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

NCT07163364 | Not Yet Recruiting Phase 3

• 1 other identifier: SYH9097-001
• Study Type: interventional
• Target: 20
• Locations: 0 countries
• Sites: N/A

Brief Summary

This study is a Single-Center, Single-Arm, open-label, Phase III clinical study to evaluate the efficacy, safety characteristics of Hydroxocobalamin Chloride Injection (20 mg/mL) for Maintenance Therapy in participants with Methylmalonic Acidemia (MMA) with Elevated Homocysteine (Cobalamin C Deficiency).

Conditions

Methylmalonic Acidemia (MMA)

Outcome Measures

Primary Outcomes (1)

• Proportion of participants achieving normalization of plasma or urinary methylmalonic acid levels post-dose.

  Week4、Week6、Week10、Week16、Week24

Secondary Outcomes (11)

• Change from baseline in plasma total homocysteine level.

  Day3、Week2、Week4、Week6、Week10、Week16、Week24、Week32、Week40、Week48

• Change from baseline in plasma propionylcarnitine (C3), plasma C3/acetylcarnitine (C2) ratio, and urinary methylcitrate.

  Day3、Week2、Week4、Week6、Week10、Week16、Week24、Week32、Week40、Week48

• Change from baseline in plasma methylmalonic acid concentration.

  Day3、Week2、Week4、Week6、Week10、Week16、Week24、Week32、Week40、Week48

• Change from baseline in urinary methylmalonic acid excretion.

  Day3、Week2、Week4、Week6、Week10、Week16、Week24、Week32、Week40、Week48

• Proportion of participants achieving plasma methylmalonic acid levels within the normal reference range.

  Week32、Week40、Week48

Study Arms (1)

Hydroxocobalamin Chloride Injection

EXPERIMENTAL

Hydroxocobalamin Chloride Injection

Drug: Hydroxocobalamin Chloride Injection

Interventions

Hydroxocobalamin Chloride Injection DRUG

1 - 20 mg per dose, 1 - 5 times per week

Hydroxocobalamin Chloride Injection

Eligibility Criteria

• Age: 6 Months - 18 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64)

You may qualify if:

• 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:
• Documented vitamin B12 responsiveness: ≥ 50 % reduction from pre-treatment baseline in plasma C3/C2 ratio and urinary methylmalonic acid following vitamin B12 therapy.
• Presence of pathogenic MMACHC gene variants in a participant with MMA associated with hyperhomocysteinemia.
• 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.
• Continuous treatment with injectable hydroxocobalamin for ≥ 3 months immediately preceding first dose of study drug.
• Written informed consent obtained from participant and/or legally authorised representative; willingness and ability to comply with all study visits and procedures.
• Female participants of childbearing potential (post-menarche) must have a negative serum β-hCG test at screening. All participants of reproductive potential (post-menarche females or males with documented spermarche) must use a highly effective contraceptive method throughout the study and for an appropriate post-study period as defined by local regulations.

You may not qualify if:

• Use of any vitamin B12 preparation other than injectable hydroxocobalamin within 3 months prior to screening.
• Participation in another clinical trial within 28 days or 5 half-lives of the investigational agent (whichever is longer) before screening initiation, except for screening-only participants who did not receive study drug.
• Prior liver or kidney transplantation, or any prior cell-based therapy.
• Any of the following laboratory abnormalities:
• Hemoglobin \< 90 g/L; or
• Platelet count \< 100 × 10⁹/L; or
• Estimated glomerular filtration rate (eGFR) \< 60 mL/min/1.73 m²; or
• Requirement for dialysis due to renal disease.
• Evidence of clinically significant hepatic dysfunction defined as:
• Alanine aminotransferase (ALT) \> 2.0 × upper limit of normal (ULN);
• Aspartate aminotransferase (AST) \> 2.0 × ULN or total bilirubin \> 1.5 × ULN;
• Prothrombin time \> 1.5 × ULN.
• Hyperammonemia characterised by blood ammonia ≥ 3 × ULN, or any acute metabolic decompensation (e.g., lethargy, restlessness, somnolence, feeding refusal, or vomiting).
• Evidence on prior imaging of a space-occupying lesion suspicious for malignancy, or any known history of malignancy.
• New York Heart Association (NYHA) Class III or IV heart failure, or moderate-to-severe pulmonary hypertension.

Sponsors & Collaborators

• CSPC ZhongQi Pharmaceutical Technology Co., Ltd.: lead

MeSH Terms

Conditions

Methylmalonic acidemia

Central Study Contacts

Clinical Trials Information Group officer

CONTACT

86-0311-69085587; ctr-contact@cspc.cn

Study Design

• Study Type: interventional
• Phase: phase 3
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Model Details: This study is a Single-Center, Single-Arm, open-label, Phase III clinical study

Study Record Dates

• First Submitted: August 19, 2025
• First Posted: September 9, 2025
• Study Start: August 31, 2025
• Primary Completion (Estimated): October 8, 2026
• Study Completion (Estimated): April 28, 2027
• Last Updated: September 9, 2025

Record last verified: 2025-08