Long-term evaluation of mRNA-3705 for treating methylmalonic acidemia

A Phase 1/2, Global, Open-Label, Extension Study to Evaluate the Long-Term Safety and Clinical Activity of mRNA-3705 in Participants Previously Enrolled in Other Clinical Studies of mRNA-3705

Phase1; Phase2 Interventional ModernaTX, Inc. · NCT05295433

This study is testing if a new treatment called mRNA-3705 is safe and effective for people with methylmalonic acidemia who have already tried it in previous studies.

Quick facts

PhasePhase1; Phase2
Study typeInterventional
Enrollment56 (estimated)
Ages1 Year and up
SexAll
SponsorModernaTX, Inc. Industry-sponsored
Locations12 sites (Los Angeles, California and 11 other locations)
Trial IDNCT05295433 on ClinicalTrials.gov

What this trial studies

This study aims to assess the long-term safety and clinical effectiveness of mRNA-3705 in patients with isolated methylmalonic acidemia (MMA) who have previously participated in other studies involving this treatment. Participants will undergo a Treatment Period followed by a Follow-up Period lasting up to two years after their last dose. The study will monitor safety and clinical outcomes, with the possibility of transitioning to market access if mRNA-3705 receives approval. The goal is to ensure continuous treatment without interruption for eligible participants.

Who should consider this trial

Good fit: Ideal candidates are individuals with isolated methylmalonic acidemia due to methylmalonyl-coenzyme A mutase deficiency who have previously participated in mRNA-3705 studies.

Not a fit: Patients who are not expected to receive clinical benefit from continued mRNA-3705 administration, as determined by the investigator, will not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide a long-term treatment option for patients with methylmalonic acidemia, potentially improving their health outcomes.

How similar studies have performed: Other studies involving mRNA therapies have shown promise, indicating potential for success with this approach, although this specific extension study is novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Completed the assigned dose regimen treatment time period in other clinical studies of mRNA-3705 or is eligible for early transition to this study because they missed more than 3 consecutive doses of study drug due to coronavirus disease 2019 (COVID-19) vaccination during Study mRNA-3705-P101 Part 1.
* Completed the End of treatment (EOT) Visit (or End of Study Visit in the case of unscheduled dosing) in Study mRNA-3705-P101 within 10 days of their first dose of mRNA-3705 in this extension study.

Exclusion Criteria:

* Not expected to receive clinical benefit from continued mRNA-3705 administration, in the opinion of the Investigator.
* Any clinical or laboratory abnormality or medical condition that, at the discretion of the Investigator, may put the individual at increased risk by participating in this study.
* History of liver and/or kidney transplant.

NOTE: Other inclusion and exclusion criteria may apply.

Where this trial is running

Los Angeles, California and 11 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Methylmalonic AcidemiaIsolated Methylmalonic acidemiaIsolated methylmalonic aciduriaElevated methylmalonic acidMetabolism, Inborn ErrorsGenetic DiseasesModernamRNA
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.