A Study to Assess Safety, Pharmacokinetics, and Pharmacodynamics of mRNA-3705 in Participants With Isolated Methylmalonic Acidemia

  • End date
    Aug 1, 2028
  • participants needed
  • sponsor
    ModernaTX, Inc.
Updated on 10 July 2022


This is a study of mRNA-3705 in participants with isolated elevated methylmalonic acid (MMA) due to methylmalonyl-coenzyme A (CoA) mutase (MUT) deficiency. The main goal of the study is to assess safety, pharmacokinetics, and pharmacodynamics of mRNA-3705.


This study comprises 2 stages; a Dose Optimization Stage followed by an optional Dose Expansion Stage. The study is designed to evaluate multiple doses and dosing intervals of mRNA-3705.

In both stages, after confirmation of eligibility, participants will enter an Observation Period (48 to 72 hours pre-dose), which includes 24 hours inpatient hospital stay, followed by a Treatment Period (up to 40 weeks). Participants who complete the Treatment Period, including the End of Treatment (EOT) Visit, are offered participation in the mRNA-3705 extension study. If the participant chooses to participate and meets eligibility criteria, they will be enrolled in the extension study; otherwise, they will transition to the 2-year follow-up part of this study.

Condition Methylmalonic Acidemia
Treatment mRNA-3705
Clinical Study IdentifierNCT04899310
SponsorModernaTX, Inc.
Last Modified on10 July 2022


Yes No Not Sure

Inclusion Criteria

Participant has a body weight of ≥11.0 kilograms (kg) at the Screening Visit
Participant has a diagnosis of isolated MMA due to MUT deficiency confirmed by molecular genetic testing
Participant has a serum/plasma vitamin B12 level equal to or above the lower limit of normal (based on laboratory reference range) confirmed in the Screening Period. For those participants found to have an elevated serum/plasma vitamin B12 level, the participant may enter if, in the opinion of the Investigator, the cause of the elevation is secondary to B12 supplementation
Participant or his/her legally authorized representative is willing and able to provide informed consent and/or assent as mandated by local regulations and willing and able to comply with study-related assessments
Sexually active females of childbearing potential and sexually active males of reproductive potential agree to use a highly-effective method of contraception during the study and for 3 months after the last administration of study drug

Exclusion Criteria

Participant has a diagnosis of isolated MMA cb1A, cb1B, or cb1D enzymatic subtypes or methylmalonyl-CoA epimerase deficiency or combined MMA with homocystinuria
Participant has previously received gene therapy for the treatment of MMA
Participant has a history of organ transplantation
Participant has an active, unstable, or clinically significant medical condition not related to MMA or history of noncompliance that, in the Investigator's opinion, could potentiate the risk while participating in this study, interfere with the interpretation of study results, or limit the participant's participation in the study. This may include, but is not limited to, history of relevant food or drug allergies; history of cardiovascular, central nervous, gastrointestinal, or infectious disease; history of clinically significant pathology; and/or history of cancer
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Additional screening procedures may be conducted by the study team before you can be confirmed eligible to participate.

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If you are confirmed eligible after full screening, you will be required to understand and sign the informed consent if you decide to enroll in the study. Once enrolled you may be asked to make scheduled visits over a period of time.

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Complete your scheduled study participation activities and then you are done. You may receive summary of study results if provided by the sponsor.

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