Temozolomide

Evidence Level: L5

Predicted Indications: 1

Temozolomide

Pharmacist Assessment Report

Temozolomide: From Anaplastic Astrocytoma / Glioblastoma to Cauda Equina Neoplasm

One-Sentence Summary

Temozolomide is an oral alkylating chemotherapy drug. Its original uses in the knowledge graph are brain tumours: anaplastic astrocytoma, astrocytoma (excluding glioblastoma) and glioblastoma. The TxGNN model predicts it may be effective for cauda equina neoplasm, but there are no registered clinical trials and only 3 publications (all case reports, one directly about a spinal tumour), so the evidence is very limited.

Quick Overview

Item	Content
Original Indication	Anaplastic astrocytoma, astrocytoma (excluding glioblastoma), brain glioblastoma (relations recorded in the knowledge graph; the Canadian licence records compiled here contain no indication text)
Predicted New Indication	Cauda equina neoplasm
TxGNN Prediction Score	0.9930
Evidence Level	L5
Canada Market Status	Marketed (marketed DINs on record: at least 20)
Number of DINs	at least 20
Number of approvals	At least 20 DINs (the list may be partial)
Recommended Decision	Hold

Why is This Prediction Reasonable?

Detailed mechanism-of-action data is not available in the data compiled for this report. Based on general knowledge of the drug class, temozolomide is an oral alkylating agent that methylates DNA (O6-guanine, N7-guanine, N3-adenine). This causes cytotoxic lesions and apoptosis in tumour cells, and the drug crosses the blood-brain barrier.

Cauda equina neoplasms are most often myxopapillary ependymomas, which are glial tumours of the central nervous system axis. The score comes from the TxGNN model (deep learning) and may reflect similarities the model learned between related diseases, such as the astrocytic and glial brain tumours for which temozolomide is a known use, not biological evidence.

Activity probably depends on MGMT promoter methylation status, which is not reported for the available cases. The very high TxGNN score is a computational prediction only and does not replace clinical evidence.

Clinical Trial Evidence

Currently no related clinical trials registered.

Literature Evidence

PMID	Year	Type	Journal	Key Findings
29270703	2018	Case report	Eur Spine J	Temozolomide showed remarkable efficacy in a relapsed spinal myxopapillary ependymoma with multiple recurrences and cerebrospinal dissemination
42760727	2026	Case report	Medicine	Nasal NUT carcinoma with repeated responses to multimodal treatment including radiotherapy; indirectly related to the predicted disease
18706663	2009	Case report	Neuro-Chirurgie	Atypical neuromeningeal cryptococcosis in a child treated for pontine glioma; not about the predicted disease

Only one report (PMID 29270703) concerns a tumour of the cauda equina region (spinal myxopapillary ependymoma), and it is a single case. No cited study directly addresses cauda equina neoplasm as a defined disease, so the evidence level is L5.

Canada Market Information

Temozolomide is marketed in Canada as single-ingredient products. At least 20 DINs are on record; the list may be partial. The records compiled here have no dosage form or approved indication text. Representative authorizations:

DIN	Product Name	Dosage Form	Approved Indication
02241093	TEMODAL	Not available	Not available
02241094	TEMODAL	Not available	Not available
02241096	TEMODAL	Not available	Not available
02312794	TEMODAL	Not available	Not available
02389835	ACH-TEMOZOLOMIDE	Not available	Not available

Other generic versions include TARO-TEMOZOLOMIDE, TEVA-TEMOZOLOMIDE and JAMP TEMOZOLOMIDE.

Cytotoxicity

Item	Content
Cytotoxicity Classification	Conventional cytotoxic (alkylating agent)
Myelosuppression Risk	Medium to high; the knowledge graph lists neutropenia, thrombocytopenia, pancytopenia, lymphopenia and aplastic anaemia as contraindication-related conditions
Emetogenicity Classification	Please refer to the package insert warnings and precautions
Monitoring Items	CBC with differential, liver function
Handling Protection	Follow cytotoxic drug handling regulations

Safety Considerations

Contraindication-related conditions (knowledge graph relations, not label text): liver failure, thrombocytopenia, neutropenia, agranulocytosis, anaemia, macrocytic anaemia, pneumocystosis, pancytopenia, lymphopenia, myelodysplastic syndrome, idiopathic aplastic anaemia, aplastic anaemia.
Drug Interactions: 100 interactions were found in total. The only one rated Moderate is naltrexone. Levofloxacin is rated Minor. Most others (for example pantoprazole, omeprazole, lansoprazole, metformin, morphine, prednisone, hydrocortisone and doxycycline) have no assigned severity level.

Please refer to the package insert for the official warnings and contraindications.

Conclusion and Next Steps

Decision: Hold

Rationale: The prediction score is high and the mechanism is plausible, but the only supporting study on the target tumour area is a single case report, and no clinical trials are registered. Evidence is at the model-prediction level (L5). The package insert safety data are also missing.

To proceed, the following is needed:

Obtain the Health Canada package insert warnings and contraindications
Obtain official mechanism-of-action data
Systematically review reports of temozolomide in spinal or cauda equina ependymoma, including MGMT status
Assess the feasibility of a prospective study or registry
Define a safety monitoring plan for myelosuppression and hepatic risk
Disclaimer

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