Vismodegib

Evidence Level: L5

Predicted Indications: 8

Vismodegib

Pharmacist Assessment Report

Vismodegib: From Basal Cell Carcinoma to Medulloblastoma with Extensive Nodularity

One-Sentence Summary

Vismodegib is an oral Hedgehog pathway inhibitor, originally used for basal cell carcinoma and related skin cancers. The TxGNN model predicts it may be effective for medulloblastoma with extensive nodularity, but the data compiled for this report contain 0 clinical trials and 0 publications for this specific subtype, so the prediction rests on the model score and mechanistic reasoning alone.

Quick Overview

Item	Content
Original Indication	Basal cell carcinoma (also skin carcinoma, sweat gland cancer, sebaceous adenocarcinoma)
Predicted New Indication	Medulloblastoma with extensive nodularity
TxGNN Prediction Score	0.9993
Evidence Level	L5
Canada Market Status	Marketed (marketed DINs: 1 of 1)
Number of DINs	1 (marketed: 1)
Recommended Decision	Hold

Why is This Prediction Reasonable?

Vismodegib inhibits Smoothened (SMO), a key signalling protein in the Hedgehog pathway. Basal cell carcinoma is driven by abnormal Hedgehog signalling, which is why blocking SMO works in that disease.

Medulloblastoma of the SHH subgroup is also driven by Hedgehog signalling. This is the mechanistic basis for the TxGNN prediction. Medulloblastoma with extensive nodularity is a recognised histological variant, and the prediction is plausible in principle.

However, the data compiled for this report contain no trials or publications for this subtype, and nothing confirms that this variant is Hedgehog-dependent. Prior experience with SMO inhibitors in paediatric medulloblastoma exists outside the data supplied and was not evaluated here. The assessment is therefore prediction-only.

Clinical Trial Evidence

Currently no related clinical trials registered.

Literature Evidence

Currently no related literature available.

Canada Market Information

DIN	Product Name
02409267	ERIVEDGE

Dosage form and approved indication text are not available in the compiled data.

Cytotoxicity

Item	Content
Cytotoxicity Classification	Targeted therapy (Hedgehog pathway / SMO inhibitor)
Myelosuppression Risk	Please refer to the package insert warnings and precautions
Emetogenicity Classification	Please refer to the package insert warnings and precautions
Monitoring Items	Please refer to the package insert warnings and precautions
Handling Protection	Please refer to the package insert warnings and precautions

Safety Considerations

Drug Interactions: 56 interactions were identified in total, and 20 are itemised in the compiled data.
- Moderate: clarithromycin.
- Minor: the remaining 19 itemised interactions, mostly acid-reducing agents and antacids. These include H2 blockers (famotidine, ranitidine, cimetidine, nizatidine), proton pump inhibitors (omeprazole, esomeprazole, lansoprazole, dexlansoprazole, pantoprazole, rabeprazole), and antacids (aluminum hydroxide, calcium carbonate, magnesium salts, sodium bicarbonate, sodium citrate).

Please refer to the package insert for warnings and contraindications.

Conclusion and Next Steps

Decision: Hold

Rationale: The prediction is mechanistically plausible because of SHH-driven medulloblastoma, but it has a very high model score and no supporting trials or literature for this subtype (L5). Safety label data are also missing, so the candidate cannot move to safety screening.

Other candidates in the compiled data have more support:

Skin cancer (L2) has several Phase 2 trials, though these are small, of uncertain status, or basket-style, and no Phase 3 RCT is present. It is closer to an indication expansion than true repurposing.
Xeroderma pigmentosum (L4) has two case reports of vismodegib treating associated basal cell carcinoma.

To proceed, the following is needed:

Health Canada package insert warnings and contraindications.
Detailed mechanism of action data.
A search for trials and literature on SMO inhibitors in medulloblastoma, including the extensive nodularity variant.
Confirmation of Hedgehog pathway dependence in this histological variant.
A paediatric-specific safety assessment, since medulloblastoma commonly affects children.
Disclaimer

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