PAXG (Cisplatin, Paclitaxel, Capecitabine, Gemcitabine) Treatment Protocol

What Is PAXG?

PAXG (cisplatin, nab-paclitaxel, capecitabine, gemcitabine) is used as neoadjuvant (preoperative) treatment for resectable, borderline resectable or locally advanced (non-metastatic) pancreatic ductal adenocarcinoma (PDAC). It is an intensive multidrug chemotherapy regimen considered in clinical practice as an alternative to FOLFIRINOX.

⚙️ Components and Mechanisms of Action

• C — Cisplatin (a platinum compound): Forms crosslinks in DNA, preventing repair/replication → apoptosis.
• P — Paclitaxel (nab-paclitaxel) (a taxane): It stabilizes microtubules and inhibits depolymerization → G2/M phase mitotic arrest and apoptosis.
• X — Capecitabine (an oral 5-FU prodrug): Converted to 5-FU in the tumor; thymidylate synthaseinhibition disrupts DNA/RNA synthesis.
• G — Gemcitabine (a nucleoside analogue): Converted to dFdCTP and incorporated into DNA; halts chain elongation and ribonucleotide reductaseis inhibited → cytotoxicity through a dual mechanism.

🎯 Goals of Treatment

• Reduce tumor burden before surgery: Shrink the tumor through neoadjuvant treatment to improve the chance of surgery.
• Increase the rate of negative surgical margins (R0): Facilitate resection without leaving tumor behind.
• Reduce the risk of lymph node involvement: Improve long-term survival by increasing the N0 rate.
• Early suppression of micrometastases: Reduce the risk of distant spread during/after surgery.
• CASSANDRA phase III data: Neoadjuvant PAXG, compared with mFOLFIRINOX, significantly prolonged event-free survival (EFS) . However, overall survival (OS) data are not yet mature, and further publications will clarify integration into guidelines.
• Decline in the CA19-9 biomarker: Considered an important biochemical indicator of treatment response.

🧾 Treatment Indication

• Resectable PDAC: Cases with minimal vascular contact in which curative surgery is intended.
• Borderline resectable PDAC: Cases with limited vascular contact (e.g., partial SMV/PV contact) in which resection can technically be attempted.
• Locally advanced (non-metastatic) PDAC: Selected cases without distant metastases in which downstaging aims to improve the chance of surgery.
• Performance status: ECOG 0–1; general fitness sufficient to tolerate intensive multidrug chemotherapy.
• Organ function: Adequate bone marrow, kidney, and liver functional reserve.
• Absence of metastases: No liver/lung/distant metastases should be detected (staging with CT/MRI ± PET).
• Multimodal plan: Neoadjuvant treatment → restaging (imaging + CA19-9) → if suitable, surgery; radiotherapy when needed. Decisions should be made by a multidisciplinary tumor board .

💉 Dosing and Premedication

• Cisplatin: 30 mg/m² IV every 14 days.
  Hydration: Current short-hydration protocols use a total of 1.75–2.25 L of IV fluid (usually 1 L before + 1 L after treatment); magnesium/potassium replacement is recommended.
• Nab-paclitaxel (Abraxane): 150 mg/m² IV every 14 days.
• Gemcitabine: 800 mg/m² IV every 14 days.
• Capecitabine: 1250 mg/m² orally, 2 times a day.

Administration Schedule: PAXG is usually given every 14 daysfor a total of 4 cycles (8 weeks) . Response is then assessed using imaging + CA19-9 to evaluate treatment effectiveness , and surgery is planned if appropriate.

⛔ Conditions That Make Treatment Unsuitable

• Poor performance status: Patients with ECOG ≥2 or Karnofsky <70 (unable to tolerate intensive chemotherapy).
• Impaired kidney function: Cisplatin is nephrotoxic; it may be contraindicated if creatinine clearance is <60 mL/min.
• Inadequate bone marrow reserve: Risk of severe myelosuppression in patients with low leukocytes, neutrophils, hemoglobin, or platelets.
• Impaired liver function: Paclitaxel, gemcitabine, and capecitabine undergo hepatic metabolism; caution is needed with elevated bilirubin and transaminases.
• Older age and comorbidities: Toxicity increases particularly in patients older than 75 with cardiac, pulmonary, or neurological comorbidities.
• Previous platinum/taxane-based treatment: Risk of resistance or cumulative toxicity.
• Severe neuropathy: Paclitaxel and cisplatin may worsen neuropathy; symptoms worsen in patients with pre-existing neuropathy.
• DPD deficiency: Capecitabine (converted to 5-FU) carries a risk of severe toxicity and death in DPD deficiency.
• Pregnancy and breastfeeding: All agents are teratogenic and contraindicated.

SGK Reimbursement Status

In Turkey, the PAXG (Cisplatin + Nab-Paclitaxel + Gemcitabine + Capecitabine) combination is used for advanced pancreatic cancer and is reimbursed by SGK.

However, nab-paclitaxel, an imported medicine , requires the following for procurement:

• a Ministry of Health Off-Label Use Approval Certificate must be obtained.
• The medicine is obtained through the Overseas Medicines Unit via TEB .

→ In short, although the regimen is covered by SGK, nab-paclitaxel procurement requires special permission and importation .

💉 Dosage

• Cisplatin: 30 mg/m² IV, every 14 days.
• Nab-paclitaxel (Abraxane): 150 mg/m² IV, every 14 days.
• Gemcitabine: 800 mg/m² IV, every 14 days.
• Capecitabine: 1250 mg/m² orally, 2 times a day (duration/cycling may vary according to the center's protocol).

Administration Schedule: PAXG is usually given every 14 days for a total of 4 cycles (8 weeks) . Response is then assessed through imaging + CA19-9 ; if suitable, surgery is planned.

⚠️ Conditions Requiring Attention

• Hematologic toxicity: Leukopenia, neutropenia, anemia, and thrombocytopenia are common. A complete blood count should be checked before each cycle; if needed, G-CSF support should be added.
• Renal toxicity (cisplatin): Creatinine, urea, and eGFR should be monitored regularly. Short hydration: usually 1 L before + 1 L after treatment (0.9% NaCl) with electrolyte support, for a total of ~1.75–2.25 L. Magnesium replacement is recommended to prevent hypomagnesemia.
• Gastrointestinal effects: Nausea, vomiting, mucositis, and loss of appetite are common. NK1 + 5-HT3 antagonist + dexamethasone is the recommended triple antiemetic regimen. During capecitabine treatment, attention should be paid to diarrhea and mouth sores.
• Hand–foot syndrome (capecitabine): Dose reduction or a treatment break may be needed for symptoms of erythrodysesthesia (redness, tenderness, peeling).
• Peripheral neuropathy: Particularly associated with nab-paclitaxel and cisplatin. The dose should be modified if numbness or tingling increases.
• Older patients / comorbidities: Toxicity risk increases in patients with ECOG ≥2 or those older than 75. Lower doses or alternative regimens should be considered.
• Drug interactions: Capecitabine + warfarin (INR monitoring is mandatory). Cisplatin + aminoglycosides/NSAIDs/contrast agents may increase nephrotoxicity.
• Nutritional status: The risk of cachexia is high. Enteral/parenteral nutritional support should be planned.
• Monitoring tumor response: After treatment, CT/MRI + CA19-9 should be assessed. If there is a response, surgery should be planned by a multidisciplinary tumor board.

📊 Side Effects

The most common adverse effects attributed to the PAXG regimen in clinical studies and their frequencies are summarized in the table below:

Note: Percentages are average data compiled from Phase II–III clinical studies (particularly CASSANDRA and the Italian PAXG studies). Actual rates may vary with the patient's performance status and supportive care.

📚 References

• CASSANDRA Phase III Study — Comparison of neoadjuvant PAXG and mFOLFIRINOX (ASCO 2025, oral presentation; OS data are not yet mature).
• Italian PAXG study group: Phase II clinical results for the nab-paclitaxel + gemcitabine + capecitabine + cisplatin regimen.
• Conroy T, et al. FOLFIRINOX or Gemcitabine as Adjuvant Therapy for Pancreatic Cancer. N Engl J Med. 2018;379:2395-2406. (For comparative context).
• Oncologist. 2023 Nov 23;29(2):e173–e186. doi:10.1093/oncolo/oyad297 — Cisplatin short-hydration protocols.
• NCCN Clinical Practice Guidelines in Oncology: Pancreatic Adenocarcinoma. Version 2025.

Note: The data summarized here are based on published studies and international guidelines. Clinical practice may vary according to the patient's performance status and the center's experience.