An Extension Study to Evaluate the Long-Term Safety and Clinical Activity of mRNA-3705 in Participants Previously Enrolled in the mRNA-3705-P101 Study
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ClinicalTrials.gov Identifier: NCT05295433 |
Recruitment Status :
Recruiting
First Posted : March 25, 2022
Last Update Posted : December 22, 2022
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Condition or disease | Intervention/treatment | Phase |
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Methylmalonic Acidemia | Drug: mRNA-3705 | Phase 1 Phase 2 |
Participants with isolated MMA due to MUT deficiency who were previously enrolled in the mRNA-3705-P101 study will have the option to enroll into this extension study provided all eligibility criteria have been met. The study will include 2 periods: 1) Treatment Period and 2) Follow-up Period (up to 2 years after the last dose of study drug).
Treatment Period will continue unless one of the following occurs: mRNA-3705 receives marketing approval and reimbursement in the country of origin of the participant, the participant discontinues study drug, the participant is no longer receiving clinical benefit (in the opinion of the Investigator), or Sponsor discontinues the development of mRNA-3705.
Study Type : | Interventional (Clinical Trial) |
Estimated Enrollment : | 33 participants |
Allocation: | N/A |
Intervention Model: | Single Group Assignment |
Masking: | None (Open Label) |
Primary Purpose: | Treatment |
Official Title: | 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 the mRNA-3705-P101 Study |
Actual Study Start Date : | March 8, 2022 |
Estimated Primary Completion Date : | April 1, 2032 |
Estimated Study Completion Date : | April 2, 2034 |

Arm | Intervention/treatment |
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Experimental: mRNA-3705
Participants will receive mRNA-3705 at the same dose levels at the same dosing interval (every 2 weeks [q2W], every 3 weeks [q3W], or every 4 weeks [q4W]) last received in the mRNA-3705-P101 study, unless the Sponsor recommends modification.
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Drug: mRNA-3705
A sterile liquid for injection
Other Names:
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- Number of Participants With Treatment-Emergent Adverse Events (AEs) [ Time Frame: Baseline up to follow-up period (up to 8 years) ]
- Change in Methylmalonic Acid and 2-Methylcitric Acid (2-MC) Levels (Primary Biomarkers) From Baseline up to 8 Years [ Time Frame: Baseline, Year 8 ]
- Pre- and Postdose Human Methylmalonyl-Coenzyme A Mutase (hMUT) mRNA and SM-86 Levels [ Time Frame: Baseline up to 6 years ]
- Number of Clinically Significant Events [ Time Frame: Baseline up to 8 years ]Clinically significant event is defined as a composite of the following: - Hospitalization (excluding hospitalizations for chronic diseases not related to MMA or elective hospitalizations for conditions not related to MMA); Emergency room visits; and Emergency interventions outside of healthcare settings to prevent an metabolic decompensation event (MDE) (sick-day diets and fluid resuscitation at home).
- Number of MDEs [ Time Frame: Baseline up to 8 years ]
- Number of Healthcare Resource Utilization Visits [ Time Frame: Baseline up to 8 years ]
- Change in Disease Impact on Missed School and Workdays From Baseline up to 8 Years [ Time Frame: Baseline, Year 8 ]
- Number of Anti-Polyethylene Glycol (PEG) and Anti-hMUT Antibodies [ Time Frame: Baseline up to 8 years ]
- Change in Health-Related Quality of Life (HRQoL) as Measured Using the Pediatric Quality of Life Inventory (PedsQL™) at Month 3 up to 8 Years [ Time Frame: Month 3, Year 8 ]

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Ages Eligible for Study: | 1 Year and older (Child, Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Inclusion Criteria:
- Completed the mRNA-3705-P101 assigned dose regimen treatment time period or is eligible for early transition to this study due to missing more than 3 consecutive doses of study drug due to coronavirus disease 2019 (COVID-19) vaccination during the mRNA-3705-P101 study.
- Completed the EOT Visit in Study mRNA-3705-P101 within 10 days of first dose of mRNA-3705 in the current 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.

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT05295433
Contact: Moderna Clinical Trials Support Center | 1-877-777-7187 | clinicaltrials@modernatx.com |
Canada, Ontario | |
Hospital For Sick Children | Recruiting |
Toronto, Ontario, Canada, M5G 1X8 | |
United Kingdom | |
Birmingham Children's Hospital NHS Foundation Trust | Recruiting |
Birmingham, United Kingdom, B4 6NH |
Responsible Party: | ModernaTX, Inc. |
ClinicalTrials.gov Identifier: | NCT05295433 |
Other Study ID Numbers: |
mRNA-3705-P101-EXT 2021-000446-17 ( EudraCT Number ) |
First Posted: | March 25, 2022 Key Record Dates |
Last Update Posted: | December 22, 2022 |
Last Verified: | December 2022 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | Undecided |
Studies a U.S. FDA-regulated Drug Product: | Yes |
Studies a U.S. FDA-regulated Device Product: | No |
Product Manufactured in and Exported from the U.S.: | Yes |
Isolated Methylmalonic acidemia Isolated methylmalonic aciduria Elevated methylmalonic acid (MMA) Metabolism, Inborn Errors |
Genetic Diseases Moderna mRNA mRNA-3705 |