition.
