Sequential or alternating administration of docetaxel (Taxotere) combined with FEC in metastatic breast cancer: a randomised phase II trial

Time-Based Switching Control of Genetic Regulatory Networks: Toward Sequential Drug Intake for Cancer Therapy

As cancer growth and development typically involves multiple genes and pathways, combination therapy has been touted as the standard of care in the treatment of cancer. However, drug toxicity becomes a major concern whenever a patient takes 2 or more drugs simultaneously at the maximum tolerable dosage. A potential solution would be administering the drugs in a sequential or alternating manner rather than concurrently. This study therefore examines the feasibility of such an approach from a switched system control perspective. Particularly, we study how genetic regulatory systems respond to sequential (switched) drug inputs using the time-based switching mechanism. The design of the time-driven drug switching function guarantees the stability of the genetic regulatory system and the repression of the diseased genes. Simulation results using proof-of-concept models and the proliferation and survival pathways with sequential drug inputs show the effectiveness of the proposed approach.

A multicenter phase III prospective randomized trial of high-dose epirubicin in combination with cyclophosphamide (EC) versus docetaxel followed by EC in node-positive breast cancer. GOIM (Gruppo Oncologico Italia Meridionale) 9902 study

BACKGROUND

The Gruppo Oncologico Italia Meridionale 9902 trial compared four cycles of high-dose epirubicin plus cyclophosphamide (EC) with four cycles of docetaxel (Taxotere, D) followed by four cycles of EC as adjuvant treatment of node-positive breast cancer.

PATIENTS AND METHODS

Patients were randomly assigned to EC (E 120 mg/m(2), C 600 mg/m(2), arm A) for four cycles or four cycles of D (100 mg/m(2)) followed by four cycles of EC (arm B), both regimens every 21 days. Hormone receptor-positive patients were given hormonal therapy for 5 years. Primary end point was 5-year disease-free survival (DFS). Secondary objectives were overall survival (OS) and safety.

RESULTS

There were 750 patients enrolled. With a median follow-up of 64 months, 5-year DFS was 73.4% in both arms, and 5-year OS was 89.5% versus 90.7% in arm A and B [hazard ratio was 0.99 (95% confidence interval for DFS 0.75-1.31; P = 0.95)], respectively. Grade 3-4 toxicity was more common in arm B.

CONCLUSIONS

This study did not show advantages from the addition of docetaxel to high-dose EC as adjuvant chemotherapy in node-positive breast cancer. The small sample size and low number of DFS events may have limited the ability to observe statistically significant difference between the two arms.

Docetaxel versus docetaxel alternating with gemcitabine as treatments of advanced breast cancer: final analysis of a randomised trial

Background: Alternating administration of docetaxel and gemcitabine might result in improved time-to-treatment failure (TTF) and fewer adverse events compared with single-agent docetaxel as treatment of advanced breast cancer.

Patients and methods: Women diagnosed with advanced breast cancer were randomly allocated to receive 3-weekly docetaxel (group D) or 3-weekly docetaxel alternating with 3-weekly gemcitabine (group D/G) until treatment failure as first-line chemotherapy. The primary end point was TTF.

Results: Two hundred and thirty-seven subjects were assigned to treatment (group D, 115; group D/G, 122). The median TTF was 5.6 and 6.2 months in groups D and D/G, respectively (hazard ratio 0.85, 95% confidence interval 0.63–1.16; P = 0.31). There was no significant difference in time-to-disease progression, survival, and response rate between the groups. When adverse events were evaluated for the worst toxicity encountered during treatment, there was little difference between the groups, but when they were assessed per cycle, alternating treatment was associated with fewer severe (grade 3 or 4) adverse effects (P = 0.013), and the difference was highly significant for cycles when gemcitabine was administered in group D/G (P < 0.001).

Conclusion: The alternating regimen was associated with a similar TTF as single-agent docetaxel but with fewer adverse effects during gemcitabine cycles.

Randomized phase II adjuvant trial of dose-dense docetaxel before or after doxorubicin plus cyclophosphamide in axillary node-positive breast cancer

PURPOSE

An anthracycline-based combination followed by, or combined with, a taxane is the sequence used in most adjuvant chemotherapy regimens. We hypothesized that administering the taxane before the anthracycline combination would be associated with fewer dose reductions and delays than the reverse sequence. To test this hypothesis, a randomized phase II multicenter adjuvant chemotherapy trial was performed.

PATIENTS AND METHODS

Fifty-six patients with axillary node-positive, nonmetastatic breast cancer were randomly assigned either to group A (docetaxel [DOC] 75 mg/m(2) intravenously [IV] every 14 days for four cycles followed by doxorubicin 60 mg/m(2) and cyclophosphamide 600 mg/m(2) [AC] IV every 14 days for four cycles); or to group B (AC followed by DOC) at the identical doses and schedule. Pegfilgrastim 6 mg subcutaneous injection was administered 1 day after the chemotherapy in all treatment cycles. The primary objective was to administer DOC without dose reductions or delays before or after AC and calculate the relative dose intensity (RDI) of DOC and AC.

RESULTS

The majority of toxicities were grade 0 to 2 irrespective of sequence. The RDI for DOC was 0.96 and 0.82, respectively, in groups A (DOC followed by AC) and B (AC followed by DOC), with more frequent dose reductions occurring in group B (46% v 18%). The RDI for AC was 0.95 and 0.98 in groups A and B, respectively.

CONCLUSION

The administration of DOC before AC results in fewer DOC dose reductions and a higher RDI than the reverse sequence. Larger trials evaluating the sequence of DOC before anthracyclines are justified.

Capecitabine and docetaxel combination for the treatment of breast cancer

The management of breast cancer depends on the tumor and patient's characteristics. Anthracycline-based regimens have been proven to decrease the risk of relapse and prolong survival time in breast cancer. Taxanes have been incorporated not only into metastatic breast cancer but also into adjuvant regimens. Capecitabine, an oral fluoropyrimidine carbamate, has good single-agent activity and, together with docetaxel, demonstrated preclinical synergy and a survival benefit in metastatic breast cancer. Recent analyses show that capecitabine/docetaxel dosing flexibility for managing side effects does not compromise efficacy, and define this combination regimen as an important treatment option for its efficacy, tolerability and cost-effectiveness.

The role of taxanes in the treatment of breast cancer

Among the novel chemotherapeutic agents introduced in the last decade, the taxanes have emerged as the most powerful group of compounds, and results available so far confirm that they will be remembered in the future as the breast cancer chemotherapy of the 1990s. Two taxanes are available (paclitaxel and docetaxel) and they share some characteristics, although they do have some significant differences both in terms of their preclinical profile and, most importantly, their clinical characteristics. There are three main clinical differences: different efficacy-toxicity ratio in relation to dose and schedule; different integrability in anthracycline- and taxane-containing regimens, secondary to differences in pharmacokinetic interactions with anthracyclines; and different level of synergism between each taxane and trastuzumab. In clinical practice, the taxanes are now standard therapy in metastatic breast cancer. Their role as monochemotherapy or in combination with anthracyclines in advanced breast cancer has suggested their potential therapeutic impact in the treatment of patients with early breast cancer. Recent results in the adjuvant setting show that taxanes, used either in combination or in sequential therapy, possess the capability to induce significant improvements, in particular in terms of survival; thus confirming the positive impact of taxanes on the natural history of breast cancer. However, further results of all completed or ongoing Phase III trials in the early setting will help define the optimal use of taxanes and maximise the induced benefits for breast cancer patients.

Docetaxel in the treatment of breast cancer: current experience and future prospects

It has become clear over the past 10 years that docetaxel, a semisynthetic taxoid antineoplastic agent, is among the most promising compounds to have been developed in the 1990s for the treatment of breast cancer. Data indicate that this drug became standard therapy in the treatment of patients with metastatic disease who have failed anthracycline treatment, and secondarily showed very encouraging results in the first-line metastatic setting either in monochemotherapy or when docetaxel was combined with an anthracycline. More recently, docetaxel also became one of the standard therapies in the adjuvant and neoadjuvant settings, and a promising partner for novel biologic therapies. Current research is further exploring the effect of docetaxel on outcome of early breast cancer in order to fully determine the extent that this chemotherapeutic agent will change the natural history of breast cancer.

Phase II trial of neoadjuvant chemotherapy with docetaxel followed by epirubicin in stage II/III breast cancer

PURPOSE

In most neoadjuvant chemotherapy regimens, the taxane is administered either in combination with an anthracycline or after an anthracycline-containing regimen. We sought to test the feasibility, safety, and determine the pathological complete response (pCR) rate of administering docetaxel first followed by epirubicin as neoadjuvant chemotherapy in women with clinical stage II, III breast cancer.

PATIENTS AND METHODS

Twenty-five women with newly diagnosed clinical stage IIB (n = 10), IIIA (n = 5), or IIIB (n = 10) received 3 cycles of docetaxel 100 mg/M2 intravenously (IV) every 3 weeks followed by 3 cycles of epirubicin 100 mg/M2 IV every 3 weeks. pCR was defined as the absence of invasive cancer in the breast at definitive surgery.

RESULTS

The median primary tumor size was 6 cm (range 1-12 cm), and 13 (52%) women had clinically palpable axillary lymph nodes. Patients received 149 of the 150 planned cycles of docetaxel and epirubicin without treatment delays, and only 3 (12%) patients had a dose reduction of docetaxel. Seven (28%) patients experienced febrile neutropenia, and 9 (36%) patients had grade 3 non-hematological toxicities with diarrhea being the most frequent in 3 (12%) patients. Six (24%) patients had pCR in the breast. Analysis of pre- and post-docetaxel biopsies from a subset of patients documented taxane-induced activation of mitogen-activated and stress-activated protein kinase pathways.

CONCLUSION

Neoadjuvant docetaxel followed by epirubicin is well tolerated and active in breast cancer. To our knowledge, this is first description of docetaxel-induced activation of mitogen-activated and stress-activated protein kinase pathways in human breast cancer.

Resistance to chemotherapy in advanced ovarian cancer: mechanisms and current strategies

Although treatment for advanced epithelial ovarian cancer has improved over recent years with the introduction of taxane–platinum chemotherapy, the majority of patients will relapse, and in most the disease remains incurable. A thorough understanding of drug resistance mechanisms is needed, as this remains the largest obstacle in treating patients with recurrent disease. Multidrug resistance proteins, mismatch repair processes and alterations in the p53 pathway are examples of properties within tumour cells that may lead to drug resistance. Novel agents designed to circumvent these mechanisms (e.g. PSC 833, ONYX-015 and ADP53) are currently being investigated for ovarian cancer patients. Further improvements may result from the optimisation of existing first-line regimens with more creative schedules, perhaps involving sequential or intraperitoneal administration of existing drugs, and the incorporation of newer noncross-resistant drugs.

Pharmacological factors influencing anticancer drug selection in the elderly

Persons over the age of 65 years are the fastest growing segment of the US population. In the next 30 years this segment will represent more than 20% of the population. Fifty percent of all cancers occur in this age group and therefore the total cancer burden is expected to rise. Data are becoming available that will better guide the use of chemotherapy in the older patient population. Studies are presented discussing pharmacokinetic data on a number of chemotherapeutic agents with an emphasis on those that have entered clinical practice over the past few years. Many of these agents seem to have a beneficial therapeutic index, particularly in regard to older patients. Aging can affect the pharmacokinetics of chemotherapy in a number of ways. Absorption is only modified minimally by age. The greater concern with the use of oral drugs is patient compliance. Volume of distribution is affected by changes in body composition, anaemia and decreased plasma albumin concentration. There are many drugs in which renal excretion plays an important role. Decline in glomerular filtration is a consistent phenomenon with aging. Drug metabolism is primarily affected by changes in the P450 system and coadministration of drugs which also interact with this important enzyme system. The selection of chemotherapy in the elderly is frequently determined by degree of comorbidity and the patients' functional status. These factors are critical and can often determine response and toxicity. This article discusses the changes that occur with antimetabolites, camptothecins, anthracyclines, taxanes, platinum compounds, epipodophyllotoxins and vinca alkaloids. There has also been an increasing trend toward the use of oral chemotherapy. Factors that must be considered in selecting chemotherapeutic agents include limitations of saturability of absorption, patient compliance and the pharmacokinetic and pharmacodynamic changes that occur in older patients. Interpatient variability and age-related changes in drug metabolism are discussed. Careful attention to the physiological changes with age and dose adjustments necessary for end-organ dysfunction (renal, hepatic) are needed to ensure the safe administration of chemotherapy. In this article specific diseases are discussed (breast, colon, ovarian and non-small lung cancers) with recommendations for drug selection in adjuvant chemotherapy and the treatment of metastatic disease. Future studies will need to incorporate these various factors to properly evaluate chemotherapy in older patients. Research and educational initiatives targeted to this population will need to be a priority.