Phase II study of paclitaxel in pretreated patients with locally advanced/metastatic cancer of the bladder and ureter

Progress in systemic therapy for advanced-stage urothelial carcinoma

Despite recent advances, advanced-stage urothelial carcinoma (aUC) remains incurable, with 5-year survival rates of approximately 10%. Platinum-based chemotherapy has a major role as first-line therapy for most patients with aUC. The approval of the anti-PD-L1 antibody avelumab as maintenance therapy for patients without initial disease progression on platinum-based chemotherapy is an important development that has improved the survival outcomes of patients with this disease. Otherwise, the use of first-line immune-checkpoint inhibitors (ICIs) targeting PD-1 or PD-L1 has been restricted to patients who are ineligible for platinum-containing chemotherapy regimens. Other important developments include the FDA-accelerated approval of first-line enfortumab vedotin plus pembrolizumab for patients ineligible to receive cisplatin and the availability of FGFR inhibitors, enfortumab vedotin and sacituzumab govitecan for subsequent lines of therapy. Several research questions remain unaddressed including the lack of adequate biomarkers, how to assign priority to the different treatment options for individual patients and which agents can be effective as monotherapies. The future is promising with the emergence of modalities such as antibody-drug conjugate-like drugs, next-generation ICIs, bispecific antibodies and cellular therapies. In this Review, we summarize the evolution of systemic therapy for patients with aUC and provide insights into the unmet needs.

Phase II study of a trastuzumab biosimilar in combination with paclitaxel for HER2-positive recurrent or metastatic urothelial carcinoma: KCSG GU18-18

BACKGROUND

Human epidermal growth factor receptor 2 (HER2) is a widely explored therapeutic target in solid tumors. We evaluated the efficacy and safety of trastuzumab-pkrb, a biosimilar of trastuzumab, in combination with paclitaxel, in HER2-positive recurrent or metastatic urothelial carcinoma (UC).

PATIENTS AND METHODS

We enrolled 27 patients; they were administered a loading dose of 8 mg/kg trastuzumab-pkrb on day 1, followed by 6 mg/kg and 175 mg/m2 paclitaxel on day 1 every 3 weeks, intravenously. All patients received six cycles of the combination treatment and continued to receive trastuzumab-pkrb maintenance until disease progression, unacceptable toxicity, or for up to 2 years. HER2 positivity (based on immunohistochemistry analysis) was determined according to the 2013 American Society of Clinical Oncology /College of American Pathologists HER2 testing guidelines. The primary endpoint was objective response rate (ORR); the secondary endpoints were overall survival (OS), progression-free survival (PFS), and safety.

RESULTS

Twenty-six patients were evaluated via primary endpoint analysis. The ORR was 48.1% (1 complete and 12 partial responses) and the duration of response was 6.9 months [95% confidence interval (CI) 4.4-9.3 months]. With a median follow-up of 10.5 months, the median PFS and OS were 8.4 months (95% CI 6.2-8.8 months) and 13.5 months (95% CI 9.8 months-not reached), respectively. The most common treatment-related adverse event (TRAE) of any grade was peripheral neuropathy (88.9%). The most common grade 3/4 TRAEs were neutropenia (25.9%), thrombocytopenia (7.4%), and anemia (7.4%).

CONCLUSIONS

Trastuzumab-pkrb plus paclitaxel demonstrates promising efficacy with manageable toxicity profiles in patients with HER2-positive recurrent or metastatic UC.

Results from a Phase 1b/2 Study of Ibrutinib Combination Therapy in Advanced Urothelial Carcinoma

Ibrutinib is a first-in-class Bruton's tyrosine kinase inhibitor approved for the treatment of various B-cell malignancies and chronic graft-versus-host disease. We evaluated the safety and efficacy of ibrutinib, alone or combined with standard-of-care regimens, in adults with advanced urothelial carcinoma (UC). Once-daily ibrutinib was administered orally at 840 mg (single-agent or with paclitaxel) or at 560 mg (with pembrolizumab). Phase 1b determined the recommended phase 2 dose (RP2D) of ibrutinib, and phase 2 assessed progression-free survival (PFS), overall response rate (ORR), and safety. Thirty-five, eighteen, and fifty-nine patients received ibrutinib, ibrutinib plus pembrolizumab, and ibrutinib plus paclitaxel at the RP2D, respectively. Safety profiles were consistent with those of the individual agents. The best-confirmed ORRs were 7% (two partial responses) with single-agent ibrutinib and 36% (five partial responses) with ibrutinib plus pembrolizumab. Median PFS was 4.1 months (range, 1.0-37.4+) with ibrutinib plus paclitaxel. The best-confirmed ORR was 26% (two complete responses). In previously treated patients with UC, ORR was higher with ibrutinib plus pembrolizumab than with either agent alone (historical data in the intent-to-treat population). ORR with ibrutinib plus paclitaxel was greater than historical values for single-agent paclitaxel or ibrutinib. These data warrant further evaluation of ibrutinib combinations in UC.

Salvage systemic therapy for metastatic urothelial carcinoma: an unmet clinical need

INTRODUCTION

Metastatic urothelial carcinoma (mUC) remains a fatal malignancy, despite the recent addition of immune check point inhibitors (ICIs), an FGFR inhibitor and an antibody-drug conjugate (ADC) to the therapeutic armamentarium. The survival rates are particularly dismal after first-line treatment failure, entailing an urgent need for more effective therapies. Advances in understanding biomarkers and identifying targetable molecules have broadened the pathways under investigation in mUC.

AREAS COVERED

This review summarizes mUC salvage therapy options, including chemotherapy, ICI, and novel promising agents, including targeted therapies, ADCs, cytotoxic agents and vaccines. For the literature review, a PubMed search and relevant data presented at international conferences were used.

EXPERT OPINION

The approval of ICIs, FGFR inhibitor erdafitinib and ADC enfortumab vedotin in the salvage setting has transformed the mUC landscape. Yet there are additional promising agents currently under study. Toxicities are observed with ADCs and FGFR inhibitors, but appear manageable in most patients. The molecular heterogeneity and complex tumor biology are challenging barriers for progress in the therapy of mUC. Advances in molecular profiling, defining validated predictive markers, rational combinations of agents and therapeutically actionable targets will help develop personalized compounds with higher efficacy and less toxicity with hopes to improve outcomes for mUC.

Systemic treatment for advanced urothelial cancer: an update on recent clinical trials and current treatment options

After cisplatin-based chemotherapy became the standard treatment for metastatic urothelial cancer (mUC), very little progress has been made in the treatment landscape of this condition until recently. With increased knowledge about the molecular biology of mUC and advances in the field of cancer immunobiology, there has been an explosion in the number of clinical trials for mUC, and systemic treatment of mUC is rapidly changing. Despite the availability of several novel therapeutic agents, cisplatin-based cytotoxic chemotherapy remains the standard, first-line treatment option. Immune checkpoint inhibitors (ICIs), including programmed death-1 and programmed death ligand-1 inhibitors, are preferred second-line treatment options that are also used in first-line cisplatin-ineligible settings. For patients with actionable fibroblast growth factor receptor 2 (FGFR2) or FGFR3 genomic alterations, erdafitinib can be considered after platinum-based treatment. Enfortumab vedotin, a monoclonal antibody targeting nectin-4 conjugated to monomethyl auristatin E, has been approved for patients who do not respond to both cytotoxic chemotherapy and ICIs. In this review, we address the clinical trial data that have established the current standard treatments and ongoing clinical trials of various agents with different mechanisms as well as provide a brief overview of current practice guidelines and recommendations in patients with mUC.

Management of metastatic bladder cancer

Important advances in the understanding of the biology and mechanisms of tumor progression of urothelial carcinoma (UC) have been achieved over the past decade. The treatment landscape for advanced-stage, unresectable or metastatic UC has shifted dramatically over a short period of time, with 6 new therapeutic agents available for clinical use. The use of traditional chemotherapy and new immune checkpoints inhibitors (ICIs) directed at programmed cell-death protein 1 (PD-1) or its ligand has led to unprecedented survival benefits in selected patients with metastatic UC. Data show that anti-PD-1 ICIs are not only improving long-term clinical benefit, but also quality of life for patients in the second-line setting. In the front-line setting, regulatory agencies have restricted the indications of atezolizumab and pembrolizumab (both ICIs) to patients with PD-L1positivity with advanced UC and who are platinum-ineligible. Very recently, erdafitinib, a pan-FGFR inhibitor, has been granted accelerated approval by FDA for platinum-pretreated advanced metastatic UC with susceptible FGFR3 or FGFR2 genetic alterations. Enfortumab vedotin, an antibody-drug conjugate, have been granted breakthrough designation by the FDA for the treatment of metastatic UC. Here we review the clinical trial data that have established standard-of-care treatment for advanced-stage UC. In addition, mechanisms of resistance and biomarkers of response to platinum-based chemotherapies and immunotherapies are also discussed, along with the clinical benefits and limitations of these therapies.

Outcomes in patients with metastatic bladder cancer in the USA: a retrospective electronic medical record study

Aim: Investigate the effectiveness of chemotherapy for first-line (1L) treatment of metastatic bladder cancer (mBC). Methods: Retrospective cohort study evaluating treatment patterns/outcomes in 1155 mBC patients receiving initial treatment in the community practice setting from January 2010 to June 2014, and followed through July 2016. Results: The most commonly utilized 1L and second-line (2L) regimens were platinum-based and taxane-based, respectively. Median (95% CI) OS for all patients from 1L initiation was 12.8 months (11.7–14.6), and median OS for all 2L regimens was 9.4 months (8.2–11.1). Conclusion: mBC patients eligible for and who received cis-based regimens experienced better OS results. Poor renal function was a key driver of cis-ineligibility. The various monotherapy and combination chemotherapy regimens in 2L produced relatively short OS outcomes.

The continuing role of chemotherapy in the management of advanced urothelial cancer

Despite intense drug development in the last decade in metastatic urothelial carcinoma and the incorporation of novel compounds to the treatment armamentarium, chemotherapy remains a key treatment strategy for this disease. Platinum-based combinations are still the backbone of first-line therapy in most cases. The role of chemotherapy in the second line has been more ill-defined due to the complexity of this setting, where patient selection remains critical. Nevertheless, two regimens, one in monotherapy (i.e. vinflunine) and one in combination with antiangiogenics (i.e. docetaxel + ramucirumab) have shown efficacy. Immunotherapy through checkpoint inhibition has revealed remarkably durable benefit in a small proportion of patients in the first and second line and is currently the preferred partner for combinations with chemotherapy. Difficult populations such as patients with liver metastases or those progressing to checkpoint inhibition represent a medical challenge and selective ways of delivering cytotoxics, like the antibody-drug conjugates, might represent a valid alternative. This article reviews the current role of chemotherapy in the management of advanced urothelial carcinoma and the ongoing and coming studies involving this treatment strategy.

PD1/PDL1 inhibitors for the treatment of advanced urothelial bladder cancer

Introduction

Until recently, systemic chemotherapy was the only option for treating bladder cancer and outcomes remained dismal. After a long gap of no progress for 40 years, immuno-therapy with checkpoint inhibitors (PDL1 and PD1) has revolutionized the treatment paradigm of bladder cancer, with five approved agents to treat platinum-refractory bladder cancer since the first approval of atezolizumab in May 2016.

Methods

This review summarizes the most recent data on approved checkpoint inhibitors currently used in management of advanced bladder cancer. Early- and late-phase trials of the five checkpoint inhibitors (pembrolizumab, nivolumab, atezolizumab, durvalumab, and avelumab) in advanced bladder cancer are reviewed in detail. This review also describes the potential application of PD1/PDL1 inhibitors in adjuvant and neoadjuvant settings and non-muscle-invasive bladder cancer, as well as with radiation in muscle-invasive bladder cancer treatment. The role of PDL1 and tumor-mutation burden and clinical considerations in choosing a particular immunotherapy are also discussed.

Results

The approved checkpoint inhibitors (PD1 and PDL1 inhibitors) have similar efficacy and safety profiles in metastatic platinum-refractory bladder cancer, but they vary in dose and frequency and cost burden. However, only pembrolizumab has shown superiority over standard chemotherapy in a randomized Phase III setting so far. In addition, in the first-line setting for cisplatin-ineligible patients, both pembrolizumab and atezolizumab are US Food and Drug Administration-approved and well tolerated. There is a lack of consensus on the utility of testing for PDL1 as a predictive biomarker, as patients with no PDL1 expression also derive some clinical benefit. Tumor-mutation burden is another predictive biomarker, but needs further validation.

Conclusion

Immunotherapy has offered a glimmer of hope to patients with bladder cancer. The current landscape is rapidly evolving, with novel immunotherapy-combination trials to improve outcomes further and evaluate predictive biomarkers to help identify patients most likely to benefit from such therapies.

Durvalumab in urothelial cancers

INTRODUCTION

Urothelial bladder cancer is one of the most predominant malignancies worldwide with a poor prognosis when presented at an advanced or metastatic stage. Improving the therapeutic landscape in this setting has been an unmet medical need. Palliative cisplatin-based chemotherapy is currently the standard of care in first line therapies, but many patients are ineligible and few alternative therapies exist. Moreover second-line chemotherapy has minimal activity. Recently, immune-checkpoint inhibitors have shifted the therapeutic armamentarium of bladder cancer and it is now necessary to redesign the therapeutic paradigm. Areas covered: In this article, we focus on the development of durvalumab and provide an overview of the safety, activity, efficacy and future perspectives of this drug in urothelial carcinoma. Expert commentary: Durvalumab is a well-tolerated drug and demonstrated major and durable response in advanced bladder cancer. Combinations with durvalumab will probably emerge as promising therapeutic strategies for the treatment of urothelial carcinoma. Further research efforts are needed to identify predictive biomarkers of response to immune-oncology agents.

Atezolizumab in urothelial bladder carcinoma

Metastatic bladder cancer is an aggressive malignancy with a poor prognosis when presenting with advanced stage. Cisplatin-based therapy has been the mainstay of first-line treatment but therapy in second-line setting has been an unmet medical need for decades. Moreover, many patients are unable to receive cisplatin-based therapy. Recently, immune-checkpoint inhibitors transformed the management and prognosis of many malignancies and will certainly redefine the standard of care for bladder cancer. Atezolizumab, an anti-PD-L1 antibody, was the first immune-checkpoint inhibitor to be approved by the US FDA in May 2016 for patients with urothelial carcinoma. In this review, we discuss the evidence behind this promising drug.

The combination of paclitaxel and carboplatin as second-line chemotherapy can be a preferred regimen for patients with urothelial carcinoma after the failure of gemcitabine and cisplatin chemotherapy

There is no established standard second-line chemotherapy after the failure of the first-line cisplatin-based chemotherapy for patients with advanced or metastatic urothelial carcinoma. With regards to second-line chemotherapy, methotrexate, vinblastine, doxorubicin and cisplatin (MVAC) was used from July 2009 onwards, and paclitaxel and carboplatin (TC) was introduced in April 2014 at the National Kyushu Cancer Center. The present study aimed to assess the prognostic factors for overall survival (OS) in second-line treatment that included best supportive care (BSC), and the tolerability and efficacy of TC chemotherapy. In total, 52 patients who were confirmed to have disease progression with first-line gemcitabine and cisplatin (GC) between June 2009 and November 2016 were enrolled in the current study. In addition, 28 patients selected BSC as second-line treatment, while 24 patients received second-line chemotherapy (MVAC, n=8; TC, n=16). The median OS for BSC, MVAC and TC was 2.8, 5.4, and 12.7 months, respectively. The difference between BSC and MVAC was not statistically significant (P=0.596). However, the difference between BSC and TC was statistically significant after Bonferroni correction (P=0.002). Multivariate analyses revealed that anemia [hazard ratio (HR), 7.047; 95% confidence interval (CI), 1.553-35.636; P=0.011], the presence of visceral metastasis (HR, 4.174; 95% CI, 1.506-13.429; P=0.005) and second-line treatment (TC HR, 0.296; 95% CI, 0.124-0.636; P=0.003) were independent prognostic factors. TC achieved an 18.7% overall response rate and a 56.2% disease control rate. Myelosuppression was the most common grade ≥3 toxicity, but no treatment-associated mortalities occurred during the study period. TC was associated with favorable benefits and safety, and may be considered a preferred regimen after the failure of GC.

The Emerging Role of PD-1/PD-L1-Targeting Immunotherapy in the Treatment of Metastatic Urothelial Carcinoma

OBJECTIVE

To summarize and evaluate immunotherapy agents targeting programmed cell death protein-1 (PD-1) and programmed death ligand-1 (PD-L1) recently approved for the treatment of metastatic urothelial carcinomas (UC).

DATA SOURCES

A literature review was performed using PubMed (2012 to June 2017), the American Society of Clinical Oncology abstract databases (2012 to June 2017 Annual Meetings/symposia), and the America Association for Cancer Research symposia (2012 to June 2017). A search using clinicaltrials.gov was conducted to identify studies for atezolizumab, avelumab, durvalumab, nivolumab, and pembrolizumab.

STUDY SELECTION AND DATA EXTRACTION

English language phase I to III studies assessing PD-1 and PD-L1 in UC were incorporated.

DATA SYNTHESIS

Atezolizumab, avelumab, durvalumab, nivolumab, and pembrolizumab have demonstrated clinical efficacy with tolerable toxicities in patients with metastatic UC with disease progression following platinum-based chemotherapy. Anti-PD-1/PD-L1 therapies may provide overall survival advantage; these are currently being evaluated in ongoing phase 3 studies. Greater objective response rates seem to be observed in PD-L1-positive patients versus PD-L1-negative patients, but methodologies in this assessment differ among clinical trials. The identification of biomarkers that provide greater insight into patients who positively respond to PD-1/PD-L1 therapies are needed.

CONCLUSIONS

Treatment options for metastatic UC have expanded to include PD-1/PD-L1 therapies. These agents should be strongly considered as second-line therapy over single-agent chemotherapy for patients who fail or progress after platinum-based treatment.

Comparison of single agent versus combined chemotherapy in previously treated patients with advanced urothelial carcinoma: a meta-analysis

Background

Platinum-based chemotherapy is the standard treatment for advanced urothelial cancer (UC) and is generally used in the first-line setting. However, the optimal salvage treatment for previously treated UC patients is unclear. We conducted a systematic review of published clinical trials of single agent versus combined chemotherapy as salvage treatment in previously treated UC patients.

Methods

Trials published between 1994 and 2015 were identified by an electronic search of public databases (MEDLINE, EMBASE, Cochrane library). All relevant studies were independently identified by two authors for inclusion. Demographic data, treatment regimens, objective response rate (ORR), disease control rate (DCR), median progression-free and overall survival (PFS, OS), and grade 3/4 toxicities were extracted and analyzed using Comprehensive Meta Analysis software (Version 2.0).

Results

Fifty cohorts with 1,685 patients were included for analysis: 814 patients were treated with single agent chemotherapy and 871 with combined chemotherapy. Pooled OS was significantly higher at 1 year for combined chemotherapy than for single agent (relative risk [RR] 1.52; 95% CI: 1.01–2.37; P=0.03) but not for 2-year OS (RR 1.31; 95% CI: 0.92–1.85; P=0.064). Additionally, combined chemotherapy significantly improved ORR (RR 2.25; 95% CI: 1.60–3.18; P<0.001) and DCR (RR 1.12; 95% CI: 1.01–1.25, P=0.033) compared to single agent for advanced UC patients. As for grade 3 and 4 toxicities, more frequencies of leukopenia and thrombocytopenia were observed in the combined chemotherapy than in single agent group, while equivalent frequencies of anemia, nausea, vomiting, and diarrhea were found between the two groups.

Conclusion

In comparison with single agent alone, combined chemotherapy as salvage treatment for advanced UC patients significantly improved ORR, DCR, and 1-year OS, but not 2-year OS. Our findings support the need to compare combined chemotherapy with single agent alone in the salvage setting in large prospective trials due to its potential survival benefit in advanced UC patients.

Efficacy of weekly paclitaxel treatment as a single agent chemotherapy following first-line cisplatin treatment in urothelial bladder cancer

The aim of the present study was to investigate the efficacy of paclitaxel following a first-line cisplatin regimen in patients with metastatic bladder cancer. The present study retrospectively evaluated the clinical effects and toxicities of second-line paclitaxel regimens following first-line cisplatin treatment in metastatic bladder cancer. A total of 42 patients with progressing metastatic urothelial bladder cancer following cisplatin-based chemotherapy were enrolled. The patients received weekly treatment with paclitaxel (80 mg/m²) with a median duration of 3 months. The overall response rate, disease control rate and median progression free survival were 9.5, 45.2 and 6.4 months, respectively. Weekly paclitaxel was well-tolerated with rare grade III or IV toxicities. Second-line weekly paclitaxel treatment following first-line cisplatin-based chemotherapy is an effective and well-tolerated regimen in urothelial metastatic bladder cancer.

Phase II study of dual phosphoinositol-3-kinase (PI3K) and mammalian target of rapamycin (mTOR) inhibitor BEZ235 in patients with locally advanced or metastatic transitional cell carcinoma

OBJECTIVE

To assess, in a multicentre phase II trial, the safety and efficacy of BEZ235, an oral pan-class I phosphoinositol-3-kinase (PI3K) and mammalian target of rapamycin (mTOR) complex1/2 inhibitor, in locally advanced or metastatic transitional cell carcinoma (TCC) after failure of platinum-based therapy.

PATIENTS AND METHODS

Patients with locally advanced or metastatic TCC progressing after platinum therapy were prospectively stratified by PI3K/Akt/mTOR pathway alterations, defined as PTEN loss and PIK3CA mutation. All patients received BEZ235 until progressive disease or unacceptable toxicity. The primary endpoint was the progression-free survival (PFS) rate at 16 weeks. This study was, however, closed prematurely because BEZ235 was withdrawn from further development.

RESULTS

A total of 20 patients (18 without and two with PI3K/Akt/mTOR alterations) were enrolled and received BEZ235. One partial response (5%) and two cases of stable disease (10%) were observed, all in patients without PI3K/mTOR pathway alterations. The PFS rate at 8 and 16 weeks was 15 and 10%, respectively; the median (range) PFS was 62 (38-588) days (95% confidence interval [CI] 53-110); and the median (range) overall survival was 127 (41-734) days (95% CI 58-309). Among the 90% of patients who experienced drug-related adverse events of any grade, 50% experienced grade 3-4 adverse events, including stomatitis (15%), fatigue (5%), nausea (5%), diarrhoea (5%), renal failure (5%), cutaneous rash (5%), hepatotoxicity (5%) and hypertension (5%).

CONCLUSION

BEZ235 showed modest clinical activity and an unfavourable toxicity profile in patients with advanced and pretreated TCC; however, a minority of patients experienced a clinical benefit, suggesting that a complete blockade of the PI3K/mTOR axis could improve outcome in some specific patients. Furthermore, this study showed that molecular stratification of patients for personalized medicine before treatment is feasible.

Second-line single-agent versus doublet chemotherapy as salvage therapy for metastatic urothelial cancer: a systematic review and meta-analysis

BACKGROUND

The efficacy and safety of a combination of chemotherapeutic agent compared with single-agent chemotherapy in the second-line setting of advanced urothelial carcinoma (UC) are unclear. We aimed to study the survival impact of single-agent compared with doublet chemotherapy as second-line chemotherapy of advanced UC.

PATIENTS AND METHODS

Literature was searched for studies including single-agent or doublet chemotherapy in the second-line setting after platinum-based chemotherapy. Random-effects models were used to pool trial-level data according to treatment arm, including median progression-free survival (PFS), overall survival (OS), objective response rate (ORR) probability, and grade 3-4 toxicity. Univariable and multivariable analyses, including sensitivity analyses, were carried out, adjusting for the percent of patients with ECOG performance status ≥1 and hepatic metastases.

RESULTS

Forty-six arms of trials including 1910 patients were selected: 22 arms with single agent (n = 1202) and 24 arms with doublets (n = 708). The pooled ORR with single agents was 14.2% [95% confidence interval (CI) 11.1-17.9] versus 31.9% [95% CI 27.3-36.9] with doublet chemotherapy. Pooled median PFS was 2.69 and 4.05 months, respectively. The pooled median OS was 6.98 and 8.50 months, respectively. Multivariably, the odds ratio for ORR and the pooled median difference of PFS were statistically significant (P < 0.001 and P = 0.002) whereas the median difference in OS was not (P = 0.284). When including single-agent vinflunine or taxanes only, differences were significant only for ORR (P < 0.001) favoring doublet chemotherapy. No statistically significant differences in grade 3-4 toxicity were seen between the two groups.

CONCLUSIONS

Despite significant improvements in ORR and PFS, doublet regimens did not extend OS compared with single agents for the second-line chemotherapy of UC. Prospective trials are necessary to elucidate the role of combination chemotherapy, with or without targeted agents, in the salvage setting. Currently, improvements in this field should be pursued considering single-agent chemotherapy as the foundation for new more active combinations.

Second Line Chemotherapy for Advanced and Metastatic Urothelial Carcinoma: Vinflunine and Beyond-A Comprehensive Review of the Current Literature

PURPOSE

We comprehensively reviewed current efforts and advances in the field of chemotherapeutic and biologically targeted treatment options after the failure of cisplatin based, first line regimens for urothelial carcinoma.

MATERIALS AND METHODS

We searched MEDLINE®, Central®, and meeting abstracts of ASCO (American Society of Clinical Oncology) and ESMO (European Society for Medical Oncology) to identify original articles, reviews and retrospective analyses on second line treatment of urothelial carcinoma. Articles were included in analysis if they described prospective phase II/III studies or larger high quality retrospective studies of second line treatment of urothelial carcinoma.

RESULTS

Although considered a chemosensitive disease, most patients with advanced or metastatic urothelial carcinoma relapse after cisplatin based first line treatment. Today none of the commonly used drugs, ie paclitaxel, carboplatin and/or gemcitabine, are approved by the FDA (Food and Drug Administration) for second line systemic treatment. In Europe vinflunine plus best supportive care is the only option approved by the EMA (European Medicines Agency) with moderate clinical efficacy. Responses to combined chemotherapy approaches are often better but associated with remarkable toxicity. In patients who respond well to first line treatment and, thus, are considered cisplatin sensitive readministration of a platinum based combination regimen may be an option. To date targeted therapies do not have a role in second line treatment of urothelial cancer. Immunotherapeutic strategies to target the PD-1/PD-L1 axis are emerging. In a recent phase I trial evaluating the PD-L1 targeted monoclonal antibody MPDL3280A a promising 43% response rate with good tolerability was achieved, which led to an immediate breakthrough therapy designation by the FDA. Combining chemotherapy with targeted agents, eg weekly paclitaxel and pazopanib, also shows promising activity in this prognostically poor treatment situation.

CONCLUSIONS

Response rates and survival are poor after second line chemotherapy for advanced or metastatic urothelial carcinoma. To improve outcomes of salvage treatment novel biologically targeted drugs as monotherapy or as part of a combination with conventional cytostatics are urgently needed.

Second-line therapies in metastatic urothelial carcinoma

Patients with relapsed or refractory urothelial carcinoma (UC) face a poor prognosis and a dearth of available treatment options that improve their survival. End-organ function and performance status play a vital role in the choice of second-line therapies. Evidence supporting the use of cytotoxic chemotherapy, as single agents or in combination, arises from small phase 2 studies with modest responses. With the evolution of genomic testing in UC, several pathways amenable to available targeted therapies have emerged. Encouraging patient participation in clinical trials is critical to improve patient outcomes and to advance the current modest treatment armamentarium.

Second-line systemic therapy for metastatic urothelial carcinoma of the bladder

While platinum-based combination chemotherapy leads to high response rates in patients with advanced urothelial cancer of the bladder, most patients will ultimately progress and optimal treatment in the second-line setting still needs to be determined. Advanced age, poor performance status, comorbidities and rapidly progressive disease have rendered accrual into trials difficult. Vinflunine is the only cytotoxic agent to demonstrate survival benefit in a randomized Phase III setting, but its response rate is disappointing and it has not been compared with other currently used agents such as taxanes. Recent years have seen a better definition of prognostic and predictive factors in patients with relapsed urothelial cancer. In addition, several trials have investigated novel biological agents to target chemoresistant disease. This review provides an update on the current systemic management of advanced urothelial cancer on progression following first-line chemotherapy, and discusses emerging data from recent Phase II/III trials.

Emerging drugs for urothelial carcinoma

INTRODUCTION

Advanced urothelial carcinoma is associated with a poor prognosis. In the metastatic setting, the response rate to first-line, cisplatin-containing chemotherapy is high, but survival is poor. Second-line treatment options are limited. Advanced age at diagnosis and the presence of comorbidities often preclude treatment with cisplatin-containing regimens.

AREAS COVERED

This review addresses the current therapy of urothelial carcinoma, the unmet needs in treatment and the status of drug development in this disease. The molecular targets identified and efforts to incorporate targeted agents into therapy will be addressed.

EXPERT OPINION

There have been no major advances in the treatment of urothelial carcinoma in three decades. Despite high response rates in the first-line setting, survival is limited. Major impediments to improved outcomes include poor durability of response to first-line chemotherapy and lack of second-line treatments. Better understanding in tumor biology has identified multiple targets in urothelial carcinoma; however, such discoveries have yet to lead to the incorporation of targeted agents into the routine treatment of urothelial carcinoma. Multiple ongoing clinical trials are investigating the use of targeted agents in urothelial carcinoma. Continued efforts are underway to better understand the molecular drivers of disease and such efforts are likely to identify additional therapeutic targets.

Paclitaxel plus doxorubicin chemotherapy as second-line therapy in patients with advanced urothelial carcinoma pretreated with platinum plus gemcitabine chemotherapy

BACKGROUND

We retrospectively evaluated the efficacy and toxicity of paclitaxel plus doxorubicin as a second-line treatment in patients with urothelial carcinoma, who had not responded to a prior platinum plus gemcitabine combination.

PATIENTS AND METHODS

All patients received intravenous infusions of paclitaxel (175 mg/m(2)/h) and doxorubicin (50 mg/m(2)/30 min) on day 1. Chemotherapy courses were repeated every 21 days.

RESULTS

The median followup duration was 13.5 months (range 2.8-22.4 months). Complete and partial responses were observed in 2 (5.6%) and 10 (27.8%) patients, respectively. Median overall survival was 8.9 months (95% confidence interval (CI): 6.2-11.6). Median time to progression was 3.8 months (95% CI: 2.7-4.8). The most common hematologic toxicities were neutropenia (n = 21, 58.3%), thrombocytopenia (n = 10, 27.8%), and anemia (n = 9, 25%). The most common nonhematologic toxicities consisted of fatigue (n = 15, 41.7%), nausea/vomiting (n = 13, 36.1%), peripheral neuropathy (n = 11, 30.6%), and mucositis (n = 6, 16.7%). Dose reductions by 25-35% were performed in 6 (16.7%) patients because of grade 3/4 toxicity. Anthracycline-related heart failure did not occur.

CONCLUSION

3-weekly courses of cyclic paclitaxel plus doxorubicin were found to be effective and tolerable in patients with urothelial carcinoma, who had not responded to prior platinum- and gemcitabine-based chemotherapy.

Methotrexate-paclitaxel-epirubicin-carboplatin as second-line chemotherapy in patients with metastatic transitional cell carcinoma of the bladder pretreated with cisplatin-gemcitabine: a phase II study

AIMS

To assess the efficacy and toxicity of methotrexate-paclitaxel-epirubicin-carboplatin combination as second-line chemotherapy in patients with metastatic transitional cell carcinoma (TCC) of the bladder pretreated with cisplatin-gemcitabine.

METHODS

In this prospective phase II study, patients with metastatic TCC of the bladder pretreated with first-line cisplatin-gemcitabine received on progression paclitaxel 175 mg/m(2) i.v. and carboplatin (area under curve of 5) on day 1, and methotrexate 40 mg/m(2) and epirubicin 40 mg/m(2) on day 15. The whole course was repeated every 28 days. The end-points included clinical tumor response, treatment toxicity, quality of life and survival.

RESULTS

A total of 40, predominantly male, patients were enrolled (median age 62 years [range 46-69]). Efficacy and survival were assessed in 38 patients only, as two patients refused treatment after the first cycle. Grade 3 neutropenia was the commonest acute severe toxicity (12/40 patients; 30%). The overall response rate was 39% (15/38 patients). The median follow up was 14 months (range 3-45). The median progression-free and overall survival were 12 and 12.5 months, respectively. The 1-year progression-free and overall survival were 24 and 35%, respectively.

CONCLUSION

Methotrexate-paclitaxel-epirubicin-carboplatin combination as second-line chemotherapy in patients with metastatic TCC of the bladder results in a modest response rate with acceptable toxicity.

Use of low-dose combined therapy with gemcitabine and paclitaxel for advanced urothelial cancer patients with resistance to cisplatin-containing therapy: a retrospective analysis

Purpose

The prognosis of patients with advanced and recurrent urothelial cancer (UC) is poor. Although cisplatin (CDDP)-containing chemotherapy is the most effective regimen in these patients, there is no other established chemotherapeutic regimen. We administered combination therapy with low-dose gemcitabine (GEM) and paclitaxel (PTX), named low-dose gemcitabine–paclitaxel (LD-GP) therapy, as salvage therapy for these patients. The aim was to evaluate the anti-tumoral effects, relief of pain, and toxicity of LD-GP therapy in patients with resistance to CDDP-containing therapy.

Patients and methods

Thirty-five patients with advanced UC, previously treated with CDDP-containing regimens, were treated with LD-GP therapy (GEM, 700 mg/m² + PTX, 70 mg/m² on day 1 and 8, repeated every 28 days). Pain was measured on a visual analog scale before and after treatment. Pain relief and survival were compared between this and other treatment regimens.

Results

None of the patients had complete response to LD-GP therapy. Partial response and stable disease were seen in 25.7 and 62.9 % of patients, respectively. Kaplan–Meier curves showed better survival in patients with LD-GP therapy than with others (p = 0.034). Twenty-eight patients (80.0 %) had adequate pain relief, and only two patients needed to increase their analgesics. Other regimens demonstrated pain relief in 30.4 % of patients. Common toxicities included leukopenia, with five patients requiring granular colony-stimulating factor therapy (14.3 %). The most common non-hematologic toxicity was fatigue (n = 7, 17.1 %).

Conclusions

LD-GP therapy is feasible and well tolerated as salvage therapy in patients with advanced UC with resistance to CDDP-containing therapy.

Taxane resistance in breast cancer: mechanisms, predictive biomarkers and circumvention strategies

BACKGROUND

Taxanes are established in the treatment of metastatic breast cancer (MBC) and early breast cancer (EBC) as potent chemotherapy agents. However, their therapeutic usefulness is limited by de-novo refractoriness or acquired resistance, which are common drawbacks to most anti-cancer cytotoxics. Considering that the taxanes will remain principle chemotherapeutic agents for the treatment of breast cancer, we reviewed known mechanisms of resistance in with an outlook of optimizing their clinical use.

METHODS

We searched the PubMed and MEDLINE databases for articles (from inception through to 9th January 2012; last search 10/01/2012) and journals known to publish information relevant to taxane chemotherapy. We imposed no language restrictions. Search terms included: cancer, breast cancer, response, resistance, taxane, paclitaxel, docetaxel, taxol. Due to the possibility of alternative mechanisms of resistance all combination chemotherapy treated data sets were removed from our overview.

RESULTS

Over-expression of the MDR-1 gene product Pgp was extensively studied in vitro in association with taxane resistance, but data are conflicting. Similarly, the target components microtubules, which are thought to mediate refractoriness through alterations of the expression pattern of tubulins or microtubule associated proteins and the expression of alternative tubulin isoforms, failed to confirm such associations. Little consensus has been generated for reported associations between taxane-sensitivity and mutated p53, or taxane-resistance and overexpression of Bcl-2, Bcl-xL or NFkB. In contrary sufficient in vitro data support an association of spindle assembly checkpoint (SAC) defects with resistance. Clinical data have been limited and inconsistent, which relate to the variety of methods used, lack of standardization of cut-offs for quantitation, differences in clinical endpoints measured and in methods of tissue collection preparation and storage, and study/patient heterogeneity. The most prominent finding is that pharmaceutical down-regulation of HER-2 appears to reverse the taxane resistance.

CONCLUSIONS

Currently no valid practical biomarkers exist that can predict resistance to the taxanes in breast cancer supporting the principle of individualized cancer therapy. The incorporation of several biomarker analyses into prospectively designed studies in this setting are needed.

Value of current chemotherapy and surgery in advanced and metastatic bladder cancer

The aim of the present paper was to review findings from the most relevant studies and to evaluate the value of current chemotherapy and surgery in advanced unresectable and metastatic bladder cancer. Studies were identified by searching the MEDLINE® and PubMed® databases up to 2011 using both medical subject heading (Mesh) and a free text strategy with the name of the known individual chemotherapeutic drug and the following key words: 'muscle-invasive bladder cancer', 'chemotherapeutics agents', and 'surgery in advanced bladder cancer'. At the end of our literature research we selected 141 articles complying with the aim of the review. The results showed that it has been many years since the MVAC (methotrexate, vinblastine, adriamycin, cisplatin) regimen was first developed. The use of cisplatin-based combination chemotherapy is associated with significant toxicity and produces long-term survival in only approximately 15-20% of patients. Gemcitabine + cisplatin represents the gold standard in the treatment of metastatic bladder cancer. In conclusion, the optimal approach in the management of advanced urothelial cancer continues to evolve. Further progress relies on the expansion of research into tumor biology and an understanding of the underlying molecular 'fingerprints' that can be used to enhance diagnostic and therapeutic strategies. Cisplatin-based therapy has had the best track record thus far.

Double-blind, randomized trial of docetaxel plus vandetanib versus docetaxel plus placebo in platinum-pretreated metastatic urothelial cancer

PURPOSE

Vandetanib is an oral once-daily tyrosine kinase inhibitor with activity against vascular endothelial growth factor receptor 2 and epidermal growth factor receptor. Vandetanib in combination with docetaxel was assessed in patients with advanced urothelial cancer (UC) who progressed on prior platinum-based chemotherapy.

PATIENTS AND METHODS

The primary objective was to determine whether vandetanib 100 mg plus docetaxel 75 mg/m(2) intravenously every 21 days prolonged progression-free survival (PFS) versus placebo plus docetaxel. The study was designed to detect a 60% improvement in median PFS with 80% power and one-sided α at 5%. Patients receiving docetaxel plus placebo had the option to cross over to single-agent vandetanib at progression. Overall survival (OS), overall response rate (ORR), and safety were secondary objectives.

RESULTS

In all, 142 patients were randomly assigned and received at least one dose of therapy. Median PFS was 2.56 months for the docetaxel plus vandetanib arm versus 1.58 months for the docetaxel plus placebo arm, and the hazard ratio for PFS was 1.02 (95% CI, 0.69 to 1.49; P = .9). ORR and OS were not different between both arms. Grade 3 or higher toxicities were more commonly seen in the docetaxel plus vandetanib arm and included rash/photosensitivity (11% v 0%) and diarrhea (7% v 0%). Among 37 patients who crossed over to single-agent vandetanib, ORR was 3% and OS was 5.2 months.

CONCLUSION

In this platinum-pretreated population of advanced UC, the addition of vandetanib to docetaxel did not result in a significant improvement in PFS, ORR, or OS. The toxicity of vandetanib plus docetaxel was greater than that for vendetanib plus placebo. Single-agent vandetanib activity was minimal.

Phase II study of a cremophor-free, polymeric micelle formulation of paclitaxel for patients with advanced urothelial cancer previously treated with gemcitabine and platinum

INTRODUCTION

Genexol-PM is a novel Cremophor® EL (CrEL)-free polymeric micelle formulation of paclitaxel. This multicenter phase II study was designed to evaluate the efficacy and safety of Genexol-PM monotherapy in patients with advanced urothelial carcinoma who developed disease progression after gemcitabine and cisplatin combination chemotherapy.

PATIENTS AND METHODS

Patients received Genexol-PM 240 mg/m(2) intravenously over 3 h every 3 weeks without premedication. Intra-patient dose escalation to 300 mg/m(2) was allowed during the second and subsequent cycles if pre-specified toxicities were not observed during the first cycle. The primary endpoint was response.

RESULTS

Thirty-seven patients were enrolled in this study. Platinum-free interval was less than 6 months in 27 (73%) patients, and 24 (64%) were categorized as having intermediate or poor prognosis according to Bajorin's criteria. Of 34 evaluable patients, there were 7 responses (21%; 95% CI, 7-34%), including one complete response (CR), with a median response duration of 6.5 months (95% CI, 3.5-9.6 months). The median time to progression was 2.7 months (95% CI, 0.9-4.6 months) with a median overall survival of 6.5 months (95% CI, 5.0-8.0 months). The most common grade 3/4 non-hematologic toxicities were peripheral neuropathy (sensory type 5.9%; motor type 8.8%) and infection (5.9%). Grade ≥3 hematologic toxicities occurred in only one patient.

CONCLUSION

Genexol-PM was generally well tolerated and demonstrated sufficient antitumor activity to warrant further development when used as second-line chemotherapy after gemcitabine-cisplatin failure in patients with urothelial carcinoma (NCT01426126).

First- and second-line therapy for metastatic urothelial carcinoma of the bladder

Urothelial cancer of the bladder is the 4th most common malignancy in American men and the 9th most common in women. Although it is a chemosensitive disease, advanced bladder cancer seems to have reached a plateau with regard to median survival of patients. Standard first-line therapy remains gemcitabine plus cisplatin (gc) or methotrexate, vinblastine, doxorubicin, and cisplatin (mvac). In patients deemed unfit to receive cisplatin, gemcitabine plus carboplatin or gemcitabine plus paclitaxel can be considered. To date, no standard therapy has been established for patients who recur or are refractory to first-line therapy. Second-line vinflunine, by way of superiority over best supportive care, has shown promise in a phase iii trial. Cisplatin-based therapy (mvac or gc) can also be offered to patients previously treated with cisplatin, especially if they responded previously and are considered platinum-sensitive. Novel targeted therapies are sorely needed to further improve the delivery and efficacy of chemotherapy.

Critical evaluation of vinflunine in the treatment of refractory metastatic urothelial carcinoma

Urothelial carcinoma (UC) accounts for 5% to 10% of malignancies in men in Europe and the United States. For locally advanced or metastatic disease, there are two standard firstline chemotherapy regimens: MVAC (methotrexate, vinblastine, doxorubicin, cisplatin) and gemcitabine/cisplatin. For refractory disease, there is currently no standard treatment. Vinflunine, a second-generation Vinca alkaloid, is the first chemotherapeutic agent to be evaluated in a large UC second-line population. This review discusses the pre-clinical and clinical data published, and compares vinflunine to alternative single agents and combination regimens tested in this setting. Based on the results of the phase II and III clinical trials, there appears to be sufficient evidence to support the use of vinflunine in the second-line setting.

Vitamin E succinate induced apoptosis and enhanced chemosensitivity to paclitaxel in human bladder cancer cells in vitro and in vivo

There have been several studies on the antitumor activities of vitamin E succinate (alpha-TOS) as complementary and alternative medicine. In the present study, we investigated the cytotoxic effect of alpha-TOS and the enhancement of chemosensitivity to paclitaxel by alpha-TOS in bladder cancer. KU-19-19 and 5637 bladder cancer cell lines were cultured in alpha-TOS and/or paclitaxel in vitro. Cell viability, flow cytometric analysis, and nuclear factor-kappa B (NF-kappaB) activity were analyzed. For in vivo therapeutic experiments, pre-established KU-19-19 tumors were treated with alpha-TOS and/or paclitaxel. In KU-19-19 and 5637 cells, the combination treatment resulted in a significantly higher level of growth inhibition, and apoptosis was significantly induced by the combination treatment. NF-kappaB was activated by paclitaxel; however, the activation of NF-kappaB was inhibited by alpha-TOS. Also, the combination treatment significantly inhibited tumor growth in mice. In the immunostaining of the tumors, apoptosis was induced and proliferation was inhibited by the combination treatment. Combination treatment of alpha-TOS and paclitaxel showed promising anticancer effects in terms of inhibiting bladder cancer cell growth and viability in vitro and in vivo. One of the potential mechanisms by which the combination therapy has synergistic cytotoxic effects against bladder cancer may be that alpha-TOS inhibits NF-kappaB induced by chemotherapeutic agents.

Management of bladder cancer: current and emerging strategies

Cancer of the urinary bladder is the fifth most prevalent solid tumour in the US. Urothelial carcinoma is the most common form of bladder cancer, accounting for about 90% of cases. About 25% of patients with bladder cancer have advanced disease (muscle-invasive or metastatic disease) at presentation and are candidates for systemic chemotherapy. Urothelial carcinoma is a chemo-sensitive disease, with a high overall and complete response rate to combination chemotherapy. In the setting of muscle-invasive urothelial carcinoma, use of neoadjuvant chemotherapy is associated with overall survival benefit. The role of adjuvant chemotherapy in this setting is yet to be validated. In the setting of metastatic disease, use of cisplatin-based regimens improves survival. However, despite initial high response rates, the responses are typically not durable leading to recurrence and death in the vast majority of these patients. Currently, there is no standard second-line therapy for patients in whom first-line chemotherapy for metastatic disease has failed. Many newer chemotherapeutic agents have shown modest activity in urothelial carcinoma. Improved understanding of molecular biology and pathogenesis of urothelial carcinoma has opened avenues for the use of molecularly targeted therapies, several of which are being tested in clinical trials. Currently, several novel drugs seem particularly promising including inhibitors of the epidermal growth factor receptor pathway, such as cetuximab, and inhibitors of tumour angiogenesis, such as bevacizumab and sunitinib. Development of reliable molecular predictive markers is expected to improve treatment decisions, therapy development and outcomes in urothelial carcinoma. Funding of and participation in clinical trials are key to advancing the care of urothelial cancer patients. Current and emerging strategies in the medical management of urothelial carcinoma are reviewed.

Phase III trial of vinflunine plus best supportive care compared with best supportive care alone after a platinum-containing regimen in patients with advanced transitional cell carcinoma of the urothelial tract

PURPOSE

Vinflunine (VFL) is a new microtubule inhibitor that has activity against transitional cell carcinoma of urothelial tract (TCCU). We conducted a randomized phase III study of VFL and best supportive care (BSC) versus BSC alone in the treatment of patients with advanced TCCU who had experienced progression after a first-line platinum-containing regimen.

PATIENTS AND METHODS

The study was designed to compare overall survival (OS) between patients receiving VFL + BSC (performance status [PS] = 0: 320 mg/m(2), every 3 weeks; PS = 0 with previous pelvic radiation and PS = 1: 280 mg/m(2) subsequently escalated to 320 mg/m(2)) or BSC.

RESULTS

Three hundred seventy patients were randomly assigned (VFL + BSC, n =253; BSC, n = 117). Both arms were well balanced except there were more patients with PS more than 1 (10% difference) in the BSC arm. Main grade 3 or 4 toxicities for VFL + BSC were neutropenia (50%), febrile neutropenia (6%), anemia (19%), fatigue (19%), and constipation (16%). In the intent-to-treat population, the objective of a median 2-month survival advantage (6.9 months for VFL + BSC v 4.6 months for BSC) was achieved (hazard ratio [HR] = 0.88; 95% CI, 0.69 to 1.12) but was not statistically significant (P = .287). Multivariate Cox analysis adjusting for prognostic factors showed statistically significant effect of VFL on OS (P = .036), reducing the death risk by 23% (HR = 0.77; 95% CI, 0.61 to 0.98). In the eligible population (n = 357), the median OS was significantly longer for VFL + BSC than BSC (6.9 v 4.3 months, respectively), with the difference being statistically significant (P = .040). Overall response rate, disease control, and progression-free survival were all statistically significant favoring VFL + BSC (P = .006, P = .002, and P = .001, respectively).

CONCLUSION

VFL demonstrates a survival advantage in second-line treatment for advanced TCCU. Consistency of results exists with significant and meaningful benefit over all efficacy parameters. Safety profile is acceptable, and therefore, VFL seems to be a reasonable option for TCCU progressing after first-line platinum-based therapy.

A single-arm, multicenter, open-label phase 2 study of lapatinib as the second-line treatment of patients with locally advanced or metastatic transitional cell carcinoma

BACKGROUND

The treatment of recurrent transitional cell carcinoma (TCC) remains an unmet clinical need. This study assessed lapatinib, a dual tyrosine kinase inhibitor of epidermal growth factor receptor (EGFR) and HER-2, as second-line therapy in patients with locally advanced or metastatic TCC.

METHODS

This was a single-arm, multicenter, open-label, prospective phase 2 study. Patients with TCC whose disease progressed on prior platinum-based chemotherapy received lapatinib until disease progression or unacceptable toxicity, with evaluations for response by Response Evaluation Criteria In Solid Tumors criteria performed every 8 weeks. The primary endpoint of the current study was objective tumor response rate. Secondary endpoints included safety, time to disease progression, and overall survival.

RESULTS

Fifty-nine patients were enrolled in the study, 25 of whom (42%) could not be evaluated for response. The primary endpoint of an objective response rate (ORR) >10% was observed in 1.7% (95% confidence interval [95% CI], 0.0%-9.1%) of patients; however, 18 (31%; 95% CI, 19%-44%) patients achieved stable disease (SD). The median time to disease progression and overall survival (OS) were 8.6 weeks (95% CI, 8.0 weeks-11.3 weeks) and 17.9 weeks (95% CI, 13.1 weeks-30.3 weeks), respectively. Clinical benefit (ORR and SD) was found to be correlated with EGFR overexpression (P = .029), and, to some extent, HER-2 overexpression. The median OS was significantly prolonged in patients with tumors that overexpressed EGFR and/or HER-2 (P = .0001). Lapatinib was well tolerated.

CONCLUSIONS

The study was considered to be negative because it did not meet its primary endpoint; however, further analysis demonstrated an improvement in OS in a subset of patients with tumors overexpressing EGFR and/or HER-2, which is encouraging and warrants further investigation.