A Study to Evaluate the Effects and Safety of Hydroxocobalamin in Participants With Combined Methylmalonic Academia (cblC Type)

What Was Tested

In this phase 3 trial, researchers set out to test Cyanocobalamin (Vitamin B12).

It had 1 arm (groups): Hydroxocobalamin Chloride Injection (experimental).

Hydroxocobalamin Chloride Injection.

The registry classes the interventions as drug.

Who Took Part

20 planned participants were the target.

It was open to people of any sex aged from 6 months up to 18 years.

Healthy volunteers were not accepted; participants needed the condition being studied.

Examples of who could join: Age 6 months (inclusive) to \< 18 years at the time of first investigational product administration; both sexes eligible. Confirmed diagnosis of cobalamin C (cbl C)-type methylmalonic acidemia (MMA) fulfilling ALL of the following:. Investigator-assessed clinical stability, defined as:. No emergency room visits or hospitalizations within 6 months prior to screening for metabolic crises (e.g., electrolyte disturbances, metabolic acidosis, dysglycaemia, multi-organ failure); AND. Plasma methylmalonic acid within the normal reference range at screening.

The full record lists 10 inclusion and 19 exclusion criteria; among the exclusions: use of any vitamin b12 preparation other than injectable hydroxocobalamin within 3 months prior to screening; prior liver or kidney transplantation, or any prior cell-based therapy; any of the following laboratory abnormalities:.

How the Study Was Run

The set-up was single-group and open-label.

Nothing was hidden in this open-label Cyanocobalamin (Vitamin B12) study: the participants and staff both knew the treatment.

Everyone received the same intervention, so there was no separate comparison group inside the trial.

It started in 2025-08-31 with completion listed for 2026-10-08.

Its stated primary purpose is treatment.

What Was Measured

It also tracked 11 secondary outcomes, for example Change from baseline in plasma total homocysteine level, Change from baseline in plasma propionylcarnitine (C3), plasma C3/acetylcarnitine (C2) ratio, and urinary methylcitrate, Change from baseline in plasma methylmalonic acid concentration, Change from baseline in urinary methylmalonic acid excretion, Proportion of participants achieving plasma methylmalonic acid levels within the normal reference range and Proportion of participants achieving urinary methylmalonic acid levels within the normal reference range.

What This Means in Plain Language

Put simply, this is a phase 3 trial of Cyanocobalamin (Vitamin B12) in 20 people.

Its size is small, so on its own it can only give an early look.

Its status is not yet recruiting; no results are posted to the registry yet, so nothing here describes outcomes.

More context: the Cyanocobalamin (Vitamin B12) compound page, all human trials.