Working to Improve Methylmalonic Acidemia (MMA) Treatment

If your child has been diagnosed with MMA, you may be interested in enrolling in a clinical trial studying a new investigative treatment option.

Working to Improve Methylmalonic Acidemia (MMA) Treatment

If your child has been diagnosed with MMA, you may be interested in enrolling in a clinical trial studying a new investigative treatment option.

About MMA and the reiMMAgine trial

MMA is a rare genetic disease that affects the body’s ability to metabolize certain amino acids and fats. It can cause frequent hospitalizations or metabolic decompensations, resulting in lethargy, vomiting, dehydration, and decreased muscle tone. Long-term complications can cause feeding problems, developmental delays, intellectual disability, and chronic kidney disease.

The reiMMAgine trial is a Phase 1/2 study which aims to investigate how children diagnosed with mut subtype isolated MMA respond to the gene therapy SEL-302 (a combination of SEL-110 and MMA-101), and if the study medication will help with their symptoms.

During the trial, SEL-302 is given once. Then SEL-110 alone will be given at month 1 and again at month 2 for a total of 3 doses. All patients will be monitored with standard clinical and laboratory evaluations throughout the trial.

All required

Participants must be between ages 3 and less than 18 years

Documented diagnosis of severe mut subtype MMA

Fully recovered from metabolic ketoacidosis or surgery at least 4 weeks before screening

If you are interested in participating in the study, you will need to provide medical records for review and undergo preliminary screening evaluations including blood tests. Additional criteria will need to be met and will be discussed with a doctor.

  • Must be 3 to <18 years at the time of consent
  • Diagnosis of mut type MMA by genetic testing and a confirmed diagnosis of severe MMA
  • A clinical history consistent with severe MMA
  • Fully recovered from any hospitalization for metabolic ketoacidosis or surgery at least 4 weeks prior to start of screening period
  • Parent or legal guardian able to provide informed consent

Additional detailed information on the Inclusion criteria can be found at

  • History of liver transplant or any organ transplant
  • History of cancer or other immunocompromising condition
  • History or presence of arrhythmia
  • History of severe allergic reaction to drug therapy, foods, etc.
  • Recipient of live virus vaccine in previous 6 weeks
  • Previously received gene therapy or mRNA for MMA
  • Participated in another clinical trial within 30 days prior to screening
  • Has any other clinically significant medical condition that could interfere with interpretation of study results or limit the subject’s participation in the study

Additional detailed information on the Exclusion criteria can be found at


A clinical trial is a research study conducted in human beings with the goal of answering questions concerning safety, tolerability, and efficacy of a new therapeutic. A First-in-Human (FIH) trial is a type of clinical trial in which a new drug is tested in humans for the first time. FIH studies take place after the new treatment shows promising possibility and has been tested in the laboratory and in animals.


To participate in any clinical trial, you must meet all eligibility criteria and be willing to follow the directions of the study doctor. A team of doctors, nurses, and trial coordinators will be working closely with you throughout the trial to monitor any symptoms or changes and ensure you remain comfortable and informed.

MMA-101 is an AAV-based (adeno-associated virus) gene therapy for the treatment of MMA. AAV is one of the most common vectors used in gene therapy and is used in many cell types, such as the liver, muscle, and central nervous system. MMA-101 contains the gene for methylmalonyl-CoA (MMUT) that will express this protein in the liver, aiming to provide a long-term correction for mut subtype MMA patients. MMA-101 received rare pediatric disease designation from the FDA in October 2020.

Inclusion of SEL-110 in the treatment regimen with MMA-101 has multiple potential benefits. The first is the potential to reduce or eliminate the formation of proteins in the blood that defend against MMA-101. This opens the possibility of redosing MMA-101 in the future if necessary. Second, SEL-110 may enhance the safety of gene therapy by reducing liver inflammation and ultimately stabilizing liver function. Lastly, SEL-110 may improve MMA-101 efficacy by enhancing expression and durability of the MMUT gene within MMA-101 while reducing immune responses against it. The MMUT gene plays a critical role in making an enzyme that serves as energy-producing centers within the cell.

The visits and all testing are free and there is no cost to you, your family, or your insurance company for this study. Selecta will pay for most of your travel expenses. If you live locally (near the NIH) we will give you some money for meals and provide lodging if necessary. If you live further away, Selecta will pay for your transportation to NIH (plane, car mileage, train, etc.), lodging, and give you some money for meals. Travel must be arranged by NIH. Participants in the study do not receive any compensation other than travel and lodging expenses.

You may respond to the study treatment, but we cannot be certain it will be effective. The study treatment may reduce the symptoms of severe MMA. There is no guarantee that you will experience any benefits from this study.

The study requires that participants remain at the NIH for 3 months for dosing. The participant will also need to travel to the NIH for assessment at 6 months (168 days) and one year (364 days) following drug administration as well as for a long-term follow-up four years after the end of the study (day 364). The total planned duration of participation in this study is approximately 5 years and 3 months.

Navigating care for someone with MMA can affect every facet of life, and feelings of uncertainty are common. The below resources may help you find valuable information.

Resources on MMA

Study Locations

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