Dabrafenib in BRAF-mutated metastatic melanoma: a multicentre, open-label, phase 3 randomised controlled trial

Phase II study of the farnesyltransferase inhibitor R115777 in advanced melanoma (CALGB 500104)

Background

Multiple farnesylated proteins are involved in signal transduction in cancer. Farnesyltransferase inhibitors (FTIs) have been developed as a strategy to inhibit the function of these proteins. As FTIs inhibit proliferation of melanoma cell lines, we undertook a study to assess the impact of a FTI in advanced melanoma. As farnesylated proteins are also important for T cell activation, measurement of effects on T cell function was also pursued.

Methods

A 3-stage trial design was developed with a maximum of 40 patients and early stopping if there were no responders in the first 14, or fewer than 2 responders in the first 28 patients. Eligibility included performance status of 0–1, no prior chemotherapy, at most 1 prior immunotherapy, no brain metastases, and presence of at least 2 cutaneous lesions amenable to biopsy. R115777 was administered twice per day for 21 days of a 28-day cycle. Patients were evaluated every 2 cycles by RECIST. Blood and tumor were analyzed pre-treatment and during week 7.

Results

Fourteen patients were enrolled. Two patients had grade 3 toxicities, which included myelosuppression, nausea/vomiting, elevated BUN, and anorexia. There were no clinical responses. All patients analyzed showed potent inhibition of FT activity (85-98%) in tumor tissue; inhibition of phosphorylated ERK and Akt was also observed. T cells showed evidence of FT inhibition and diminished IFN-γ production.

Conclusions

Despite potent target inhibition, R115777 showed no evidence of clinical activity in this cohort of melanoma patients. Inhibition of T cell function by FTIs has potential clinical implications.

Clinicaltrials.gov number NCT00060125

Clinical cancer advances 2012: annual report on progress against cancer from the american society of clinical oncology

A MESSAGE FROM ASCO'S PRESIDENT

I am delighted to present you with “Clinical Cancer Advances 2012: Annual Report on Progress Against Cancer From the American Society of Clinical Oncology.” The American Society of Clinical Oncology (ASCO) uses this opportunity each year to share the steady progress occurring in our understanding and treatment of cancer. For 2012, we offer again an inspiring perspective on clinical cancer advances over the past year, but with a cautionary note: if current threats to federal funding materialize, future progress in cancer research will be seriously undermined.

Continued progress against cancer. As you read the following pages of this report, I hope you will share my unabashed enthusiasm—and pride—in how far we have come. To appreciate what this progress has meant to the millions of people who receive a cancer diagnosis each year, consider the following: (1) two of three people in the United States live at least 5 years after a cancer diagnosis (up from roughly one of two in the 1970s); (2) the nation's cancer death rate has dropped 18% since the early 1990s, reversing decades of increases; and (3) individuals with cancer are increasingly able to live active, fulfilling lives because of better management of symptoms and treatments with fewer adverse effects.

Importance of clinical cancer trials. These dramatic trends—and the advances highlighted in this report—would have been unthinkable without the engine that drives life-saving cancer treatment: clinical cancer research. Advances in technology and in our knowledge of how patient-specific molecular characteristics of the tumor and its environment fuel the growth of cancer have brought new hope to patients. Clinical trials are the key to translating cutting-edge laboratory discoveries into treatments that extend and improve the lives of those with cancer.

But progress is only part of the story. Cancer remains a challenge, with many cancers undetected until their latest stages and others resisting most attempts at treatment. Tragically, cancer still kills more than 500,000 people in the United States every year, and its global burden is growing rapidly.

Bridges to better care. To conquer cancer, we need to build bridges to the future—bridges that will get scientific advances to the patient's bedside quicker, bridges that will enable us to share information and learn what works in real time, and bridges that will improve care for all patients around the world.

At ASCO, we recognize the unique role that oncologists must play. ASCO's “Accelerating Progress Against Cancer: Blueprint for Transforming Clinical and Translational Cancer Research,”1published last year, presents our vision and recommendations to make cancer research and patient care vastly more targeted, more efficient, and more effective. We have also launched a groundbreaking initiative, CancerLinQ, that aims to improve cancer care and speed research by drawing insights from the vast pool of data on patients in real-world settings.

Renewing a national commitment to cancer research. We are on the threshold of major advances in cancer prevention, detection, and treatment—but only if, as a nation, we remain committed to this critical endeavor.

The federally funded cancer research system is currently under threat by larger federal budget concerns. Clearly, Congress faces a complex budget environment, but now is not the time to retreat from our nation's commitment to conquering a disease that affects nearly all of us. Bold action must be taken to ensure that we can take full advantage of today's scientific and technologic opportunities.

Please join me in celebrating our nation's progress against cancer and in recommitting ourselves to supporting cancer research. Millions of lives depend on it.

Sandra M. Swain, MD

President

American Society of Clinical Oncology

Is combination therapy the next step to overcome resistance and reduce toxicities in melanoma?

In the last few years, several drugs targeting signalling proteins critical for melanoma entered clinical evaluation. In 2011 vemurafenib (Zelboraf®, F. Hoffman-La Roche Ltd.) was approved for BRAF V600-positive melanoma and showed high overall response rates (48-53%). However recent results from a phase II clinical trial also showed that the median duration of response was 6.7months and median progression free survival was 6.8months with tumour relapse. Resistance to targeted agents is quite common and understanding of the underlying molecular mechanisms might predict response or failure. The knowledge of the mechanisms involved in intrinsic and acquired resistance to mutated BRAF is increasing swiftly. Subsequently the elucidation of these mechanisms resulted in the development of rational combination therapies to overcome toxicity and resistance. These combination therapies will be discussed.

Metastatic melanoma - a review of current and future drugs

Background:

Melanoma is one of the most aggressive cancers, and it is estimated that 76,250 men and women will be diagnosed with melanoma of the skin in the USA in 2012. Over the last few decades many drugs have been developed but only in 2011 have new drugs demonstrated an impact on survival in metastatic melanoma.

Methods:

A systematic search of literature was conducted, and studies providing data on the effectiveness of current and/or future drugs used in the treatment of metastatic melanoma were selected for review. This review discusses the advantages and limitations of these agents, evaluating past, current and future clinical trials designed to overcome such limitations.

Results:

To date, there are four drugs approved by the Food and Drug Administration for melanoma (dacarbazine, interleukin-2, ipilimumab and vemurafenib). Despite efforts to develop new drugs, few of them have demonstrated any clinical benefits. Approved in 1975, dacarbazine remains the gold standard in chemotherapy, although ipilimumab and vemurafenib have raised many hopes in the last few years. Combining dacarbazine or other chemotherapy agents with new pharmacological agents may be a new way to achieve better clinical responses in patients with metastatic melanoma.

Discussion:

Advances in the molecular knowledge of melanoma have led to major improvements in the treatment of patients with metastatic melanoma, providing new targets and insights. However, heterogeneity amongst study populations, different approaches to treatment and the different melanoma types and localisations included in the trials makes their comparison difficult. New studies focusing on drugs developed in recent decades are warranted.

Combined BRAF and MEK inhibition in melanoma with BRAF V600 mutations

BACKGROUND

Resistance to therapy with BRAF kinase inhibitors is associated with reactivation of the mitogen-activated protein kinase (MAPK) pathway. To address this problem, we conducted a phase 1 and 2 trial of combined treatment with dabrafenib, a selective BRAF inhibitor, and trametinib, a selective MAPK kinase (MEK) inhibitor.

METHODS

In this open-label study involving 247 patients with metastatic melanoma and BRAF V600 mutations, we evaluated the pharmacokinetic activity and safety of oral dabrafenib (75 or 150 mg twice daily) and trametinib (1, 1.5, or 2 mg daily) in 85 patients and then randomly assigned 162 patients to receive combination therapy with dabrafenib (150 mg) plus trametinib (1 or 2 mg) or dabrafenib monotherapy. The primary end points were the incidence of cutaneous squamous-cell carcinoma, survival free of melanoma progression, and response. Secondary end points were overall survival and pharmacokinetic activity.

RESULTS

Dose-limiting toxic effects were infrequently observed in patients receiving combination therapy with 150 mg of dabrafenib and 2 mg of trametinib (combination 150/2). Cutaneous squamous-cell carcinoma was seen in 7% of patients receiving combination 150/2 and in 19% receiving monotherapy (P=0.09), whereas pyrexia was more common in the combination 150/2 group than in the monotherapy group (71% vs. 26%). Median progression-free survival in the combination 150/2 group was 9.4 months, as compared with 5.8 months in the monotherapy group (hazard ratio for progression or death, 0.39; 95% confidence interval, 0.25 to 0.62; P<0.001). The rate of complete or partial response with combination 150/2 therapy was 76%, as compared with 54% with monotherapy (P=0.03).

CONCLUSIONS

Dabrafenib and trametinib were safely combined at full monotherapy doses. The rate of pyrexia was increased with combination therapy, whereas the rate of proliferative skin lesions was nonsignificantly reduced. Progression-free survival was significantly improved. (Funded by GlaxoSmithKline; ClinicalTrials.gov number, NCT01072175.).

Vemurafenib: the first drug approved for BRAF-mutant cancer

The identification of driver oncogenes has provided important targets for drugs that can change the landscape of cancer therapies. One such example is the BRAF oncogene, which is found in about half of all melanomas as well as several other cancers. As a druggable kinase, oncogenic BRAF has become a crucial target of small-molecule drug discovery efforts. Following a rapid clinical development path, vemurafenib (Zelboraf; Plexxikon/Roche) was approved for the treatment of BRAF-mutated metastatic melanoma in the United States in August 2011 and the European Union in February 2012. This Review describes the underlying biology of BRAF, the technology used to identify vemurafenib and its clinical development milestones, along with future prospects based on lessons learned during its development.

The prognostic value of BRAF mutation in colorectal cancer and melanoma: a systematic review and meta-analysis

BACKGROUND

Mutation of BRAF is a predominant event in cancers with poor prognosis such as melanoma and colorectal cancer. BRAF mutation leads to a constitutive activation of mitogen activated protein kinase pathway which is essential for cell proliferation and tumor progression. Despite tremendous efforts made to target BRAF for cancer treatment, the correlation between BRAF mutation and patient survival is still a matter of controversy.

METHODS/PRINCIPAL FINDINGS

Clinical studies on the correlation between BRAF mutation and patient survival were retrieved from MEDLINE and EMBASE databases between June 2002 and December 2011. One hundred twenty relevant full text studies were categorized based on study design and cancer type. Publication bias was evaluated for each category and pooled hazard ratio (HR) with 95% confidence interval (CI) was calculated using random or fixed effect meta-analysis based on the percentage of heterogeneity. Twenty six studies on colorectal cancer (11,773 patients) and four studies on melanoma (674 patients) were included in our final meta-analysis. The average prevalence of BRAF mutation was 9.6% in colorectal cancer, and 47.8% in melanoma reports. We found that BRAF mutation increases the risk of mortality in colorectal cancer patients for more than two times; HR = 2.25 (95% CI, 1.82-2.83). In addition, we revealed that BRAF mutation also increases the risk of mortality in melanoma patients by 1.7 times (95% CI, 1.37-2.12).

CONCLUSIONS

We revealed that BRAF mutation is an absolute risk factor for patient survival in colorectal cancer and melanoma.

Dabrafenib in patients with Val600Glu or Val600Lys BRAF-mutant melanoma metastatic to the brain (BREAK-MB): a multicentre, open-label, phase 2 trial

BACKGROUND

Brain metastases are common in patients with metastatic melanoma and median overall survival from their diagnosis is typically 17-22 weeks. We assessed dabrafenib in patients with Val600Glu or Val600Lys BRAF-mutant melanoma metastatic to the brain.

METHODS

We undertook a multicentre, open-label, phase 2 trial in 24 centres in six countries. We enrolled patients with histologically confirmed Val600Glu or Val600Lys BRAF-mutant melanoma and at least one asymptomatic brain metastasis (≥5 mm and ≤40 mm in diameter). Eligible patients were aged 18 years or older, had an Eastern Cooperative Oncology Group performance status of 0 or 1, and had adequate organ function. Patients were split into two cohorts: those in cohort A had not received previous local treatment for brain metastases and those in cohort B had progressive brain metastases after previous local treatments. Patients received 150 mg oral dabrafenib twice a day until disease progression, death, or unacceptable adverse events. The primary endpoint was the proportion of patients with Val600Glu BRAF-mutant melanoma who achieved an overall intracranial response, which was defined as a complete response or partial response assessed with a modified form of Response Evaluation Criteria in Solid Tumors (RECIST 1.1). We included patients who received at least one dose of dabrafenib in efficacy and safety analyses. This study is registered with ClinicalTrials.gov, number NCT01266967.

FINDINGS

Between Feb 2, 2011, and Aug 5, 2011, we enrolled 172 patients: 89 (52%) in cohort A and 83 (48%) in cohort B. 139 (81%) had Val600Glu BRAF-mutant melanoma. 29 (39·2%, 95% CI 28·0-51·2) of 74 patients with Val600Glu BRAF-mutant melanoma in cohort A achieved an overall intracranial response, as did 20 (30·8%, 19·9-43·4) of 65 in cohort B. One (6·7%, 0·2-31·9) of 15 patients with Val600Lys BRAF-mutant melanoma achieved an overall intracranial response in cohort A, as did four (22·2%, 6·4-47·6) of 18 such patients in cohort B. Treatment-related adverse events of grade 3 or worse occurred in 38 (22%) patients. Eleven (6%) patients developed squamous-cell carcinoma (five [6%] patients in cohort A, of whom one also had keratoacanthoma; six [7%] in cohort B). Four grade 4 treatment-related adverse events occurred in cohort A: one blood amylase increase, one convulsion, one lipase increase, and one neutropenia. Two grade 4 events occurred in cohort B: one agranulocytosis and one intracranial haemorrhage. 51 (30%) patients had a serious adverse event. The three most frequent serious adverse events were pyrexia (ten [6%] patients), intracranial haemorrhage (ten [6%]; one treatment-related), and squamous-cell carcinoma (11 [6%]).

INTERPRETATION

Dabrafenib has activity and an acceptable safety profile in patients with Val600Glu BRAF-mutant melanoma and brain metastases irrespective of whether they are untreated or have been previously treated but have progressed.

FUNDING

GlaxoSmithKline.

Overwhelming response to Dabrafenib in a patient with double BRAF mutation (V600E; V600M) metastatic malignant melanoma

The recent findings brought the necessity of testing the mutational status of a series of genes which had been already identified as responsible for melanomas development and progression, such as BRAF, CKIT and PTEN: the consequent results are, in fact, essential to guide the assessment of the novel treatment protocols based on tailored targeted therapies. We present here the case of a 66 year-old male patient, diagnosed with an advanced melanoma in June 2011, and treated with Dabrafenib for double mutant metastatic disease. The patient was referred to our attention for a large exophytic malignant melanoma on the left shoulder. After complete surgical excision and elective lymph node dissection for presence of metastatic sentinel lymph node, the patient has started high-dose interferon alfa-2b injections as adjuvant therapy for a complete negative staging. The treatment was interrupted in August 2011 due to the appearance of metastatic lymph nodes. Tumor burden was rapidly growing reaching in few months the size of a tennis ball for the tumor mass located in the shoulder. Mutational study of the tumor revealed a double BRAF mutation on V-600E and V600M. This finding incited us to enroll the patient in compassionate Dabrafenib clinical trial. The therapy was started on may 2012 at 150 mg bid dosage. Almost surprisingly for the rapidity of the effect, one week later the lesion on the shoulder has reduced its size by 60% and one month later it has completely disappeared from sight. CT scan of June 2012 documented the astonishing clinical response.

(18)F-labelled fluorodeoxyglucose-positron emission tomography (FDG-PET) heterogeneity of response is prognostic in dabrafenib treated BRAF mutant metastatic melanoma

BACKGROUND

Little is known about the prevalence and clinical significance of heterogeneity of positron emission tomography with (18)F-labelled fluorodeoxyglucose-positron emission tomography (FDG-PET) response. We aim to determine the prevalence, and clinicopathologic correlates of intra-patient heterogeneity of FDG-PET response in metastatic melanoma treated with dabrafenib, and to determine whether heterogeneity predicts clinical outcome.

METHODS

Patients with BRAF mutant metastatic melanoma and ≥ 2 FDG avid lesions treated on the Phase I trial of dabrafenib at a single institution (n=23) were included. FDG-PET response was assessed by comparing baseline PET scans with scans at day 15. A heterogeneous response was defined as responding and new or metabolically progressing lesion(s) in a patient, or >10% of lesions with a stable metabolic response and responding lesions in a patient.

RESULTS

Six (26%) patients had a heterogeneous PET response. The median time to progression (TTP) was 7.4 months (95% confidence interval (CI): 6.5-8.3) for PET homogeneous responders and 3.0 months (95%CI: 0.6-5.4) for PET heterogeneous responders. There were no homogeneous non-responders. Age, BRAF mutation genotype, dose, and lactate dehydrogenase, did not predict for heterogeneity of PET response. Heterogeneity did not correlate with tumour response. Lung metastases were more likely to respond than other visceral metastatic sites.

CONCLUSIONS

Heterogeneous FDG-PET responses are common in metastatic melanoma treated with dabrafenib, and heterogeneity is associated with a shorter TTP. FDG-PET heterogeneity may predict molecular heterogeneity, and FDG-PET directed biopsies may facilitate investigation into mechanisms of resistance to signal pathway inhibitors.

Diagnosis and treatment of melanoma. European consensus-based interdisciplinary guideline--Update 2012

Cutaneous melanoma (CM) is potentially the most dangerous form of skin tumour and causes 90% of skin cancer mortality. A unique collaboration of multi-disciplinary experts from the European Dermatology Forum (EDF), the European Association of Dermato-Oncology (EADO) and the European Organization of Research and Treatment of Cancer (EORTC) was formed to make recommendations on CM diagnosis and treatment, based on systematic literature reviews and the experts' experience. Diagnosis is made clinically and staging is based upon the AJCC system. CMs are excised with one to two centimetre safety margins. Sentinel lymph node dissection (SLND) is routinely offered as a staging procedure in patients with tumours more than 1mm in thickness, although there is as yet no clear survival benefit for this approach. Interferon-α treatment may be offered to patients with stage II and III melanoma as an adjuvant therapy, as this treatment increases at least the disease-free survival (DFS) and less clear the overall survival (OS) time. The treatment is however associated with significant toxicity. In distant metastasis, all options of surgical therapy have to be considered thoroughly. In the absence of surgical options, systemic treatment is indicated. BRAF inhibitors like vemurafenib for BRAF mutated patients as well as the CTLA-4 antibody ipilimumab offer new therapeutic opportunities apart from conventional chemotherapy. Therapeutic decisions in stage IV patients should be primarily made by an interdisciplinary oncology team ('tumour board').