Trastuzumab treatment in multiple lines: current data and future directions

Trastuzumab improves response rate, time to progression, and overall survival when combined with first-line chemotherapy in patients with human epidermal growth factor receptor 2-positive (HER2-positive) metastatic breast cancer (MBC). However, the benefits of continuing trastuzumab beyond disease progression have not been clearly established. The literature was reviewed to obtain data on trastuzumab use beyond disease progression. In general, data from retrospective and observational studies suggest that there may be clinical benefit when trastuzumab is used beyond disease progression. These results are supported by prospective non-randomized studies. Response rates and survival outcomes have generally been superior in patients who have continued trastuzumab after disease progression compared with those who have not. Moreover, recent data from two prospective randomized phase III trials have shown that adding trastuzumab to the treatment regimen in patients with MBC who have progressed on trastuzumab-based therapy significantly prolongs progression-free survival. Emerging evidence from randomized controlled trials supports the potential clinical utility of continuing trastuzumab-based therapy beyond progression and supports the National Comprehensive Cancer Network recommendation to consider this treatment approach. Future treatment of HER2-positive MBC may involve trastuzumab being used in successive regimens in combination with other targeted therapies.     

Retrospective evaluation of clinical outcomes in patients with HER2-positive advanced breast cancer progressing on trastuzumab-based therapy in the pre-lapatinib era

BackgroundPatients with HER2-positive breast cancer whose disease has become resistant to the anti-HER2 monoclonal antibody trastuzumab can benefit from lapatinib, a dual epidermal growth factor receptor/HER2 tyrosine kinase (TK) inhibitor. Before the availability of this compound, trastuzumab was often continued beyond disease progression, usually in addition to further chemotherapy, an approach which was not based on randomized studies. We sought to retrospectively compare the clinical outcomes of patients who, upon progression during an initial trastuzumab-based regimen, stopped or continued trastuzumab in addition to further chemotherapy.Patients and MethodsFrom the clinical records of 407 patients with HER2-positive advanced breast cancer, we identified 279 patients progressing during an initial trastuzumab-based treatment. Of these patients, 83 continued trastuzumab in addition to chemotherapy, and 112 received chemotherapy alone.ResultsWe found no difference in response rate (28% vs. 30%; P = .5), median time to second tumor progression (8.4 months vs. 7 months; P = .24), or median postprogression survival (20.6 months and 15.4 months; P = .29) according to whether patients continued or stopped trastuzumab. At multivariate analysis, continuation of trastuzumab was associated with a statistically insignificant trend toward reduced risk of second progression (hazard ratio, 0.753; P = .08).ConclusionPatients with HER2-positive advanced breast cancer developing tumor progression during an initial trastuzumab-based regimen did not seem to benefit significantly from the continuation of trastuzumab in addition to chemotherapy. For these patients, there is evidence from a large randomized trial that effective HER2 targeting can be accomplished by inhibiting the HER2 TK activity with lapatinib.     

Prolonged survival of patients receiving trastuzumab beyond disease progression for HER2 overexpressing metastatic breast cancer (MBC)

BACKGROUND: The aim of this retrospective analysis was to evaluate the impact of trastuzumab-based regimens on the survival of patients with HER2-overexpressing metastatic breast cancer (MBC). The study specifically focussed on the influence of the continuation of trastuzumab-based treatment despite tumor progression on survival. PATIENTS AND METHODS: Patients with HER2 overexpressing MBC were included in this retrospective analysis. HER2 overexpression was determined by the immunohistochemical staining score (DAKO Hercep Test). Trastuzumab was applied at a loading dose of 4 mg/kg and a maintenance dose of 2 mg/kg. RESULTS: Among 136 HER2 overexpressing patients (DAKO score 3+), 66 patients received first-line trastuzumab, 47 patients received trastuzumab as second-line therapy and 23 patients received trastuzumab beyond disease progression. There was no significant difference regarding the duration of trastuzumab-based treatment (first-line: 29.5 weeks vs. second-line: 25 weeks). Moreover, there was no difference in the response rate (first-line: 37.9% vs. second-line: 35.7%) or the median survival (p = 0.47 log rank). Patients who received = 2 trastuzumab-based regimens for MBC survived significantly longer compared to those who had received only 1 regimen (= 2 regimens: 62.4 months vs. 1 regimen: 38.5 months; p = 0.01 log rank). CONCLUSIONS: Trastuzumab is highly effective in the treatment of HER2 overexpressing MBC. Compared to historical controls, overall survival appears to be markedly prolonged, particularly in patients who received sequential trastuzumab-based treatment beyond disease progression.     

曲妥珠单抗治疗后进展的转移性乳腺癌继续曲妥珠单抗治疗的疗效及安全性分析

目的：评价曲妥珠单抗治疗后进展的转移性乳腺癌患者继续行曲妥珠单抗治疗的疗效及安全性。方法回顾性分析曲妥珠单抗治疗过程中出现疾病进展,继续行曲妥珠单抗治疗,仅更换化疗方案的30例HER2阳性转移性乳腺癌患者的临床资料,并评价疗效及不良反应。结果30例HER2阳性转移性乳腺癌患者,均在复发转移阶段接受过曲妥珠单抗治疗,中位治疗时间6.0个月（95%CI为1.7~10.3个月）;30例患者在出现疾病进展后,均继续进行曲妥珠单抗治疗,仅更换联合的化疗方案。30例患者均可评价疗效,其中部分缓解（PR）7例（23.3%）,疾病稳定（SD）12例（40.0%）,疾病进展（PD）11例（36.7%）,无完全缓解（CR）患者。客观缓解率为23.3%,临床获益率为43.3%。总无进展生存期（PFS）为5.0个月（95%CI为3.0~7.0个月）。有临床获益的13例患者的PFS明显长于17例无临床获益者（9.0个月vs 3.0个月,P﹤0.001）。最常见的不良反应为血液学不良反应,考虑主要与化疗药物相关。结论对于曲妥珠单抗治疗过程中出现疾病进展的患者,继续使用曲妥珠单抗,更换化疗方案有较好的临床获益。     

A phase II trial of gemcitabine/carboplatin with or without trastuzumab in the first-line treatment of patients with metastatic breast cancer

PurposeThe purpose of this study was to evaluate the efficacy and toxicity of the combination of gemcitabine and carboplatin (and with trastuzumab in patients with HER2-positive disease) as first-line treatment for patients with metastatic breast cancer (MBC).Patients and MethodsSeventy-four patients who had received no previous chemotherapy for MBC were enrolled. Patients with HER2-negative breast cancer received treatment with gemcitabine 1000 mg/m² intravenously (I.V.) on days 1 and 8 and carboplatin area under the curve (AUC) 5 I.V. on day 1. Cycles were repeated every 21 days. Patients with HER2-positive disease also received trastuzumab 8-mg/kg I.V. loading dose, then 6 mg/kg I.V. every 21 days. After the first 29 patients were treated, the carboplatin dose was lowered to AUC 4. Patients were re-evaluated every 6 weeks; responses were measured using Response Evaluation Criteria in Solid Tumors criteria.ResultsIn patients with HER2-negative disease, gemcitabine/carboplatin produced a 34% major response rate; an additional 28% of patients had stable disease ≥ 6 months (overall disease control rate, 62%). Gemcitabine/carboplatin/trastuzumab produced an overall response rate of 66%, with a disease control rate of 77%. Grade 3/4 myelosuppression was common, even after reduction of the carboplatin dose. Only 3 patients treated with the lower dose regimen developed neutropenia and fever, but platelet and red blood cell transfusions were necessary in 24% and 40% of patients, respectively. Trastuzumab did not add to hematologic toxicity. Severe nonhematologic toxicity was uncommon.ConclusionGemcitabine/carboplatin and gemcitabine/carboplatin/trastuzumab are active first-line regimens for patients with MBC. The gemcitabine/carboplatin combination causes more grade 3/4 myelosuppression than other standard combination regimens for MBC; however, severe nonhematologic toxicity is minimal.     

Increased overall survival independent of RECIST response in metastatic breast cancer patients continuing trastuzumab treatment: evidence from a retrospective study

Recent studies have reported the potential clinical utility for metastatic breast cancer (MBC) patients of continuing trastuzumab beyond progression. Based on those results, here the authors have examined the benefits of trastuzumab-continuation by specifically evaluating RECIST responses upon first line trastuzumab-treatment as a potential predictive marker for therapeutic effect of trastuzumab-continuation beyond metastatic disease progression. The authors carried out a retrospective analysis of 272 HER2 positive MBC patients under trastuzumab treatment at 22 different oncology Italian centers during the years of 2000 and 2001 who progressed under first line trastuzumab-treatment. The primary end point of the study was the survival from the date of first documented progression upon first line trastuzumab treatment of disease. Data analysis involved the use of matching on propensity score to balance variables between treated and untreated subjects and to reduce bias. Of the 272 HER2-positive MBC patients, 154 (56.6%) continued treatment. 79 (51.3%) of those 154 patients showed responses based on RECIST criteria during first-line trastuzumab-treatment. Of the 118 patients that suspended trastuzumab, RECIST responses had been observed in 44 (37.3%). Cox proportional hazards analysis of progressed patients, matched using propensity score, showed that discontinuation of trastuzumab at metastatic disease progression was a risk factor for significantly reduced overall survival in both responder (HR = 2.23; 95% CI = 1.03-4.82) and non-responder groups (HR = 3.53, 95% CI = 1.73-7.21), with no significant differences in the two estimated HRs (P-value of the likelihood-ratio test = 0.690). Continued trastuzumab treatment after disease progression has clinically and statistically significant effects in both RECIST responder and non-responder MBC patients.     

A phase II study of weekly vinorelbine and trastuzumab in patients with HER2-positive metastatic breast cancer

BACKGROUND: Trastuzumab combined with cytotoxic agents presents encouraging results in metastatic breast cancer (MBC), but cardiac toxicity limits some combinations. The synergism shown with trastuzumab and the favorable tolerability profile of vinorelbine provided the rationale for investigating this combination. PATIENTS AND METHODS: Patients with HER2-positive MBC who had received <2 lines of chemotherapy for metastatic disease were included. Vinorelbine (25 mg/m2 on day 2, then weekly on day 1) and trastuzumab (4 mg/kg on day 1, then 2 mg/kg weekly) were administered for a maximum of 6 cycles (1 cycle=3 weeks). RESULTS: A total of 52 patients were enrolled. The median age was 50 years (range, 26-79 years). Ninety percent of the patients had received adjuvant chemotherapy, 42% received a first line of chemotherapy for MBC, and 69% had disease at visceral sites. The overall response rate was 58% (95% CI, 43%-71%). The median time to progression and overall survival were 7 months (95% CI, 5-9 months) and 26 months (95% CI, 20-32 months), respectively. Grade 4 neutropenia was present in 3 courses; neutropenic fever was not reported. The main grade 3 nonhematologic toxicities were asthenia, neuropathy, diarrhea, alopecia, and nausea/vomiting. No patients experienced serious cardiac toxicity. CONCLUSION: These results confirm that weekly vinorelbine/trastuzumab is an active and safe regimen in patients with HER2-positive MBC with an unfavorable prognosis.     

Phase II study of trastuzumab plus gemcitabine in chemotherapy-pretreated patients with metastatic breast cancer

We evaluated the efficacy and toxicity of trastuzumab plus gemcitabine in patients with HER2-positive metastatic breast cancer (MBC). Sixty-four patients were enrolled, the majority of whom (95%) had been treated with an anthracycline and a taxane before study enrollment. Eligible women were treated with gemcitabine (1200 mg/m(2) weekly for 2 weeks with the third week off on a 21-day cycle) plus weekly doses of trastuzumab (4-mg/kg loading dose; 2 mg/kg thereafter) until disease progression. The median patient age was 55 years, and the median number of previously administered (including adjuvant) chemotherapy regimens was 3. Twenty-two patients were scored as 2+ for HER2 expression by immunohistochemistry; 39 patients scored 3+. Three patients were assessed as HER2-negative on central pathology review and were ineligible for evaluation. Fifty-nine of the 61 patients remained evaluable for response. The objective response rates were 38% in the intent-to-treat population (23 of 61) and 44% among the 39 patients with HER2 3+ expression. The median response duration was 5.8 months, median overall survival was 14.7 months, and median time to disease progression was 5.8 months. Trastuzumab plus gemcitabine was well tolerated. No cases of clinical congestive heart failure occurred. Grade 3/4 toxicities included asthenia in 4 patients, fever in 4, neutropenia in 18, dyspnea in 6, abdominal or back pain in 3, and edema and nausea in 1 patient each. The combination of trastuzumab plus gemcitabine appears to be well tolerated and effective for patients with HER2-positive MBC previously treated with chemotherapy.     

Association between HER2 status and response to neoadjuvant anthracycline followed by paclitaxel plus carboplatin chemotherapy without trastuzumab in breast cancer

Background

We recently showed HER2-positive breast cancers are less likely to respond to neoadjuvant anthracycline chemotherapy. Here, we investigated whether HER2-positive breast cancers responded to sequential neoadjuvant anthracycline followed by paclitaxel plus carboplatin regimen in the absence of trastuzumab.

Methods

Women (n=372) with operable primary breast cancer initially received two cycles of neoadjuvant anthracyclines, the clinical tumor response was assessed, then patients were received four cycles of paclitaxel plus carboplatin regimen. All the patients did not received trastuzumab treatment in the neoadjuvant setting. HER2 status was determined by immunohistochemistry and/or by fluorescence in situ hybridization in core-biopsy breast cancer tissue obtained before the neoadjuvant chemotherapy.

Results

Eighteen percent (67/372) of patients achieved a pathologic complete response (pCR) in their breast. HER2-positive tumors had a significant higher pCR rate than HER2-negative tumors (33.0% versus 13.5%, P<0.001) in this cohort of 372 patients, and positive HER2 status remained an independent favorable predictor of pCR in a multivariate analysis [odds ratio (OR), 2.26; 95% confidence interval (CI), 1.18 to 4.36, P=0.015]. Furthermore, patients who responded to initial anthracycline regimens were more likely to respond to paclitaxel plus carboplatin than patients who did not (pCR, 27.2% versus 14.6%, P=0.005). Patients with HER2-positive tumors exhibited a significant higher pCR rate than did patients with HER2-negative tumors in both anthracycline response group (40.5% versus 20.0%, P=0.025) and anthracycline non-response group (28.3% versus 11.3%, P=0.002).

Conclusions

Under the circumstance of no trastuzumab treatment, women with HER2-positive cancers derive a large benefit from paclitaxel-carboplatin-based neoadjuvant chemotherapy.     

Time to first tumor progression as a predictor of efficacy of continued treatment with trastuzumab beyond progression in human epidermal growth factor receptor 2-positive metastatic breast cancer

Background  

Trastuzumab demonstrates significant clinical benefits in HER2-positive metastatic breast cancer (MBC), and recent clinical trials suggest that trastuzumab should be continued in combination with other chemotherapy beyond progression. There is an urgent need to assess if patients could substantially benefit from continuing trastuzumab-based therapy.     

Trastuzumab plus vinorelbine or taxane chemotherapy for HER2-overexpressing metastatic breast cancer: the trastuzumab and vinorelbine or taxane study

BACKGROUND: The optimal trastuzumab-based chemotherapy regimen for HER2-overexpressing, metastatic breast cancer is not known. The trastuzumab and vinorelbine or taxane (TRAVIOTA) study was a prospective, multicenter, randomized trial that was designed to compare these regimens. METHODS: Eligible patients had HER2-overexpressing, metastatic breast cancer and had received no prior chemotherapy for advanced disease. Patients were randomized 1:1 to receive either trastuzumab with weekly vinorelbine therapy or weekly taxane therapy (paclitaxel or docetaxel at the investigator's choice). Originally planned for 250 patients, the study was closed because of poor accrual with 81 evaluable patients, including 41 patients who received vinorelbine and 40 patients who received taxane. RESULTS: Response rates were 51% and 40% for the vinorelbine/trastuzumab arm and the taxane/trastuzumab arm, respectively (Fisher exact test; P = .37). The median time to disease progression was 8.5 months and 6.0 months for the vinorelbine- and taxane-based arms, respectively (log-rank test; P = .09). Treatment with either regimen generally was well tolerated, yielding comparable rates of neurologic and gastrointestinal toxicity. Vinorelbine-based treatment was associated with more anemia and neutropenia and with 2 episodes of cardiotoxicity. Taxane-based therapy was associated with more dermatologic toxicity, myalgias, and fluid retention. CONCLUSIONS: Both vinorelbine/trastuzumab and taxane/trastuzumab treatments were active as first-line therapy for HER2-positive, metastatic breast cancer and had comparable rates of efficacy and tolerability. The toxicities observed were the result of recognized side effects associated with each of the chemotherapy agents and schedules. These data can inform treatment decision making in this clinical setting.     

Perspective of trastuzumab treatment

Trastuzumab (Herceptin) has many benefits for metastatic breast cancer patients with HER2 overexpression/amplification. Trastuzumab alone or trastuzumab in combination with chemotherapy regimens are standard treatment worldwide as first line therapy for metastatic breast cancer patients with HER2 overexpression/amplification. Furthermore, an international collaboration for adjuvant trastuzumab trials showed last year that trastuzumab treatment improves disease-free and overall survival after or in combination with adjuvant chemotherapy. However, there are many uncertain issues concerning trastuzumab adjuvant and metastatic treatment, such as treatment beyond disease progression (PD), combination with hormone therapy, duration of adjuvant treatment, and cardiac safety of long term treatment.     

Phase II study of efficacy, safety, and pharmacokinetics of trastuzumab monotherapy administered on a 3-weekly schedule.

PURPOSE: This phase II study investigated the efficacy, safety, and pharmacokinetics of trastuzumab monotherapy given as first-line treatment once every 3 weeks (3-weekly) in women with human epidermal growth factor receptor 2 (HER2) -positive metastatic breast cancer (MBC). PATIENTS AND METHODS: Patients with previously untreated HER2-positive MBC received a loading dose of trastuzumab, 8 mg/kg intravenously (IV) and then 6 mg/kg IV at 3-week intervals until disease progression or patient withdrawal. RESULTS: In total, 105 patients received a median of five cycles of therapy (range, 1 to 35+). The overall response rate was 19% (23% in patients with measurable centrally confirmed immunohistochemistry [IHC] 3+ and/or fluorescence in situ hybridization [FISH] -positive disease) and clinical benefit rate (complete and partial responses plus stable disease for at least 6 months) was 33% (36% in patients with measurable centrally confirmed IHC 3+ and/or FISH-positive disease). Median time to progression was 3.4 months (range, 0.6 to 23.6 months). The most common treatment-related adverse events were rigors, pyrexia, headache, nausea, and fatigue. Median baseline left ventricular ejection fraction was 63%; this did not significantly change over the course of the study. The average exposure to trastuzumab observed in this study was similar to that in previous studies of the weekly regimen. However, as expected, mean trough trastuzumab concentrations were lower and peak levels were higher with 3-weekly trastuzumab compared with weekly treatments. CONCLUSION: Administering higher doses on a 3-weekly schedule did not compromise the efficacy and safety of trastuzumab in women with HER2-positive MBC, and average exposure was similar to that observed with weekly therapy. Three-weekly trastuzumab may represent a convenient alternative to weekly administration.     

跨线曲妥珠单抗联合不同化疗方案治疗HER2阳性晚期乳腺癌的临床研究

目的 观察跨线曲妥珠单抗联合不同化疗方案治疗人表皮生因子受体2（human epidermal growth factor receptor 2, HER2）阳性晚期乳腺癌的疗效、不良反应和生存期。方法 收集2009年1月至2014年6月间应用跨线曲妥珠单抗（H）联合不同化疗方案治疗HER2阳性的晚期乳腺癌患者71例,均完成一线H治疗,30例患者疾病进展后继续二线H治疗,19例患者疾病再次进展后继续三线H治疗,主要观察疗效、不良反应、生存情况及预后分析。结果 一、二、三线治疗中,曲妥珠单抗联合紫杉类方案和联合非紫杉类方案相比在有效率（RR）和临床获益率（clinical benefit rate, CBR）方面差异均无统计学意义（P＞0.05）。一、二、三线治疗的中位无进展生存时间（PFS）和中位总生存时间（OS）分别为14、9、4月和26、39、53月,总的中位PFS为11月,总的中位OS为36月。一线治疗的PFS较二、三线治疗明显延长（P=0.000）,曲妥珠单抗持续应用至三线的中位OS较仅一线治疗的有延长（P=0.008）。全组患者的1、2、3年生存率分别为88%、66%、39%。71例患者中14例出现了17次心脏相关事件,1例患者因左心室射血分数（LVEF）下降至48%停止曲妥珠单抗治疗,无治疗相关性死亡发生。在OS的Log rank单因素分析中,术后淋巴结转移的个数、有无脑转移、治疗线数、一线治疗的PFS时间与OS有关（P=0.026, P=0.042, P=0.028, P=0.005）。在OS的多因素Cox比例风险模型分析中,治疗线数、有无脑转移、DFS和一线PFS时间为对OS有影响的独立因素（P=0.004,P=0.021, P=0.018, P=0.000）。结论 在HER-2阳性晚期乳腺癌治疗中,疾病进展后跨线曲妥珠单抗联合化疗的疗效优于未继续使用曲妥珠单抗的方案,曲妥珠单抗的跨线使用可以使患者持续获益,跨线曲妥珠单抗联合化疗的方案疗效确切,不良反应可以耐受,值得进一步研究。     

Weekly Gemcitabine and Trastuzumab in the Treatment of Patients With HER2-Overexpressing Metastatic Breast Cancer

BackgroundThe use of trastuzumab in combination with either a taxane or vinorelbine has improved the efficacy of treatment for women with HER2-positive (HER+) breast cancer. We investigated the activity and toxicity of the gemcitabine/trastuzumab combination as first- or second-line treatment in women with HER2+ metastatic breast cancer (MBC).Patients and MethodsForty-one women with HER2+ MBC were treated with gemcitabine 1000 mg/m² intravenously (I.V.) days 1, 8, and 15 and trastuzumab 4-mg/kg I.V. loading dose and then 2 mg/kg weekly. Cycles were repeated every 28 days. Patients were evaluated after 8 weeks of treatment; responders/stable patients continued treatment until progression.ResultsPatients received a median of 28 weeks of treatment. Eleven of 37 evaluable patients (30%; 95% CI, 17%–46%) had major responses. The median progression-free survival (PFS) was 4 months (95% CI, 1.9–5.3 months), with a 1-year PFS of 17%. Four of 15 patients (27%) who had previously received trastuzumab for MBC had partial responses. The gemcitabine/trastuzumab combination was well tolerated.ConclusionThe combination of gemcitabine and trastuzumab is an active regimen but appears less active than trastuzumab in combination with either taxanes or vinorelbine. The role of gemcitabine/trastuzumab (versus gemcitabine alone) in women who have already received a trastuzumab-containing regimen for HER2+ MBC is not defined by this study.     

Emerging approaches for treating HER2-positive metastatic breast cancer beyond trastuzumab

Because metastatic breast cancer (MBC) is incurable in most cases, the goals of treatment are improvement in quality of life, management of symptoms, and prolonged survival. The human epidermal growth factor receptor 2 (HER2) is overexpressed in up to 30% of breast tumors, and before the development of HER-targeted therapy, HER2 positivity was predictive of poorer clinical outcomes. Trastuzumab and pertuzumab (anti-HER2 monoclonal antibodies), lapatinib (a small molecule inhibitor of HER2 and the epidermal growth factor receptor [EGFR]) are approved for treating HER2-positive MBC in the United States. Although trastuzumab plus chemotherapy is currently regarded as the first-line standard of care for HER2-positive MBC, it is not without shortcomings; these include its association with certain adverse events (e.g. cardiotoxic effect) and development of resistance. A number of investigational agents that target HER2 and other members of that receptor family are in clinical development for patients with HER2-positive MBC whose disease has progressed on trastuzumab. In addition, in an effort to overcome treatment resistance, clinical trials are evaluating combination therapy (investigational HER-targeted agents with trastuzumab or lapatinib). This review discusses recently completed and ongoing phase II and III clinical trials of investigational HER-targeted agents in the setting of trastuzumab-progressive, HER2-positive MBC.     

Phase II Trial of Weekly Docetaxel,Vinorelbine, and Trastuzumab in the First-Line Treatment of Patients with HER2-Positive Metastatic Breast Cancer

BackgroundThe combinations of trastuzumab/docetaxel and trastuzumab/vinorelbine are highly active in the treatment of patients with HER2-positive metastatic breast cancer (MBC). We investigated the feasibility and safety of a 3-drug combination of trastuzumab, docetaxel, and vinorelbine as first-line therapy in this patient group.Patients and MethodsSixty patients with previously untreated, measurable HER2-positive MBC (immunohistochemistry 3+ and/or fluorescence in situ hybridization positive) were treated with docetaxel 30 mg/m² intravenously (I.V.) and vinorelbine 25 mg/m² I.V. on days 1 and 8 of each 3-week cycle. Trastuzumab was given weekly (4-mg/kg loading dose followed by 2 mg/kg/week). Patients were evaluated after 6 weeks; responders/stable patients continued treatment until progression.ResultsPatients received a median of 11 treatment cycles (range, 1–22 cycles). Forty-one of 60 patients (68%) had major responses (16 complete responses [27%], 25 partial responses [42%]). An additional 13 patients (22%) had stable disease for ≥ 6 months. After a median follow-up of 58 months, median progression-free survival was 12 months (95% CI, 9.1–16.3 months), and the median overall survival was 40.8 months (95% CI, 25-not reached). Neutropenia (72% grade 4) was the most common hematologic toxicity; 8 patients were hospitalized for febrile neutropenia. A total of 67% of patients required dose modifications for neutropenia during cycles 1 or 2. Other grade 3/4 toxicities included fatigue (12%), hyperglycemia (7%), and myalgias (7%). There were no treatment-related deaths.ConclusionThe combination of trastuzumab, docetaxel, and vinorelbine is highly active as first-line treatment for patients with HER2-positive MBC. However, this regimen offers no obvious advantages over other less myelosuppressive trastuzumab-containing regimens, and its routine use is not supported by the study.     

What is the best schedule for administration of gemcitabine-taxane?

Until recently, standard adjuvant chemotherapy for metastatic breast cancer (MBC) consisted of anthracycline-based regimens, followed by a taxane. However, data suggest that taxane-based combinations can be more effective than taxanes alone for the second part of treatment. Synergy between paclitaxel and gemcitabine was demonstrated in vitro when paclitaxel was followed by gemcitabine. Dose-dense regimens administered every 2 weeks are more effective than standard 3 weekly regimens. In a phase II study, gemcitabine plus paclitaxel every 2 weeks as first-line chemotherapy of MBC was associated with an overall response rate (ORR) of 71%. Women with HER2 ECD-positive tumours have a poor ORR (40%) to first-line chemotherapy. The addition of trastuzumab to dose-dense paclitaxel-gemcitabine as first-line chemotherapy in women with HER2-positive MBC was associated with a dramatic increase in ORR to 78%, with no serious toxicity observed. Two phase III clinical trials of gemcitabine-paclitaxel as adjuvant chemotherapy in women with histologically-confirmed MBC are currently underway. Preliminary data show that this drug combination is well-tolerated, and the efficacy results are eagerly awaited.     

Outcome of patients with HER2-positive advanced breast cancer progressing during trastuzumab-based therapy

We sought to describe patterns of treatment and clinical outcome in patients with HER2-positive advanced breast cancer progressing on trastuzumab-based therapy. One hundred eighty-four consecutive HER2-positive advanced breast cancer patients received trastuzumab-based therapy between September 1999 and September 2004. Patients were followed up until death or May 2005. For patients progressing on trastuzumab-based therapy, we calculated the response rate (RR) to the first post-progression treatment, overall survival (OS) from the first administration of trastuzumab, time to second progression (TT-SP), and post-progression survival (PPS), according to treatment. At the time of this analysis, 132 patients had progressed on trastuzumab-based therapy, and 89 had died. Of the progressing patients, 21 experienced rapid progression and could not receive additional anticancer treatments;40 patients continued trastuzumab either alone (12 patients with isolated central nervous system progression), with chemotherapy (23 patients), or with endocrine therapy (5 patients); and 71 stopped trastuzumab and received chemotherapy (61 patients) or endocrine therapy (10 patients) as the first post-progression treatment. Excluding patients with rapid progression, clinical outcomes were similar whether trastuzumab was continued or not, in terms of RR (18% and 27%, respectively), OS (31 and 30 months, respectively), TT-SP (6 and 7 months, respectively), and PPS (21 and 19 months, respectively). The clinical outcome of patients with HER2-positive advanced breast cancer progressing during trastuzumab-based therapy might not be influenced by continuing trastuzumab. The optimal therapeutic strategy in this setting of patients needs evaluation in randomized trials.     

Isolated central nervous system metastases in patients with HER2-overexpressing advanced breast cancer treated with first-line trastuzumab-based therapy.

PURPOSE: The aim of this study was to characterize the prevalence and predictors of central nervous system (CNS) metastasis among women with HER2-overexpressing metastatic breast cancer receiving trastuzumab-based therapy. METHODS: The frequency and time course of isolated CNS progression were characterized among women with HER2-positive metastatic breast cancer, receiving chemotherapy with or without trastuzumab as first-line treatment for metastatic disease in two clinical trials. The first trial was a multicenter randomized phase III study of chemotherapy (doxorubicin/cyclophosphamide or paclitaxel) +/- trastuzumab, and the second was a multicenter phase II trial of vinorelbine + trastuzumab. All patients had measurable disease and were free of symptomatic CNS disease at initiation of study treatment. RESULTS: Nearly 10% of patients receiving trastuzumab in combination with chemotherapy developed isolated CNS metastases as first site of tumor progression. Progression in the CNS tended to be a later event than progression at other sites among women receiving trastuzumab-based therapy. Trastuzumab-based treatment did not substantially delay onset of CNS metastases as initial site of progression. Following diagnosis with primary breast cancer, tumors with HER2 gene amplification tend to be associated with greater risk of isolated CNS progression compared with those lacking gene amplification. CONCLUSIONS: Patients with HER2-overexpressing metastatic breast cancer are at risk for isolated CNS progression, reflecting improved peripheral tumor control and patient survival through use of trastuzumab-based therapy, and a relative lack of CNS activity with trastuzumab. Clinicians should be aware of this association. Better treatments for CNS recurrences are needed.