Efficacy and safety of trastuzumab plus capecitabine in heavily pretreated patients with HER2-positive metastatic breast cancer

PURPOSE

We retrospectively evaluated the efficacy and safety of combination therapy of trastuzumab plus capecitabine in heavily pretreated patients with HER2-positive metastatic breast cancer (MBC).

METHODS

Patients with HER2-positive MBC who had been administered the combination therapy between July 2003 and July 2006 at the Cancer Institute Hospital, Tokyo, were retrospectively reviewed. Capecitabine (828 mg/m(2)) was given twice daily for 3 weeks followed by a 1-week rest period; this was repeated every 4 weeks. Trastuzumab was given at 4 mg/kg as an initial loading dose intravenously, followed by 2 mg/kg weekly. We investigated objective response rate (ORR), clinical benefit rate (CBR), and time-to-treatment failure (TTF) according to the Response Evaluation Criteria in Solid Tumors guidelines. Adverse events were graded according to the National Cancer Institute, Common Toxicity Criteria, version 3.0.

RESULTS

A total of 49 patients were assessed and median follow-up time of patients was 16.2 months (1.4-43.5 months). ORR was 16% (95% confidence interval: 7-30%) and CBR was 47% (95% confidence interval: 32-62%). Median TTF was 5.4 months. Common adverse effects were hand-foot syndrome, liver dysfunction, and bone marrow suppression. Grade 3 adverse events were observed in nine patients (18%). One patient (2%) suffered from symptomatic chronic heart failure, which improved after discontinuation of trastuzumab.

CONCLUSIONS

The combination therapy of trastuzumab plus capecitabine is effective and tolerable for heavily pretreated patients with HER2-positive MBC.

A phase II study of trastuzumab and capecitabine for patients with HER2-overexpressing metastatic breast cancer: Japan Breast Cancer Research Network (JBCRN) 00 Trial

PURPOSE

To determine the response rate and toxicity profile of trastuzumab and capecitabine in women with HER2-overexpressing advanced breast cancer.

PATIENTS AND METHODS

A total of 59 patients from 6 participating centers in Japan entered onto the study of trastuzumab and capecitabine. Eighty six percent of women had received prior chemotherapy as part of adjuvant (21.4%) or metastatic treatment (48.2%), or both (16.1%), including substantial portions of patients who had previously received either CMF (7.1%), anthracyclines (28.6%), taxanes (25.0%), or both types (25.0%) of chemotherapy.

RESULTS

Responses were observed in 28 of 56 patients (overall response rate, 50%). The response rate was 65.0% in patients treated with trastuzumab and capecitabine as first-line therapy for metastatic disease, and 62.5% among HER2 +3 positive patients, while high response rates were also seen in women treated with second- or third-line therapy. Patients receiving trastuzumab and capecitabine as first-line therapy had a longer TTP than did patients receiving this treatment as second- or third-line therapy (median TTP, 280 vs. 130 days, P < 0.05). Further, patients receiving trastuzumab and capecitabine as first-line therapy had longer OS than did patients receiving this treatment as second- or third-line therapy (median OS, 780 days vs. 480 weeks, P < 0.05). The treatment-related adverse events were hand-foot syndrome (30.4%), nausea (25%), diarrhea (10.7%), stomatitis (10.7%), fatigue (7.1%), and vomiting (5.4%). However, the majority were Grade 1-2 adverse events and only six patients experienced Grade 3 adverse events. Further Grade 1 cardiac toxicity was observed in one patient, while there were no cases of alopecia and treatment-related death.

CONCLUSION

Trastuzumab in combination with capecitabine is highly active in women with HER2-overexpressing metastatic breast cancer and is well tolerated.

Capecitabine in Combination with Novel Targeted Agents in the Management of Metastatic Breast Cancer: Underlying Rationale and Results of Clinical Trials

At present there is no established standard of care for metastatic breast cancer and prognosis remains poor, although the use of newer chemotherapeutic regimens has led to modest improvements in survival. Capecitabine, an oral prodrug of 5-fluorouracil, is a promising addition to these approaches, having already shown single-agent activity against metastatic breast cancer. Following a pivotal trial demonstrating that capecitabine confers increased survival when used in combination with docetaxel, it is being investigated intensively in combined regimens using other standard chemotherapeutic agents, as well as with novel molecularly targeted therapies. Among the novel agents, the most intensively studied in combination with capecitabine is trastuzumab. Despite preclinical data suggesting that these two agents might not show additive effects, clinical trials have been very encouraging for both heavily pretreated patients and for patients receiving first-line therapy in the metastatic setting. This work is being further extended in an ongoing trial in the neoadjuvant setting. An initial trial in combination with bevacizumab, enrolling heavily pretreated patients, was less successful, but following the example of the E2100 trial, this combination is being re-examined in less heavily treated patients. In addition, this review discusses ongoing trials with an array of newer molecularly targeted agents. Significant improvement in time to progression has already been demonstrated in the combination of lapatinib and capecitabine compared with capecitabine monotherapy; for the most part, however, these trials are still in early stages.

Progress and new standards of care in the management of HER-2 positive breast cancer

The aim of this review article is to examine the available evidence regarding diagnosis and treatment of HER-2 positive breast cancer. This group of breast tumours (up to 30% of the total number of breast cancers) is known for having a more aggressive behaviour. The current recommendations for HER-2 positive tumour diagnosis are discussed since accurate identification of HER-2 amplification or overexpression is key for allowing a correct risk assessment and treatment. HER-2 positive tumours can be treated with trastuzumab (Herceptin, Hoffmann-La Roche, Basel, Switzerland), a monoclonal antibody targeted against the HER-2 receptor. The role of this drug in the metastatic, adjuvant and neoadjuvant setting is reviewed. The results of the recently reported adjuvant trials are commented, as the positive results of these trials changed the standard of care for patients with this particular type of breast cancer.

Capecitabine monotherapy: safe and effective treatment for metastatic breast cancer

Optimal management for metastatic breast cancer frequently involves cytotoxic chemotherapy. Over the years, several complex multidrug regimens have been developed that were based upon a rationale of synergistic antitumor activity and nonoverlapping toxicities. However, recently the clinical value of these complex regimens has been called into question as several drugs used alone (monotherapy) or in sequence (serial single agent) have been shown to be both efficacious and better tolerated. Capecitabine (an orally administered fluoropyrimidine carbamate) is one such agent that has been proven to be effective when used alone for metastatic breast cancer, metastatic colorectal cancer, and adjuvant colon cancer. In this review, published (or reported in abstract form) data examining various aspects of clinical response and tolerability with single-agent capecitabine for (primarily) first- and second-line metastatic breast cancer are examined. For the most part, response rates are comparable with those of the more complex regimens. Dose reductions from the labeled dose of 1,250 mg/m(2) twice daily are relatively common. Toxicities (following dose reductions if needed) are generally manageable, even by more frail patients. Elderly patients are more likely to have impaired renal function or be receiving warfarin treatment, and special attention to these factors is warranted. Nonetheless, the drug administered alone is a reasonable choice when single-agent chemotherapy is entertained as a treatment option for metastatic breast cancer, including in the first-line setting.

The Role of Capecitabine in First‐Line Treatment for Patients with Metastatic Breast Cancer

Capecitabine is an important drug in the therapeutic armamentarium for metastatic breast cancer. A comprehensive worldwide clinical trial program involving >10,000 patients with locally advanced and metastatic breast cancer has provided evidence for the current treatment strategies. On the basis of data demonstrating consistent activity across several trials in patients with heavily pretreated breast cancer, capecitabine was approved in the U.S. in 1998 for the treatment of patients with metastatic disease resistant to paclitaxel and anthracycline-containing therapy, with later European Union approval for single-agent capecitabine in the metastatic setting. Capecitabine plus docetaxel (XT) was approved by the U.S. Food and Drug Administration for the treatment of metastatic breast cancer in 2001 on the basis of the large phase III trial comparing XT with docetaxel alone, which showed a survival advantage for combination therapy compared with single-agent therapy. This was shortly followed by European approval for the combination in metastatic breast cancer. The clinical utility of capecitabine in the management of breast cancer is supported by its convenient oral dosing schedule and favorable safety profile, as well as its excellent clinical activity in primary and metastatic breast cancer. Recently, clinical trials have studied single-agent capecitabine as first-line treatment and evaluated other capecitabine-containing combinations with cytotoxic and novel targeted agents.

MYCN deregulation as a potential target for novel therapies in rhabdomyosarcoma

Rhabdomyosarcoma is the most common soft-tissue sarcoma of childhood. Treatment requires a multimodality approach combining chemotherapy with surgery and radiotherapy. Although overall outcomes have improved considerably, the outlook for patients with high-risk disease, particularly the alveolar subtype, remains bleak and there is a clear need for new chemotherapeutic strategies. This review focuses on the possibilities for interventions targeting myc myelocytomatosis viral related oncogene, neuroblastoma derived (MYCN). The importance of aberrant expression of this oncogene is well established in neuroblastoma and recent data indicate that MYCN deregulation also occurs in up to a quarter of alveolar subtype cases. A range of possible approaches to target MYCN is discussed, including nucleic acid-based and immunotherapy strategies.