Bevacizumab plus chemotherapy as first-line treatment for patients with metastatic colorectal cancer: results from a large German community-based observational cohort study

BACKGROUND

After approval of bevacizumab in Germany in 2005 for the treatment of unresectable advanced or refractory colorectal cancer (CRC), this observational cohort study was initiated to assess the efficacy and safety of bevacizumab with various chemotherapy regimen in patients with metastatic CRC (mCRC).

MATERIAL AND METHODS

To facilitate enrolment of a typical mCRC population, eligibility criteria were minimised. Choice of chemotherapy regimen was at the physicians' discretion, but influenced by current registration status. Predefined endpoints were treatment characteristics, response rate, progression-free survival (PFS), overall survival (OS) and adverse events assessed as potentially related to bevacizumab treatment. Patients were followed for up to four years.

RESULTS

In total 1777 eligible patients were enrolled at 261 sites from January 2005 to June 2008. Median age: 64 years (range 19-100); male 62%; ECOG performance status 0-1/≥ 2 89%/11%. Chemotherapy choice was fluoropyrimidine (FU) 12%, FU/oxaliplatin 18%, FU/irinotecan 64%, no chemotherapy concurrent to bevacizumab 2% and other 4%. Best investigator-assessed response rate was 60% (complete response 10%, partial response 51%). Median PFS was 10.2 months and median OS was 24.8 months.

CONCLUSIONS

The efficacy and safety profile of bevacizumab in this population of mCRC patients with different chemotherapy regimens is consistent with that observed in other patient registries/non-randomised trials and also corresponds well with data from similar treatment arms of phase III trials.

Maintenance therapy following first-line chemotherapy in metastatic colorectal cancer: toxicity and efficacy-single-institution experience

A role of maintenance chemotherapy (mCT) in patients (pts) with metastatic colorectal cancer (mCRC) is still controversial. The purpose of this retrospective study was to investigate the toxicity and efficacy of mCT in pts with mCRC. There were 97/291 (33 %) pts with mCRC completed 18-20 weeks of first-line CT from 2007 to 2013 in our center. Then, pts who had no disease progression were non-randomly allocated to mCT with capecitabine ± bevacizumab (n = 35) or surveillance (n = 62). PFS was used as a primary endpoint and was calculated from the date of completion of first-line CT. Multivariate Cox stepwise regression analysis was performed to determine independent prognostic factors. Median follow-up time was 15 (range 5-60) months. Median PFS and OS were higher in pts with mCT: 7 versus 3 months (HR 0.5, 95 %CI 0.28-0.82, p = 0.007) and 29 vs 16 months (HR 0.6, 95 %CI 0.3-1.1, 0.04-Gehan-Breslow-Wilcoxon test). Following independent negative prognostic factors was significant on multivariate analysis: CEA level >2.5 ng/ml before start of first-line CT (p = 0.02), liver metastases (p = 0.03) and number of metastatic zones >2 (p = 0.008). MCT had an independent positive impact on PFS (HR 0.5, p = 0.003). MCT prolonged PFS in pts with at least one negative prognostic factors (7 vs. 3 months, p = 0.001, HR 0.38, 95 % CI 0.22-0.68). The mCT was most beneficial in pts with negative prognostic factors: CEA level >2.5 ng/ml before start of first-line CT and/or liver metastases and/or number of metastatic zones >2.

Maintenance treatment for metastatic colorectal cancer

SUMMARY 

Metastatic colorectal cancer is now commonly treated with doublet chemotherapy plus targeted chemotherapy and initially was used until progression or development of unacceptable toxicities. However, even in responding patients it is difficult to continue the treatment for more than 4–6 months due to toxicities, such as neutropenia, sensory neuropathy and asthenia or hand and foot syndrome. This is detrimental for the quality of life and patients often want a break off of intensive therapy. Maintenance treatment as a strategy to decrease the toxicity without compromising survival outcome has become the standard of care. This manuscript will discuss different strategies for maintenance and the evidence to support them.

Targeted therapies in metastatic colorectal cancer: a systematic review and assessment of currently available data

BACKGROUND

Survival of patients with metastatic colorectal cancer (mCRC) has been significantly improved with the introduction of the monoclonal antibodies targeting the vascular endothelial growth factor (VEGF) and the epidermal growth factor receptor (EGFR). Novel molecular-targeted agents such as aflibercept and regorafenib have recently been approved. The aim of this review is to summarize and assess the effects of molecular agents in mCRC based on the available phase II and III trials, pooled analyses, and meta-analyses/systematic reviews.

METHODS

A systematic literature search was conducted using the meta-database of the German Institute of Medical Documentation and Information. Criteria of the Scottish Intercollegiate Guidelines Network were used to assess the quality of the controlled trials and systematic reviews/meta-analyses.

RESULTS

Of the 806 retrieved records, 40 publications were included. For bevacizumab, efficacy in combination with fluoropyrimidine-based chemotherapy in first- and subsequent-line settings has been shown. The benefit of continued VEGF targeting has also been demonstrated with aflibercept and regorafenib. Cetuximab is effective with fluoropyrimidine, leucovorin, and irinotecan (FOLFIRI) in first-line settings and as a single agent in last-line settings. Efficacy for panitumumab has been shown with oxaliplatin with fluoropyrimidine in first-line settings, with FOLFIRI in second-line settings, and as monotherapy in last-line settings. Treatment of anti-EGFR antibodies is restricted to patients with tumors that do not harbor mutations in Kirsten rat sarcoma and in neuroblastoma RAS.

CONCLUSION

Among various therapeutic options, the future challenge will be a better selection of the population that will benefit the most from specific anti-VEGF or anti- EGFR treatment and a careful consideration of therapy sequence.

From conventional chemotherapy to targeted therapy: use of monoclonal antibodies (moAbs) in gastrointestinal (GI) tumors

In recent years, significant progress has been made in the diagnosis and treatment of gastrointestinal cancers. Researches and clinicians however are still faced with challenges, not the least is the detection and management of tumors with varied gene mutation status. Clarification of the molecular pathology of gastrointestinal cancers may improve treatment options as well as quality of life and the long-term survival of this patient class. Therefore, molecular-targeted therapies have emerged as clinically useful drugs for gastrointestinal cancers cure, and predictive biomarkers have been heralded as the way to develop the right drug for the right patient. Moving from such appealing molecular background, we wrote an overview of the main targeted therapies, with particular interest to monoclonal antibodies that have already been approved in clinical practice or are being tested in gastrointestinal cancers treatment.

[Use of maintenance therapy and complete discontinuation for therapeutic management of non-resectable metastatic colorectal cancer]

Management of unresectable metastatic colorectal cancer dramatically changed over the past 20 years. News standards of care combine cytotoxic drugs like fluoropyrimidines, irinotecan and oxaliplatin, with targeted therapies such as anti-EGFR monoclonal antibodies and anti-angiogenic agents. Survival benefit results from these new options but correlates with more exposure to chemotherapy and cumulative toxicities. The main concern for these patients remains to find the optimal balance between efficacy, toxicity and quality of life. This article reviewed the main studies designed to evaluate the concept of maintenance therapy after induction chemotherapy and discontinuation strategy. Available therapeutic standards and options to shorten duration of chemotherapy and reduce toxicities are reported and discussed.

The "angiogenetic ladder", step-wise angiogenesis inhibition in metastatic colorectal cancer

The number of anti-angiogenic drugs who demonstrated activity in metastatic colorectal cancer patients is arising but there is still much debate on which is the optimal use of this class of agents, with particular emphasis given on when (meant as in which line of treatment) and how (meant as in duration of treatment). We sampled the data of randomised phase II-III trials employing this type of drugs, with particular emphasis on trying to "highlight" situations where anti-angiogenetic treatment could provide most benefit. The review displays all relevant clinical data regarding the use of anti-angiogenic drugs in metastatic colorectal cancer and comments on potential implications of these trials in everyday clinical practice.

Palliative treatment of metastatic colorectal cancer: what is the optimal approach?

Worldwide, colorectal cancer (CRC) is responsible for over 600,000 deaths annually and remains a significant public health concern. Because of therapeutic advancements over the past two decades, patients with metastatic CRC are living longer with an improved quality of life. This review will highlight recent trial evidence that improves outcomes for patients with metastatic disease. Topics will include the optimal use of first-line combination chemotherapy, bevacizumab in patients with advanced age or comorbidities, maintenance chemotherapy, first-line use of anti-EGFR therapies, first-line cetuximab versus bevacizumab, anti-angiogenic therapies past progression, and management of treatment-refractory disease. Clinical trial evidence will be presented, along with guidance on how to integrate recent evidence into clinical practice. Finally, this review will examine innovative drug development strategies, and will discuss potentially actionable targets identified by molecular testing.

Maintenance treatment with the immunomodulator MGN1703, a Toll-like receptor 9 (TLR9) agonist, in patients with metastatic colorectal carcinoma and disease control after chemotherapy: a randomised, double-blind, placebo-controlled trial

PURPOSE

This phase II study evaluated the synthetic DNA-based immunomodulator and Toll-like receptor 9 agonist MGN1703 as maintenance treatment in metastatic colorectal carcinoma (mCRC).

METHODS

Fifty-nine patients with mCRC and disease control after standard first-line chemotherapy were randomised to MGN1703 60 mg (N = 43) or placebo (N = 16).

RESULTS

The hazard ratio (HR) for the primary endpoint [progression-free survival (PFS) from the start of maintenance] was 0.56 (95 % CI 0.29-1.08; P = 0.07) and 0.55 (95 % CI 0.3-1.0; P = 0.04) by independent and investigator review, respectively. MGN1703 significantly improved PFS measured from the start of induction therapy versus placebo on independent (HR 0.49; 95 % CI 0.26-0.94; P = 0.03) and investigator review (HR 0.50; 95 % CI 0.31-1.02; P = 0.02). Overall survival (OS) data remain immature (HR 95 %; 95 % CI 0.3-1.5; P = 0.29) with 28/43 patients alive after a medium follow-up of >17 months. Retrospective subgroup analysis showed a significant effect of MGN1703 on PFS versus placebo in patients with greater than median tumour size reduction and normalised carcinoembryonic antigen concentrations following induction therapy, and in patients with elevated activated NKT cells ≥3.08 %. Adverse events were mild to moderate and limited to injection-site reactions or linked to general immune system activation.

CONCLUSIONS

MGN1703 maintenance treatment was well tolerated and appears to induce durable and prolonged PFS and disease control in a subgroup of patients with mCRC following induction therapy. Activated NKT cells may be a predictive biomarker for selecting patients likely to benefit more from MGN1703.

Intermittent chemotherapy plus either intermittent or continuous cetuximab for first-line treatment of patients with KRAS wild-type advanced colorectal cancer (COIN-B): a randomised phase 2 trial

BACKGROUND

Advanced colorectal cancer is treated with a combination of cytotoxic drugs and targeted treatments. However, how best to minimise the time spent taking cytotoxic drugs and whether molecular selection can refine this further is unknown. The primary aim of this study was to establish how cetuximab might be safely and effectively added to intermittent chemotherapy.

METHODS

COIN-B was an open-label, multicentre, randomised, exploratory phase 2 trial done at 30 hospitals in the UK and one in Cyprus. We enrolled patients with advanced colorectal cancer who had received no previous chemotherapy for metastases. Randomisation was done centrally (by telephone) by the Medical Research Council Clinical Trials Unit using minimisation with a random element. Treatment allocation was not masked. Patients were assigned (1:1) to intermittent chemotherapy plus intermittent cetuximab or to intermittent chemotherapy plus continuous cetuximab. Chemotherapy was FOLFOX (folinic acid and oxaliplatin followed by bolus and infused fluorouracil). Patients in both groups received FOLFOX and weekly cetuximab for 12 weeks, then either had a planned interruption (those taking intermittent cetuximab) or planned maintenance by continuing on weekly cetuximab (continuous cetuximab). On RECIST progression, FOLFOX plus cetuximab or FOLFOX was recommenced for 12 weeks followed by further interruption or maintenance cetuximab, respectively. The primary outcome was failure-free survival at 10 months. The primary analysis population consisted of patients who completed 12 weeks of treatment without progression, death, or leaving the trial. We tested BRAF and NRAS status retrospectively. The trial was registered, ISRCTN38375681.

FINDINGS

We registered 401 patients, 226 of whom were enrolled. Results for 169 with KRAS wild-type are reported here, 78 (46%) assigned to intermittent cetuximab and 91 (54%) to continuous cetuximab. 64 patients assigned to intermittent cetuximab and 66 of those assigned to continuous cetuximab were included in the primary analysis. 10-month failure-free survival was 50% (lower bound of 95% CI 39) in the intermittent group versus 52% (lower bound of 95% CI 41) in the continuous group; median failure-free survival was 12.2 months (95% CI 8.8-15.6) and 14.3 months (10.7-20.4), respectively. The most common grade 3-4 adverse events were skin rash (21 [27%] of 77 patients vs 20 [22%] of 92 patients), neutropenia (22 [29%] vs 30 [33%]), diarrhoea (14 [18%] vs 23 [25%]), and lethargy (20 [26%] vs 19 [21%]).

INTERPRETATION

Cetuximab was safely incorporated in two first-line intermittent chemotherapy strategies. Maintenance of biological monotherapy, with less cytotoxic chemotherapy within the first 6 months, in molecularly selected patients is promising and should be validated in phase 3 trials.

Selected gastrointestinal cancer presentations from the American Society of Clinical Oncology annual meeting 2013 in review: it is not about the destination, it is about the journey

INTRODUCTION

In the GI tumors area, key findings from the American Society of Clinical Oncology 2013 annual meeting were long awaited, particularly in colorectal, gastric and pancreatic cancer.

AREAS COVERED

The following pages briefly present and comment on a selection of those studies considered most relevant for clinical practice and future research planning. The following trials were then reviewed: the FIRE-3, Triplet + beva (TRIBE), new EPOC, CAIRO-3 and SAKK in colorectal cancer, the TRIO-013/LOGIC and COUGAR-02 in gastric cancer and the metastatic adenocarcinoma of the pancreas (MPACT) and LAP07 in pancreatic cancer.

EXPERT OPINION

Although the proportion of clinical questions that these trials were able to answer was almost exactly paralleled by the introduction of new questions to be responded in the next (hopefully) few years, globally they represented a significant improvement in our knowledge about colorectal cancer and pancreatic tumors.

Conference Scene: Annual Meeting of the American Society of Clinical Oncology

Annual Meeting of the American Society of Clinical Oncology, Chicago, IL, USA, 31 May–4 June 2013

Every year the American Society of Clinical Oncology Annual Meeting is one of the most awaited events for medical oncologists all around the world. This report briefly summarizes some of the most relevant news in the treatment of metastatic colorectal cancer patients with special regard to notable results from randomized trials in first-line treatment and the maintenance setting, and to new data regarding molecular determinants that will shortly enter the daily clinical practice.