Trastuzumab with either docetaxel or vinorelbine as first-line treatment for patients with HER2-positive advanced breast cancer: a retrospective comparison

Trends in Phase II Trials for Cancer Therapies

Background: Drug combinations are the standard of care in cancer treatment. Identifying effective cancer drug combinations has become more challenging because of the increasing number of drugs. However, a substantial number of cancer drugs stumble at Phase III clinical trials despite exhibiting favourable efficacy in the earlier Phase. Methods: We analysed recent Phase II cancer trials comprising 2165 response rates to uncover trends in cancer therapies and used a null model of non-interacting agents to infer synergistic and antagonistic drug combinations. We compared our latest efficacy dataset with a previous dataset to assess the progress of cancer therapy. Results: Targeted therapies reach higher response rates when used in combination with cytotoxic drugs. We identify four synergistic and 10 antagonistic combinations based on the observed and expected response rates. We demonstrate that recent targeted agents have not significantly increased the response rates. Conclusions: We conclude that either we are not making progress or response rate measured by tumour shrinkage is not a reliable surrogate endpoint for the targeted agents.

Recent Advances and Perspectives in Cancer Drug Design

Cancer is one of the leading causes of death worldwide. With the increase in life expectancy, the number of cancer cases has reached unprecedented levels. In this scenario, the pharmaceutical industry has made significant investments in this therapeutic area. Despite these efforts, cancer drug research remains a remarkably challenging field, and therapeutic innovations have not yet achieved expected clinical results. However, the physiopathology of the disease is now better understood, and the discovery of novel molecular targets has refreshed the expectations of developing improved treatments. Several noteworthy advances have been made, among which the development of targeted therapies is the most significant. Monoclonal antibodies and antibody-small molecule conjugates have emerged as a worthwhile approach to improve drug selectivity and reduce adverse effects, which are the main challenges in cancer drug discovery. This review will examine the current panorama of drug research and development (R&D) with emphasis on some of the major advances brought to clinical trials and to the market in the past five years. Breakthrough discoveries will be highlighted along with the medicinal chemistry strategies used throughout the discovery process. In addition, this review will provide perspectives and updates on the discovery of novel molecular targets as well as drugs with innovative mechanisms of action.

Clinical effects of prior trastuzumab on combination eribulin mesylate plus trastuzumab as first-line treatment for human epidermal growth factor receptor 2 positive locally recurrent or metastatic breast cancer: results from a Phase II, single-arm, multicenter study

Eribulin mesylate, a novel nontaxane microtubule dynamics inhibitor in the halichondrin class of antineoplastic drugs, is indicated for the treatment of patients with metastatic breast cancer who previously received ≥2 chemotherapy regimens in the metastatic setting. Primary data from a Phase II trial for the first-line combination of eribulin plus trastuzumab in human epidermal growth factor receptor 2 positive patients showed a 71% objective response rate and tolerability consistent with the known profile of these agents. Here, we present prespecified analyses of efficacy of this combination based on prior trastuzumab use. Patients received eribulin mesylate 1.4 mg/m² (equivalent to 1.23 mg/m² eribulin [expressed as free base]) intravenously on days 1 and 8 plus trastuzumab (8 mg/kg intravenously/cycle 1, then 6 mg/kg) on day 1 of each 21-day cycle. Objective response rates, progression-free survival, and tolerability were assessed in patients who had and had not received prior adjuvant or neoadjuvant (neo/adjuvant) trastuzumab treatment. Fifty-two patients (median age: 59.5 years) received eribulin/trastuzumab for a median treatment duration of ~31 weeks; 40.4% (n=21) had been previously treated with neo/adjuvant trastuzumab prior to treatment with eribulin plus trastuzumab for metastatic disease (median time between neo/adjuvant and study treatment: 23 months). In trastuzumab-naïve patients (n=31) compared with those who had received prior trastuzumab, objective response rate was 77.4% versus 61.9%, respectively; duration of response was 11.8 versus 9.5 months, respectively; clinical benefit rate was 87.1% versus 81.0%, respectively; and median progression-free survival was 12.2 versus 11.5 months, respectively. The most common grade 3/4 treatment-emergent adverse events (occuring in ≥5% of patients) in patients who received prior trastuzumab versus trastuzumab naïve patients, respectively, were neutropenia (47.6% vs 32.3%), peripheral neuropathy (14.3% vs 25.8%), febrile neutropenia (14.3% vs 3.2%), fatigue (9.5% vs 6.5%), nausea (9.5% vs 0%), vomiting (9.5% vs 3.2%), and leukopenia (9.5% vs 3.2%). In patients with human epidermal growth factor receptor 2 positive metastatic breast cancer, first-line eribulin/trastuzumab treatment demonstrated substantial antitumor activity and was well tolerated, regardless of prior neo/adjuvant trastuzumab treatment.

Phase 1 combination study of eribulin mesylate with trastuzumab for advanced or recurrent human epidermal growth factor receptor 2 positive breast cancer

Eribulin mesylate (Halaven®) is a novel inhibitor of microtubule dynamics that has demonstrated a survival benefit in patients with locally recurrent or metastatic breast cancer who previously received at least two chemotherapeutic regimens including an anthracycline and a taxane. Although trastuzumab is indicated for patients with human epidermal growth factor receptor 2 positive (HER2+) breast cancer, a phase 1 study to evaluate tolerability/safety of eribulin mesylate with trastuzumab has not been conducted. Therefore, a study of eribulin mesylate in combination with trastuzumab was conducted to evaluate dose limiting toxicity (DLT), tolerability/safety, pharmacokinetics (PK), and efficacy and to estimate the recommended dose in Japanese patients with advanced or recurrent HER2+ breast cancer. Eribulin mesylate (1.4 mg/m²) was administered on days 1 and 8 of every 3 week cycle. Trastuzumab was administered with a 4 mg/kg loading dose followed by 2 mg/kg weekly doses or with an 8 mg/kg loading dose followed by 6 mg/kg tri-weekly doses. A total of 12 patients (six for each regimen) received eribulin mesylate and trastuzumab. No DLT was observed and the recommended dose of eribulin mesylate in combination with trastuzumab was estimated as 1.4 mg/m². Common adverse events were neutropenia, leukopenia, anaemia and alopecia. This combination therapy was well tolerated and the neutropenia observed was manageable. No PK drug-drug interaction between eribulin and trastuzumab was observed. Since a transient ejection fraction decreased was observed in two patients, cardiac function should be routinely assessed in patients receiving the combination therapy of eribulin mesylate with trastuzumab (ClinicalTrials.gov Identifier: NCT01432886).

Vinorelbine with or without Trastuzumab in Metastatic Breast Cancer: A Retrospective Single Institution Series

Background. We report our experience with vinorelbine, a widely used chemotherapeutic, in unselected metastatic breast cancer patients treated in clinical routine. Patients and Methods. The data of all patients with metastatic breast cancer receiving vinorelbine with or without trastuzumab during a six year period were reviewed. Patients received vinorelbine intravenous 25–30 mg/m² or 60–80 mg/m² orally in days 1 and 8 of a 21 day cycle. Results. Eighty-seven women were included. Sixty-two patients received vinorelbine alone and 25 patients received vinorelbine in combination with trastuzumab. In 67 patients this was the first line treatment for metastatic disease and in 20 patients it was 2nd or later line of treatment. The median TTP was six months (range: 1–45). The median overall survival was 11.5 months (range: 1–83). Seventy patients were evaluable for response. In patients receiving first line treatment 44.4% had a response while in the second and subsequent lines setting 12.5% of patients responded (P = 0.001). Objective response was obtained in 63.6% of patients receiving concomitant trastuzumab and in 25% of patients receiving vinorelbine alone (P = 0.0002). Conclusion. This study confirms a high disease control rate. Response rate and TTP were superior in first line treatment compared to subsequent lines.

A systematic review of vinorelbine for the treatment of breast cancer

The purpose of this study was to investigate the efficacy and safety profile of vinorelbine-based chemotherapy in different settings for the treatment of breast cancer. We performed a computerized search using combinations of the following keywords: "breast cancer", "breast neoplasms", "trial", "vinorelbine" and "navelbine". A total of 20 trials were included in this analysis, with a total of 5,080 patients accrued. Taxane was associated with enhanced overall survival (OS; p = 0.027) and response rate (RR; p = 0.037) as compared with vinorelbine in monotherapy, but did not show significantly favored progression-free survival (PFS; p = 0.136). Vinorelbine alone was equivalent to fluoropyrimidine treatment in RR (p = 0.79) for the treatment of metastatic breast cancer. For vinorelbine-combined regimens, the analysis showed that the vinorelbine group gave similar results as other regimens for OS (p = 0.849) and PFS (p = 0.143). The RR of vinorelbine-combined regimens was slightly better than that of the other regimens (OR, 1.17), but the difference was not statistically significant. In neoadjuvant setting, vinorelbine treatment was as active as AC (doxorubicin, cyclophosphamide) or DAC (doxorubicin, cyclophosphamide, docetaxel) regimens with respect to RR (p = 0.76) and pathologic complete response (pCR; p = 0.77), but showed lower occurrence of grade 3/4 adverse effects. The analysis also demonstrated that vinorelbine-containing therapy is effective as adjuvant, front-line or salvage therapy of metastatic breast cancer, even for patients who were previously treated with anthracyclines or taxanes.

Taxane-based mono- or combination therapy for managing metastatic breast cancer (MBC) in routine practice: a multinational prospective observational study

OBJECTIVES

Taxanes are standard for first-line chemotherapy of metastatic breast cancer (MBC), but indications for single-agent versus combination treatment remain controversial. This non-interventional study in 12 different countries explored treatment patterns and progression-free survival (PFS) in routine practice.

RESEARCH DESIGN AND METHODS

The prospective study was designed to determine factors associated with the choice of taxane-based regimens for MBC. Data were collected at the start of first-line treatment planned by the physician (baseline), and at subsequent routine practice visits. Patients were followed up until death, disease progression or change of treatment regimen, for a maximum of 8 months. Upon analysis, patients were classified into taxane single-agent (TM) or taxane-based combination (TC) cohorts according to scheduled first-line therapy. Logistic regression was used to investigate the relationship between choice of TM vs. TC and baseline factors.

RESULTS

Among the 465 patients enrolled (22.4% HER2+), 160 were prescribed TM (69% docetaxel, 31% paclitaxel) and 305 TC, frequently combined with gemcitabine (39%) or capecitabine (24%). HER2+ status was the only factor associated with choosing TC (p < 0.001). Median PFS [95% CI] was 11.5 [8.7-13.3] months for TM and 10.3 [8.4-14.4] months for TC. Among HER2+ patients (N = 104), only 59% received trastuzumab, none had previous adjuvant trastuzumab. Median PFS was 19.7 [9.3-unestimated] months for TC including trastuzumab, 18.8 [5.0-22.0] months for TC and 6.1 [3.8-13.3] months for TM without trastuzumab.

CONCLUSIONS

In patients from 12 different countries treated during routine practice, TCs were prescribed more frequently than single agents. HER2+ status was significantly associated with TC use. 41% of HER2+ patients received no anti-HER2 treatment; PFS results for TC with and without trastuzumab (19.7 and 18.8 months) suggested TCs without trastuzumab might be worth further investigation in these patients. However, the study was not randomized; treatment evaluation bias can therefore not be excluded.

Phase II Study of Vinorelbine Plus Trastuzumab in HER2 Overexpressing Metastatic Breast Cancer Pretreated with Anthracyclines and Taxanes

Purpose

The role of first-line trastuzumab-based therapy has been firmly established in patients with human epidermal growth factor receptor-2 (HER2) positive metastatic breast cancer. In this trial, we evaluated the efficacy and safety of a vinorelbine and trastuzumab combination chemotherapy in patients who were pretreated with anthracyclines and taxanes.

Methods

Thirty-three patients with HER2 overexpressing metastatic breast cancer, all of whom had previously been treated with anthracyclines and taxanes, were included in this study. The patients were treated with 25 mg/m² of vinorelbine (over a 15-minute infusion) on days 1 and 8 every 3 weeks. Additionally, trastuzumab was administered at an initial dose of 4 mg/kg over 90 minutes, and was subsequently administered at weekly doses of 2 mg/kg (over 30 minutes).

Results

The median age of the patients was 53 years (range, 39-72 years). The overall response rate was 30.3% (10 patients; 95% confidence interval [CI], 23-57%). The median time to progression was 6.8 months (95% CI, 5.3-8.2 months). The median overall survival was 12.4 months (95% CI, 10.3-14.6 months). In the 194 cycles of treatment, the incidence rates of grade ≥3 neutropenia and anemia were 7.2% and 1.0%, respectively. Neutropenic fever was detected in three cycles (1.5%). The non-hematological toxicities were not severe: grade 1 or 2 nausea or vomiting was detected in 15.2%, and grade 2 neuropathy was noted in 6.1% of patients. None of the patients experienced any serious cardiac toxicity, and no treatment-related deaths occurred.

Conclusion

These results show that a combination chemotherapy consisting of vinorelbine and trastuzumab is useful in patients with HER2-overexpressing metastatic breast cancer who were pretreated with anthracyclines and taxanes, with a favorable toxicity profile.

A phase II study of weekly nanoparticle albumin-bound paclitaxel with or without trastuzumab in metastatic breast cancer

INTRODUCTION

Weekly administration of nanoparticle albumin-bound (nab) paclitaxel as a first-line treatment for metastatic breast cancer (MBC) has not been fully investigated. The addition of trastuzumab, a monoclonal antibody against human epidermal growth factor receptor 2 (HER2), is less understood. This phase II study evaluated the efficacy and safety of weekly nab paclitaxel in the first-line MBC setting. Patients whose tumors overexpressed HER2 also received trastuzumab.

PATIENTS AND METHODS

Patients with locally advanced or metastatic breast cancer received nab paclitaxel (125 mg/m(2)) by 30-minute intravenous infusion weekly for 3 of 4 weeks. Patients who were HER2-positive received concurrent trastuzumab.

RESULTS

Seventy-two patients were enrolled; HER2 expression was detected in 22 patients. The overall response rate (ORR) was 42.2% (95% CI, 30%-55%); 5 patients had a complete response (CR) and 22 patients had a partial response (PR). Additionally, 17 patients experienced stable disease (SD), providing an overall benefit (CR + PR + SD) of 68.8%. Patients with HER2-positive tumors had an ORR of 52.4%; the ORR was 38.1% in the HER2-negative population (P = .3). Median progression-free survival was 14.5 months (range, 1-49.3 months) and survival rates at 1 year and 2 years were 69% and 62%, respectively. The most commonly observed toxicities were pain (64%), fatigue (58%), sensory neuropathy (54%), infection (46%), nausea (38%), alopecia (33%), and anemia (33%).

CONCLUSION

Our findings demonstrate that weekly nab paclitaxel has a favorable safety profile and is well tolerated as a first-line treatment for MBC. An ORR of 42% and an overall benefit of 69% is extremely encouraging, particularly in the HER2-positive population where 52% of patients responded.

Comparison of overall survival between the early use and delayed use of Trastuzumab therapy groups: a retrospective analysis of 128 patients with HER-2-positive advanced breast cancer

Trastuzumab has been the standard treatment in first-line treatment of HER-2-positive advanced breast cancer (H2ABC). This study explored whether the delayed and repeated use of trastuzumab could influence overall survival (OS). A total of 128 patients with H2ABC who had received at least one line of trastuzumab-based regimens were included. The primary endpoint was OS defined as from the date of first diagnosis of H2ABC to death. The median OS of initiating trastuzumab in first-line group (n = 56), in the second-line group (n = 32), and the third- or more-line group (n = 40) was 40.6 m, 39.5 m, and 38 m, respectively (P = 0.867). For patients who had received over one line of trastuzumab (n = 46), the median OS was 44 m, and for those receiving only one line (n = 67), it was 27.6 m (P = 0.059). The delayed use of trastuzumab has no negative effect on the OS of patients with H2ABC. There is a trend of improved OS over the repeated use of trastuzumab.