Repurposing 5-Azacytidine for the Treatment of Muscle Contractures in Children With Cerebral Palsy

In this controlled dose-escalation study, we will study the initial safety, biological properties, and potential efficacy of 5-azacytidine (AZA). Our overarching aspiration is for AZA to evolve into an approved pharmacological treatment, fostering muscle growth and enhancing body movement, ultimately contributing to an improved quality of life in children with CP.

The main questions this study aims to answer are:

1. What is the optimal dose of AZA injection that can be used safely in children with CP?
2. Can the optimal safe dose of AZA improve the function of muscle-generating stem cells in children with CP?

Each participant will have up to five research visits over the course of the study duration, in which they will participate in: blood draws, pregnancy test(s) (if applicable), medical assessments, and a muscle biopsy during a surgery for muscle contractures.

Researchers will compare participants with four different dosages of AZA injections to those with four different dosages of placebo injections. A placebo is a look-alike substance that contains no active drug. They will see if a single injection of AZA at a standard concentration currently approved by the FDA to treat myelodysplastic syndromes, can also safely improve muscle growth and function in children with CP.

Cerebral palsy (CP) has an enduring impact on the development of the muscles after birth. Research showed that a drug that is currently approved by the FDA to treat myelodysplastic syndromes in adults and children, can be potentially adapted ("repurposed") to support muscle growth. In a controlled dose-escalation study, we will study the preliminary safety, biological properties, and efficacy of this drug, called 5-Azacytidine (AZA). Our hope and overarching expectations are that one day AZA will become a new approved pharmacological treatment to support muscle growth and improve body movement and quality of life in children with CP.

Research participants will have five study visits.

1. The first study visit will be a screening within 30 days of the baseline visit and will determine eligibility for the study. The participant will have their blood drawn to check for normal kidney and liver functioning, do a pregnancy test (if applicable), and then the researcher will complete a medical assessment.
2. If the participant is eligible, they will be invited to a second study visit approximately 15 days prior to their scheduled surgery for contracture release. At this visit, the participants will get their blood drawn, do a pregnancy test (if applicable), have a medical assessment performed, and receive their injection. The injection will be a single sub-cutaneous shot in their leg, near the muscle group that will undergo surgical repair.
3. The third visit will be at the participant's scheduled surgery. A small sample of the muscle (i.e., about the size of a pencil eraser) will be surgically removed by the researcher from a muscle group that is already exposed during the procedure. The biopsy will add approximately two to five minutes to the overall procedure time. The participant will also have their blood drawn.
4. The participants will be seen approximately one week after their surgery to complete a medical assessment.
5. The last visit will be about four weeks after the surgery at their post-operative appointment. At this visit, the participant will have their blood drawn and complete a medical assessment to test their range of motion following the surgery.

The amount of blood drawn at each time point will be approximately 3 mL, equating to 12 mL of blood total (less than a tablespoon). The purpose of the blood draws is to evaluate safety and biological efficacy of the study drug. The medical assessment will consist of range of motion assessment and wound check performed by the clinicians. These are the same assessments that the clinicians would typically do as part of usual care prior to and after surgery. The purpose of the medical assessment is to evaluate the efficacy of the study drug and ensure the surgical site is healing.

Eligibility Criteria:
Inclusion Criteria:

1. Diagnosis of cerebral palsy.
2. Either achilles or hamstring spasticity with contracture necessitation surgical lengthening.
3. Between 2 and 18 years of age
4. Normal renal and liver function as defined by NCI-CTCAE criteria.71

   a. Renal Function (Grade 0 - Normal): i. Creatinine: Within the normal range or ≤ 1.0 times the upper limit of normal (ULN).

   ii. Glomerular filtration rate (GFR): No significant decrease. b. Liver Function (Grade 0 - Normal): i. Aspartate aminotransferase (AST) or alanine aminotransferase (ALT): Within the normal range or ≤ ULN.

   ii. Total bilirubin: Within the normal range or ≤ 1.0 times ULN
5. A negative pregnancy test for females of childbearing potential\*.
6. Females of childbearing potential must agree to use contraception consistently from screening to 6 months after their injection. Highly effective methods of contraception are required for females of childbearing potential:

   1. Total abstinence from sexual intercourse.
   2. Intrauterine device (IUD) or intrauterine hormone-releasing system (IUS).
   3. Combined (estrogen and progestogen containing) hormonal contraception associated with inhibition of ovulation, which may be oral, intravaginal, or transdermal used in accordance with medical direction.
   4. Progestogen-only hormonal contraception associated with inhibition of ovulation, which may be oral, injected, or implanted, and used in accordance with medical direction.
7. Males of childbearing potential\*\* must agree to use contraception consistently from screening until 3 months after the injection. Acceptable methods of contraception for males of childbearing potential are:

   1. Total abstinence from sexual intercourse.
   2. Condom with spermicide (cream, spray, foam, gel, suppository, or polymer film).

      * Female of childbearing potential is defined as a female capable of becoming pregnant, which includes patients who have had their first menstrual cycle (menarche).

        * Male of childbearing potential is defined as a subject who has reached spermarche.

Exclusion Criteria:

1. Active infection.
2. Cardiac disease.
3. Allergy to AZA or mannitol.
4. Patient or family who is non-compliant.
5. Received chemotherapy in the preceding three months.
6. Evidence of a hematologic precondition or other malignancy.