A phase Ib study of adavosertib, a selective Wee1 inhibitor, in patients with locally advanced or metastatic solid tumors.

Adavosertib selectively inhibits Wee1, which regulates intra-S and G2/M cell-cycle checkpoints. This study investigated dosing schedules for adavosertib monotherapy, determining the maximum tolerated dose (MTD) and recommended Phase II dose (RP2D) in patients with advanced solid tumors.Patients received oral adavosertib qd or bid on a 5/9 schedule (5 days on treatment, 9 days off) in 14-day cycles, or qd on one of two 5/2 schedules (weekly, or for 2 of 3 weeks) in 21-day cycles. Safety, efficacy, and pharmacokinetic analyses were performed.Sixty-two patients (female, 64.5%; median age, 61.5 years; most common primary tumors: lung [24.2%], ovary [21.0%]) received treatment (qd schedules, n = 50; bid schedules, n = 12) for 1.8 months (median). Median time to maximum adavosertib concentration was 2.2-4.1 h; mean half-life was 5-12 h. Adverse events (AEs) caused dose reductions, interruptions and discontinuations in 17 (27.4%), 25 (40.3%) and 4 (6.5%) patients, respectively. Most common grade ≥ 3 AEs were anemia, neutropenia (each n = 9, 14.5%) and diarrhea (n = 8, 12.9%). Seven (11.3%) patients experienced 10 treatment-related serious AEs (pneumonia n = 2 [3.2%], dehydration n = 2 [3.2%], anemia n = 1 [1.6%], febrile neutropenia n = 1 [1.6%], and thrombocytopenia n = 1 [1.6%]). Overall objective response rate was 3.4% (2/58); disease control rate was 48.4% (30/62); median progression-free survival was 2.7 months.MTDs were 125 mg (bid 5/9) and 300 mg (qd 5/9 and 5/2 for 2 of 3 weeks); RP2D was 300 mg (qd 5/2 for 2 of 3 weeks). The safety profile was manageable, acceptable, and generally concordant with the known safety profile.

Adavosertib plus gemcitabine for platinum-resistant or platinum-refractory recurrent ovarian cancer: a double-blind, randomised, placebo-controlled, phase 2 trial.

BACKGROUND: The Wee1 (WEE1hu) inhibitor adavosertib and gemcitabine have shown preclinical synergy and promising activity in early phase clinical trials. We aimed to determine the efficacy of this combination in patients with ovarian cancer. METHODS: In this double-blind, randomised, placebo-controlled, phase 2 trial, women with measurable recurrent platinum-resistant or platinum-refractory high-grade serous ovarian cancer were recruited from 11 academic centres in the USA and Canada. Women were eligible if they were aged 18 years or older, had an Eastern Cooperative Oncology Group performance status of 0-2, a life expectancy of more than 3 months, and normal organ and marrow function. Women with ovarian cancer of non-high-grade serous histology were eligible for enrolment in a non-randomised exploratory cohort. Eligible participants with high-grade serous ovarian cancer were randomly assigned (2:1), using block randomisation (block size of three and six) and no stratification, to receive intravenous gemcitabine (1000 mg/m2 on days 1, 8, and 15) with either oral adavosertib (175 mg) or identical placebo once daily on days 1, 2, 8, 9, 15, and 16, in 28-day cycles until disease progression or unacceptable toxicity. Patients and the team caring for each patient were masked to treatment assignment. The primary endpoint was progression-free survival. The safety and efficacy analysis population comprised all patients who received at least one dose of treatment. The trial is registered with ClinicalTrials.gov, NCT02151292, and is closed to accrual. FINDINGS: Between Sept 22, 2014, and May 30, 2018, 124 women were enrolled, of whom 99 had high-grade serous ovarian cancer and were randomly assigned to adavosertib plus gemcitabine (65 [66%]) or placebo plus gemcitabine (34 [34%]). 25 women with non-high-grade serous ovarian cancer were enrolled in the exploratory cohort. After randomisation, five patients with high-grade serous ovarian cancer were found to be ineligible (four in the experimental group and one in the control group) and did not receive treatment. Median age for all treated patients (n=119) was 62 years (IQR 54-67). Progression-free survival was longer with adavosertib plus gemcitabine (median 4·6 months [95% CI 3·6-6·4] with adavosertib plus gemcitabine vs 3·0 months [1·8-3·8] with placebo plus gemcitabine; hazard ratio 0·55 [95% CI 0·35-0·90]; log-rank p=0·015). The most frequent grade 3 or worse adverse events were haematological (neutropenia in 38 [62%] of 61 participants in the adavosertib plus gemcitabine group vs ten [30%] of 33 in the placebo plus gemcitabine group; thrombocytopenia in 19 [31%] of 61 in the adavosertib plus gemcitabine group vs two [6%] of 33 in the placebo plus gemcitabine group). There were no treatment-related deaths; two patients (one in each group in the high-grade serous ovarian cancer cohort) died while on study medication (from sepsis in the experimental group and from disease progression in the control group). INTERPRETATION: The observed clinical efficacy of a Wee1 inhibitor combined with gemcitabine supports ongoing assessment of DNA damage response drugs in high-grade serous ovarian cancer, a TP53-mutated tumour type with high replication stress. This therapeutic approach might be applicable to other tumour types with high replication stress; larger confirmatory studies are required. FUNDING: US National Cancer Institute Cancer Therapy Evaluation Program, Ontario Institute for Cancer Research, US Department of Defense, Princess Margaret Cancer Foundation, and AstraZeneca.

Epidermal growth factor receptor mutation analysis in tissue and plasma from the AURA3 trial: Osimertinib versus platinum-pemetrexed for T790M mutation-positive advanced non-small cell lung cancer.

BACKGROUND: This study assesses different technologies for detecting epidermal growth factor receptor (EGFR) mutations from circulating tumor DNA in patients with EGFR T790M-positive advanced non-small cell lung cancer (NSCLC) from the AURA3 study (NCT02151981), and it evaluates clinical responses to osimertinib and platinum-pemetrexed according to the plasma T790M status. METHODS: Tumor tissue biopsy samples were tested for T790M during screening with the cobas EGFR Mutation Test (cobas tissue). Plasma samples were collected at screening and at the baseline and were retrospectively analyzed for EGFR mutations with the cobas EGFR Mutation Test v2 (cobas plasma), droplet digital polymerase chain reaction (ddPCR; Biodesix), and next-generation sequencing (NGS; Guardant360, Guardant Health). RESULTS: With cobas tissue test results as a reference, the plasma T790M positive percent agreement (PPA) was 51% (110 of 215 samples) by cobas plasma, 58% (110 of 189) by ddPCR, and 66% (136 of 207) by NGS. Plasma T790M detection was associated with a larger median baseline tumor size (56 mm for T790M-positive vs 39 mm for T790M-negative; P < .0001) and the presence of extrathoracic disease (58% for M1b-positive vs 39% for M0-1a-positive; P = .002). Progression-free survival (PFS) was prolonged in randomized patients (tissue T790M-positive) with a T790M-negative cobas plasma result in comparison with those with a T790M-positive plasma result in both osimertinib (median, 12.5 vs 8.3 months) and platinum-pemetrexed groups (median, 5.6 vs 4.2 months). CONCLUSIONS: PPA was similar between ddPCR and NGS assays; both were more sensitive than cobas plasma. All 3 test platforms are suitable for routine clinical practice. In patients with tissue T790M-positive NSCLC, an absence of detectable plasma T790M at the baseline is associated with longer PFS, which may be attributed to a lower disease burden.

A Phase Ib Study Assessing the Safety, Tolerability, and Efficacy of the First-in-Class Wee1 Inhibitor Adavosertib (AZD1775) as Monotherapy in Patients with Advanced Solid Tumors.

BACKGROUND: Adavosertib (AZD1775) is a first-in-class, selective, small-molecule inhibitor of Wee1. OBJECTIVE: The safety, tolerability, pharmacokinetics, and efficacy of adavosertib monotherapy were evaluated in patients with various solid-tumor types and molecular profiles. PATIENTS AND METHODS: Eligible patients had the following: confirmed diagnosis of ovarian cancer (OC), triple-negative breast cancer (TNBC), or small-cell lung cancer (SCLC); previous treatment for metastatic/recurrent disease; and measurable disease. Patients were grouped into six matched cohorts based on tumor type and presence/absence of biomarkers and received oral adavosertib 175 mg twice a day on days 1-3 and 8-10 of a 21-day treatment cycle. RESULTS: Eighty patients received treatment in the expansion phase; median total treatment duration was 2.4 months. The most common treatment-related adverse events (AEs) were diarrhea (56.3%), nausea (42.5%), fatigue (36.3%), vomiting (18.8%), and decreased appetite (12.5%). Treatment-related grade ≥ 3 AEs and serious AEs were reported in 32.5% and 10.0% of patients, respectively. AEs led to dose interruptions in 22.5%, reductions in 11.3%, and discontinuations in 16.3% of patients. One patient died following serious AEs of deep vein thrombosis (treatment related) and respiratory failure (not treatment related). Objective response rate, disease control rate, and progression-free survival were as follows: 6.3%, 68.8%, 4.5 months (OC BRCA wild type); 3.3%, 76.7%, 3.9 months (OC BRCA mutation); 0%, 69.2%, 3.1 months (TNBC biomarker [CCNE1/MYC/MYCL1/MYCN] non-amplified [NA]); 0%, 50%, 2 months (TNBC biomarker amplified); 8.3%, 33.3%, 1.3 months (SCLC biomarker NA); and 0%, 33.3%, 1.2 months (SCLC biomarker amplified). CONCLUSION: Adavosertib monotherapy was tolerated and demonstrated some antitumor activity in patients with advanced solid tumors. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT02482311; registered June 2015.

Human rabies prevention--United States, 2008: recommendations of the Advisory Committee on Immunization Practices.

These recommendations of the Advisory Committee on Immunization Practices (ACIP) update the previous recommendations on human rabies prevention (CDC. Human rabies prevention--United States, 1999: recommendations of the Advisory Committee on Immunization Practices. MMWR 1999;48 [No. RR-1]) and reflect the status of rabies and antirabies biologics in the United States. This statement 1) provides updated information on human and animal rabies epidemiology; 2) summarizes the evidence regarding the effectiveness/efficacy, immunogenicity, and safety of rabies biologics; 3) presents new information on the cost-effectiveness of rabies postexposure prophylaxis; 4) presents recommendations for rabies postexposure and pre-exposure prophylaxis; and 5) presents information regarding treatment considerations for human rabies patients. These recommendations involve no substantial changes to the recommended approach for rabies postexposure or pre-exposure prophylaxis. ACIP recommends that prophylaxis for the prevention of rabies in humans exposed to rabies virus should include prompt and thorough wound cleansing followed by passive rabies immunization with human rabies immune globulin (HRIG) and vaccination with a cell culture rabies vaccine. For persons who have never been vaccinated against rabies, postexposure antirabies vaccination should always include administration of both passive antibody (HRIG) and vaccine (human diploid cell vaccine [HDCV] or purified chick embryo cell vaccine [PCECV]). Persons who have ever previously received complete vaccination regimens (pre-exposure or postexposure) with a cell culture vaccine or persons who have been vaccinated with other types of vaccines and have previously had a documented rabies virus neutralizing antibody titer should receive only 2 doses of vaccine: one on day 0 (as soon as the exposure is recognized and administration of vaccine can be arranged) and the second on day 3. HRIG is administered only once (i.e., at the beginning of antirabies prophylaxis) to previously unvaccinated persons to provide immediate, passive, rabies virus neutralizing antibody coverage until the patient responds to HDCV or PCECV by actively producing antibodies. A regimen of 5 1-mL doses of HDCV or PCECV should be administered intramuscularly to previously unvaccinated persons. The first dose of the 5-dose course should be administered as soon as possible after exposure (day 0). Additional doses should then be administered on days 3, 7, 14, and 28 after the first vaccination. Rabies pre-exposure vaccination should include three 1.0-mL injections of HDCV or PCECV administered intramuscularly (one injection per day on days 0, 7, and 21 or 28). Modifications were made to the language of the guidelines to clarify the recommendations and better specify the situations in which rabies post- and pre-exposure prophylaxis should be administered. No new rabies biologics are presented, and no changes were made to the vaccination schedules. However, rabies vaccine adsorbed (RVA, Bioport Corporation) is no longer available for rabies postexposure or pre-exposure prophylaxis, and intradermal pre-exposure prophylaxis is no longer recommended because it is not available in the United States.

Tissue and Plasma EGFR Mutation Analysis in the FLAURA Trial: Osimertinib versus Comparator EGFR Tyrosine Kinase Inhibitor as First-Line Treatment in Patients with EGFR-Mutated Advanced Non-Small Cell Lung Cancer.

PURPOSE: To assess the utility of the cobas EGFR Mutation Test, with tissue and plasma, for first-line osimertinib therapy for patients with EGFR-mutated (EGFRm; Ex19del and/or L858R) advanced or metastatic non-small cell lung cancer (NSCLC) from the FLAURA study (NCT02296125). EXPERIMENTAL DESIGN: Tumor tissue EGFRm status was determined at screening using the central cobas tissue test or a local tissue test. Baseline circulating tumor (ct)DNA EGFRm status was retrospectively determined with the central cobas plasma test. RESULTS: Of 994 patients screened, 556 were randomized (289 and 267 with central and local EGFR test results, respectively) and 438 failed screening. Of those randomized from local EGFR test results, 217 patients had available central test results; 211/217 (97%) were retrospectively confirmed EGFRm positive by central cobas tissue test. Using reference central cobas tissue test results, positive percent agreements with cobas plasma test results for Ex19del and L858R detection were 79% [95% confidence interval (CI), 74-84] and 68% (95% CI, 61-75), respectively. Progression-free survival (PFS) superiority with osimertinib over comparator EGFR-TKI remained consistent irrespective of randomization route (central/local EGFRm-positive tissue test). In both treatment arms, PFS was prolonged in plasma ctDNA EGFRm-negative (23.5 and 15.0 months) versus -positive patients (15.2 and 9.7 months). CONCLUSIONS: Our results support utility of cobas tissue and plasma testing to aid selection of patients with EGFRm advanced NSCLC for first-line osimertinib treatment. Lack of EGFRm detection in plasma was associated with prolonged PFS versus patients plasma EGFRm positive, potentially due to patients having lower tumor burden.

EGFR mutation analysis for prospective patient selection in AURA3 phase III trial of osimertinib versus platinum-pemetrexed in patients with EGFR T790M-positive advanced non-small-cell lung cancer.

OBJECTIVES: In AURA3 (NCT02151981), osimertinib treatment provided significant clinical benefit compared with platinum-pemetrexed in patients with epidermal growth factor receptor (EGFR) T790M-positive advanced non-small-cell lung cancer (NSCLC), whose tumors had progressed on previous EGFR-tyrosine kinase inhibitor therapy. This retrospective analysis investigated detection rates for T790M, common (exon 19 deletion and L858R), and rare EGFR mutations in tissue samples from the screened population of AURA3. MATERIALS AND METHODS: In AURA3, eligible patients were randomized 2:1 to receive oral osimertinib 80 mg once daily or intravenous platinum-pemetrexed every 3 weeks for up to six cycles. Tumor tissue samples were centrally tested for EGFR mutations using the cobas® EGFR Mutation Test (Version 2). T790M-positive status was a key inclusion criteria. RESULTS: A total of 820 screened patients had a valid EGFR mutation test result, of whom 452 (55%) were T790M-positive. Detection rates were similar by ethnicity (Asian versus non-Asian) for T790M (53% versus 58%) and exon 19 deletions (56% versus 63%). Conversely, the L858R rate was higher among Asian patients versus non-Asian patients (39% versus 28%; p = 0.0017). In the overall population, a higher proportion of patients had T790M detected against a background of exon 19 deletion versus L858R mutations (64% versus 47%; p < 0.0001). Rare EGFR mutations were detected in 28 (3%) patients, including G719X (2%), exon 20 insertion (1%), and S768I (<1%). CONCLUSION: Among AURA3 screened patients with EGFR mutation-positive advanced NSCLC, approximately half had detectable T790M in their tumor tissue, a rate unaffected by ethnicity. Results are consistent with previous reports of T790M detection rate in this patient population.

Human infection with avian influenza A(H7N2) virus-Virginia, 2002.

BACKGROUND: In March 2002, an outbreak of low-pathogenic avian influenza (LPAI) A(H7N2) was detected among commercial poultry operations in Virginia. METHODS: We performed a serosurvey of 80 government workers involved in efforts to control the outbreak. RESULTS: One study participant who assisted with disposal of infected birds tested positive for neutralizing antibodies to influenza A(H7N2) by microneutralization assay and H7-specific IgM antibodies by enzyme-linked immunosorbent assay (ELISA). The acute infection was temporally associated with an influenza-like illness that resolved without hospitalization. CONCLUSION: This study documents the earliest evidence of human infection with an H7 influenza virus of the North American lineage.

EGFR T790M mutation testing within the osimertinib AURA Phase I study.

OBJECTIVES: Reliable epidermal growth factor receptor (EGFR) mutation testing techniques are required to identify eligible patients with EGFR mutation/T790M positive advanced non-small cell lung cancer (NSCLC), for treatment with osimertinib (AZD9291), an oral, potent, irreversible EGFR tyrosine kinase inhibitor (TKI) selective for EGFR-TKI-sensitizing and T790M resistance mutations over wild-type EGFR. There is no current consensus regarding the best method to detect EGFR T790M mutations. The aim of this study was to describe the concordance between local testing, which used a variety of methods, and central testing, using the cobas® EGFR Mutation Test, for EGFR-sensitizing mutations and the T790M resistance mutation. MATERIALS AND METHODS: Tumor samples were obtained from all patients screened for inclusion onto the osimertinib Phase I expansion component of the AURA Phase I/II study (NCT01802632). Samples underwent central laboratory testing for EGFR-sensitizing mutations and T790M resistance mutation using the cobas® EGFR Mutation Test. Results were compared with local laboratory test results, based on other testing methodologies including Sanger sequencing, therascreen®, PNAClamp™, and Sequenom MassARRAY®. RESULTS: Central laboratory testing was successful in 99% of samples passing histopathology review and testing success rates were comparable across the three central laboratories. Concordance between central and local testing for common sensitizing mutations was high (>98%) and concordance for the T790M mutation was also high (>90%). Tumor heterogeneity, along with other technical factors may have influenced this result. CONCLUSIONS: Within the osimertinib AURA Phase I study, EGFR mutation testing across three centralized laboratories using the cobas® EGFR Mutation Test was feasible and successful, with strong concordance between local and central laboratory results, including for T790M. The cobas® EGFR Mutation Test has subsequently been approved as the companion diagnostic test for osimertinib in the USA and Japan.

Plasma ctDNA Analysis for Detection of the EGFR T790M Mutation in Patients with Advanced Non-Small Cell Lung Cancer.

INTRODUCTION: Tumor biopsies for detecting EGFR mutations in advanced NSCLC are invasive, costly, and not always feasible for patients with late-stage disease. The clinical utility of the cobas EGFR Mutation Test v2 (Roche Molecular Systems, Inc., Pleasanton, CA) with plasma samples from patients with NSCLC at disease progression after previous EGFR tyrosine kinase inhibitor therapy was investigated to determine eligibility for osimertinib treatment. METHODS: Matched tumor tissue and plasma samples from patients screened for the AURA extension and AURA2 phase II studies were tested for EGFR mutations by using tissue- and plasma-based cobas EGFR mutation tests. Plasma test performance was assessed by using the cobas tissue test and a next-generation sequencing method (MiSeq [Illumina Inc., San Diego, CA]) as references. The objective response rate, measured by blinded independent central review, was assessed in patients receiving osimertinib with a plasma T790M mutation-positive status. RESULTS: During screening, 551 patients provided matched tumor tissue and plasma samples. Pooled analysis of the positive and negative percent agreements between the cobas plasma and tissue tests for detection of T790M mutation were 61% and 79%, respectively. Comparing cobas plasma test with next-generation sequencing demonstrated positive and negative percent agreements of 90% or higher. The objective response rate was 64% (95% confidence interval: 57-70) in T790M mutation-positive patients by both cobas tissue and plasma tests (evaluable for response). CONCLUSIONS: The cobas plasma test detected the T790M mutation in 61% of tumor tissue T790M mutation-positive patients. To mitigate the risk of false-negative plasma results, patients with a negative plasma result should undergo a tissue test where feasible.

EGFR Mutation Analysis for Prospective Patient Selection in Two Phase II Registration Studies of Osimertinib.

INTRODUCTION: Osimertinib is an oral, central nervous system-active, EGFR tyrosine kinase inhibitor (TKI) for the treatment of EGFR T790M-positive advanced NSCLC. Here we have evaluated EGFR mutation frequencies in two phase II studies of osimertinib (AURA extension and AURA2). METHODS: After progression while receiving their latest line of therapy, patients with EGFR mutation-positive advanced NSCLC provided tumor samples for mandatory central T790M testing for the study selection criteria. Tumor tissue mutation analysis for patient selection was performed with the Roche cobas EGFR Mutation Test (European Conformity-in vitro diagnostic, labeled investigational use only) (Roche Molecular Systems, Pleasanton, CA). Patients should not have been prescreened for T790M mutation status. The cobas test results were compared with those of the MiSeq next-generation sequencing system (Illumina, San Diego, CA), which was used as a reference method. RESULTS: Samples from 324 and 373 patients screened for AURA extension and AURA2, respectively, produced valid cobas test results. The T790M detection rates were similar between AURA extension and AURA2 (64% and 63%, respectively). The pooled T790M rate was 63%, with no difference by ethnicity (63% for Asian and non-Asian patients alike) or immediately prior treatment with an EGFR TKI (afatinib, 69%; erlotinib, 69%; and gefitinib, 63%). A higher proportion of patients had T790M detected against a background of exon 19 deletions versus L858R mutation (73% versus 58% [p = 0.0002]). In both trials the cobas test demonstrated high sensitivity (positive percent agreement) and specificity (negative percent agreement) for T790M detection when compared with the next-generation sequencing reference method: positive percent agreement of 91% versus 89% and negative percent agreement of 97% versus 98%. CONCLUSIONS: In both trials, the rate of detection of T790M mutation in patients with advanced NSCLC was approximately 63% and was unaffected by immediately prior treatment with an EGFR TKI or ethnicity.

EGFR mutation detection in ctDNA from NSCLC patient plasma: A cross-platform comparison of leading technologies to support the clinical development of AZD9291.

OBJECTIVES: To assess the ability of different technology platforms to detect epidermal growth factor receptor (EGFR) mutations, including T790M, from circulating tumor DNA (ctDNA) in advanced non-small cell lung cancer (NSCLC) patients. MATERIALS AND METHODS: A comparison of multiple platforms for detecting EGFR mutations in plasma ctDNA was undertaken. Plasma samples were collected from patients entering the ongoing AURA trial (NCT01802632), investigating the safety, tolerability, and efficacy of AZD9291 in patients with EGFR-sensitizing mutation-positive NSCLC. Plasma was collected prior to AZD9291 dosing but following clinical progression on a previous EGFR-tyrosine kinase inhibitor (TKI). Extracted ctDNA was analyzed using two non-digital platforms (cobas(®) EGFR Mutation Test and therascreen™ EGFR amplification refractory mutation system assay) and two digital platforms (Droplet Digital™ PCR and BEAMing digital PCR [dPCR]). RESULTS: Preliminary assessment (38 samples) was conducted using all four platforms. For EGFR-TKI-sensitizing mutations, high sensitivity (78-100%) and specificity (93-100%) were observed using tissue as a non-reference standard. For the T790M mutation, the digital platforms outperformed the non-digital platforms. Subsequent assessment using 72 additional baseline plasma samples was conducted using the cobas(®) EGFR Mutation Test and BEAMing dPCR. The two platforms demonstrated high sensitivity (82-87%) and specificity (97%) for EGFR-sensitizing mutations. For the T790M mutation, the sensitivity and specificity were 73% and 67%, respectively, with the cobas(®) EGFR Mutation Test, and 81% and 58%, respectively, with BEAMing dPCR. Concordance between the platforms was >90%, showing that multiple platforms are capable of sensitive and specific detection of EGFR-TKI-sensitizing mutations from NSCLC patient plasma. CONCLUSION: The cobas(®) EGFR Mutation Test and BEAMing dPCR demonstrate a high sensitivity for T790M mutation detection. Genomic heterogeneity of T790M-mediated resistance may explain the reduced specificity observed with plasma-based detection of T790M mutations versus tissue. These data support the use of both platforms in the AZD9291 clinical development program.

Third international meeting on the genetic epidemiology of complex traits, April 4-6, 2002, Cambridge, UK.

The Third International Meeting on the Genetic Epidemiology of Complex Traits was held at Churchill College, Cambridge, UK on April 4-6, 2002. The event was organized by the Twin Research and Genetic Epidemiology Unit, St Thomas' Hospital, London and sponsored by Roche Genetics and Insightful. It provided an interactive forum for discussion of topical issues relating to the genetic analysis of complex diseases and traits. Topics discussed included linkage disequilibrium mapping and candidate gene analysis, as well as cutting edge advances in both technologies and statistical analysis methods. Details of the meeting can be found at http://www.twin-research.ac.uk/.

Syngeneic bone marrow transduced with a recombinant retroviral vector to express endoplasmic reticulum signal-sequence-deleted major histocompatibility complex class-I alloantigen can induce specific immunologic unresponsiveness in vivo.

BACKGROUND: Long-term survival of fully allogeneic cardiac grafts can be induced in mice through transduction of recipient bone marrow cells (BMCs) with a recombinant retroviral vector encoding a single full-length major histocompatibility complex (MHC) class I alloantigen. This study investigated whether cell surface expression of the transduced MHC antigen was necessary for the induction of specific unresponsiveness. METHOD The signal sequence for translocation into the endoplasmic reticulum was deleted from H-2K (SDELKb). Syngeneic BMCs from CBA.Ca (H2k) recipients were transduced with an MFG retroviral vector encoding either wild-type Kb or the mutant SDELKb and reinfused in conjunction with an anti-CD4 therapy. Four weeks later, the recipients underwent transplantation with a fully allogeneic C57BL/10 cardiac graft. Graft survival and the development of transplant arteriosclerosis were assessed. RESULTS: Expression of both the wild-type Kb or SDELK in recipient CBA mice before transplantation resulted in prolonged survival of C57BL/10 grafts. Grafts from recipients pretreated with SDELKb developed 48%+/-22% intimal proliferation compared with 61%+/-21% in grafts from recipients pretreated with wild-type Kb. However, this difference did not reach statistical significance. CONCLUSION Cell surface expression, and therefore direct recognition, of an MHC class I alloantigen is not required to induce long-term survival of fully allogeneic cardiac grafts after retroviral transduction of recipient BMCs.

Sequence variants in the melatonin-related receptor gene (GPR50) associate with circulating triglyceride and HDL levels.

The gene encoding the melatonin-related receptor (GPR50) is highly expressed within hypothalamic nuclei concerned with the control of body weight and metabolism. We screened GPR50 for mutations in an obese cohort and identified an insertion of four amino acid residues (TTGH) at position 501, two common coding polymorphisms (T528A and V602I), and one noncoding polymorphism (C-16X2GPR50T). Single-nucleotide polymorphisms were then typed in 500 English Caucasian subjects, and associations were sought to intermediate obesity phenotypes. Although no association was seen with body mass index, carriers of two copies of the mutant allele at C-16X2GPR50T, Ins501Del, and A1582G had significantly higher fasting circulating triglyceride levels (P < 0.05). In a separate set of 585 subjects, the associations were replicated, with statistically significant effects of similar magnitude and direction. The association of C-16X2GPR50T with fasting triglycerides was highly significant (P < 0.001). In addition, a significant association between C-16X2GPR50T and circulating HDL levels was observed in the combined population, with C-16X2GPR50T carriers having significantly lower circulating HDL-cholesterol levels (1.39 mM) than wild-type subjects (1.47 mM) (P < 0.01). These findings suggest a previously unexpected role for this orphan receptor in the regulation of lipid metabolism that warrants further investigation.

High-throughput SNP genotyping.

Whole genome approaches using single nucleotide polymorphism (SNP) markers have the potential to transform complex disease genetics and expedite pharmacogenetics research. This has led to a requirement for high-throughput SNP genotyping platforms. Development of a successful high-throughput genotyping platform depends on coupling reliable assay chemistry with an appropriate detection system to maximise efficiency with respect to accuracy, speed and cost. Current technology platforms are able to deliver throughputs in excess of 100 000 genotypes per day, with an accuracy of >99%, at a cost of 20-30 cents per genotype. In order to meet the demands of the coming years, however, genotyping platforms need to deliver throughputs in the order of one million genotypes per day at a cost of only a few cents per genotype. In addition, DNA template requirements must be minimised such that hundreds of thousands of SNPs can be interrogated using a relatively small amount of genomic DNA. As such, it is predicted that the next generation of high-throughput genotyping platforms will exploit large-scale multiplex reactions and solid phase assay detection systems.

Intrathymic delivery of plasmid-encoding endoplasmic reticulum signal-sequence-deleted MHC class I alloantigen can induce long-term allograft survival.

Intrathymic (IT) delivery of donor alloantigen is a potent strategy to induce operational tolerance. In this study we determined whether this effect was dependent on direct allorecognition of the tolerogen. Ten microgrammes of plasmid, encoding either the wildtype major histocompatibility complex (MHC) class I molecule K(b) or a truncated form in which the signal sequence for translocation into the endoplasmic reticulum was deleted, preventing cell surface expression and direct allorecognition of the tolerogen, was administered intrathymically to CBA.Ca (H2(k)) recipients. In addition, recipients were treated with anti-CD4 antibody (YTA3.1) at the time of IT injection and underwent transplantation 28 days later with a fully mismatched C57BL/10 (H2(b)) cardiac allograft. Wildtype, as well as truncated K(b) genes, were able to induce long-term survival of the cardiac allografts, in contrast to empty control plasmid. Reverse-transcriptase PCR showed expression of the K(b) genes for up to 28 days in thymus and spleen of pretreated recipients. These data show that direct allorecognition of the tolerogen was not required for the induction of long-term allograft survival following the introduction of plasmid-encoded MHC alloantigen into the thymus.