What Is Docetaxel? FDA Approval, Licensing in Turkey, and Reimbursement

• FDA Approved: Yes (First approval date: May 14, 1996)
• Brand Names and Manufacturers, Availability in Turkey: The original brand name is Taxotere (Sanofi-Aventis), Docevo (Koçak Farma), Doctaxel (Deva), Docel (Nobel İlaç), Docetax (Sandoz), Dotaxel (Onko & Koçsel), Dotax (Mefar İlaç), and Doxel (İdol)
• Active Ingredient: Docetaxel
• Route of Administration: Intravenous
• Class: Taxane, antimicrotubule agent
• Category: Chemotherapy medicine
• Cancers for Which It Is Approved: It is FDA-approved and is used in various cancers, including breast cancer, non-small cell lung cancer, prostate cancer, stomach cancer, and head and neck cancer.

What Is Docetaxel?

Docetaxel is a semisynthetic chemotherapy medicine derived from the needles of the yew tree.

How Does It Work?

• This medicine binds strongly to microtubules, an important part of the cell's cytoskeleton, and stabilizes them. This binding prevents microtubules from moving flexibly as they normally should and stops cell division.
• Docetaxel acts during “mitosis”, the division phase of the cell cycle. In other words, by stopping cells from dividing and multiplying, it prevents cancer cells from growing.

FDA (United States Food and Drug Administration) Approval History

• May 19, 1996: Docetaxel (Taxotere) received FDA approval for advanced or metastatic breast cancer. This approval was for use as a single agent in patients who had previously received anthracycline-based treatment.
• June 19, 2004: The FDA approved Taxotere in combination with doxorubicin and cyclophosphamide as first-line treatment for patients with metastatic breast cancer.
• October 22, 2004: The FDA approved Taxotere for advanced or metastatic non-small cell lung cancer that had not responded to platinum-based chemotherapy. In this setting, Taxotere could be used alone or together with platinum-based agents.
• May 19, 2004: The FDA approved Taxotere in combination with prednisone for the treatment of metastatic prostate cancer. This approval was for patients with hormone-independent disease (resistant to androgen suppression).
• October 17, 2006: Taxotere was approved by the FDA in combination with cisplatin and 5-fluorouracil (5-FU) for the treatment of locally advanced head and neck cancer.
• December 28, 2015: Teikoku Pharma USA, Inc. received FDA approval for an alcohol-free Docetaxel Injection formulation.

Licensing in Turkey

Therapeutic Indications

Breast Cancer;

• Docetaxel, in concurrent combination with or sequentially after an anthracycline and cyclophosphamide, is indicated for the adjuvant treatment of patients with operable node-positive breast cancer and patients with operable node-negative breast cancer whose tumor size is 2 cm or greater. According to internationally established criteria for early breast cancer, adjuvant treatment in patients with operable node-negative breast cancer is limited to patients eligible for chemotherapy.
• Docetaxel, in combination with trastuzumab, is used in patients who have undergone surgery, have no axillary lymph node metastasis, are considered high risk, and have HER-2(+) or 3 (+) status by immunohistochemistry, or HER-2(+) status by FISH/CISH.
• Docetaxel, in combination with doxorubicin, is indicated as first-line treatment for patients with locally advanced or metastatic breast cancer who have not previously received cytotoxic treatment.
• Docetaxel is indicated for patients with locally advanced or metastatic breast cancer whose previous chemotherapy was unsuccessful. Previous chemotherapy must have included an anthracycline or an alkylating agent.
• Docetaxel, in combination with trastuzumab, is indicated for patients with metastatic breast cancer who have not previously received chemotherapy for metastatic disease and have strong positivity for HER-2 neu (Human Epidermal Growth Factor Receptor 2: Human Epidermal Growth Factor Receptor 2), defined as 3 positive or positive by FISH.
• The combination of docetaxel and capecitabine is indicated for patients with locally advanced or metastatic breast cancer whose previous chemotherapy was unsuccessful. Previous treatment must have included an anthracycline.

Non-Small Cell Lung Cancer;

• Docetaxel, in combination with cisplatin, is indicated for patients with unresectable locally advanced or metastatic non-small cell lung cancer who have not previously received chemotherapy for this disease.
• Docetaxel is indicated for patients with locally advanced or metastatic non-small cell lung cancer whose previous chemotherapy was unsuccessful and who have not responded to platinum-based treatment.

Ovarian Cancer;

• Docetaxel is used in combination with a platinum agent as first-line treatment for epithelial ovarian cancer.
• Docetaxel is indicated for platinum-sensitive or platinum-refractory recurrent ovarian cancer.

Head and Neck Cancer;

• Docetaxel is indicated for the treatment of locally advanced, recurrent, and metastatic head and neck cancers.

Prostate Cancer;

• Docetaxel, in combination with prednisone or prednisolone, is indicated for patients with hormone-refractory metastatic prostate cancer.

Gastric Adenocarcinoma;

• Docetaxel, in combination with cisplatin and 5-fluorouracil, is indicated for patients with metastatic gastric adenocarcinoma, including metastatic gastroesophageal junction adenocarcinoma, who have not previously received chemotherapy for metastatic disease.

Is Docetaxel Reimbursed?

It is included in the list of medicines for which no indication requirement applies in cancer diagnoses, and is reimbursed by Turkey's Social Security Institution (SGK) for all cancer diagnoses.

Mechanisms of Resistance

• Tubulin Changes: Changes in the structure of tubulin in cancer cells make it difficult for docetaxel to bind effectively to tubulin. These changes reduce the medicine's effectiveness in cancer cells and lead to resistance.
• Multidrug Resistance (MDR-1) Phenotype: A protein called P170 increases in cancer cells, causing the medicine to be expelled from the cell more quickly. This reduces the accumulation of docetaxel inside the cell and lowers its effectiveness. This resistance mechanism can cause resistance not only to docetaxel but also to certain other medicines, such as vinca alkaloids, anthracyclines, and other taxanes.

Absorption

Docetaxel is administered only intravenously (IV); it has no oral bioavailability.

Distribution

It is distributed widely throughout body tissues and shows more than 90% binding to plasma and cellular proteins.

Metabolism

Docetaxel is extensively metabolized by the liver's P450 enzyme system and is eliminated from the body through feces. Approximately 75% of the medicine is excreted in feces, while less than 10% is eliminated unchanged (as the parent compound). The remainder is converted into metabolites and excreted. Renal excretion is very low, accounting for less than 10% of total drug clearance. Elimination from plasma follows a three-phase model, and the medicine's half-life in the body is approximately 11 hours.

Dose Range

1. Metastatic Breast Cancer:
• It is administered intravenously at a dose of 60, 75, or 100 mg/m² every 3 weeks, or
• It is administered at 35-40 mg/m² once a week for 3 weeks, followed by a 1-week break.
2. Breast Cancer:
• For adjuvant treatment with doxorubicin and cyclophosphamide, it is administered intravenously at 75 mg/m² every 3 weeks.
3. Non-Small Cell Lung Cancer (NSCLC):
• It is administered intravenously at 75 mg/m² every 3 weeks, or
• at 35-40 mg/m² once a week for 3 weeks, followed by a 1-week break (after platinum-based chemotherapy).
4. Non-Small Cell Lung Cancer (NSCLC):
• For patients who have not previously received chemotherapy, it is administered at 75 mg/m² every 3 weeks in combination with cisplatin.
5. Metastatic Prostate Cancer:
• It is administered intravenously at 75 mg/m² every 3 weeks together with prednisone.
6. Advanced Stomach Cancer:
• It is administered intravenously at 75 mg/m² every 3 weeks together with cisplatin and 5-FU.
7. Head and Neck Cancer:
• For locally advanced disease, it is administered intravenously at 75 mg/m² every 3 weeks together with cisplatin and 5-FU.

Drug Interactions

• Interaction with Radiotherapy: Docetaxel acts as a radiosensitizing agent. When docetaxel is used together with radiotherapy, this property helps make cancer cells more sensitive to radiation and may thereby increase treatment effectiveness.
• Interaction with CYP3A4 Enzyme Inducers and Inhibitors: Docetaxel is metabolized by the liver's CYP3A4 enzyme system. When it is used together with medicines that affect CYP3A4 (such as cyclosporine, ketoconazole, and erythromycin), the way docetaxel acts in the body and its toxic effects may therefore change. These medicines may slow down or accelerate docetaxel metabolism, which may increase both treatment effectiveness and the risk of adverse effects.

Conditions Requiring Caution

• Docetaxel should be used cautiously in patients with impaired liver function. Patients with abnormal liver function are at greater risk of treatment-related toxicity and death.
• Periodic complete blood counts are recommended in patients receiving docetaxel. In particular, docetaxel should not be administered to patients with a neutrophil count below 1,500 cells/mm³.
• To reduce the severity of fluid retention and hypersensitivity reactions associated with docetaxel treatment, oral dexamethasone (e.g., Kordexa) at 8 mg twice daily for 3 days, starting one day before treatment, is recommended.
• Docetaxel can cause allergic and hypersensitivity reactions due to polysorbate 80, the drug's vehicle. These reactions generally occur during the first or second treatment. Emergency equipment and medicines (a bag-valve mask, ECG device, fluids, vasopressors, etc.) should therefore be available at the patient's side before treatment begins.
• Docetaxel is contraindicated in patients with known hypersensitivity to docetaxel or polysorbate 80.
• Only glass or polypropylene bottles, or polypropylene or polyolefin plastic bags, should be used for docetaxel infusions. The medicine should be administered through polyethylene-lined infusion sets.
• Patients' daily weight and fluid balance (intake and output) should be monitored, and they should be assessed for signs of peripheral edema.
• Docetaxel is classified as pregnancy category D and has the potential to harm the fetus during pregnancy. Its use is also not recommended in breastfeeding mothers.

Adverse Effects

1. Bone Marrow Suppression: Conditions such as neutropenia, thrombocytopenia, and anemia may occur. Neutropenia (a reduction in white blood cells), in particular, is common and may increase the risk of infection. This adverse effect is dose-dependent and generally resolves after treatment.
2. Hypersensitivity Reactions: Signs of drug allergy or hypersensitivity may generally include skin redness, rash, itching, low blood pressure, shortness of breath, and bronchospasm (narrowing of the airways). These reactions occur mainly during the first or second dose and may be reduced by giving steroid medicines beforehand.
3. Fluid Retention: This may present as weight gain, swelling of the legs or body (edema), fluid accumulation in the chest cavity (pleural effusion), or fluid accumulation in the abdominal cavity (ascites). Its severity may increase with the total dose received.
4. Skin and Nail Problems: Skin adverse effects may include rash on the hands and forearms, dry skin, itching, and brown discoloration of the nails. These effects occur in approximately 50% of patients and tend to begin one week after treatment starts.
5. Hair Loss (Alopecia): Hair loss may occur in up to 80% of patients. This is common but temporary; hair grows back after treatment ends.
6. Mucosal Inflammation and Diarrhea: Inflammation of the oral mucosa (mucositis) and/or diarrhea may occur in 40% of patients. Mild to moderate nausea and vomiting may also occur but are generally short-lived.
7. Peripheral Neuropathy: Nerve damage may cause tingling, numbness, or a burning sensation in the hands and feet. This adverse effect is observed less frequently in patients treated with docetaxel than in those receiving paclitaxel.
8. Fatigue and Muscle Pain: General fatigue and weakness occur in 60-70% of patients. Joint pain (arthralgia) and muscle pain (myalgia) may also occur occasionally.
9. Elevated Liver Enzymes: Blood tests related to liver function may show temporary elevations (serum transaminases, alkaline phosphatase, bilirubin), but these generally return to normal after treatment.
10. Phlebitis and Injection-Site Swelling: Inflammation of a vein (phlebitis) or swelling may occur at the injection site.