Participants in this study will be assigned to receive either MRM-3379, which is taken as a hard capsule by oral use, or a placebo. This is a double-blind study, meaning that neither the participants nor the researchers know who is receiving the active medication or the placebo during the course of the trial. The study will monitor how the body processes the drug and observe any side effects that may occur.

The study will involve adult males between 18 and 45 years old who have been diagnosed with Fragile X syndrome through genetic testing. Participants will need to have a parent or caregiver who can attend all study visits with them and help provide information throughout the study. The treatment period will last for 42 days, with the maximum daily dose being 150 milligrams of CTH120. During the study, doctors will monitor participants for any unwanted effects and will check vital signs, heart activity through an ECG (a test that records the electrical activity of the heart), and laboratory test results from blood samples.

Throughout the study, various assessments will be performed to understand how the treatment affects participants. These will include measurements of behavior, thinking abilities, anxiety levels, sleep quality, daily living skills, and overall quality of life through questionnaires completed by caregivers. The study will also use electroencephalography (a test that measures brain wave activity), eye-tracking technology to observe social attention, and activity monitors worn on the body to track movement and sleep patterns. Blood samples will be taken to measure drug levels and certain proteins including FMRP (a protein that is typically low or absent in people with Fragile X syndrome) and BDNF (a substance that supports nerve cell health).

The purpose of the study is to assess how well the ZYN002 gel works and how safe it is for patients with Fragile X Syndrome. Participants in the study will be randomly assigned to receive either the ZYN002 gel or a placebo gel, which looks the same but does not contain the active ingredient. The study will last for a period of 16 weeks, during which participants will apply the gel to their skin as directed. Throughout the study, participants will be monitored to see if there are any changes in their behavior and to ensure their safety.

Researchers will be looking at specific aspects of behavior, such as social interactions and irritability, to determine if there are improvements from the start of the study to the end. The study aims to provide valuable information on whether the ZYN002 gel can be a helpful treatment option for managing symptoms of Fragile X Syndrome.

Participants in this study include children, adolescents, and young adults who have previously been involved in a study with the same treatment. They continue to use the gel because their caregivers believe it has been beneficial. The study will last for up to 48 months, during which time the participants will regularly apply the gel and attend follow-up visits to monitor their health and any changes in their symptoms.

Throughout the study, various assessments will be conducted to ensure the safety of the participants. These include physical and neurological examinations, heart tests using a method called 12-lead ECG, and laboratory tests to check blood and urine. Additionally, the study will observe any changes in behavior and symptoms related to Fragile X Syndrome to understand the long-term impact of the treatment. Participants and their caregivers will be asked to provide feedback on any improvements or side effects they notice during the study.