Temozolomide

證據等級: L5

預測適應症: 2 個

Temozolomide: From Glioblastoma/Anaplastic Astrocytoma to Adult Astrocytic Tumour

One-Sentence Summary

Temozolomide is an oral alkylating agent whose established therapeutic role is glioblastoma and anaplastic astrocytoma, delivered as concomitant and adjuvant chemotherapy with radiotherapy (the Stupp protocol). The TxGNN model's top prediction — Adult Astrocytic Tumour — largely restates this already-established standard of care rather than pointing to a genuinely new indication. The evidence base is unusually strong for a "prediction": 2 clinical trials (including a Phase 3 RCT with 500 patients) and 20 publications, several of them practice-defining RCTs (NEJM, Lancet, JAMA).

Quick Overview

Item	Content
Original Indication	Not recorded in the regulatory data provided (licenses list is empty). Per the literature and repurposing rationale in this pack, temozolomide's established indication is glioblastoma / anaplastic astrocytoma.
Predicted New Indication	Adult astrocytic tumour
TxGNN Prediction Score	99.36%
Evidence Level	L1
Germany Market Status	✗ Not marketed
Number of Authorizations	0
Recommended Decision	Proceed with Guardrails

Why is This Prediction Reasonable?

Currently, a structured mechanism-of-action record is not available for this drug (data gap DG002). However, the evidence pack's repurposing rationale describes temozolomide as an oral alkylating agent that crosses the blood–brain barrier and is converted to MTIC, which methylates DNA at the O6 position of guanine. This DNA damage triggers apoptosis and is particularly cytotoxic to rapidly proliferating glial tumour cells — the mechanistic basis for its activity in CNS malignancies.

Importantly, "adult astrocytic tumour" is not a distant or unexpected new indication for temozolomide — it sits within the drug's known therapeutic category (glioblastoma/anaplastic astrocytoma). The evidence pack itself flags this as "not a typical repurposing case, but rather an extension of existing clinical standard-of-care evidence (Stupp protocol)." In other words, TxGNN's top-ranked prediction here largely reconstructs a well-established indication rather than surfacing a novel therapeutic hypothesis. This should be factored into how the prediction is used: it is strong validation of the model's ability to recover known drug–disease links, but it should not be marketed internally as a "new" discovery.

Clinical Trial Evidence

Trial Number	Phase	Status	Enrollment	Key Findings
NCT00052455	Phase 3	Completed	500	RCT comparing temozolomide vs. PCV (procarbazine, lomustine, vincristine) in recurrent WHO grade III/IV astrocytic tumours; directly supports temozolomide's efficacy in this population.
NCT00960492	Phase 1	Completed	26	Dose-finding study of XL184 (cabozantinib) combined with temozolomide + radiotherapy in newly diagnosed glioblastoma; provides combination safety/PK data rather than temozolomide monotherapy evidence.

Literature Evidence

PMID	Year	Type	Journal	Key Findings
15758009	2005	RCT	N Engl J Med	Landmark EORTC-NCIC trial establishing concomitant + adjuvant temozolomide plus radiotherapy as the new standard of care for newly diagnosed glioblastoma.
19269895	2009	RCT	Lancet Oncol	5-year follow-up of the EORTC-NCIC trial confirming durable survival benefit of temozolomide + radiotherapy over radiotherapy alone.
22578793	2012	RCT	Lancet Oncol	NOA-08 Phase 3 trial: temozolomide alone vs. radiotherapy alone in elderly patients with malignant astrocytoma.
24552317	2014	RCT	N Engl J Med	RCT adding bevacizumab to standard temozolomide + radiotherapy in newly diagnosed glioblastoma; confirms temozolomide + radiotherapy as the standard-of-care backbone.
26670971	2015	RCT	JAMA	EF-14 trial: Tumor Treating Fields plus maintenance temozolomide vs. temozolomide alone, showing significantly improved overall survival with the combination.
30782343	2019	RCT	Lancet	CeTeG/NOA-09 Phase 3 trial: lomustine-temozolomide combination superior to temozolomide monotherapy in MGMT-methylated newly diagnosed glioblastoma.
40779733	2025	RCT	J Clin Oncol	NRG Oncology BN007 Phase II/III trial of dual immune checkpoint blockade in MGMT-unmethylated glioblastoma, with temozolomide-based standard therapy as background/comparator.
25920709	2015	Review	J Neurooncol	Exploratory cohort analysis of radiotherapy plus temozolomide in anaplastic astrocytic gliomas.
36809318	2023	Review	JAMA	Comprehensive review of glioblastoma and other primary adult brain malignancies, including temozolomide-based standard of care.
39516198	2024	Review	Nat Commun	Methodological review of regulatory programs underlying neural cancer plasticity; tangential relevance to temozolomide's clinical indication.

Cytotoxicity

Temozolomide is a conventional cytotoxic chemotherapeutic agent (alkylating agent, imidazotetrazine class), so this section applies.

Item	Content
Cytotoxicity Classification	Conventional cytotoxic (alkylating agent)
Myelosuppression Risk	Please refer to the package insert warnings and precautions (TFDA label data currently unavailable — see DG001)
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

Please refer to the package insert for safety information.

Conclusion and Next Steps

Decision: Proceed with Guardrails

Rationale: The evidence supporting temozolomide in adult astrocytic tumour is exceptionally strong (L1: multiple Phase 3 RCTs including landmark NEJM/Lancet/JAMA trials), but this largely confirms an already-established standard-of-care indication rather than a novel repurposing signal — it should be framed internally as validation, not discovery. Regulatory and safety data are currently missing, which blocks a full risk assessment.

To proceed, the following is needed:

TFDA/BfArM package insert with warnings, contraindications, and drug interaction data (DG001, blocking)
Structured mechanism-of-action record from DrugBank (DG002)
Confirmation of Taiwan/Germany marketing and licensing status before positioning this as an actionable repurposing candidate
Disclaimer

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