Paclitaxel-induced neuropathy

Neurologic complications of cancer therapy

Neurologic complications of chemotherapy are relatively common. The diagnosis of chemotherapy-associated neurotoxicity remains a clinical one, and is largely based on the exclusion of other possible causes. The goal of this review is to describe the neurotoxicity associated with established chemothrerapeutic agents and with some of the newer biologic agents, monoclonal antibodies and targeted molecular therapies used in the treatment of cancer.

Phase I and pharmacological studies of the cryptophycin analogue LY355703 administered on a single intermittent or weekly schedule

LY355703 is a synthetic derivative of the marine cryptophycins, cytotoxic agents which induce mitotic arrest by binding at the microtubule vinca binding domain. Promising preclinical features of LY355703 were the 40-400 greater potency than paclitaxel or vinca alkaloids, the broad spectrum of antitumor activity in xenografts and the antitumour activity in multidrug resistant (MDR)-expressing murine tumours. Aims of this study were to define the maximum tolerated dose (MTD) and the dose recommended for Phase II, the pattern of toxicity, the pharmacokinetic profile and to document hints of antitumour activity of LY355703 given as 2-h infusion on day 1 every 3 weeks (Study 1) or, later on, on days 1, 8 and 15 every 4 weeks (Study 2). The latter weekly regimen was selected because of the acute dose-related toxicity reported in Study 1. The dose was escalated using a modified Continual Reassessment Method. Pharmacokinetic studies were performed on day 1 of cycle 1 in both studies; LY355703 plasma concentrations were assessed by liquid chromatography with tandem mass spectrometry. A total of 35 adult patients with solid tumours entered Study 1; the dose was escalated from 0.1 to 1.92 mg/m(2); at this dose 2 of 5 patients presented grade 3 neuropathy and myalgias; 1.48 mg/m(2) was then recommended for Phase II study. A total of 8 patients were treated in Study 2 at 1 mg/m(2); cumulative long-lasting neuroconstipation and neurosensory toxicity precluded the completion of the cycle in 9 out of 15 cycles; the clinical development of the weekly regimen was then discontinued. Other toxicities included cardiac dysrhythmia and mild alopecia. Pharmacokinetics of LY355703 appeared to be linear over the dose range studied. The administration of LY355703 on a 3-week schedule is associated with an acute dose-dependent peripheral neuropathy and myalgia of high interpatient variability for which possible risk factors and pharmacokinetic correlates could not be identified.

Role of protein kinase Cepsilon and protein kinase A in a model of paclitaxel-induced painful peripheral neuropathy in the rat

The clinical use of the antineoplastic agent paclitaxel (Taxol) is significantly limited in its effectiveness by a dose-related painful peripheral neuropathy. To evaluate underlying mechanisms, we developed a model of Taxol-induced painful peripheral neuropathy in the rat and determined the involvement of two second messengers that contribute to enhanced nociception in other models of inflammatory and neuropathic pain, protein kinase Cepsilon and protein kinase A. Taxol administered acutely, or chronically over 12 days, produced a decrease in mechanical nociceptive threshold. Acutely, Taxol induced hyperalgesia that was significant within 1 h, maximal after 6 h and resolved completely by 24 h after a single treatment. Chronically, Taxol treatment resulted in a dose (0.1-1 mg/kg/day)-dependent decrease in nociceptive threshold, measured 24 h after administration, maximal within 5 days from the commencement of Taxol administration and resolving by 2 weeks after the last dose of Taxol. Chronic Taxol treatment also increased the number of action potentials evoked by sustained (60-s) threshold and suprathreshold (10-g) stimulation of a sub-population of C-fibers in rats with Taxol-induced hyperalgesia. Mechanical allodynia and thermal hyperalgesia were also present in Taxol-treated rats. Hyperalgesia, produced by both acute and chronic Taxol, was attenuated by intradermal injection of selective second messenger antagonists for protein kinase Cepsilon and protein kinase A. These findings provide insight into the mechanism of Taxol-induced painful peripheral neuropathy that may help control side effects of chemotherapy and improve its clinical efficacy.

Paclitaxel affects cytosolic calcium signals by opening the mitochondrial permeability transition pore

We have characterized the effects of the antimitotic drug paclitaxel (Taxol(TM)) on the Ca(2+) signaling cascade of terminally differentiated mouse pancreatic acinar cells. Using single cell fluorescence techniques and whole-cell patch clamping to record cytosolic Ca(2+) and plasma membrane Ca(2+)-dependent Cl(-) currents, we find that paclitaxel abolishes cytosolic Ca(2+) oscillations and in more than half of the cells it also induces a rapid, transient cytosolic Ca(2+) response. This response is not affected by removal of extracellular Ca(2+) indicating that paclitaxel releases Ca(2+) from an intracellular Ca(2+) store. Using saponin-permeabilized cells, we show that paclitaxel does not affect Ca(2+) release from an inositol trisphosphate-sensitive store. Furthermore, up to 15 min after paclitaxel application, there is no significant effect on either microtubule organization or on endoplasmic reticulum organization. The data suggest a non-endoplasmic reticulum source for the intracellular Ca(2+) response. Using the mitochondrial fluorescent dyes, JC-1 and Rhod-2, we show that paclitaxel evoked a rapid decline in the mitochondrial membrane potential and a loss of mitochondrial Ca(2+). Cyclosporin A, a blocker of the mitochondrial permeability transition pore, blocked both the paclitaxel-induced loss of mitochondrial Ca(2+) and the effect on Ca(2+) spikes. We conclude that paclitaxel exerts rapid effects on the cytosolic Ca(2+) signal via the opening of the mitochondrial permeability transition pore. This work indicates that some of the more rapidly developing side effects of chemotherapy might be due to an action of antimitotic drugs on mitochondrial function and an interference with the Ca(2+) signal cascade.

A short course of induction chemotherapy followed by two cycles of high-dose chemotherapy with stem cell rescue for chemotherapy naive metastatic breast cancer: sequential phase I/II studies

Two cycles of high-dose chemotherapy with stem cell support (HDC) may increase the total dose delivered and dose intensity. A brief induction phase and different non-cross-resistant agents for each HDC cycle were used to avoid drug resistance. Twenty-six women with metastatic BC had induction and stem cell mobilization with two cycles of doxorubicin/G-CSF given every 14 days. Patients with stable disease or better after induction received HD CTCb followed by HD melphalan and dose-escalated paclitaxel. At 475 mg/m(2) of paclitaxel by 24-h infusion, dose-limiting transient peripheral sensory neuropathy was encountered. No toxic deaths occurred. Complete and near complete response after completion of therapy was achieved in 22 (85%) of 26 patients. The median EFS was 38 months. The median OS has not yet been reached. At a median follow-up of 33 (25-43) months, actuarial EFS and OS were 54% (95% confidence interval (CI), 39-69%) and 69% (95% CI, 56-79%), respectively. This double transplant approach lasts only 14 weeks and is feasible, safe, and tolerable. Whilst selection biases may in part contribute to favorable EFS and OS, a randomized comparison of standard therapy vs double transplant in both metastatic and locally advanced breast cancer is warranted.

Phase I trial of weekly paclitaxel plus oral estramustine phosphate in patients with hormone-refractory prostate cancer

OBJECTIVES

To exploit the favorable dose intensity and safety profile of weekly paclitaxel, we conducted a Phase I trial of paclitaxel by 3-hour infusion in combination with estramustine phosphate (EM) in men with hormone-refractory prostate cancer (HRPC). The antimicrotubule drug combination of paclitaxel by 96-hour infusion plus EM is active in HRPC.

METHODS

Twenty-four patients with metastatic HRPC and progressive tumor after antiandrogen withdrawal were enrolled in this study. Oral EM was taken at a dose of 600 mg/m(2) daily for the initial 21 patients and on a reduced schedule of 280 mg twice daily for the final 3 patients. Paclitaxel was escalated from 60 to 118 mg/m(2).

RESULTS

The major toxicities were gastrointestinal and thromboembolic complications related to daily oral dosing of EM. Of the first 21 patients, one third (n = 7) discontinued therapy within 4 weeks because of protracted nausea and/or thrombotic complications. Dose-limiting toxicities at 118 mg/m(2) paclitaxel were fatigue and hepatotoxicity. Of 13 patients with measurable soft-tissue lesions, 6 had objective partial regressions, and 9 (37.5%) of 24 patients (95% confidence interval 19.1% to 59.1%) with elevated prostate-specific antigen levels had a 50% or greater decline of at least 4 weeks' duration.

CONCLUSIONS

Weekly paclitaxel at doses of 60 to 107 mg/m(2) were feasible in combination with oral EM, but daily oral EM produced unacceptable toxicity. On the basis of these results, a Phase II trial of weekly paclitaxel with the reduced dose and schedule of EM was initiated by the Eastern Cooperative Oncology Group to assess further the benefits and risks of this treatment in men with metastatic HRPC.

Taxanes in lung cancer: a review with focus on the European experience

The introduction of new agents in the treatment of lung cancer raised in the past few years new interest in clinical research on this topic. The use of taxanes as paclitaxel and docetaxel may represent a significant progress in the treatment of lung cancer. Taxanes used as single agents show a substantial activity in lung cancer and, because of their unique mechanism of action, it is possible to combine these drugs with other non-cross-resistant agents. Taxanes share a radiosensitizing effect and their use with concurrent radiotherapy appears to become a new standard. This review will focus on the European clinical experience in the treatment of lung cancer with the two compounds.

An antimicrotubule agent, TZT-1027, does not induce neuropathologic alterations which are detected after administration of vincristine or paclitaxel in animal models

One of the major dose-limiting toxicities induced by antimicrotubule antitumor agents such as vinca alkaloids and taxanes is peripheral neuropathy. The neurotoxicity of TZT-1027 (a dolastatin 10 derivative antimicrotubule agent) was thus assessed using the animal models for antimicrotubule agent-induced neurotoxicity. Rabbits were intravenously given TZT-1027 or vincristine weekly for 5 weeks. In the mouse study, TZT-1027, vincristine or paclitaxel was intravenously given every 2 days and/or weekly. Despite the neuropathologic evidence such as myelinated axonal and fiber degeneration in the peripheral nerves and in the sensory tracts of the spinal cord following the treatment with vincristine or paclitaxel, no drug-induced alteration was observed in the TZT-1027 groups. Although there are reports that some other dolastatin derivatives with antimicrotubule activity showed no neurotoxic potential in humans, the present study represents the first demonstration in experimental animals that a dolastatin derivative has no, or at least a lower, neurotoxic potential compared to other antimicrotubule agents.

Phase II study of paclitaxel, ifosfamide, and carboplatin in patients with recurrent or metastatic head and neck squamous cell carcinoma

BACKGROUND

In the current study the authors assessed the antitumor activity (including response rate, duration of response, and survival) and toxicity profile (including anorexia, fatigue, emesis, and peripheral neuropathy) of a combination of paclitaxel, ifosfamide, and carboplatin (TIC) in patients with recurrent or metastatic squamous cell carcinoma of the head and neck (SCCHN). The trial hypothesis was that the TIC therapeutic index would be as high as that of paclitaxel, ifosfamide, and cisplatin (TIP) in this setting, but with less toxicity.

METHODS

Patients with recurrent or metastatic SCCHN were treated with 175 mg/m(2) of paclitaxel as a 3-hour infusion on Day 1, 1000 mg/m(2) of ifosfamide as a 2-hour infusion on Days 1-3, 600 mg/m(2) of mesna on Days 1-3, and carboplatin (area under the concentration-time curve of 6) as a 30-minute infusion on Day 1; the regimen was repeated every 3-4 weeks. All patients were premedicated with dexamethasone, diphenhydramine, and cimetidine before paclitaxel infusion. Prophylactic hematopoietic growth factors were not given.

RESULTS

Among 56 patients entered onto the study, 55 patients were analyzed for survival rates (locoregional recurrence alone in 56% of patients and distant metastasis with or without locoregional recurrence in 44% of patients). Fifty-four patients were evaluable for tumor response and toxicity. A total of 32 patients (59%) had disease that responded to treatment; the complete response rate was 17% (9 of 54 patients). The median duration of the responses was 3.7 months (95% confidence interval [95% CI], 3.4-7.8 months) and that of complete responses was 9.7 months (95% CI, 7.4 months to date of last follow-up). The median duration of follow-up care in all patients was 13.5 months. The median survival time for all patients was 9.1 months (95% CI, 7.9-12.2 months). The regimen was well tolerated. Neutropenic fever developed in 30% of the patients; 1 patient died of neutropenia and sepsis. Other toxic effects included Grade 2-3 anorexia in 13% of patients, Grade 2-3 weight loss in 11% of patients, Grade 2-3 fatigue in 27% of patients, Grade 2-3 nausea/emesis in 13% of patients, and Grade 2-3 peripheral neuropathy in 9% of patients (toxicity grading based on the National Cancer Institute's Common Toxicity Criteria). Red blood cell and platelet transfusions were required in 13% and 7% of patients, respectively.

CONCLUSIONS

The TIC regimen had high antitumor activity in patients with recurrent or metastatic SCCHN, with a 59% major response rate (17% complete response rate with relatively durable complete responses). Neutropenic fever developed in 30% of the patients, the incidence of which might have been decreased by prophylactic antibiotics or hematopoietic growth factor support. Other toxic effects included significantly lower rates and less severe instances of anorexia, emesis, fatigue, and peripheral neuropathy than those reported with the previously studied TIP regimen. The TIC regimen currently is being studied as an induction chemotherapy regimen in previously untreated patients with locally advanced SCCHN. The activity of TIC (a novel paclitaxel and ifosfamide-based regimen) in patients with recurrent or metastatic SCCHN should be confirmed in a Phase III randomized trial.

Salvage treatment with paclitaxel, ifosfamide, and cisplatin plus high-dose carboplatin, etoposide, and thiotepa followed by autologous stem-cell rescue in patients with relapsed or refractory germ cell cancer

PURPOSE

To study feasibility and efficacy of a new salvage regimen in patients with relapsed and/or refractory germ cell tumors.

PATIENTS AND METHODS

Between May 1995 and February 1997, 80 patients were entered onto a phase II study. Conventional-dose salvage treatment with three cycles of paclitaxel 175 mg/m(2), ifosfamide 5 x 1.2 g/m(2), and cisplatin 5 x 20 mg/m(2) (TIP) was followed by one cycle of high-dose chemotherapy (HDCT) with carboplatin 500 mg/m(2) x 3, etoposide 600 mg/m(2) x 4, and thiotepa 150 to 250 mg/m(2) x 3 (CET). In 23 patients, one additional cycle of paclitaxel 175 mg/m(2) and ifosfamide 5 g/m(2) (TI) was given immediately before TIP to improve stem-cell mobilization.

RESULTS

Fifty-five (69%) of 80 patients responded to TIP, 24 (30%) of 80 patients had stable disease (n = 5) or tumor progression (n = 19), and one patient died. Only 62 (78%) of 80 patients received subsequent HDCT. Among those, 41 (66%) of 62 patients responded and 20 (32%) of 62 patients had stable disease (n = 3) or tumor progression (n = 17). One patient died after HDCT from multiorgan failure. Survival probabilities at 3 years were 30% for overall and 25% for event-free survival. Peripheral neurotoxicity with sensorimotor impairment grade 2 through 4 in 29%, paresthesias grade 2 through 4 in 24%, and skin toxicity grade 2 through 3 in 15% of patients were the most relevant side effects.

CONCLUSION

Treatment with TIP followed by high-dose CET is feasible and can induce long-term remissions in 25% of patients with relapsed or refractory germ cell tumors. Peripheral nervous toxicity in approximately one third of patients is a disadvantage of this salvage strategy.

Paclitaxel-induced stomal neuropathy: a unique cause of pain in a patient with ileal conduit

We present a case of unusual chemotherapy-induced neurotoxicity in a patient who had undergone radical cystoprostatectomy and ileal conduit diversion for invasive bladder cancer. On routine computed tomography scan several years later, he was diagnosed with metastatic transitional cell carcinoma involving the retroperitoneal lymph nodes. The patient received systemic chemotherapy, including a combination of paclitaxel (Taxol) and gemcitabine (Gemzar). During this treatment, the patient developed spasmodic pain and dysesthesia in the stoma area, with no apparent skin irritation or any other local finding. These symptoms resolved about 3 months after completion of the therapy.

Peripheral neuropathy due to biweekly paclitaxel, epirubicin and cisplatin in patients with advanced ovarian cancer

We assessed the peripheral neuropathic changes induced by biweekly combination chemotherapy including paclitaxel 100-165 mg/m2 (in a 3-h infusion), epirubicin 75 mg/m2 and cisplatin 50 mg/m2 (TEC) in patients with advanced ovarian cancer. Neurologic evaluation, including a standardized questionnaire, bed-side neurological examination, and quantitative determination of vibratory perception thresholds (VPT) and grip strength took place before therapy, after 3 and 6 cycles, and thereafter whenever possible. During chemotherapy all patients received granulocyte colony-stimulating factor from days 2 to 12. Pretreated patients received amifostine two times, before epirubicin and before cisplatin administration. Neuropathic symptoms developed in 11/13 non-pretreated patients and in 7/9 chemotherapy-pretreated patients. Neuropathic signs developed in all patients. Neuropathic symptoms and signs were predominantly sensory in character. VPT changes developed primarily in the feet. According to National Cancer Institute of Canada Common Toxicity Criteria, grade 3 peripheral neuropathy after 6 cycles developed in 1/6 and 2/4 non-pretreated patients who received TEC containing paclitaxel 150 and 165 mg/m2, respectively. We conclude that peripheral neuropathy is dose-limiting in chemonaïve patients treated with biweekly TEC combination chemotherapy, at paclitaxel dose level 165 mg/m2 in a 3-h intravenous administration.

A phase II study of paclitaxel in chemonaïve patients with recurrent high-grade glioma

BACKGROUND

The prognosis of malignant gliomas remains poor. In recurrent disease, chemotherapy can be considered.

PATIENTS AND METHODS

In this phase II study we determined the anti-tumour efficacy of paclitaxel 200 mg/m2 in a three-hour intravenous infusion every three weeks in chemonaïve patients with recurrent high-grade glioma in terms of response, survival, and quality of life.

RESULTS

In 17 patients (14 glioblastoma multiforme, 3 anaplastic astrocytoma) 69 paclitaxel cycles were administered. Partial or complete responses were not observed. Stable disease for four to six months was observed in five patients (29%). Median time to progression and median survival were two and 10 months, respectively. Toxicity due to paclitaxel was as to be expected and minor in most cases. Quality of life and mood estimates appeared rather stable over time.

CONCLUSIONS

We conclude that three-weekly 200 mg/m2 paclitaxel chemotherapy for patients with recurrent high-grade gliomas did not lead to major complications or adverse effects on quality of life and mood. However, this therapy is of only very limited value in terms of response and survival in such patients.

Paclitaxel derivatives for targeted therapy of cancer: toward the development of smart taxanes

The pharmacologic efficacy of the promising antitumor agent paclitaxel (Taxol) may be potentially enhanced through derivatization of the drug to a water-soluble tumor-recognizing conjugate. This work reports the design and synthesis of the first tumor-directed derivative of paclitaxel. A 7-amino acid synthetic peptide, BBN[7-13], which binds to the cell surface bombesin/gastrin-releasing peptide (BBN/GRP) receptor, was conjugated to the paclitaxel-2'-hydroxy function by a heterobifunctional poly(ethylene glycol) linker. The resulting conjugate, designated PTXPEGBBN[7-13], was soluble to the upper limit of tested concentrations (250 mg/mL). The conjugate completely retained the receptor binding properties of the attached peptide as compared with those of the unconjugated BBN[7-13]. In experiments with NCI-H1299 human nonsmall cell lung cancer cells, the cytotoxicity of the PTXPEGBBN[7-13] conjugate at a 15 nM dose was enhanced by a factor of 17.3 for 24 h and 10 for 96 h exposure times, relative to paclitaxel. The IC(50) of the conjugate, tested against the same cell line, was lower than the free drug by a factor of 2.5 for both 24 h and 96 h exposures. These results describe, for the first time, the design and synthesis of a soluble tumor-directed paclitaxel prodrug which may establish a new mode for the utilization of this drug in cancer therapy.

Randomized phase II study of high-dose paclitaxel with or without amifostine in patients with metastatic breast cancer

PURPOSE

To determine whether the neurotoxicity of paclitaxel 250 mg/m(2) given over 3 hours every 3 weeks could be reduced by pretreatment with amifostine 910 mg/m(2). Secondary objectives included comparing myelosuppression, myalgias, and response rates of the two groups.

PATIENTS AND METHODS

Forty women with metastatic breast cancer were randomized to receive either paclitaxel alone (arm 1) or paclitaxel preceded by amifostine (arm 2). All were assessable for toxicity, and 37 were assessable for response. At baseline and after each cycle, all patients completed questionnaires for neurologic symptoms and had standardized neurologic examinations, including objective assessments of power and vibration sense. In addition, standard follow-up assessments for other toxicities and tumor response were undertaken. Changes from baseline after courses 1, 2, and 3 were assessed. The sample size was sufficient to detect a 50% improvement in the expected determination in sensory change.

RESULTS

There were no differences observed in any of the measures of neurotoxicity. Other toxicity was similar in arms 1 and 2, including hair loss (95% v 90%), neurosensory changes (100% v 100%), fatigue/lethargy (85% v 90%), myalgia (95% v 90%), and grade 4 neutropenia (47% v 60%). Nausea, vomiting, dizziness, hypotension, and sneezing were more common in the amifostine arm. Response rates (22.2% v 36.8%) and paclitaxel pharmacokinetics were not significantly different.

CONCLUSION

There was no protection from paclitaxel-related neurotoxicity or hematologic toxicity in this study. These results suggest that the mechanism of action of paclitaxel-related toxic effects is not amenable to the cytoprotective action of amifostine.

Bilateral facial nerve palsy secondary to the administration of high-dose paclitaxel

Bilateral facial nerve palsy is an uncommon occurrence. We describe a case of bilateral facial nerve palsy secondary to a single cycle of high-dose paclitaxel therapy (825 mg/m2), in a woman with breast cancer. Prior to her high-dose therapy, she had a residual grade 2 peripheral neuropathy following treatment with ten cycles of standard-dose paclitaxel (total dose 3200 mg). The features of the peripheral neuropathy due to standard-dose paclitaxel, which can be both motor and sensory, are well described. Cumulative paclitaxel dose is considered a risk factor for development of the neuropathy. Although facial nerve palsy secondary to paclitaxel is not previously reported, other cranial nerve toxicity has been described. Consistent with reports of the reversibility of paclitaxel-induced peripheral neuropathy, the facial nerve palsies in our patient resolved over 23 months. Ongoing studies of high-dose paclitaxel warrant close attention to its cumulative neurotoxic effects, particularly in patients previously treated with neurotoxic chemotherapy.

Docetaxel and cisplatin in combination as first-line chemotherapy for advanced epithelial ovarian cancer. Scottish Gynaecological Cancer Trials Group

PURPOSE

A prospective, nonrandomized, multicenter, open feasibility study of cisplatin and docetaxel as first-line chemotherapy in International Federation of Gynecology and Obstetrics (FIGO) stage IC-IV epithelial ovarian cancer was conducted. The primary end point was the incidence of severe fluid retention that necessitated treatment withdrawal.

PATIENTS AND METHODS

Cisplatin and docetaxel were administered every 3 weeks for six planned cycles, with a 5-day prophylactic dexamethasone regimen (8 mg two times per day). One hundred patients (median age, 53 years; range, 24 to 71 years) received a total of 512 cycles of chemotherapy in two cohorts: cohort 1, 49 patients, 258 cycles (cisplatin 75 mg/m(2) and docetaxel 75 mg/m(2)); cohort 2, 51 patients, 254 cycles (cisplatin 75 mg/m(2) and docetaxel 85 mg/m(2)).

RESULTS

No patients were taken off study because of fluid retention. Sixty-six patients completed six cycles of protocol therapy; 16 stopped early because of toxicity (neurotoxicity in six patients, nephrotoxicity in three, neutropenia in two, and hypersensitivity, diarrhea and vomiting, skin rash, clinical deterioration, and patient's wishes in one patient each). Grade 3/4 neutropenia was observed in more than 75% of patients and seemed to be cumulative. Patients in cohort 2 had significantly more severe neutropenia and lethargy than those in cohort 1. In addition, there were five treatment-related deaths in cohort 2 (three neutropenia and two upper gastrointestinal hemorrhage). Neurotoxicity (mainly sensory, > grade 1) was observed in 23 patients. The overall clinical response rate was 69% (complete response, 38%; partial response, 31%); CA-125 response rate was 73%. Median progression-free survival for the group was 12 months.

CONCLUSION

Cisplatin and docetaxel can be administered at doses of 75 mg/m(2) and 75 mg/m(2), respectively, every 3 weeks, and the utility of this regimen is not limited by fluid retention. However, 33 of 100 patients were unable to complete the planned six cycles, which may explain, in part, the poor overall progression-free survival. Increasing the docetaxel dose to 85 mg/m(2) adds unacceptable hematologic toxicity and potential risks to the patient.

Neuromuscular toxicities of paclitaxel 210 mg m(-2) by 3-hour infusion

We retrospectively analysed neuromuscular toxicity associated with paclitaxel 210 mg m(-2) given by 3-h infusion in 247 patients. The severity correlated significantly with total cumulative dose, but could not be predicted by the pretreatment clinical variables or by pharmacokinetic parameters. The toxicity tended to occur in early treatment cycles.

Paclitaxel. An update of its use in the treatment of metastatic breast cancer and ovarian and other gynaecological cancers

The antitumour agent paclitaxel has proved to be effective for the treatment of patients with metastatic breast or ovarian cancer, and limited data also indicate its clinical potential in patients with cervical or endometrial cancer. The regimen of paclitaxel administration has varied in clinical trials, the most common including a dosage of between 135 and 250 mg/m2 administered over an infusion period of 3 or 24 hours once every 3 weeks. Promising results have been achieved in phase I/II trials of a weekly regimen of paclitaxel (60 to 175 mg/m2). The objective response rate in patients with metastatic breast cancer (either pretreated or chemotherapy-naive) is generally between 20 and 35% with paclitaxel monotherapy, which compares well with that of other current treatment options including the anthracycline doxorubicin. Combination therapy with paclitaxel plus doxorubicin appears superior to treatment with either agent alone in terms of objective response rate and median duration of response. However, whether combination therapy also provides a survival advantage remains unclear; recent results of a phase III study indicate that it does not. Paclitaxel is also a useful second-line option in some patients with anthracycline-resistant disease. Combination therapy with paclitaxel and cisplatin has proved highly effective as first-line therapy for patients with advanced ovarian cancer, showing superior efficacy to cyclophosphamide/cisplatin in terms of progression-free survival time and median duration of survival. Combination therapy with paclitaxel and carboplatin has also shown promising results. Paclitaxel monotherapy is a useful second-line option for patients with platinum-refractory metastatic ovarian cancer (objective response rates have ranged from 15 to 48%). The major dose-limiting adverse events associated with paclitaxel include myelotoxicity and peripheral neuropathy. Paclitaxel has acceptable tolerability in most patients, although adverse events are common.

CONCLUSION

Paclitaxel generally appears to be as effective as other antineoplastic agents used in the treatment of metastatic breast cancer, including doxorubicin. Importantly, it is a useful second-line option for some patients with anthracycline-resistant disease. Combination therapy with both paclitaxel and doxorubicin is a highly effective first-line option for metastatic breast cancer; however, recent results indicate no survival advantage versus monotherapy. Paclitaxel is a valuable agent for second-line treatment of patients with platinum-refractory metastatic ovarian cancer and, when combined with cisplatin or carboplatin, is recommended as first-line therapy for this disease.

Clinical phase II evaluation of paclitaxel in combination with cisplatin in metastatic or recurrent squamous cell carcinoma of the head and neck

BACKGROUND

Paclitaxel as single agent has shown marked activity in several malignancies. The aim of the present phase II trial was to determine the activity of paclitaxel/cisplatin in patients with metastatic or recurrent squamous cell carcinoma of the head and neck.

PATIENTS AND METHODS

200 mg/m2 paclitaxel was administered over three hours followed by cisplatin (100 mg/m2), repeated every 22 days. Twenty-eight patients were entered and received a total of 99 cycles (median 2, range 1-6). All patients were evaluable for toxicity, and 25 for response.

RESULTS

Hematologic toxicities included leukopenia CTC grade 3 in 13 patients, and grade 4 in five patients, neutropenia grade 3 in nine patients, and grade 4 in eight patients, grade 3 anemia and grade 2 thrombocytopenia in one patient each. Non-hematologic toxicities included hypotension grade 2 (six patients), grade 3 (four patients), and grade 4 (two patients). A decline in renal function was observed in 15 courses and 10 patients, leading to a median delay of 2.5 days. Neurosensory and neuromotor toxicity grade 1 were observed in 13 patients (grade 2: 12 patients; grade 3: one patient), myalgia grade 3 in one patient, asthenia grade 3 in two and grade 4 in one patient. Partial responses were observed in 12 patients for an overall response rate of 48% (95% CI: 28%-68%) with a median response duration of 6.5 months (range 1-10 months). Stable disease was observed in seven patients, of who two also had clinical benefit.

CONCLUSIONS

Paclitaxel 200 mg/m2 administered over three hours combined with cisplatin 100 mg/m2 is an active regimen warranting further evaluation.

A phase I study of paclitaxel and 5-fluorouracil in advanced gastric cancer

This is a phase I study to determine the maximum tolerated dose (MTD) and toxicity of a combination of paclitaxel and 5-Fluorouracil (5-FU) in advanced gastric cancer patients. The patients, refractory to the PELF regimen (5-FU, leucovorin, cisplatin, epidoxorubicin), received weekly 5-FU at the fixed dose of 500 mg/m2, and escalating doses of paclitaxel every 3 weeks with a starting dose of 150 mg/m2 given as in 3-h infusion. The dose was escalated by 25 mg/m2 every 3 patients. Fifteen patients entered the study. The upper paclitaxel dose (225 mg/m2) was given to 6 patients. Up to this dose, no severe toxicity (grade 3-4) was recorded. Apart from alopecia, grade 1-2 leukopenia occurred in 5 patients and grade 1-2 neurotoxicity in 2 patients. All patients were evaluable for response (at least 2 cycles): 2 patients achieved an objective response (200 and 225 mg/m2). In 6 patients, treatment resulted in notable relief from symptoms. Out-patient paclitaxel given over 3 h and 5-FU may be combined safely for the treatment of patients with advanced gastric cancer. The recommended doses for phase II study are paclitaxel 225 mg/m2 and 5-FU 500 mg/m2.

Paclitaxel neurotoxicity: clinical and neurophysiological study of 23 patients

Paclitaxel is the prototype of a new class of chemotherapeutic agents with an antimitotic effect that is related to its ability to interfere with the microtubule system. It causes peripheral neurological toxicity by means of its activity on the axonal microtubules. To define the clinical and neurophysiological characteristics of paclitaxel neuropathy 23 patients undergoing paclitaxel therapy at a dose of 175 mg/m2 were studied. The patients were divided into two groups, with only one group receiving pretreatment with potentially neurotoxic drugs such as cisplatin and carboplatin. The results showed a high incidence of mild neurotoxicity in both groups. Treatment was discontinued due to severe neurotoxicity in only one patient pretreated with platinum-compounds. The clinical and neurophysiological data make it possible to define paclitaxel neurotoxicity as a distal axonal neuropathy with a summatory effect in patients pretreated with cisplatin; the possible reversibility of paclitaxel neurotoxicity requires further confirmation.

Clinical characteristics of severe peripheral neuropathy induced by docetaxel (Taxotere)

BACKGROUND

Docetaxel, a semi-synthetic taxane may cause a usually mild sensory neuropathy. We describe the clinical characteristics of five patients who developed a more severe neuropathy following treatment with docetaxel.

PATIENTS AND METHODS

All patients were treated in phase II studies with 100 mg/m2 docetaxel in three weekly cycles, without steroid administration.

RESULTS

The clinical picture in these patients was dominated by a sensory neuropathy, but in one case severe weakness was present. Another patient developed Lhermitte's sign. Signs and symptoms are usually reversible after discontinuation of docetaxel administration, but in three patients symptoms worsened for some time after the end of treatment before improvement occurred.

CONCLUSION

Severe docetaxel neuropathy may especially occur following treatment with cumulative dosage over 600 mg/m2; in patients treated with this dosage a moderate or severe neuropathy may not be rare.

Phase I study of paclitaxel (Taxol) and ifosfamide in previously untreated patients with advanced non-small-cell lung cancer. A study of the National Cancer Institute of Canada Clinical Trials Group

BACKGROUND

Paclitaxel (Taxol) and ifosfamide are among the most active single agents for the treatment of non-small-cell lung cancer. We undertook this phase I dose escalation study to determine the maximum tolerated doses of these drugs which could be administered without growth factors to untreated patients with tumours of this type.

PATIENTS AND METHODS

Forty patients with advanced non-small-cell lung cancer were treated with a 3-hour infusion of paclitaxel and a 1-hour infusion of ifosfamide every 3 weeks. Groups of 3 patients were entered at escalating dose levels in traditional phase I design. Starting doses were paclitaxel, 100 mg/m2, and ifosfamide 3 g/m2, and all patients received premedication with dexamethasone, diphenhydramine and a 5-HT3 blocker. Dose escalation occurred only after full toxicity assessment for 2 cycles for all patients in the dose level.

RESULTS

Dose escalation of paclitaxel continued to 225 mg/m2 without dose-limiting toxicity, but further escalation was not attempted because of the known likelihood of neuro-toxicity above this level. Instead, ifosfamide was increased to 4 g/m2 for the final level. At these doses, dose-limiting myelosuppression was not seen, and there was only 1 episode of febrile neutropenia in 164 treatment cycles. Drug-related toxicities of ifosfamide included gross hematuria and confusion in 1 patient each, and paclitaxel-related symptoms included flu-like syndrome in most patients, mild to moderate arthralgia and/or myalgia in 8 and 25 patients, respectively, parasthesiae in 15 patients and mild to moderate hypersensitivity reactions in 15 patients each. Partial response was seen in 20.5% of patients (CI 9.3%-36.5%).

SUMMARY

Out-patient paclitaxel given over 3 hours and single-dose ifosfamide over 1 hour may be combined safely without the need for hematopoietic growth factors for the treatment of patients with non-small-cell lung cancer. The recommended doses for phase II study are paclitaxel, 225 mg/m2 and ifosfamide, 4 g/m2 every 3 weeks.