Gemcitabine

證據等級: L5 預測適應症: 10

目錄

  1. Gemcitabine
  2. Gemcitabine: From Pancreatic Cancer to Female Breast Carcinoma
    1. One-Sentence Summary
    2. Quick Overview
    3. Why is This Prediction Reasonable?
    4. Clinical Trial Evidence
    5. Literature Evidence
    6. Philippines Market Information
    7. Cytotoxicity
    8. Safety Considerations
    9. Conclusion and Next Steps
    10. Disclaimer

## 藥師評估報告

Gemcitabine: From Pancreatic Cancer to Female Breast Carcinoma

One-Sentence Summary

Gemcitabine is a cytotoxic nucleoside analog originally developed and widely used for the treatment of pancreatic cancer and other solid tumors. The TxGNN model predicts it may be effective for Female Breast Carcinoma, with 50 clinical trials and 20 publications currently supporting this direction. Notably, gemcitabine in combination with paclitaxel has already received US FDA approval for metastatic breast cancer, strongly validating this prediction.


Quick Overview

Item Content
Original Indication Pancreatic cancer, non-small cell lung cancer, bladder cancer (no Philippines registration data available)
Predicted New Indication Female Breast Carcinoma
TxGNN Prediction Score 99.98%
Evidence Level L1 (≥2 completed Phase 3 RCTs)
Philippines Market Status ✗ Not marketed
Number of Registrations 0
Recommended Decision Proceed with Guardrails

Why is This Prediction Reasonable?

Gemcitabine (2’,2’-difluorodeoxycytidine) is a pyrimidine nucleoside antimetabolite that inhibits DNA synthesis by incorporating into the growing DNA strand and causing chain termination. It also inhibits ribonucleotide reductase, depleting intracellular deoxynucleotide pools needed for DNA replication. These mechanisms make it broadly effective against rapidly dividing cells, including breast cancer cells.

The mechanistic rationale for using gemcitabine in breast cancer is well-established. When combined with taxanes (paclitaxel or docetaxel), gemcitabine produces a synergistic dual cytotoxic effect: gemcitabine inhibits DNA repair pathways while taxanes disrupt microtubule function, preventing mitotic division. This non-overlapping mechanism and partially non-overlapping toxicity profile make the combination particularly attractive. The landmark Phase III trial (NCT00006459) demonstrated that gemcitabine plus paclitaxel significantly improved both overall survival and progression-free survival compared with paclitaxel alone in metastatic breast cancer.

The TxGNN prediction score of 99.98% is exceptionally high and is corroborated by the fact that gemcitabine has already received US FDA approval for metastatic breast cancer in combination with paclitaxel (approved 2004). This represents a case where the model’s prediction has been independently validated by regulatory approval in another jurisdiction, although the drug is not yet registered in the Philippines for any indication.


Clinical Trial Evidence

Trial Number Phase Status Enrollment Key Findings
NCT00006459 Phase 3 Completed N/A Gemcitabine + Paclitaxel vs Paclitaxel alone in unresectable/metastatic breast cancer. Pivotal trial leading to FDA approval.
NCT00039546 Phase 3 Unknown N/A tAnGo trial: evaluating addition of gemcitabine to paclitaxel-containing epirubicin-based adjuvant chemotherapy in ER/PgR-poor early breast cancer.
NCT00561119 Phase 3 Completed 326 Maintenance vs observation after 6 cycles of gemcitabine + paclitaxel (GP) as first-line chemotherapy for metastatic/recurrent breast cancer.
NCT00408408 Phase 3 Unknown 1206 Neoadjuvant trial evaluating capecitabine or gemcitabine added to docetaxel before AC ± bevacizumab, measuring pathologic complete response (pCR).
NCT00070278 Phase 3 Unknown 800 Neoadjuvant sequential EC → Paclitaxel ± Gemcitabine in poor-risk early breast cancer.
NCT00440622 Phase 3 Terminated 90 Gemcitabine + Herceptin vs Capecitabine + Herceptin in pretreated HER2+ metastatic breast cancer.
NCT00003540 Phase 2 Completed 30 Gemcitabine monotherapy in metastatic breast cancer previously treated with adriamycin and taxol.
NCT00110084 Phase 2 Completed 50 Nab-paclitaxel (Abraxane) + gemcitabine in metastatic breast cancer.
NCT02252887 Phase 2 Completed 45 Gemcitabine + trastuzumab + pertuzumab in metastatic HER2+ breast cancer after prior pertuzumab-based therapy.
NCT06027268 Phase 2 Active, not recruiting 36 Trilaciclib + pembrolizumab + gemcitabine + carboplatin in locally advanced/metastatic triple-negative breast cancer (TNBC).

Literature Evidence

PMID Year Type Journal Key Findings
24175966 2014 Clinical Study Asia-Pac J Clin Oncol Phase 3 trial (n=529): gemcitabine-paclitaxel significantly improved OS and PFS vs paclitaxel monotherapy; consistent efficacy between East Asian and global populations.
14754468 2004 Clinical Study Clin Breast Cancer Gemcitabine + platinum combinations in patients pretreated with anthracyclines/taxanes; demonstrated non-cross-resistant activity with favorable toxicity profile.
40779028 2025 Phase I Trial Breast Cancer Res Treat Phase I trial of carboplatin + gemcitabine + mifepristone for advanced breast cancer; GR antagonism may enhance chemotherapy-induced apoptosis in GR+ tumors.
12138397 2002 Review Semin Oncol Comprehensive review: gemcitabine single-agent ORR 16-37%; in combinations with platinum/taxanes/vinorelbine, ORR up to 68%.
14768404 2003 Review Oncology Review of gemcitabine + anthracycline + taxane combinations in advanced breast cancer; favorable activity with manageable toxicity.
15685819 2004 Review Oncology Review of gemcitabine + paclitaxel Phase II/III data: 52% ORR (114/221 patients) with established dosing schedules.
15685821 2004 Review Oncology Review of gemcitabine + platinum-based chemotherapy in metastatic breast cancer after anthracycline/taxane failure.
12057038 2002 Review Clin Breast Cancer Overview of gemcitabine single-agent therapy: unique MOA involving DNA chain termination and self-potentiation via masked chain termination.
38262235 2024 Phase I Study Gynecol Oncol MIRV + gemcitabine in FRα+ cancers including TNBC; established MTD and RP2D for the combination.
26372358 2016 Translational Mol Oncol Machine learning-derived genomic signatures predicting paclitaxel and gemcitabine resistance in breast cancer; potential for precision medicine.

Philippines Market Information

Gemcitabine is currently not registered in the Philippines. There are no active marketing authorizations on record.

Item Status
Market Status Not marketed
Total Registrations 0
Available Dosage Forms None registered

Cytotoxicity

Item Content
Cytotoxicity Classification Conventional cytotoxic (Antimetabolite — Nucleoside analog / Pyrimidine antagonist)
Myelosuppression Risk High (dose-limiting toxicity; neutropenia, thrombocytopenia, and anemia are common and dose-dependent)
Emetogenicity Classification Low to moderate
Monitoring Items CBC with differential (weekly during treatment), liver function tests (AST, ALT, bilirubin), renal function (BUN, creatinine), pulmonary function (risk of pneumonitis)
Handling Protection Must follow cytotoxic drug handling regulations; use PPE including gloves, gown, and eye protection during preparation and administration

Safety Considerations

Please refer to the package insert for safety information. Local regulatory safety data (package insert warnings, contraindications, and drug-drug interactions) were not available at the time of this evaluation.

Known general safety concerns for gemcitabine (from international references):

  • Myelosuppression: Dose-limiting; requires regular hematologic monitoring
  • Hepatotoxicity: Transient elevations in transaminases are common; rarely hepatic veno-occlusive disease
  • Pulmonary toxicity: Dyspnea and interstitial pneumonitis have been reported; discontinue if unexplained dyspnea occurs
  • Hemolytic uremic syndrome (HUS): Rare but serious; discontinue permanently if HUS occurs
  • Capillary leak syndrome: Rare; reported in combination settings

Conclusion and Next Steps

Decision: Proceed with Guardrails

Rationale: Gemcitabine’s efficacy in breast cancer is supported by the highest level of clinical evidence (L1), including multiple completed Phase III randomized controlled trials. The combination of gemcitabine and paclitaxel has already received US FDA approval for metastatic breast cancer (2004), and the TxGNN prediction score of 99.98% is fully validated by existing clinical data. The primary barrier is the absence of Philippines market registration.

To proceed, the following is needed:

  • Obtain Philippines FDA registration data or pursue local marketing authorization
  • Acquire detailed package insert for safety assessment (key warnings, contraindications, DDI profile)
  • Confirm detailed mechanism of action (MOA) documentation from DrugBank
  • Establish local safety monitoring protocol aligned with myelosuppression risk management
  • Evaluate route compatibility and available dosage forms for Philippines healthcare infrastructure
  • Develop prescribing guidelines appropriate for the local population, including dose adjustments for hepatic/renal impairment

Disclaimer: This report is for research purposes only and does not constitute medical advice. Drug repurposing candidates require clinical validation before clinical application.

Disclaimer

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



Copyright © 2026 PhTxGNN Project. For research purposes only.

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