Michael P Brown

Royal Adelaide Hospital, Tarndarnya, South Australia, Australia

Are you Michael P Brown?

Claim your profile

Publications (49)262.44 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Resistance to conventional cancer treatments is a major problem associated with solid tumours. Tumour hypoxia is associated with a poor prognosis and with poor treatment outcomes; therefore, there is a need for treatments that can kill hypoxic tumour cells. One potential option is targeted α-radioimmunotherapy, as α-particles can directly kill hypoxic tumour cells. The murine monoclonal antibody DAB4 (APOMAB), which binds dead tumour cells after DNA-damaging treatment, was conjugated and radiolabelled with the α-particle-emitting radionuclide thorium-227 (Th). Mice bearing Lewis lung tumours were administered Th-DAB4 alone or after chemotherapy and the tissue biodistribution of the radioimmunoconjugate was examined, as was the effect of these treatments on tumour growth and survival. Th-DAB4 accumulated in the tumour particularly after chemotherapy, whereas the distribution in healthy tissues did not change. Th-DAB4 as a monotherapy increased survival, with more pronounced responses observed when given after chemotherapy. We have shown that targeted α-therapy of necrotic tumour cells with Th-DAB4 had significant and surprising antitumour activity as it would occur only through a cross-fire effect.
    Nuclear Medicine Communications 09/2014; · 1.38 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Over the last decade, the significance of the homeostatic CC chemokine receptor-7 and its ligands CC chemokine ligand-19 (CCL19) and CCL21, in various types of cancer, particularly mammary carcinoma, has been highlighted. The chemokine receptor CCX-CKR is a high-affinity receptor for these chemokine ligands but rather than inducing classical downstream signalling events promoting migration, it instead sequesters and targets its ligands for degradation, and appears to function as a regulator of the bioavailability of these chemokines in vivo. Therefore, in this study, we tested the hypothesis that local regulation of chemokine levels by CCX-CKR expressed on tumours alters tumour growth and metastasis in vivo. Expression of CCX-CKR on 4T1.2 mouse mammary carcinoma cells inhibited orthotopic tumour growth. However, this effect could not be correlated with chemokine scavenging in vivo and was not mediated by host adaptive immunity. Conversely, expression of CCX-CKR on 4T1.2 cells resulted in enhanced spontaneous metastasis and haematogenous metastasis in vivo. In vitro characterisation of the tumourigenicity of CCX-CKR-expressing 4T1.2 cells suggested accelerated epithelial-mesenchymal transition (EMT) revealed by their more invasive and motile character, lower adherence to the extracellular matrix and to each other, and greater resistance to anoikis. Further analysis of CCX-CKR-expressing 4T1.2 cells also revealed that transforming growth factor (TGF)-β1 expression was increased both at mRNA and protein levels leading to enhanced autocrine phosphorylation of Smad 2/3 in these cells. Together, our data show a novel function for the chemokine receptor CCX-CKR as a regulator of TGF-β1 expression and the EMT in breast cancer cells.Immunology and Cell Biology advance online publication, 15 July 2014; doi:10.1038/icb.2014.58.
    Immunology and Cell Biology 07/2014; · 3.93 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Purpose: Dabrafenib is a selective, potent ATP-competitive inhibitor of the BRAFV600-mutant kinase that has demonstrated efficacy in clinical trials. We report the rationale for dose selection in the first-in-human study of dabrafenib, including pharmacokinetics, tissue pharmacodynamics, 18F-labelled fluorodeoxyglucose-positron emission tomography (FDG-PET) pharmacodynamics, and dose-response relationship. Methods: Dabrafenib was administered orally once, twice (BID), or three times (TID) daily. Selected dose cohorts were expanded to collect adequate data on safety, pharmacokinetics, or pharmacodynamics. A recommended phase 2 dose (RP2D) was chosen based on safety, pharmacokinetic, pharmacodynamic, and response data. Results: 184 patients were enrolled and treated with doses ranging from 12mg once daily to 300mg BID in 10 cohorts. Pharmacokinetic assessment of dabrafenib demonstrated a less-than-dose-proportional increase in exposure after repeat dosing above 150mg BID. Similar to parent drug concentrations, exposure for all metabolites demonstrated less-than-dose-proportional increases. Predicted target inhibition of pERK (>80%) was achieved at 150mg BID, with a similar magnitude of inhibition at higher doses in BRAFV600mutation melanoma biopsy samples. Although there was large variability between patients, FDG uptake decreased with higher daily doses in patients with BRAFV600 mutation-positive melanoma. A favorable activity and tolerability profile was demonstrated at 150mg BID. There was no improvement with TID dosing compared with BID dosing, based on FDG-PET and tumor response analyses in melanoma patients. Conclusion: The RP2D of dabrafenib was determined to be 150mg BID after considering multiple factors, including pharmacokinetics, tissue pharmacodynamics, FDG-PET pharmacodynamics, and the dose-response relationship. A maximum tolerated dose for dabrafenib was not determined.
    Clinical cancer research : an official journal of the American Association for Cancer Research. 06/2014;
  • [Show abstract] [Hide abstract]
    ABSTRACT: To develop effective combination therapy against pancreatic ductal adenocarcinoma (PDAC) with a combination of chemotherapy, Chk1 inhibition and EGFR-targeted radioimmunotherapy.
    Clinical cancer research : an official journal of the American Association for Cancer Research. 05/2014;
  • Michael P Brown, Georgina V Long
    [Show abstract] [Hide abstract]
    ABSTRACT: Metastatic melanoma remains one of the major causes of death related to skin cancers and has been resistant to traditional anticancer therapies. The clinical development of vemurafenib in the treatment of metastatic melanoma with the V600 mutation of the BRAF gene has provided meaningful improvements in the overall survival and progression-free survival of metastatic melanoma patients. However, significant side effects have been noted with this therapy, in particular cutaneous adverse events (AEs) such as rashes, squamous cell carcinoma and severe photosensitivity to UVA light among others. With an emphasis on the Australian perspective, this review provides an overview of the clinical development of vemurafenib, its attendant dose-limiting toxicities and other AEs, recommendations for safety monitoring, supportive treatments of AEs and dose modifications, with the aim of maximizing the chances of continuing beneficial treatment.
    Asia-Pacific Journal of Clinical Oncology 04/2014; 10 Suppl S3:1-15. · 0.91 Impact Factor
  • Michael P Brown, Alexander H Staudacher
    [Show abstract] [Hide abstract]
    ABSTRACT: Evaluation of: Younes A, Connors JM, Park SI et al. Brentuximab vedotin combined with ABVD or AVD for patients with newly diagnosed Hodgkin's lymphoma: a Phase 1, open-label, dose-escalation study. Lancet Oncol. 14(13), 1348-1356 (2013). With exceptionally high response rates, the CD30-directed antibody-drug conjugate brentuximab vedotin (BV) was US FDA approved for treatment of patients with relapsed/refractory Hodgkin lymphoma (HL). Now in Phase I clinical trial, it has been shown that combining BV with multiagent chemotherapy (excluding bleomycin) as first-line treatment in HL patients with high-risk disease is feasible. Complete response rates were over 90% and toxicity was manageable. Given that the malignant cell population comprises a minority of HL lesions, and that BV releases a diffusible cytotoxin via a cathepsin B-cleavable linker, we argue that a significant proportion of the antitumor activity of BV can be attributed to bystander cytotoxicity in addition to direct killing of CD30-expressing malignant cells.
    Immunotherapy 04/2014; 6(4):371-5. · 2.39 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Early identification of tumor responses to treatment is crucial for devising more effective and safer cancer treatments. No widely applicable, noninvasive method currently exists for specifically detecting tumor cell death after cytotoxic treatment and thus for predicting treatment outcomes. We have further characterized the targeting of the murine monoclonal antibody DAB4 specifically to dead tumor cells in vitro, in vivo, and in clinical samples. We found that sustained DAB4 binding to treated cells was closely associated with markers of intrinsic apoptosis and DNA double-strand break formation. In a competition binding assay, DAB4 bound EL4 murine thymic lymphoma cells in preference to the normal counterpart of murine thymocytes. Defective in vivo clearance of apoptotic cells augmented in vivo accumulation of DAB4 in tumors particularly after chemotherapy but was unchanged in normal tissues. Tumor targeting of DAB4 was selective for syngeneic murine tumors and for human tumor xenografts of prostate cancer (PC-3) and pancreatic cancer (Panc-1) before and more so after chemotherapy. Furthermore, DAB4 was shown to bind to dead primary acute lymphoblastic leukemic blasts cultured with cytotoxic drugs and dead epithelial cancer cells isolated from peripheral blood of small cell lung carcinoma patients given chemotherapy. Collectively, these results further demonstrate the selectivity of DAB4 for chemotherapy-induced dead tumor cells. This postchemotherapy selectivity is related to a relative increase in the availability of DAB4-binding targets in tumor tissue rather than in normal tissues. The in vitro findings were translated in vivo to human xenograft models and to ex vivo analyses of clinical samples, providing further evidence of the potential of DAB4 as a marker of tumor cell death after DNA-damaging cytotoxic treatment that could be harnessed as a predictive marker of treatment responses.
    Journal of Nuclear Medicine 03/2014; · 5.77 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The orally available BRAF kinase inhibitor vemurafenib, compared with dacarbazine, shows improved response rates, progression-free survival (PFS), and overall survival in patients with metastatic melanoma that has a BRAF(V600) mutation. We assessed vemurafenib in patients with advanced metastatic melanoma with BRAF(V600) mutations who had few treatment options. In an open-label, multicentre study, patients with untreated or previously treated melanoma and a BRAF(V600) mutation received oral vemurafenib 960 mg twice a day. The primary endpoint was safety. All analyses were done on the safety population, which included all patients who received at least one dose of vemurafenib. This report is the third interim analysis of this study. This study is registered with ClinicalTrials.gov, number NCT01307397. Between March 1, 2011, and Jan 31, 2013, 3226 patients were enrolled in 44 countries. 3222 patients received at least one dose of vemurafenib (safety population). At data cutoff, 868 (27%) patients were on study treatment and 2354 (73%) had withdrawn, mainly because of disease progression. Common adverse events of all grades included rash (1592 [49%]), arthralgia (1259 [39%]), fatigue (1093 [34%]), photosensitivity reaction (994 [31%]), alopecia (826 [26%]), and nausea (628 [19%]). 1480 (46%) patients reported grade 3 or 4 adverse events, including cutaneous squamous cell carcinoma (389 [12%]), rash (155 [5%]), liver function abnormalities (165 [5%]), arthralgia (106 [3%]), and fatigue (93 [3%]). Grade 3 and 4 adverse events were reported more frequently in patients aged 75 years and older (n=257; 152 [59%, 95% CI 53-65] and ten [4%, 2-7], respectively) than in those younger than 75 years (n=2965; 1286 [43%, 42-45] and 82 [3%, 2-3], respectively). Vemurafenib safety in this diverse population of patients with BRAF(V600) mutated metastatic melanoma, who are more representative of routine clinical practice, was consistent with the safety profile shown in the pivotal trials of this drug. F Hoffmann-La Roche.
    The Lancet Oncology 02/2014; · 25.12 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The lupus-associated (La)-specific murine monoclonal antibody DAB4 (APOMAB(R)) specifically binds dead cancer cells. Using DAB4, we examined La expression in human lung cancer samples to assess its suitability as a cancer-selective therapeutic target. We evaluated the safety and effectiveness of radioimmunotherapy (RIT) using DAB4 radiolabeled with Lutetium-177 (177Lu) in the murine Lewis Lung (LL2) carcinoma model, and determined whether combining RIT with DNA-damaging cisplatin-based chemotherapy, a PARP inhibitor (PARPi), or both alters treatment responses. The expression of La mRNA in human lung cancer samples was analysed using the online database Oncomine, and the protein expression of La was examined using a TissueFocus Cancer Survey Tissue Microarray. The binding of DAB4 to cisplatin-treated LL2 cells was assessed in vitro. LL2 tumour-bearing mice were administered escalating doses of 177Lu-DAB4 alone or in combination with chemotherapy, and tumour growth and survival measured. Biodistribution analysis was used to determine tissue uptake of 177Lu-DAB4 or its isotype control (177Lu-Sal5), when delivered alone or after chemotherapy. PARPi (rucaparib; AG-014699) was combined with chemotherapy and the effects of combined treatment on tumour growth, tumour cell DNA damage and death, and intratumoural DAB4 binding were also analysed. The effect of the triple combination of PARPi, chemotherapy and 177Lu- DAB4 on tumour growth and survival of LL2 tumour-bearing mice was tested. La was over-expressed at both mRNA and protein levels in surgical specimens of human lung cancer and the over-expression of La mRNA conferred a poorer prognosis. DAB4 bound specifically to cisplatin-induced dead LL2 cells in vitro. An anti-tumour dose response was observed when escalating doses of 177Lu-DAB4 were delivered in vivo, with supra-additive responses observed when chemotherapy was combined with 177Lu-DAB4. Combining PARPi with chemotherapy was more effective than chemotherapy alone with increased tumour cell DNA damage and death, and intratumoural DAB4 binding. The combination of PARPi, chemotherapy and 177Lu-DAB4 was well-tolerated and maximised tumour growth delay. The La antigen represents a dead cancer cell-specific target in lung cancer, and DAB4 specifically targeted tumour tissue in vivo, particularly after chemotherapy. Tumour uptake of DAB4 increased further after the combination of PARPi and chemotherapy, which generated new dead tumour cell-binding targets. Consequently, combining 177Lu-DAB4 with PARPi and chemotherapy produced the greatest anti-tumour response. Therefore, the triple combination of PARPi, chemotherapy and RIT may have broad clinical utility.
    EJNMMI research. 01/2014; 4(1):2.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Radio-resistant hypoxic tumor cells are significant contributors to the locoregional recurrences and distant metastases that mark failure of radiotherapy. Due to restricted tissue oxygenation, chronically hypoxic tumor cells frequently become necrotic and thus there is often an association between chronically hypoxic and necrotic tumor regions. This simulation study is the first in a series to determine the feasibility of hypoxic cell killing after first targeting adjacent areas of necrosis with either an α- or β-emitting radioimmunoconjugate.
    Applied Radiation and Isotopes 01/2014; · 1.18 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Nutlin-3a is a small molecule antagonist of p53/MDM2 that is being explored as a treatment for sarcoma. In this study, we examined the molecular mechanisms underlying the sensitivity of sarcomas to Nutlin-3a. In an ex vivo tissue explant system, we found that TP53 pathway alterations (TP53 status, MDM2/MDM4 genomic amplification/mRNA overexpression, MDM2 SNP309, and TP53 SNP72) didn't confer apoptotic or cytostatic responses in sarcoma tissue biopsies (n=24). Unexpectedly, MDM2 status didn't predict Nutlin-3a sensitivity. RNA sequencing revealed that the global transcriptomic profiles of these sarcomas provided a more robust prediction of apoptotic responses to Nutlin-3a. Expression profiling revealed a subset of TP53 target genes which were transactivated specifically in sarcomas that were highly sensitive to Nutlin-3a. Of these target genes, the GADD45A promoter region was shown to be hypermethylated in 82% of wild-type TP53 sarcomas that didn't respond to Nutlin-3a, thereby providing mechanistic insight into the innate ability of sarcomas to resist apoptotic death following Nutlin-3a treatment. Collectively, our findings argue that the existing benchmark biomarker for MDM2 antagonist efficacy (MDM2 amplification) should not be used to predict outcome, but rather global gene expression profiles and epigenetic status of sarcomas dictate their sensitivity to p53/MDM2 antagonists.
    Cancer Research 12/2013; · 9.28 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: It is uncertain whether survival increases from melanoma recorded by some population registries include a treatment effect. The US Surveillance, Epidemiology and End Results (SEER) programme has good data quality control, large numbers of cases enabling high statistical precision and summary stage plus thickness, which we consider to be a best-case population registry scenario to investigate potential for a treatment effect. We have investigated SEER data to indicate whether survivals increases are fully attributable to earlier diagnosis and other non-treatment factors. Through relative survival regression, the effects of diagnostic period on 5-year excess mortality were investigated, adjusting for socio-demographic factors, lesion sub-site, histology, thickness and stage at diagnosis in 1990-2009 (n = 99 690 cases). The reduction in excess mortality (95% confidence interval) between 1990-1999 and 2000-2009 was 31 (20-41)% for localised melanoma, 18 (12-22)% for regional melanoma and 3 (-5-10)% for melanomas with distant spread. Younger age was predictive of a greater percentage reduction. Treatment benefits are inferred from the higher survivals in 2000-2009 but uncertainty remains due to incomplete data to adjust for non-treatment factors and a lack of treatment data. Registries should use new information systems to collect more complete data on stage, other prognostic indicators, co-morbidities and treatment, to provide more definitive and detailed information on population effects of cancer control.
    Journal of Evaluation in Clinical Practice 09/2013; · 1.51 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Dabrafenib is a selective inhibitor of V600-mutant BRAF kinase, which recently demonstrated improved progression free survival (PFS) as compared with dacarbazine, in metastatic melanoma patients. The current study examined potential genetic markers associated with response and PFS in the phase I study of dabrafenib. Baseline (pre-treatment or archival) melanoma samples were evaluated in 41 patients using a custom genotyping melanoma-specific assay, sequencing of PTEN, and copy number analysis using multiplex ligation amplification and array based comparative genomic hybridization. Nine patients had on-treatment and/or progression samples available. All baseline patient samples had BRAFV600E/K confirmed. Baseline PTEN loss/mutation was not associated with best overall response (BOR) to dabrafenib, but it showed a trend for shorter median progression free survival (PFS) (18.3 [95% confidence interval (CI) 9.1-24.3] vs. 32.1 weeks [95% CI 24.1-33], p=0.059). Higher copy number of CCND1 (p=0.009) and lower copy number of CDKN2A (p=0.012) at baseline were significantly associated with decreased PFS. Although no melanomas had high level amplification of BRAF, the two patients with progressive disease as their best response had BRAF copy gain in their tumors. Copy number changes in CDKN2A, CCND1, and mutation/copy number changes in PTEN correlated with the duration of PFS in patients treated with dabrafenib. The results suggest that these markers should be considered in the design and interpretation of future trials with selective BRAF inhibitors in advanced melanoma patients.
    Clinical Cancer Research 07/2013; · 7.84 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The present study evaluated the efficacy of drozitumab, a human monoclonal agonistic antibody directed against death receptor 5 (DR5), as a new therapeutic avenue for the targeted treatment of bone and soft-tissue sarcomas. The antitumour activity of drozitumab as a monotherapy or in combination with Nutlin-3a was evaluated in a panel of sarcoma cell lines in vitro and human sarcoma patient samples ex vivo. Knockdown experiments were used to investigate the central role of p53 as a regulator of drozitumab cytotoxicity. Pre-activation of the p53 pathway through Nutlin-3a upregulated DR5, subsequently sensitising sarcoma cell lines and human sarcoma specimens to the pro-apoptotic effects of drozitumab. Silencing of p53 strongly decreased DR5 mRNA expression resulting in abrogation of drozitumab-induced apoptosis. Our study provides the first pre-clinical evaluation of combination therapy using p53-activating agents with drozitumab to further sensitise sarcomas to the cytotoxic effects of DR5 antibody therapy.
    Oncology Reports 05/2013; · 2.30 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Introduction One standard of care for advanced non-small cell lung cancer (NSCLC) is paclitaxel plus carboplatin ± bevacizumab. This two-step phase I study evaluated the feasibility of adding everolimus to paclitaxel plus carboplatin ± bevacizumab for advanced NSCLC. Methods Adults with advanced NSCLC naive to systemic therapy were enrolled. A Bayesian dose-escalation model was used to identify feasible daily or weekly everolimus doses given with paclitaxel (200 mg/m(2) q21 days) and carboplatin (AUC 6 mg/mL/min q21 days) (step 1) and paclitaxel (200 mg/m(2) q21 days), carboplatin (AUC 6 mg/mL/min q21 days), and bevacizumab (15 mg/kg q21 days) (step 2). Primary endpoint was end-of-cycle 1 dose-limiting toxicity (DLT) rate. Secondary endpoints included safety; relative dose intensities of paclitaxel, carboplatin, and bevacizumab; pharmacokinetics; and tumor response. Results Fifty-two patients were enrolled and received everolimus 5 mg/day plus carboplatin and paclitaxel (step 1 daily; n = 13); everolimus 30 mg/week plus carboplatin and paclitaxel (step 1 weekly; n = 13); everolimus 5 mg/day plus carboplatin, paclitaxel, and bevacizumab (step 2 daily; n = 13); or everolimus 30 mg/week plus carboplatin, paclitaxel, and bevacizumab (step 2 weekly; n = 13). End-of-cycle 1 DLT rate was 16.7 % (step 1 daily), 30.8 % (step 1 weekly), 30.0 % (step 2 daily), and 16.7 % (step 2 weekly). Cycle 1 DLTs were grade 3 neutropenia, anal abscess, diarrhea, and thrombocytopenia and grade 4 myalgia, cellulitis, neutropenia, febrile neutropenia, pulmonary embolism, and thrombocytopenia. The most common adverse events were neutropenia, fatigue, anemia, and thrombocytopenia. One patient (step 2 daily) experienced complete response, 10 patients partial response. Conclusions The feasible everolimus doses given with carboplatin and paclitaxel ± bevacizumab were 5 mg/day and 30 mg/week. Neither schedule was very well tolerated in this unselected NSCLC population.
    Investigational New Drugs 04/2013; · 3.50 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Triple-negative breast cancer (TNBC) is associated with poor survival. Chemotherapy is the only standard treatment for TNBC. The prevalence of BRCA1 inactivation in TNBC has rationalized clinical trials of poly(adenosine diphosphate ribose) polymerase (PARP) inhibitors. Similarly, the overexpression of epidermal growth factor receptor (EGFR) rationalized anti-EGFR therapies in this disease. However, clinical trials using these 2 strategies have not reached their promise. In this study, we used EGFR as a target for radioimmunotherapy and hypothesized that EGFR-directed radioimmunotherapy can deliver a continuous lethal radiation dose to residual tumors that are radiosensitized by PARP inhibitors and chemotherapy. METHODS: We analyzed EGFR messenger RNA in published gene expression array studies and investigated EGFR protein expression by immunohistochemistry in a cohort of breast cancer patients to confirm EGFR as a target in TNBC. Preclinically, using orthotopic and metastatic xenograft models of EGFR-positive TNBC, we investigated the effect of the novel combination of (177)Lu-labeled anti-EGFR monoclonal antibody, chemotherapy, and PARP inhibitors on cell death and the survival of breast cancer stem cells. RESULTS: In this first preclinical study of anti-EGFR radioimmunotherapy in breast cancer, we found that anti-EGFR radioimmunotherapy is safe and that TNBC orthotopic tumors and established metastases were eradicated in mice treated with anti-EGFR radioimmunotherapy combined with chemotherapy and PARP inhibitors. We showed that the superior response to this triple-agent combination therapy was associated with apoptosis and eradication of putative breast cancer stem cells. CONCLUSION: Our data support further preclinical investigations toward the development of combination therapies using systemic anti-EGFR radioimmunotherapy for the treatment of recurrent and metastatic TNBC.
    Journal of Nuclear Medicine 04/2013; · 5.77 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Antibody-dependent cellular cytotoxicity (ADCC) is a major mechanism of action of therapeutic monoclonal antibodies (mAbs) such as cetuximab, rituximab and trastuzumab. Fc gamma receptors (FcgR) on human white blood cells are an integral part of the ADCC pathway. Differential response to therapeutic mAbs has been reported to correlate with specific polymorphisms in two of these genes: FCGR2A (H131R) and FCGR3A (V158F). These polymorphisms are associated with differential affinity of the receptors for mAbs. This review critically examines the current evidence for genotyping the corresponding single nucleotide polymorphisms (SNPs) to predict response to mAbs in patients with cancer.
    Journal of Hematology & Oncology 01/2013; 6(1):1. · 4.46 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Passive immunotherapies utilising polyclonal antibodies could have a valuable role in preventing and treating infectious diseases such as influenza, particularly in pandemic situations but also in immunocompromised populations such as the elderly, the chronically immunosuppressed, pregnant women, infants and those with chronic diseases. The aim of this study was to optimise current methods used to generate ovine polyclonal antibodies. Polyclonal antibodies to baculovirus-expressed recombinant influenza haemagglutinin from A/Puerto Rico/8/1934 H1N1 (PR8) were elicited in sheep using various immunisation regimens designed to investigate the priming immunisation route, adjuvant formulation, sheep age, and antigen dose, and to empirically ascertain which combination maximised antibody output. The novel adjuvant CoVaccine HT™ was compared to Freund’s adjuvant which is currently the adjuvant of choice for commercial production of ovine polyclonal Fab therapies. CoVaccine HT™ induced significantly higher titres of functional ovine anti-haemagglutinin IgG than Freund’s adjuvant but with fewer side effects, including reduced site reactions. Polyclonal hyperimmune sheep sera effectively neutralised influenza virus in vitro and, when given before or after influenza virus challenge, prevented the death of infected mice. Neither the age of the sheep nor the route of antigen administration appeared to influence antibody titre. Moreover, reducing the administrated dose of haemagglutinin antigen minimally affected antibody titre. Together, these results suggest a cost effective way of producing high and sustained yields of functional ovine polyclonal antibodies specifically for the prevention and treatment of globally significant diseases.
    PLoS ONE 01/2013; 8(7):e68895. · 3.73 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Peanut-allergen hypersensitivity reactions, which can result in anaphylactic episodes and death, affect approximately 1% of the general population. Currently, strict avoidance of allergenic food is the only available treatment for this food-induced allergic reaction; however, the innocuous presence of trace amounts of peanut protein contaminating food products makes avoidance extremely difficult, especially in children. Therefore, safe and inexpensive therapeutic strategies aimed at prevention and treatment of peanut allergies is urgently required. This review summarizes the current state of knowledge of adaptive immune recognition and responsiveness to peanut allergens and how this can be integrated and subverted into new therapeutic treatment regimens for these dangerous allergic responses. The potential for new strategic vaccination-based interventions to either moderate or prevent these types of responses from occurring is also discussed.
    Expert Review of Vaccines 12/2012; 11(12):1471-81. · 4.22 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Dabrafenib is an inhibitor of BRAF kinase that is selective for mutant BRAF. We aimed to assess its safety and tolerability and to establish a recommended phase 2 dose in patients with incurable solid tumours, especially those with melanoma and untreated, asymptomatic brain metastases. We undertook a phase 1 trial between May 27, 2009, and March 20, 2012, at eight study centres in Australia and the USA. Eligible patients had incurable solid tumours, were 18 years or older, and had adequate organ function. BRAF mutations were mandatory for inclusion later in the study because of an absence of activity in patients with wild-type BRAF. We used an accelerated dose titration method, with the first dose cohort receiving 12 mg dabrafenib daily in a 21-day cycle. Once doses had been established, we expanded the cohorts to include up to 20 patients. On the basis of initial data, we chose a recommended phase 2 dose. Efficacy at the recommended phase 2 dose was studied in patients with BRAF-mutant tumours, including those with non-Val600Glu mutations, in three cohorts: metastatic melanoma, melanoma with untreated brain metastases, and non-melanoma solid tumours. This study is registered with ClinicalTrials.gov, number NCT00880321. We enrolled 184 patients, of whom 156 had metastatic melanoma. The most common treatment-related adverse events of grade 2 or worse were cutaneous squamous-cell carcinoma (20 patients, 11%), fatigue (14, 8%), and pyrexia (11, 6%). Dose reductions were necessary in 13 (7%) patients. No deaths or discontinuations resulted from adverse events, and 140 (76%) patients had no treatment-related adverse events worse than grade 2. Doses were increased to 300 mg twice daily, with no maximum tolerated dose recorded. On the basis of safety, pharmacokinetic, and response data, we selected a recommended phase 2 dose of 150 mg twice daily. At the recommended phase 2 dose in 36 patients with Val600 BRAF-mutant melanoma, responses were reported in 25 (69%, 95% CI 51·9-83·7) and confirmed responses in 18 (50%, 32·9-67·1). 21 (78%, 57·7-91·4) of 27 patients with Val600Glu BRAF-mutant melanoma responded and 15 (56%, 35·3-74·5) had a confirmed response. In Val600 BRAF-mutant melanoma, responses were durable, with 17 patients (47%) on treatment for more than 6 months. Responses were recorded in patients with non-Val600Glu BRAF mutations. In patients with melanoma and untreated brain metastases, nine of ten patients had reductions in size of brain lesions. In 28 patients with BRAF-mutant non-melanoma solid tumours, apparent antitumour activity was noted in a gastrointestinal stromal tumour, papillary thyroid cancers, non-small-cell lung cancer, ovarian cancer, and colorectal cancer. Dabrafenib is safe in patients with solid tumours, and an active inhibitor of Val600-mutant BRAF with responses noted in patients with melanoma, brain metastases, and other solid tumours. GlaxoSmithKline.
    The Lancet 05/2012; 379(9829):1893-901. · 39.06 Impact Factor

Publication Stats

546 Citations
262.44 Total Impact Points

Institutions

  • 2007–2014
    • Royal Adelaide Hospital
      • Department of Medical Oncology
      Tarndarnya, South Australia, Australia
  • 2011–2013
    • Queensland Institute of Medical Research
      • Signal Transduction Laboratory
      Brisbane, Queensland, Australia
  • 2010–2013
    • University of Adelaide
      • • Centre for Personalised Cancer Medicine
      • • Discipline of Medicine
      Adelaide, South Australia, Australia
  • 2006–2013
    • Hanson Institute
      Tarndarnya, South Australia, Australia
  • 2007–2010
    • University of South Australia
      • School of Pharmacy and Medical Sciences
      Tarndarnya, South Australia, Australia