Adjuvant bevacizumab for melanoma patients at high risk of recurrence: survival analysis of the AVAST-M trial

Background

Bevacizumab is a recombinant humanised monoclonal antibody to vascular endothelial growth factor shown to improve survival in advanced solid cancers. We evaluated the role of adjuvant bevacizumab in melanoma patients at high risk of recurrence.

Patients and methods

Patients with resected AJCC stage IIB, IIC and III cutaneous melanoma were randomised to receive either adjuvant bevacizumab (7.5 mg/kg i.v. 3 weekly for 1 year) or standard observation. The primary end point was detection of an 8% difference in 5-year overall survival (OS) rate; secondary end points included disease-free interval (DFI) and distant metastasis-free interval (DMFI). Tumour and blood were analysed for prognostic and predictive markers.

Results

Patients (n=1343) recruited between 2007 and 2012 were predominantly stage III (73%), with median age 56 years (range 18–88 years). With 6.4-year median follow-up, 515 (38%) patients had died [254 (38%) bevacizumab; 261 (39%) observation]; 707 (53%) patients had disease recurrence [336 (50%) bevacizumab, 371 (55%) observation]. OS at 5 years was 64% for both groups [hazard ratio (HR) 0.98; 95% confidence interval (CI) 0.82–1.16, P = 0.78). At 5 years, 51% were disease free on bevacizumab versus 45% on observation (HR 0.85; 95% CI 0.74–0.99, P = 0.03), 58% were distant metastasis free on bevacizumab versus 54% on observation (HR 0.91; 95% CI 0.78–1.07, P = 0.25). Forty four percent of 682 melanomas assessed had a BRAF^V600 mutation. In the observation arm, BRAF mutant patients had a trend towards poorer OS compared with BRAF wild-type patients (P = 0.06). BRAF mutation positivity trended towards better OS with bevacizumab (P = 0.21).

Conclusions

Adjuvant bevacizumab after resection of high-risk melanoma improves DFI, but not OS. BRAF mutation status may predict for poorer OS untreated and potential benefit from bevacizumab.

Clinical Trial Information

ISRCTN 81261306; EudraCT Number: 2006-005505-64

DOC-MEK: a double-blind randomized phase II trial of docetaxel with or without selumetinib in wild-type BRAF advanced melanoma

BACKGROUND

Treatment options for wild-type BRAF melanoma patients remain limited. Selumetinib, a MEK 1/2 inhibitor, suppresses pERK levels independent of BRAF and NRAS mutation status, and combination with docetaxel has demonstrated synergy in xenograft models. The aim of this study was to assess the efficacy and safety of selumetinib plus docetaxel as first-line treatment in patients with wild-type BRAF advanced melanoma.

PATIENTS AND METHODS

In this double-blind multicentre phase II trial patients with wild-type BRAF melanoma were randomized (1:1) to docetaxel with selumetinib or placebo. Docetaxel 75 mg/m(2) was administered intravenously every 3 weeks up to six cycles. Selumetinib 75 mg or placebo was given orally twice daily until disease progression or unacceptable toxicity. The primary end point was progression-free survival (PFS). Tumour NRAS mutation status was analysed retrospectively and correlated with treatment outcomes.

RESULTS

Eighty-three patients were randomized to docetaxel plus selumetinib (n = 41) or docetaxel plus placebo (n = 42). The PFS hazard ratio (HR) (selumetinib:placebo) was 0.75 [90% confidence interval (CI) 0.50-1.14; P = 0.130], with a median PFS of 4.23 months (90% CI 3.63-6.90) for docetaxel plus selumetinib and 3.93 months (90% CI 2.07-4.16) for docetaxel alone. There was no significant difference in overall survival. The objective response rate was 32% with selumetinib versus 14% with placebo (P = 0.059). In a retrospective subset analysis, NRAS mutation status did not affect significantly upon clinical outcomes in either arm. The combination of docetaxel and selumetinib could be administered effectively to patients with metastatic melanoma, although the combination was less well tolerated than docetaxel alone.

CONCLUSIONS

The combination of docetaxel with selumetinib showed no significant improvement in PFS compared with docetaxel alone, although more patients showed a response to combination therapy. We found no evidence to support using tumour NRAS mutation as a basis for selecting patients for combined MEK inhibitor and chemotherapy.

CLINICAL TRIAL

DOC-MEK (EudraCT no: 2009-018153-23).

Therapeutic opportunities in noncutaneous melanoma

Recent evidence suggests that the biology of noncutaneous melanoma differs significantly from cutaneous melanoma and may provide therapeutic opportunity. The most frequent sites of origin of noncutaneous melanoma are the eye and mucosal surfaces. Although noncutaneous melanomas are an uncommon group of cancers (representing less than 10% of all melanomas) a greater understanding of their genetic and molecular abnormalites is being translated into novel treatment strategies. These developments are important because there is currently no effective systemic therapy for noncutaneous melanoma. Significant attention has been focused on the role of c-kit (KIT, CD117), a transmembrane receptor with tyrosine kinase activity. In vitro and ex vivo evidence suggests that c-kit is frequently expressed/over expressed/mutated in noncutaneous melanoma. Anti-tumour effects with c-kit inhibitors are seen in pre-clinical models. A variety of multitargeted kinase inhibitors which have activity against c-kit are currently in early phase clinical trials in metastatic ocular, mucosal and acral melanoma. The few case reports of significant clinical activity with targeted therapies provides hope that greater understanding of the biology of noncutaneous melanoma can be translated into effective treatment.

Sequential FDG-PET/CT as a surrogate marker of response to sunitinib in metastatic clear cell renal cancer

301

Background: The purpose of this study was to investigate sequential FDG PET-CT as a correlative marker in metastatic clear cell renal cancer (mRCC) patients treated with first line sunitinib. Three sequential scans were performed to determine the importance of the timing of scans.

Methods: Forty-four untreated mRCC patients with MSKCC intermediate risk and poor risk disease were enrolled into a prospective study. FDG PET-CT scans were performed before (n=44), after 4 weeks (n=43) and 16 weeks (n=40) of sunitinib given at standard doses as the translational aspect of this trial ( NCT01024205 ). The primary endpoint was to determine whether 18F-FDG PET-CT response (defined as a 20% reduction in SUVmax) correlated with survival.

Results: Forty-three (98%) patients had FDG PET-CT avid lesions at diagnosis (median SUVmax 6.8 range: <2.5–18.4). In multivariate analysis a high SUVmax and increased number of PET positive lesions correlated with worse overall survival (OS) (HR: 3.30 (95%CI: 1.36–8.45) and 3.67 (95%CI: 1.43–9.39) respectively[p<0.05]). After 4 weeks of sunitinib, metabolic responses occurred in 24 (57%) patients at 4 weeks, but this did not correlate with progression-free survival [PFS] (HR for responders= 0.87 [95%CI: 0.40–1.99]) or OS (HR for responders= 0.80 [95%CI: 0.34–1.85]) (p>0.05 for both). After 16 weeks of treatment, FDG PET-CT demonstrated disease progression in 28% (n=12) patients. At this time point, the FDG PET-CT correlated with both OS and PFS (HR 5.96 [95%CI: 2.43–19.02] and HR 12.13 [95%CI: 3.72–46.45] respectively).

Conclusions: Baseline FDG PET prior to sunitinib yields prognostically significant data. FDG PET response at 16 weeks predicts outcome, which is not the case at 4 weeks. This subsets of patients with a poor prognosis at 16 weeks could be investigated within the context of a randomized clinical trial.

[Table: see text]

CT response assessment combining reduction in size and arterial enhancement correlates with time to progression in metastatic renal cancer patients treated with TKIs

e16062

Background: Targeted therapy is now the standard of care in advanced Renal Carcinoma (RCC). Response assessment by RECIST criteria is insensitive as treated tumours often have only a modest change in size despite the induction of significant necrosis and does not correlate with time to progression (TTP). The Choi criteria (10% size reduction or 15% contrast enhancement reduction) are routinely used in the assessment of GIST tumours treated with targeted agents. We report the use of combined size and density assessment in RCC metastases treated with either sunitinib or cediranib. Methods: CT scans from 32 patients with metastatic RCC treated with either sunitinib (18) or cediranib (14) were assessed. Scans from 10 patients were not evaluable as non-contrast enhanced scans were performed due to impaired renal function. Scans from a further 2 patients were excluded as they ceased treatment due to toxicity rather than progression. Scans from 20 evaluable patients at baseline and 12 weeks on treatment were assessed using RECIST, Choi, and modified criteria in which both a 10% decrease in size and 15% decrease in enhancement in the arterial phase were required to define a response (PR). A total of 60 lesions were assessed. Response assessment was performed using each of the three methods and correlated with time to disease progression (itself RECIST defined). Statistical analysis was performed using the Mann-Whitney U test. Results: There was no difference in TTP between RECIST defined PR (346.8 days) and SD (328.5 days) (P=0.965). TTP in Choi defined PR (358.4 days) and SD (189.6 days) groups showed improved but non-significant separation of TTP duration (P=0.266). TTP in PR (421.5 days) and SD (200.3 days) groups defined by a combined assessment of reduction in size and enhancement showed greatly improved separation (P=0.064). Conclusions: A combined reduction in both size and arterial phase enhancement of RCC metastases treated with TKIs correlates with time to progression. RECIST and standard Choi criteria appear inferior.

No significant financial relationships to disclose.

Profiling cytochrome P450 CYP1 enzyme expression in primary melanoma and disseminated disease utilizing spectral imaging microscopy (SIM)

8556

Background: The aim of this study was to profile cytochrome CYP1 family (CYP1A1/1A2, and CYP1B1) mono-oxygenase enzymes during the malignant progression of primary melanoma and metastatic disease. Methods: Tissue microarrays of primary (n = 75), and metastatic (n = 104) melanoma were constructed with the patient demographics: (1) primary melanoma; age 22 to 93 (median 59); sex M/F 36/44; Breslow thickness 0.4 to 15 mm (median 2.5 mm); ulceration 25/80, and (2) metastatic melanoma; age 26 to 92 (median 60 mm); sex M/F 54/49; ulceration 30/104; number of nodes 1 to 15 (median 2); extra-capsular spread 20/95. CYP1 protein was detected by IHC using validated selective poly- and monoclonal antibodies. Vector SG (grey) stain for CYP1 was used with nuclear fast red counterstain to aid spectral resolution from background melanin. Staining intensity was scored visually (negative 0, weak 1, moderate 2, strong 3) and using SIM at every pixel of a captured image of each melanoma core. Reference spectra of individual chromophores were used to spectrally ‘un-mix’ CYP1 staining before the mean normalised absorbance intensity was determined. Grading was by the 2002 AJCC classification system: primary stage I n = 27 (1A 8, 1B 19), and stage II n = 48 (2A 22, 2B 16, 2C 10), lymph node metastasis stage III n = 98 (3B 53, 3C 45), visceral metastasis stage IV n = 6. Normal skin (n = 27), benign naevi (n = 14), and dysplastic naevi (n = 21) were also included. Results: CYP1B1 was not in normal skin but was over-expressed in both primary and metastatic melanoma (visual: 71% & 65%, SIM: 91% & 83%). Primary melanoma (stage I & II) was significantly greater (p = 0.004) than metastasis (stage III & IV). CYP1B1 did not correlate with ulceration or Breslow thickness but did correlate with N stage lymph node metastasis (p = 0.005). CYP1B1 expression in dysplastic naevi indicated up-regulation at an early stage of melanoma progression. CYP1A1/1A2 was not expressed in normal skin nor primary/metastatic melanoma. Conclusions: CYP1B1 protein expression is maintained with advancing AJCC stage from primary through to visceral metastasis. Future work will seek to correlate protein expression with functionality with a view to exploiting CYP1B1 in the enzyme/prodrug therapy of malignant melanoma.

No significant financial relationships to disclose.

A phase I study of BIBF 1120, an orally active triple angiokinase inhibitor (VEGFR, PDGFR, FGFR) given continuously to patients with advanced solid tumours, incorporating dynamic contrast enhanced magnetic resonance imaging (DCE-MRI)

3015

Background: BIBF 1120 is a potent inhibitor of VEGFR, PDGFR, FGFR kinases, and of members of the Src family of tyrosine kinases (Src, Lck, Lyn). Methods: Patients (Pts) with advanced solid tumours were enrolled. BIBF 1120 was administered orally once daily (q.d.) continuously, starting at 100 mg/day. Dosing was later amended to twice daily (b.i.d.) in view of transaminitis seen with q.d. dosing. DCE-MRI studies were performed at baseline, days 2 and 28. All pts underwent pharmacokinetic (PK) sampling. Results: 51 pts (26M/25F; median age 57 y, range 22–78 y; ECOG PS 0/1 = 22/27) were treated at: 100 mg q.d. (n = 6), 200 mg q.d. (n = 6), 300 mg q.d. (n = 7), 400 mg q.d. (n = 16), 450 mg q.d. (n = 5); 250 mg b.i.d. (n = 11). Median treatment duration was 57 days (range: 1 day– 22 m). The most common toxicities were nausea, vomiting, diarrhoea, abdominal pain and fatigue, all ≤ grade (G)2. Asymptomatic, reversible elevation of liver enzymes which was dose limiting in 2/5 pts at 450 mg q.d. defined the MTD at 400 mg q.d. At 250 mg b.i.d., 2/11 pts had DLT (G3 elevation in liver enzymes: n = 1; G3 abdominal pain: n = 1). 44 pts treated for ≥2 m were assessable for response: 13 pts had SD for ≥3 m (median 7m, range 3–22 m; renal, prostate, colorectal, chondrosarcoma, leiomyomatosis, fibromatosis). 3 pts with renal cancer had SD for 8, 14+ and 22 m respectively. PK evaluations generally showed increasing gMean Cmax and AUC values with increasing doses, with high inter-patient variability. Tmax was ∼2h post-dosing. gMean t1/2 values ranged from 6.8–26.4h. DCE-MRI of target lesions in 35 pts showed significant antivascular/antiangiogenic effects in some patients and dose cohorts, particularly at 200 mg q.d. and ≥400 mg q.d. DCE-MRI effects were most pronounced at 28 days, especially in metastatic liver lesions. Conclusions: BIBF 1120 is well-tolerated in patients with advanced solid malignancies and induces in vivo antiangiogenic effects detectable by DCE-MRI. Some patients experienced clinically meaningful disease stabilisation. The recommended dose for future Phase II studies was determined to be 250 mg b.i.d.

[Table: see text]

Epithelial Ovarian Cancer: A Review of Current Management

Epithelial ovarian cancer is the most lethal gynaecological cancer among women worldwide, with 6000 new cases diagnosed in the UK each year. Most women present with advanced disease, but, despite a good initial response to treatment, most relapse. The overall 5-year survival rate is 46%, although this drops to about 13% in women with advanced disease. Transvaginal ultrasound and the tumour marker CA125 are being investigated for screening in ongoing randomised trials. Treatment of ovarian cancer is dependent on clinical stage, and should always be managed within a multidisciplinary team. Most cases will require a pelvic clearance and adjuvant chemotherapy. Current guidelines by the National Institute of Clinical Excellence (NICE) recommend that first-line chemotherapy should include a platinum-based regimen with or without paclitaxel. Relapsed ovarian cancer is incurable; however, chemotherapy can improve quality of life and survival. Gene therapy, immunotherapy and signal transduction inhibitors are all potential future therapies, and are being investigated in ongoing clinical research. In this paper we review the literature on the epidemiology, pathology, clinical features and the current treatment options in epithelial ovarian cancer.

Regulation of the BamHI restriction-modification system by a small intergenic open reading frame, bamHIC, in both Escherichia coli and Bacillus subtilis

BamHI, from Bacillus amyloliquefaciens H, is a type II restriction-modification system recognizing and cleaving the sequence G--GATCC. The BamHI restriction-modification system contains divergently transcribed endonuclease and methylase genes along with a small open reading frame oriented in the direction of the endonuclease gene. The small open reading frame has been designated bamHIC (for BamHI controlling element). It acts as both a positive activator of endonuclease expression and a negative repressor of methylase expression of BamHI clones in Escherichia coli. Methylase activity increased 15-fold and endonuclease activity decreased 100-fold when bamHIC was inactivated. The normal levels of activity for both methylase and endonuclease were restored by supplying bamHIC in trans. The BamHI restriction-modification system was transferred into Bacillus subtilis, where bamHIC also regulated endonuclease expression when present on multicopy plasmid vectors or integrated into the chromosome. In B. subtilis, disruption of bamHIC caused at least a 1,000-fold decrease in endonuclease activity; activity was partially restored by supplying bamHIC in trans.

Characterization of the cloned BamHI restriction modification system: its nucleotide sequence, properties of the methylase, and expression in heterologous hosts

The BamHI restriction modification system was previously cloned into E. coli and maintained with an extra copy of the methylase gene on a high copy vector (Brooks et al., (1989) Nucl. Acids Res. 17, 979-997). The nucleotide sequence of a 3014 bp region containing the endonuclease (R) and methylase (M) genes has now been determined. The sequence predicts a methylase protein of 423 amino acids, Mr 49,527, and an endonuclease protein of 213 amino acids, Mr 24,570. Between the two genes is a small open reading frame capable of encoding a 102 amino acid protein, Mr 13,351. The M. BamHI enzyme has been purified from a high expression clone, its amino terminal sequence determined, and the nature of its substrate modification studied. The BamHI methylase modifies the internal C within its recognition sequence at the N4 position. Comparisons of the deduced amino acid sequence of M. BamHI have been made with those available for other DNA methylases: among them, several contain five distinct regions, 12 to 22 amino acids in length, of pronounced sequence similarity. Finally, stability and expression of the BamHI system in both E. coli and B. subtilis have been studied. The results suggest R and M expression are carefully regulated in a 'natural' host like B. subtilis.

An analysis of myeloma plasma cell phenotype using antibodies defined at the IIIrd International Workshop on Human Leucocyte Differentiation Antigens

Fresh bone marrow from 43 cases of myeloma and three cases of plasma cell leukaemia has been phenotyped both by indirect immune-rosetting and, on fixed cytospin preparations, by indirect immunofluorescence. Both clustered and unclustered B cell associated antibodies from the IIIrd International Workshop on Human Leucocyte Differentiation Antigens were used. The results confirm the lack of many pan-B antigens on the surface of myeloma plasma cells, i.e. CD19-23, 37, 39, w40. Strong surface reactivity is seen with CD38 antibodies and with one CD24 antibody (HB8). Weak reactions are sometimes obtained with CD9, 10 and 45R. On cytospin preparations CD37, 39 and w40 are sometimes weakly positive, and anti-rough endoplasmic reticulum antibodies are always strongly positive. Specific and surface-reacting antiplasma cell antibodies are still lacking.

An antigenic study of human plasma cells in normal tissue and in myeloma: identification of a novel plasma cell associated antigen

A mouse monoclonal antibody named BU11 which detects an antigen strongly expressed on human plasma cells is described. The antibody stains plasma cells in tonsil sections, fresh and cultured plasmacytoid cells from the bone marrow of patients with multiple myeloma and cells of the plasmacytoid cell line RPMI 8226 used as the immunogen. In vitro studies of pokeweed mitogen (PWM) stimulated peripheral blood B cells and Epstein-Barr virus (EBV) stimulated tonsil B cells show that the antigen is present mainly on cells coexpressing the OKT10 antigen and containing cytoplasmic immunoglobulin (cIg). The BU11 antigen is expressed weakly on some normal B cells and is not present on T cells, monocytes or granulocytes. The antigen is of molecular weight 58kD under reducing conditions and is biochemically distinct from previously described plasma cell antigens.

Use of monoclonal antibodies reactive with secretory epithelial cells for the immunocytochemical identification of plasma cells

Six monoclonal antibodies (McAbs) were identified as plasma cell-reactive when screened on sections of human tonsil. They were all produced following immunisation of mice with cells of a human plasmacytoid line. Three of the antibodies also stained the cytoplasm (but not the surface) of blood B cells and were unreactive with other leucocytes; one McAb showed broad lymphocyte reactivity and two were completely unreactive with blood leucocytes; on testing with a panel of cell lines specificity for the plasmacytoid line was demonstrated by three of the McAbs. In spite of the marked restriction shown by the reactivity of these antibodies in tests on cells of haemopoietic origin, tests on other human tissues - including thyroid and pancreas - showed that a related antigen was present in the cytoplasm of secretory epithelial cells. The overall patterns of reactivity of the individual McAbs on various tissues and blood lymphocytes were different. Comparisons were made with the established McAb OKT10, which binds to plasma cells, early stem cells and activated lymphocytes; its binding to plasma cells was confirmed and it was shown that it did not stain secretory epithelia. The potent reactions obtained with the new McAbs suggest that antibodies to antigens associated with epithelial cell secretory apparatus provide potentially useful reagents for studying plasma cells.

Amino acid precursors of Myxococcus xanthus antibiotic TA

The production of Myxococcus xanthus antibiotic TA was stimulated by addition of alanine, serine and glycine to Casitone medium. These three amino acids served as the major biosynthetic precursors of the antibiotic. Alanine and serine were incorporated via acetate. In Casitone medium supplemented with alanine and serine, 29 to 30 of the 34 carbon atoms of antibiotic TA were derived from these two amino acids. Both carbon atoms of glycine were incorporated into antibiotic TA by a mechanism not involving acetate as an intermediate. Antibiotic TA was split into two fragments by alkaline hydrolysis followed by periodate oxidation. Radioactive alanine was incorporated into both fragments, whereas glycine was incorporated only into the smaller, polar fragment.