Gemcitabine

證據等級: L5

預測適應症: 10 個

Gemcitabine: From Antimetabolite Chemotherapy to Female Breast Carcinoma

One-Sentence Summary

Gemcitabine is a deoxycytidine-analogue antimetabolite chemotherapy agent (DrugBank DB00441); this evidence pack does not contain Australian licensing records specifying its original approved indication (0 ARTG entries on file, market status “Not Marketed”), so the original-indication field below reflects general pharmacological knowledge, not TGA data. The TxGNN model predicts it may be effective for Female Breast Carcinoma, with roughly 50 clinical trials and 20 publications identified in this dataset supporting the direction.

Quick Overview

Item	Content
Original Indication	Not specified in this evidence pack — no ARTG licences on record. (Gemcitabine is internationally established as a cytotoxic antimetabolite used across pancreatic cancer, NSCLC and other solid tumours; this is general background, not sourced from this pack.)
Predicted New Indication	Female Breast Carcinoma
TxGNN Prediction Score	99.98%
Evidence Level	L1
Australia Market Status	Not Marketed
Number of ARTG Entries	0
Recommended Decision	Proceed with Guardrails

Why is This Prediction Reasonable?

Currently, a detailed mechanism-of-action record was not returned for this pack (flagged as a High-severity data gap, DG002). Based on known pharmacology, gemcitabine is a deoxycytidine (pyrimidine nucleoside) analogue that inhibits ribonucleotide reductase and is incorporated into DNA, causing chain termination — a broad-spectrum, cell-cycle-specific (S-phase) antimetabolite mechanism.

This mechanism is not indication-specific: antimetabolite/DNA-synthesis-disrupting chemotherapy is active across a wide range of solid tumours, which is consistent with gemcitabine’s known off-label and combination use in multiple cancer types. Notably, gemcitabine plus paclitaxel is already an internationally recognised combination regimen for metastatic breast cancer, meaning the TxGNN prediction aligns with existing global clinical practice rather than proposing an entirely novel mechanistic hypothesis.

The key caveat is regulatory, not mechanistic: this evidence pack shows gemcitabine as not currently marketed in Australia (0 ARTG entries), so before any breast-cancer repurposing pathway could be pursued locally, the more fundamental question of TGA market registration would need to be addressed first.

Clinical Trial Evidence

Trial Number	Phase	Status	Enrolment	Key Findings
NCT00039546	Phase 3	Unknown	N/A	‘tAnGo’ RCT: gemcitabine added to paclitaxel-containing, epirubicin-based adjuvant chemotherapy for ER/PgR-poor early breast cancer
NCT00561119	Phase 3	Completed	326	Maintenance vs. observation after 6 cycles of gemcitabine+paclitaxel as 1st-line therapy for metastatic/recurrent breast cancer
NCT00440622	Phase 3	Terminated	90	Gemcitabine+trastuzumab vs. capecitabine+trastuzumab in pretreated HER2-positive metastatic breast cancer
NCT00408408	Phase 3	Unknown	1206	Neoadjuvant: adding capecitabine or gemcitabine to docetaxel before AC ± bevacizumab, evaluating pathologic complete response
NCT00070278	Phase 3	Unknown	800	Neoadjuvant epirubicin/cyclophosphamide + paclitaxel ± gemcitabine in poor-risk early breast cancer
NCT00006459	Phase 3	Completed	N/A	Gemcitabine+paclitaxel vs. paclitaxel alone in unresectable, locally recurrent or metastatic breast cancer
NCT00110084	Phase 2	Completed	50	Weekly nab-paclitaxel + gemcitabine in metastatic breast cancer
NCT06027268	Phase 2	Active, not recruiting	36	ToPCourT: trilaciclib+pembrolizumab+gemcitabine+carboplatin in locally advanced/metastatic triple-negative breast cancer
NCT00005991	Phase 1/2	Completed	76	Gemcitabine + liposomal doxorubicin (Doxil) in advanced solid tumours/breast cancer
NCT02252887	Phase 2	Completed	45	Gemcitabine+trastuzumab+pertuzumab in metastatic HER2-positive breast cancer after prior anti-HER2 therapy

No ANZCTR-registered trials were identified for this indication in the pack.

Literature Evidence

PMID	Year	Type	Journal	Key Findings
12138397	2002	Review	Seminars in Oncology	Gemcitabine as single agent and in combination shows 16–37% response rates in metastatic breast cancer across ~20 phase II trials
14754468	2004	Review/Clinical experience	Clinical Breast Cancer	Gemcitabine+platinum combinations in anthracycline/taxane-pretreated breast cancer
14719116	2004	Review	International Journal of Oncology	Rationale for the use of gemcitabine in breast cancer
15685819	2004	Review	Oncology (Williston Park)	Gemcitabine+paclitaxel in metastatic breast cancer — dosing schedules and phase II/III response rates
15685820	2004	Review	Oncology (Williston Park)	Gemcitabine+docetaxel in metastatic breast cancer — combination rationale and regimens
15685821	2004	Review/Clinical experience	Oncology (Williston Park)	Gemcitabine and platinum-based chemotherapy in metastatic breast cancer
15685824	2004	Review	Oncology (Williston Park)	Gemcitabine with trastuzumab and/or platinum salts in HER2-overexpressing breast cancer
12057038	2002	Review	Clinical Breast Cancer	Overview: gemcitabine as single-agent therapy for advanced breast cancer
12722022	2003	Review/Trial summary	Seminars in Oncology	Gemcitabine+trastuzumab phase II trial in heavily pretreated metastatic breast cancer
25398698	2015	Clinical study	Cancer Chemotherapy and Pharmacology	Docetaxel+gemcitabine+bevacizumab as salvage therapy for HER2-negative metastatic breast cancer

Australia Market Information

Gemcitabine currently has no ARTG-registered products on file in this evidence pack (market status: Not Marketed; total licences: 0). Australian marketing/registration status would need to be established as a separate step from the indication-repurposing assessment.

Cytotoxicity

Gemcitabine is a cytotoxic antineoplastic agent (pyrimidine nucleoside analogue/antimetabolite class), so this section applies.

Item	Content
Cytotoxicity Classification	Conventional cytotoxic chemotherapy (nucleoside analogue / antimetabolite class)
Myelosuppression Risk	Please refer to the Product Information (PI) warnings and precautions
Emetogenicity Classification	Please refer to the Product Information (PI) warnings and precautions
Monitoring Items	Please refer to the Product Information (PI) warnings and precautions
Handling Protection	Please refer to the Product Information (PI) warnings and precautions

Detailed toxicity/monitoring data was not returned for this pack — TGA warnings and contraindications are logged as a Blocking data gap (DG001), so specifics above should not be inferred beyond drug-class classification.

Safety Considerations

Please refer to the TGA-approved Product Information (PI) for safety information. No key warnings, contraindications, or drug interaction data were returned in this evidence pack (DDI query status: not found).

Conclusion and Next Steps

Decision: Proceed with Guardrails

Rationale: Two completed Phase 3 RCTs (NCT00561119, NCT00006459) plus multiple additional Phase 2/3 trials and supportive review literature give strong (L1) evidence that gemcitabine-containing regimens are active in breast cancer, consistent with gemcitabine+paclitaxel already being an internationally used combination. However, gemcitabine is not currently marketed in Australia per this pack, and formal safety/PI data is missing.

To proceed, the following is needed:

TFDA/TGA-approved Product Information (warnings, contraindications) — currently a Blocking data gap (DG001)
Confirmed mechanism-of-action documentation from DrugBank (DG002)
Clarification of Australian market/registration pathway, since 0 ARTG entries are on file
Formal relevance triage of the “pending” clinical-trial and literature entries in this pack to confirm which are breast-cancer-specific vs. tangential (e.g. urothelial carcinoma trials appearing under this indication)
Disclaimer

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