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What is the CAPOX (XELOX) chemotherapy regimen?

Medically reviewed by Kristianne Hannemann, PharmD. Last updated on May 10, 2025.

Official Answer by Drugs.com

The CAPOX regimen, also known as XELOX, is a combination chemotherapy protocol primarily used to treat advanced colorectal cancer, including colon and rectal cancers. It combines two medications: capecitabine (Xeloda) and oxaliplatin. The CAPOX regimen is typically delivered in cycles, each lasting 21 days (3 weeks).

What Does CAPOX Stand For?

CAPOX combines two drugs:

Both medications interfere with cancer cell DNA replication, stopping growth and spread. Capecitabine is converted in the body to 5-fluorouracil, which disrupts DNA synthesis in rapidly dividing cells, such as cancer cells. Oxaliplatin forms cross-links in DNA, preventing replication and transcription, which leads to cell death.

When Is CAPOX Used?

CAPOX is commonly used for advanced or metastatic colorectal cancer, both as initial therapy and as adjuvant (post-surgical) treatment:

It is also sometimes used for gastric, esophageal, or pancreatic cancer (off-label or trial-based). CAPOX may be preferred in patients who want to avoid central lines, since capecitabine is taken by mouth and oxaliplatin does not require central venous access.

How Is CAPOX Administered?

The CAPOX regimen is typically delivered in cycles, each lasting 21 days. The standard protocol for each cycle is as follows:

Day 1:

Days 1–14:

Days 15–21:

This 3-week cycle is repeated, with the total number of cycles depending on the specific cancer type, stage, and treatment goals. For example, adjuvant therapy for colon cancer may involve 4–8 cycles.

How Effective Is CAPOX?

Research consistently shows that CAPOX is effective as an adjuvant and first-line treatment, with efficacy comparable to other regimens.

Effectiveness in Colon Cancer

In high-risk stage II and stage III colon cancer, CAPOX is as effective as FOLFOX for relapse-free survival, especially when used for 3 months instead of 6. The effectiveness of CAPOX has been evaluated in multiple clinical trials and real-world studies.

Related questions

Effectiveness in Rectal Cancer

What Are the Side Effects of CAPOX?

Common side effects of CAPOX include:

Dose modifications or delays may be necessary in response to side effects or laboratory abnormalities, such as low white blood cell or platelet counts, or liver function changes. Supportive care may include antiemetics, hydration, antidiarrheals, and hand/foot care.

Special Considerations and Monitoring

The CAPOX regimen requires careful monitoring and individualized management to balance efficacy with toxicity. Your healthcare provider will regularly order tests and monitor you for side effects during treatment. Some tests your provider might order include:

In addition to the blood tests listed above, your healthcare provider will watch for side effects such as peripheral neuropathy (numbness and tingling in your arms or legs), lung toxicity, hand-foot syndrome, posterior reversible encephalopathy syndrome (PRES), changes in heart rhythm, skin rash or blisters, and rhabdomyolysis.

Harm to Babies

Based on animal studies, medications in CAPOX may cause harm to unborn babies when taken during pregnancy. Therefore, it is recommended to use an effective form of contraception when taking CAPOX. It is not recommended to breastfeed during treatment and for 3 months after the final dose of oxaliplatin.

Adherence to Oral Chemotherapy

While oral chemotherapy may be more convenient for some patients, it can also be harder to remember compared to receiving treatment intravenously. Make sure to set an alarm to help you remember to take your doses every day on time. This will ensure your treatment is as effective as it can be for you.

Take capecitabine within 30 minutes after a meal to decrease the occurrence of side effects. Do not cut or crush the tablets, since this can cause eye irritation, skin rash, diarrhea, and other side effects.

Summary

The CAPOX chemotherapy regimen includes capecitabine and oxaliplatin. It is a widely used and effective chemotherapy protocol for advanced colorectal and other gastrointestinal cancers. It combines oral capecitabine and intravenous oxaliplatin, administered in 3-week cycles, and is tailored to maximize efficacy while managing side effects through careful monitoring and supportive care. Common side effects include hand-foot syndrome, nausea, diarrhea, neuropathy, and low blood cells.

References
  1. American Cancer Society. 2024. Treatment of Colon Cancer, by Stage. Accessed May 10, 2025 at https://www.cancer.org/cancer/types/colon-rectal-cancer/treating/by-stage-colon.html
  2. Capecitabine [package insert]. Updated 2024. Camber Pharmaceuticals, Inc. Accessed May 10, 2025 at https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=3e7d6317-1439-4976-ae00-6f62619ec3dd
  3. Degirmencioglu, S., et. al. 2019. Retrospective comparison of efficacy and safety of CAPOX and FOLFOX regimens as adjuvant treatment in patients with stage III colon cancer. The Journal of international medical research, 47(6), 2507–2515. https://doi.org/10.1177/0300060519848258
  4. eviQ. 2023. Adjuvant CAPOX (XELOX) (capecitabine and oxaliplatin). Accessed on May 10, 2025 at https://www.eviq.org.au/medical-oncology/colorectal/adjuvant-and-neoadjuvant/4019-adjuvant-capox-xelox-capecitabine-and-oxal
  5. Grothey, A., et. al. 2018. Duration of Adjuvant Chemotherapy for Stage III Colon Cancer. In: The New England Journal of Medicine. https://doi.org/10.1056/NEJMoa1713709
  6. Hattori, N., et. al. 2020. Phase II study of capecitabine plus oxaliplatin (CapOX) as adjuvant chemotherapy for locally advanced rectal cancer (CORONA II). International journal of clinical oncology, 25(1), 118–125. https://doi.org/10.1007/s10147-019-01546-3
  7. Iveson, T. J., et. al. 2021. Duration of Adjuvant Doublet Chemotherapy (3 or 6 months) in Patients With High-Risk Stage II Colorectal Cancer. In: Journal of Clinical Oncology. DOI: https://doi.org/10.1200/JCO.20.01330
  8. Jongeneel, G., et. al. 2020. Model-based evaluation of the cost effectiveness of 3 versus 6 months’ adjuvant chemotherapy in high-risk stage II colon cancer patients. Therapeutic Advances in Gastroenterology, 13. https://doi.org/10.1177/1756284820954114
  9. Kosakowska, E. A., et. al. 2020. Evaluation of the efficacy of chemotherapy with capecitabine and oxaliplatin in patients with disseminated colorectal cancer. The impact of primary cancer focus on treatment efficacy. In: Oncology in Clinical Practice. DOI: http://dx.doi.org/10.5603/OCP.2020.0046
  10. Lapeyre-Prost, A., et. al. 2016. Feasibility of Capecitabine and Oxaliplatin Combination Chemotherapy Without Central Venous Access Device in Patients With Stage III Colorectal Cancer. Clinical colorectal cancer, 15(3), 250–256. https://doi.org/10.1016/j.clcc.2015.11.004
  11. MacMillan Cancer Support. XELOX (CAPOX). Accessed on May 10, 2025 at https://www.macmillan.org.uk/cancer-information-and-support/treatments-and-drugs/xelox-or-capox
  12. National Cancer Institute. CAPOX regimen. In: NCI Dictionary of Cancer Terms. Accessed May 10, 2025 at https://www.cancer.gov/publications/dictionaries/cancer-terms/def/capox-regimen
  13. NHS Northern Cancer Alliance. 2021. CAPOX (XELOX) Capecitabine & Oxaliplatin. Accessed on May 10, 2025 at https://www.northerncanceralliance.nhs.uk/wp-content/uploads/2018/11/CR008CAPOX-oxaliplatin-capecitabine-CRP09-CR008-v1.5.pdf
  14. Oxaliplatin [package insert]. 2023. Nextgen Pharmaceuticals LLC. Accessed on May 10, 2025 at https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=95b05292-36a1-4946-b8b3-835a3a77f4a7&type=display
  15. Schmoll, H. J., et. al. 2015. Capecitabine Plus Oxaliplatin Compared With Fluorouracil/Folinic Acid As Adjuvant Therapy for Stage III Colon Cancer: Final Results of the NO16968 Randomized Controlled Phase III Trial. Journal of clinical oncology : official journal of the American Society of Clinical Oncology, 33(32), 3733–3740. https://doi.org/10.1200/JCO.2015.60.9107
  16. Sobrero, A., et. al. 2018. FOLFOX or CAPOX in Stage II to III Colon Cancer: Efficacy Results of the Italian Three or Six Colon Adjuvant Trial.. Journal of clinical oncology : official journal of the American Society of Clinical Oncology, 36 15, 1478-1485. https://doi.org/10.1200/JCO.2017.76.2187

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