Pharmacology: Class: Docetaxel is an antineoplastic agent which acts by promoting the assembly of tubulin into stable microtubules and inhibits their disassembly which leads to a marked decrease of free tubulin. The binding of docetaxel to microtubules does not alter the number of protofilaments.
Site and mode of action: Docetaxel has been shown
in vitro to disrupt the microtubular network in cells which is essential for vital mitotic and interphase cellular functions.
Pharmacodynamics: Preclinical data: Docetaxel was found to be cytotoxic
in vitro against various murine and human tumour cell lines and against freshly excised human tumour cells in clonogenic assays. Docetaxel achieves high intracellular concentrations with a long cell residence time. In addition, docetaxel was found to be active on some, but not all, cell lines overexpressing the p-glycoprotein, which is encoded by the multidrug resistance gene.
In vivo, docetaxel is schedule independent and has a broad spectrum of experimental antitumour activity against advanced murine and human grafted tumours. Against transplantable murine tumours
in vivo, docetaxel was synergistic with vincristine (administered at the same time), etoposide, cyclophosphamide or fluorouracil, but not with vincristine (administered 24 hours apart), cisplatin or doxorubicin.
Clinical Trials: Breast Cancer: Metastatic Breast Cancer: Monotherapy: Eight phase II studies were conducted in patients with locally advanced or metastatic breast carcinoma. A total of 172 patients had received no prior chemotherapy (previously untreated) and 111 patients had received prior chemotherapy (previously treated) which included 83 patients who had progressive disease during anthracycline therapy (anthracycline resistant). In these clinical trials, docetaxel was administered at a dose of 75 mg/m
2 in 55 previously untreated patients and at a dose of 100 mg/m
2 in 117 previously untreated and 111 previously treated patients. In these trials, docetaxel was administered as a one hour infusion every three weeks.
Patients treated at 75 mg/m
2: In the intent to treat analysis on previously untreated patients, the overall response rate was 47% with 9% complete responses. The median duration of response was 34 weeks and the time to progression was 22 weeks.
There was a high response rate in patients with visceral metastases (48.6% in 35 untreated patients).
In patients with two or less organs involved, the response rate was 58.6% and in patients with three or more organs involved, it was 29.4%.
A significant response rate was seen in patients with liver metastases (45% in untreated patients). The same activity is maintained in untreated patients with soft tissue disease (55.5%).
Patients treated at 100 mg/m
2: Phase II trials: In the intent to treat analysis on previously untreated patients, the overall response rate was 56% with 9.4% complete responses. The overall response rate was 48.6% with 3.6% complete responses in the previously treated population including 48.2% overall response rate with 3.6% complete response in the anthracycline resistant patients. The median duration of response was 30 weeks in the previously untreated population, 28 weeks in the previously treated population and 27 weeks in the anthracycline resistant patients. The time to treatment failure was 21 weeks in the previously untreated population, 19 weeks in the previously treated population and 19 weeks in the anthracycline resistant patients.
The 100 mg/m
2 dose is associated with higher toxicity.
There was a high response rate in patients with visceral metastases (53.8% in 78 untreated patients, 55.1% in 69 pretreated patients and 53.1% in the subgroup of 49 anthracycline resistant patients).
In patients with three or more organs involved, the response rate was 54.3% in previously untreated patients, 55.8% in previously treated patients and 50% in the subgroup of anthracycline resistant patients.
A significant response rate was seen in patients with liver metastases (59.5% in untreated patients, 47.2% in previously treated patients and 40% in the subgroup of anthracycline resistant patients). The same activity is maintained in patients with visceral involvement (70.4% in previously untreated patients, 63.6% in previously treated patients and 63.2% in the subgroup of anthracycline resistant patients).
Patients treated at 100 mg/m
2: Phase III trials: Two randomised phase III comparative studies, involving a total of 326 alkylating agent failure and 392 anthracycline failure metastatic breast cancer patients, have been performed with docetaxel 100 mg/m
2 administered every three weeks for seven and ten cycles, respectively. In alkylating agent failure patients, there were no significant differences in median time to progression or median survival between docetaxel (D; n = 161) and doxorubicin (DX; n = 165; 75 mg/m
2 every three weeks) on intent to treat and evaluable patient analyses. For the intent to treat analysis, median time to progression was 5.9 months for docetaxel and 4.9 months for doxorubicin (D-DX diff: 1.0 month; 95% confidence interval (CI) for diff: -0.5 to 1.9); median overall survival was 14.7 months for docetaxel and 14.3 months for doxorubicin (D-DX diff: 0.4 months; 95% CI for diff: -1.9 to 2.7). There was a significant difference in response rates between the two groups: 47.8% for docetaxel and 33.3% for doxorubicin (D-DX diff: 14.5%, 95% CI for diff: 3.9 to 25.0) in the intent to treat analysis.
In anthracycline failure patients, docetaxel (n = 203) was compared to the combination of mitomycin C and vinblastine (MV; n = 189; 12 mg/m
2 every six weeks and 6 mg/m
2 every three weeks, respectively). For the intent to treat analysis, docetaxel increased response rate (30% versus 11.6%; D-MV diff: 18.4%; 95% CI for diff: 10.6 to 26.2), prolonged median time to progression (4.3 months versus 2.5 months; D-MV diff: 1.8 months; 95% CI for diff: 1.0 to 2.4) and prolonged median overall survival (11.5 months versus 8.7 months; D-MV diff: 2.8 months; 95% CI for diff: 0.1 to 4.3). Similar results were observed in the evaluable patient analysis.
An open label, multicentre, randomised phase III study was conducted to compare docetaxel and paclitaxel in the treatment of advanced breast cancer in patients whose previous therapy should have included an anthracycline. A total of 449 patients were randomised to receive either docetaxel 100 mg/m
2 as a one hour infusion or paclitaxel 175 mg/m
2 as a three hour infusion. Both regimes were administered every three weeks. Efficacy results are described in Table 1. (See Table 1.)
Click on icon to see table/diagram/image
The most frequent adverse events reported for docetaxel were neutropenia, febrile neutropenia, gastrointestinal disorders, neurological disorders, asthenia and fluid retention. More grade 3/4 events were observed from docetaxel (55.4%) compared to paclitaxel (23.0%). No unexpected toxicities were reported for docetaxel.
Combination with capecitabine: Docetaxel in combination with capecitabine was assessed in an open label, multicentre, randomised trial. A total of 511 patients with locally advanced and/or metastatic breast cancer resistant to, or recurring after an anthracycline containing therapy, or relapsing during or recurring within two years of completing an anthracycline containing adjuvant therapy were enrolled. In this trial, 255 patients were randomised to receive capecitabine (1,250 mg/m
2 twice daily for two weeks followed by a one week rest period) in combination with docetaxel (75 mg/m
2 as a one hour intravenous infusion every three weeks). 256 patients received docetaxel 100 mg/m
2 alone.
Docetaxel in combination with capecitabine resulted in statistically significant improvements in time to disease progression, overall survival and objective response rate compared to monotherapy with docetaxel as shown in Table 2. Health related quality of life (HRQoL) was assessed using the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaires (EORTC-QLQ), (C30 version 2, including Breast Cancer Module BR23). HRQoL was similar in the two treatment groups. (See Table 2.)
Click on icon to see table/diagram/image
Combination with trastuzumab (HER2+): Docetaxel in combination with trastuzumab was studied for the treatment of patients with metastatic breast cancer whose tumours overexpress HER2 and who previously had not received chemotherapy for metastatic disease. One hundred and eighty six patients received docetaxel (100 mg/m
2) with or without trastuzumab; 60% of patients received prior anthracycline based adjuvant chemotherapy. Docetaxel plus trastuzumab was efficacious in patients whether or not they had received prior adjuvant anthracyclines. The main test used to determine HER2 positivity in this pivotal trial was immunohistochemistry (IHC). A minority of patients were tested using fluorescence
in situ hybridisation (FISH). In this trial, 87% of patients had disease that was IHC 3+, and 95% of patients entered had disease that was IHC 3+ and/or FISH positive. Efficacy results are summarised in Table 3. (See Table 3.)
Click on icon to see table/diagram/image
Adjuvant Treatment of Breast Cancer: Combination with doxorubicin and cyclophosphamide: Data from a multicentre open label randomised trial support the use of docetaxel for the adjuvant treatment of patients with node positive breast cancer and KPS (Karnofsky Performance Score) greater than or equal to 80%, between 18 and 70 years of age. After stratification according to the number of positive lymph nodes (1-3, 4+), 1,491 patients were randomised to receive either docetaxel 75 mg/m
2 administered one hour after doxorubicin 50 mg/m
2 and cyclophosphamide 500 mg/m
2 (TAC arm), or doxorubicin 50 mg/m
2 followed by fluorouracil 500 mg/m
2 and cyclophosphamide 500 mg/m
2 (FAC arm). Both regimens were administered once every three weeks for six cycles. Docetaxel was administered as a one hour infusion; all other drugs were given as IV (intravenous) bolus on day 1. G-CSF was administered in both arms as secondary prophylaxis to patients who experienced febrile neutropenia, prolonged neutropenia or neutropenic infection. Patients in the docetaxel arm who continued to experience these reactions remained on G-CSF and had their dose reduced to 60 mg/m
2. Patients on the TAC arm received antibiotic prophylaxis with ciprofloxacin 500 mg orally b.i.d. (twice daily) for ten days starting on day 5 of each cycle, or equivalent. In both arms, after the last cycle of chemotherapy, patients with positive oestrogen and/or progesterone receptors received tamoxifen 20 mg daily for up to five years. Adjuvant radiation therapy was prescribed according to guidelines in place at participating institutions and was given to 69% of patients who received TAC and 72% of patients who received FAC.
An interim analysis was performed with a median follow-up of 55 months. Significantly longer disease-free survival for the TAC arm compared to the FAC arm was demonstrated. In the TAC arm, 23% of subjects had experienced disease progression, compared to 30% in the FAC arm. TAC treated patients had a 28% reduction in the risk of relapse compared to those treated with FAC (hazard ratio = 0.72, 95% CI (0.59 to 0.88), p = 0.001). Overall survival was also significantly longer in the TAC arm, with TAC treated patients having a 30% reduction in the risk of death compared to FAC (hazard ratio = 0.70, 95% CI (0.53 to 0.91), p = 0.008). In the TAC arm, 12% of patients had died compared to 17% on the FAC arm.
In the adjuvant breast cancer trial (TAX316), docetaxel in combination with doxorubicin and cyclophosphamide was administered to 744 patients of whom 48 (6%) were 65 years of age or greater. The number of elderly patients who received this regimen was not sufficient to determine whether there were differences in safety and efficacy between elderly and younger patients.
TAC treated patient subsets according to prospectively defined major prognostic factors were analysed (see Table 4).
Click on icon to see table/diagram/image
The beneficial effect of TAC was seen in both hormone receptor positive and negative patients.
Combination with doxorubicin, cyclophosphamide and trastuzumab and with carboplatin and trastuzumab (HER2+): The efficacy and safety of docetaxel in combination with trastuzumab was studied for the adjuvant treatment of patients with operable breast cancer whose tumours overexpress HER2 (with node positive and high risk node negative). A total of 3,222 women were randomised in the study, and 3,174 were treated with either: AC-T, AC-TH or TCH.
AC-T (control arm): Doxorubicin 60 mg/m
2 IV in combination with cyclophosphamide 600 mg/m
2 IV every 3 weeks for 4 cycles, followed by docetaxel 100 mg/m
2 as a 1 hour IV infusion every 3 weeks for 4 cycles.
AC-TH: Doxorubicin 60 mg/m
2 IV in combination with cyclophosphamide 600 mg/m
2 IV every 3 weeks for 4 cycles. Three weeks after the last cycle of AC, trastuzumab 4 mg/kg loading dose by IV infusion over 90 minutes on day 1 of cycle 5 was administered, followed by trastuzumab 2 mg/kg by IV infusion over 30 minutes weekly starting day 8 of cycle 5; and docetaxel 100 mg/m
2 administered by IV infusion over 1 hour on day 2 of cycle 5, then on day 1 every 3 weeks for a total of 4 cycles of docetaxel. Beginning three weeks after the last cycle of chemotherapy, trastuzumab 6 mg/kg by IV infusion over 30 minutes was given every 3 weeks (for 1 year from the date of first administration).
TCH: Trastuzumab 4 mg/kg loading dose by IV infusion over 90 minutes on day 1 of cycle 1 only, followed by trastuzumab 2 mg/kg by IV infusion over 30 minutes weekly starting on day 8 until three weeks after the last cycle of chemotherapy. Docetaxel 75 mg/m
2 was administered on day 2 of cycle 1, then on day 1 of all subsequent cycles by IV infusion over 1 hour followed by carboplatin (AUC 6 mg/mL/min) as a 30-60 minute IV infusion, for a total of six cycles of docetaxel and carboplatin. Beginning three weeks after the last cycle of chemotherapy, trastuzumab 6 mg/kg by IV infusion over 30 minutes was given every 3 weeks (for 1 year from the date of first administration).
The patients and disease characteristics at baseline were well balanced between the 3 treatment arms.
Disease free survival (DFS) was the primary endpoint, and overall survival (OS) was the secondary endpoint.
Results of the second interim analysis, performed with a median follow-up of 36 months, demonstrated that docetaxel and trastuzumab given concurrently as part of either an anthracycline based (AC-TH) or non-anthracycline based (TCH) adjuvant treatment regimens, for patients with HER2 positive operable breast cancer, statistically prolonged both DFS and OS compared with the control arm (AC-T). The AC-TH and TCH regimens significantly improved disease free survival compared with AC-T at the significance level of 0.003 required for the interim analysis. Overall survival was significantly better with AC-TH but not TCH compared to AC-T in the interim analysis. There was no statistically significant difference between the two trastuzumab containing arms AC-TH and TCH for DFS and OS. Efficacy results are summarised in Table 5. (See Table 5.)
Click on icon to see table/diagram/image
There were 29% of patients with high risk node negative disease included in the study. The benefit observed for the overall population was irrespective of the nodal status. (See Table 6.)
Click on icon to see table/diagram/image
Combination with Cyclophosphamide: Docetaxel in combination with cyclophosphamide (TC) was investigated in a phase III randomised prospective clinical trial, in comparison with the standard treatment regimen of doxorubicin and cyclophosphamide (AC). Results of the trial were only available in the form of two published papers. A total of 1016 patients with operable stage I to III invasive breast cancer were randomly assigned to receive either four cycles of AC (60 and 600 mg/m
2 respectively every three weeks; n=510), or four cycles of TC (75 mg and 600 mg/m
2 every three weeks; n=506) as adjuvant chemotherapy after complete surgical excision of the primary tumour. Patients had to have a primary tumour of ≥1 cm and <7 cm, and no evidence of metastatic disease. Neoadjuvant chemotherapy was not permitted.
Both treatment groups were well balanced for major prognostic factors; including age, race, stage, histology, hormone receptor status and nodal status. On completion of four cycles of chemotherapy (with or without radiotherapy) tamoxifen was administered to all patients with hormone receptor positive breast cancer for 5 years.
After median follow up of 5 years, the results demonstrated an improvement in disease free survival (DFS) for TC compared with AC. In the TC arm 435/506 (86%) remained alive and disease-free, compared to 408/510 (80%) in the AC arm (HR = 0.67; 95% CI 0.50 to 0.94; p=0.015).
Non-Small Cell Lung Cancer: Patients treated at 75 mg/m
2: One phase II study was conducted in 20 previously untreated patients with locally advanced or metastatic non-small cell lung cancer. In this clinical trial, docetaxel was administered at a dose of 75 mg/m
2 given as a one hour infusion every three weeks. The response rate was 10%.
Patients treated at 100 mg/m
2: Six phase II studies were conducted in patients with locally advanced or metastatic non-small cell lung cancer. A total of 160 patients had received no prior chemotherapy (previously untreated) and 88 patients had received prior platinum based chemotherapy (previously treated) which included 37 patients who had progressive disease with platinum therapy (platinum refractory). In these clinical trials, docetaxel was administered at a dose of 100 mg/m
2 given as a one hour infusion every three weeks.
The 100 mg/m
2 dose is associated with higher toxicity.
In the intent to treat analysis on previously untreated patients, the overall response rate was 26.9% and in the previously treated population it was 17%. The survival time for all previously untreated patients or previously treated patients was nine and eight months, respectively.
Ovarian Cancer: Patients treated at 100 mg/m
2: Docetaxel was studied in five uncontrolled trials in patients with advanced epithelial ovarian cancer who had failed previous treatment with cisplatin or carboplatin. These patients (n = 377) received docetaxel 100 mg/m
2 in a one hour intravenous infusion every three weeks.
In the intent to treat analysis, median time to progression ranged from 9.2 to 13.1 weeks, median survival ranged from 7 to 10.3 months, overall response rate ranged from 8.3 to 24.0% and complete response rate ranged from 2.8 to 8.3%.
Prostate Cancer: The safety and efficacy of docetaxel in patients with androgen independent (hormone refractory) metastatic prostate cancer were evaluated in a randomised multicentre phase III trial. A total of 1,006 patients with KPS greater than or equal to 60 were randomised to the following treatment groups: Docetaxel 75 mg/m
2 every three weeks for ten cycles; Docetaxel 30 mg/m
2 administered weekly for the first five weeks in a six week cycle for five cycles; Mitozantrone 12 mg/m
2 every three weeks for ten cycles.
All three regimens were administered in combination with prednisone or prednisolone 5 mg twice daily, continuously.
Patients who received docetaxel every three weeks demonstrated significantly longer overall survival compared to those treated with mitozantrone (p = 0.0094). The increase in survival seen in the docetaxel weekly arm was not statistically significant compared to the mitozantrone control arm. Efficacy endpoints for the docetaxel three weekly arm versus the control arm are summarised in Table 7. (See Table 7.)
Click on icon to see table/diagram/image
Head and Neck Cancer: Induction therapy followed by radiotherapy (TAX323): The safety and efficacy of docetaxel in the induction treatment of patients with squamous cell carcinoma of the head and neck (SCCHN) were evaluated in a phase III, multicentre, open label, randomised trial (TAX323). In this study, 358 previously untreated patients with locally advanced inoperable stage III/IV SCCHN and World Health Organization (WHO) performance status 0 or 1, were randomised to one of two treatment arms. Patients on the docetaxel arm received docetaxel (T) 75 mg/m
2 followed by cisplatin (P) 75 mg/m
2 on day 1, followed by fluorouracil (F) 750 mg/m
2 per day as a continuous infusion on days 1 to 5. The cycles were repeated every three weeks for four cycles. Patients whose disease did not progress received radiotherapy (RT) according to institutional guidelines (TPF/RT). Patients on the comparator arm received cisplatin 100 mg/m
2 on day 1, followed by fluorouracil 1,000 mg/m
2 (PF) as a continuous infusion on days 1 to 5. The cycles were repeated every three weeks for four cycles. Patients whose disease did not progress received RT according to institutional guidelines (PF/RT). At the end of chemotherapy, with a minimal interval of four weeks and a maximal interval of seven weeks, patients whose disease did not progress received radiotherapy (RT) according to institutional guidelines.
Conventional locoregional radiotherapy was given to approximately 77% of the patients at a total dose of 66 to 70 Gy (1.8 to 2.0 Gy once a day, five days/week) while accelerated/hyperfractionated regimens of radiation therapy were used in approximately 23% of patients (twice a day, with a minimum interfraction interval of six hours, five days/week).
A total of 70 Gy was recommended for accelerated regimens and 74 Gy for hyperfractionated schemes. Surgical resection was allowed following chemotherapy, before or after radiotherapy. The primary endpoint in this study, progression free survival (PFS), was significantly longer in the TPF arm compared to the PF arm, p = 0.0042 (median PFS: 11.4 versus 8.3 months, respectively) with an overall median follow-up time of 33.7 months. Median overall survival (OS) was significantly longer in favour of the TPF arm compared to the PF arm (median OS: 18.6 versus 14.5 months, respectively) with a 28% risk reduction of mortality, p = 0.0128. Patients with tumours of the nasopharynx and the nasal/paranasal cavities were excluded from this study. Efficacy results are presented in Table 8. (See Table 8.)
Click on icon to see table/diagram/image
Clinical benefit parameters: Patients treated with TPF experienced significantly less deterioration of their global health score compared to those treated with PF (p = 0.01, using EORTC QLQ-C30).
The performance status scale for head and neck, designed to measure disturbances of speech and eating, was significantly in favour of TPF treatment.
The median time to first deterioration of WHO performance status was significantly (p = 0.0158) longer in the TPF arm (13.7 months; 95% CI: 10.7 to 21.0 months) compared to PF (8.3 months; 95% CI: 7.3 to 9.6 months). However, no significant difference in WHO performance status was apparent between the two arms (odds ratio = 0.96, 95% CI: 0.66 to 1.41). There was no difference in pain intensity in patients treated with TPF or PF.
Induction chemotherapy followed by chemoradiotherapy (TAX324): The safety and efficacy of docetaxel in the induction treatment of patients with locally advanced (technically unresectable, low probability of surgical cure, or candidates for organ preservation) SCCHN was evaluated in a randomised, multicentre open label, phase III trial (TAX324). Patients with tumours of the nasopharynx and nasal/paranasal cavities were excluded from this study. In this study, 501 patients with locally advanced SCCHN, and a WHO performance status of 0 or 1 were randomised to one of two arms. Patients on the docetaxel arm received docetaxel (T) 75 mg/m
2 by IV infusion on day 1, followed by cisplatin (P) 100 mg/m
2 administered as a 30 minute to three hour IV infusion, followed by the continuous IV infusion of fluorouracil (F) 1,000 mg/m
2/day from day 1 to day 4. The cycles were repeated every three weeks for three cycles. All patients who did not have progressive disease were to receive chemoradiotherapy (CRT) as per protocol (TPF/CRT). Patients on the comparator arm received cisplatin (P) 100 mg/m
2 administered as a 30 minute to three hour IV infusion, followed by the continuous IV infusion of fluorouracil (F) 1,000 mg/m
2/day from day 1 to day 5. The cycles were repeated every three weeks for three cycles. All patients who did not have progressive disease were to receive CRT as per protocol (PF/CRT).
Patients in both treatment arms were to receive seven weeks of CRT following induction chemotherapy with a minimum interval of three weeks and no later than eight weeks after start of the last cycle (day 22 to day 56 of last cycle). During radiotherapy, carboplatin (AUC 1.5) was given weekly as a one hour IV infusion for a maximum of seven doses. Radiation was delivered with megavoltage equipment using once daily fractionation (2 Gy per day, five days per week for seven weeks, for a total dose of 70 to 72 Gy). Surgery on the primary site of disease and/or neck could be considered at any time following completion of CRT.
The primary efficacy endpoint in this study, OS was significantly longer (log rank test p = 0.0058) with the docetaxel containing regimen compared to PF (median OS: 70.6 versus 30.1 months, respectively), with a 30% risk reduction in mortality compared to PF (hazard ratio (HR) = 0.70, 95% CI = 0.54 to 0.90). The secondary endpoint PFS demonstrated a 29% risk reduction of progression or death and a 22 month improvement in median PFS (35.5 months for TPF and 13.1 for PF). This was also statistically significant with an HR of 0.71; 95% CI 0.56 to 0.90; log rank test p = 0.004. Efficacy results are presented in Table 9. (See Table 9.)
Click on icon to see table/diagram/image
Pharmacokinetics: Absorption: Hospira Docetaxel Concentrated Injection is administered by intravenous infusion. By definition, absorption is complete at the end of the infusion.
Distribution: The pharmacokinetics of docetaxel have been evaluated in cancer patients after administration of 5 to 115 mg/m
2 in phase I studies. The kinetic profile of docetaxel is dose independent and consistent with a three compartment pharmacokinetic model with half-lives for the alpha, beta and gamma phases of 4 minutes, 36 minutes and 11.1 hours, respectively. The initial rapid decline represents distribution to the peripheral compartments and the late phase is due, in part, to a relatively slow efflux of docetaxel from the peripheral compartment. Following the administration of a 100 mg/m
2 dose given as a one hour infusion, a mean peak plasma level of 3.7 microgram/mL was obtained with a corresponding area under the curve (AUC) of 4.6 hour.microgram/mL. Mean values for total body clearance and steady-state volume of distribution were 21 L/hour/m
2 and 113 L, respectively.
Metabolism and excretion: A study of
14C-docetaxel has been conducted in three cancer patients. Docetaxel was eliminated in both the urine and faeces following oxidative metabolism of the tert-butyl ester group; within seven days, the urinary and faecal excretion account for about 6 and 75% of the administered radioactivity, respectively. About 80% of the radioactivity (60% of the administered dose) recovered in faeces is excreted during the first 48 hours as one major and three minor inactive metabolites and very low amounts of unchanged drug.
A population pharmacokinetic analysis has been performed with docetaxel in 577 patients. Pharmacokinetic parameters estimated by the model were very close to those estimated from phase I studies. The pharmacokinetics of docetaxel were not altered by the age or sex of the patient. In a small number of patients (n = 23) with clinical chemistry data suggestive of mild to moderate liver function impairment (ALT, AST greater than or equal to 1.5 times the upper limit of normal, associated with alkaline phosphatase greater than or equal to 2.5 times the upper limit of normal), total clearance was lowered by, on average, 27% (see Dosage & Administration). Docetaxel clearance was not modified in patients with mild to moderate fluid retention. No data are available in patients with severe fluid retention.
Docetaxel is more than 95% bound to plasma proteins. Dexamethasone did not affect protein binding of docetaxel.
The effect of prednisone on the pharmacokinetics of docetaxel administered with standard dexamethasone premedication has been studied in 42 patients. No effect of prednisone on the pharmacokinetics of docetaxel was observed.
Phase I studies evaluating the effect of capecitabine on the pharmacokinetics of docetaxel and the effect of docetaxel on the pharmacokinetics of capecitabine showed no effect of capecitabine on the pharmacokinetics of docetaxel (C
max and AUC) and no effect of docetaxel on the pharmacokinetics of the main capecitabine metabolite 5'DFUR.
The combined administration of docetaxel, cisplatin and fluorouracil in 12 patients with solid tumours had no influence on the pharmacokinetics of each individual drug.