Hydroxocobalamin

Evidence Level: L5

Predicted Indications: 10

Hydroxocobalamin
Hydroxocobalamin: From Vitamin B12 Deficiency to Esophageal Varices with Bleeding

## Pharmacist Assessment Report

Hydroxocobalamin: From Vitamin B12 Deficiency to Esophageal Varices with Bleeding

Note on scope: This Evidence Pack contains 10 TxGNN-predicted indications for Hydroxocobalamin. Per the reporting convention, this report focuses on the top-ranked prediction (Esophageal Varices with Bleeding). A summary of all 10 predictions is provided in the “Other Predicted Indications in This Batch” section, because the top-ranked prediction has no supporting evidence while a lower-ranked one does.

One-Sentence Summary

Hydroxocobalamin (DB00200) is the parenteral form of vitamin B12; formal original-indication and mechanism-of-action data are flagged as data gaps in this pack, and no EU marketing authorization record exists for it in this dataset. The TxGNN model’s top prediction is Esophageal Varices with Bleeding (score 99.23%), but this prediction currently has zero clinical trials and zero publications supporting it, and the model’s own rationale flags the mechanistic link as unsubstantiated — this is an L5, AI-prediction-only candidate.

Quick Overview

Item	Content
Original Indication	Not available in this pack (no EU license record; `original_indications` and `original_moa` are data gaps). Hydroxocobalamin is generally known as an injectable vitamin B12 form used for B12 deficiency and as a cyanide-poisoning antidote — general background knowledge, not confirmed by this Evidence Pack
Predicted New Indication	Esophageal Varices with Bleeding
TxGNN Prediction Score	99.23%
Evidence Level	L5 (model prediction only, no supporting trials or literature)
EU Market Status	Not Marketed
Number of Authorizations	0
Recommended Decision	Hold

Why is This Prediction Reasonable?

Currently, detailed mechanism of action data is not available for Hydroxocobalamin in this pack (flagged as a High-severity data gap, DG002). Based on known pharmacology, Hydroxocobalamin is a cobalamin (vitamin B12) analogue whose established actions are (1) correction of B12 deficiency and (2) detoxification of cyanide, via binding of the cyanide ion to form cyanocobalamin, which is renally excreted.

Esophageal varices with bleeding is a complication of portal hypertension secondary to cirrhosis — a vascular/hemodynamic disease process with no established connection to B12 metabolism or cyanide detoxification. The Evidence Pack’s own rationale for this prediction states that the high TxGNN score “very likely reflects an indirect connection through vascular/bleeding-related nodes in the knowledge graph, lacking pharmacological plausibility,” and no clinical trial or literature evidence was found for this drug–disease pair.

In short: mechanistically, this prediction is not well supported. The high score most plausibly reflects a knowledge-graph artifact (shared “bleeding/vascular” neighbor nodes) rather than a genuine pharmacological signal, and should be treated as a low-confidence hypothesis requiring independent mechanistic validation before any further investment.

Clinical Trial Evidence

Currently no related clinical trials registered.

Literature Evidence

Currently no related literature available.

EU Market Information

No EU marketing authorization records were found for Hydroxocobalamin in this dataset (market status: Not Marketed; 0 licenses on file).

Safety Considerations

Please refer to the SmPC for safety information.

(Key warnings, contraindications, and DDI data are all marked as data gaps in this pack — DG001, “TFDA/EMA label warnings and contraindications,” is flagged as a Blocking severity gap that must be resolved before any Stage 1 safety assessment.)

Other Predicted Indications in This Batch

Because the top-ranked prediction (above) has no supporting evidence, the full batch is summarized here for transparency:

Rank	Disease	TxGNN Score	Evidence Level	Decision Stage	Recommendation
1	Esophageal varices with bleeding	99.23%	L5	S0	Hold
2	Esophageal varices without bleeding	99.23%	L5	S0	Hold
3	Varicose disease	98.89%	L5	S0	Hold
4	Immune-mediated necrotizing myopathy	98.69%	L5	S0	Hold
5	Antisynthetase syndrome	98.64%	L5	S0	Hold
6	Focal myositis	98.56%	L5	S0	Hold
7	Inflammatory myopathy with abundant macrophages	98.46%	L5	S0	Hold
8	Idiopathic eosinophilic myositis	98.46%	L5	S0	Hold
9	Vitamin deficiency disorder	98.44%	L2	S3	Proceed with Guardrails*
10	Congenital prothrombin deficiency	98.32%	L5	S0	Hold

* Important caveat: “Vitamin deficiency disorder” is the only candidate in this batch with real supporting evidence (below), but this most likely represents Hydroxocobalamin’s already-established core use (B12/cobalamin deficiency treatment) resurfacing as a “new” prediction — an artifact of the original_indications field being empty in this pack (data gap), not a genuine repurposing discovery. It is presented below for completeness, not as the headline finding.

Supporting Evidence for “Vitamin Deficiency Disorder” (Rank 9, for reference only)

Clinical Trials (10 most relevant of 50 returned, by relevance grade):

Trial Number	Phase	Status	Enrollment	Key Findings
NCT06441721	N/A	Not yet recruiting	60	Evaluates B12 level in chronic haemodialysis patients and its effect on anaemia and neuropathy
NCT00843453	N/A	Completed	36	Long-term PPI use and B12 deficiency in institutionalized elderly; tested cyanocobalamin nasal spray for repletion
NCT00710138	N/A	Completed	100	Cobalamin status in young children with developmental delay/regression; cobalamin treatment resolved symptoms
NCT00326833	Phase 4	Unknown	50	Studies actual clinical need for vitamin B12 injection therapy
NCT05099185	N/A	Completed	39	Measures water-soluble vitamin (incl. B12) loss during post-dilution haemodiafiltration
NCT03489538	N/A	Completed	708	Homocysteine/B12-related metabolic changes after laparoscopic Roux-en-Y gastric bypass
NCT00276198	Phase 3	Completed	771	Multi-micronutrient (incl. B12) supplementation effect on nutritional/health indicators in infants
NCT04160767	Phase 4	Unknown	90	Probiotic supplementation effect on B6/B12/folate/vitamin D status in celiac patients
NCT01465867	N/A	Completed	56	Selenium (not B12) supplementation in autoimmune thyroid disease during pregnancy
NCT00197743	Phase 3	Completed	1085	General multivitamin supplementation in HIV+ pregnant women, not B12-specific

Literature (10 most relevant, prioritized by Guideline/Review tier):

PMID	Year	Type	Journal	Key Findings
24942828	2014	Guideline	British Journal of Haematology	Diagnosis/treatment guidelines for cobalamin and folate disorders
27905001	2017	Guideline	Journal of Inherited Metabolic Disease	Guidelines for cobalamin-related remethylation disorders (cblC, cblD, etc.)
25117994	2015	Review	European Journal of Clinical Nutrition	Clarifies treatment choice among methylcobalamin, cyanocobalamin, and hydroxocobalamin for B12 deficiency
25189324	2014	Review	BMJ	Overview of vitamin B12 deficiency
38987879	2024	Review	Food and Nutrition Bulletin	Brief overview of diagnosis and treatment of cobalamin (B12) deficiency
32332011	2020	Review	BMJ	Overview of pernicious anaemia
36669740	2023	Review	Revista Clínica Española	Vitamin B12/hydroxocobalamin uses beyond megaloblastic anemia
11757269	2001	Review	La Revue du Praticien	Biermer’s disease (autoimmune atrophic gastritis causing B12 deficiency)
26597770	2016	Review	Nutrition Research	Metabolic B12 deficiency as a missed opportunity to prevent dementia/stroke
4213505	1973	Case Report	Survey of Ophthalmology	Tobacco amblyopia case linked to B12 status

Conclusion and Next Steps

Decision: Hold

Rationale: The headline TxGNN prediction (Esophageal Varices with Bleeding, 99.23%) has no clinical trial or literature support and a mechanistically implausible rationale per the model’s own annotation — this does not meet even the lowest bar for further investment. The one candidate in this batch with real evidence (Vitamin Deficiency Disorder, L2/S3) is very likely a recapitulation of Hydroxocobalamin’s known core indication rather than a novel repurposing opportunity, given that original_indications is empty in the source data. Additionally, this drug has no EU marketing authorization on record and two critical drug-level data gaps (label warnings/contraindications — Blocking; MOA — High) remain unresolved, which independently precludes any safety-stage progression.

To proceed, the following is needed:

Resolve DG001 (Blocking): retrieve TFDA/EMA SmPC warnings and contraindications before any Stage 1 safety review
Resolve DG002 (High): confirm mechanism of action via DrugBank API to properly assess mechanistic plausibility
Backfill original_indications so genuine repurposing signals can be distinguished from known-indication recapitulation (needed to correctly interpret the Vitamin Deficiency Disorder result)
If Esophageal Varices with Bleeding is still of interest, commission dedicated preclinical/mechanistic studies, since no existing evidence base exists
Re-evaluate whether the 8 myositis/vascular predictions (ranks 1–8, all L5/S0) reflect a systematic knowledge-graph artifact rather than independent signals, given their near-identical, unsupported rationale pattern
Disclaimer

This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.