Response to omalizumab using patient enrichment criteria from trials of novel biologics in asthma.

BACKGROUND: Recent efficacy studies of asthma biologics have included highly enriched patient populations. Using a similar approach, we examined factors that predict response to omalizumab to facilitate selection of patients most likely to derive the greatest clinical benefit from therapy. METHODS: Data from two phase III clinical trials of omalizumab in patients with allergic asthma were examined. Differences in rates of asthma exacerbations between omalizumab and placebo groups during the 16-week inhaled corticosteroid (ICS) dose-stable phase were evaluated with respect to baseline blood eosinophil counts (eosinophils <300/µL [low] vs ≥300/µL [high]) and baseline markers of asthma severity (emergency asthma treatment in prior year, asthma hospitalization in prior year, forced expiratory volume in 1 second [FEV1 ; FEV1 <65% vs ≥65% predicted], inhaled beclomethasone dipropionate dose [<600 vs ≥600 µg/day], and long-acting beta-agonist [LABA] use [yes/no]). RESULTS: Adults/adolescents (N = 1071) were randomized to receive either omalizumab (n = 542) or placebo (n = 529). In the 16-week ICS dose-stable phase, rates of exacerbations requiring ≥3 days of systemic corticosteroid treatment were 0.066 and 0.147 with omalizumab and placebo, respectively, representing a relative rate reduction in omalizumab-treated patients of 55% (95% CI, 32%-70%; P = .002). For patients with eosinophils ≥300/µL or with more severe asthma, this rate reduction was significantly more pronounced. CONCLUSION: In patients with allergic asthma, baseline blood eosinophil levels and/or clinical markers of asthma severity predict response to omalizumab.

The response to combination therapy treatment regimens in severe/difficult-to-treat asthma.

The aim of the present study was to assess the response of high-dose salmeterol/fluticasone combination (SFC) and low-dose SFC compared with regimens without inhaled corticosteroid (ICS) plus long-acting beta-agonist (LABA) in a large cohort with severe or difficult-to-treat asthma. Subjects were administered low-dose SFC (100/50 or 250/50 microg) or high-dose SFC (500/50 microg), and a control group received medications that could include ICS or LABA but not both. The present authors calculated unadjusted and propensity score-adjusted differences in outcomes consistent with components of asthma control, comparing high-dose and low-dose SFC cohorts with controls. The low-dose SFC cohort had higher asthma-related quality of life and fewer asthma control problems compared with controls. The high-dose SFC cohort had higher forced expiratory volume in one second but higher odds of having severe asthma compared with controls. The present results support the evidence that some asthmatics achieve better outcomes while receiving a low-dose salmeterol/fluticasone combination, but also suggest that those on a high-dose salmeterol/fluticasone combination fail to achieve significant improvement in many control-related health outcomes as compared with similar patients not receiving salmeterol/fluticasone combination. These findings suggest a limited value of high-dose salmeterol/fluticasone combination compared with the alternatives. While additional studies are needed, the present findings call for alternative therapeutic approaches in severe/difficult-to-treat asthma for those unable to attain asthma control with or without salmeterol/fluticasone combination.

PCR-mediated recombination in amplification products derived from polyploid cotton.

PCR recombination describes a process of in vitro chimera formation from non-identical templates. The key requirement of this process is the inclusion of two partially homologous templates in one reaction, a condition met when amplifying any locus from polyploid organisms and members of multigene families from diploid organisms. Because polyploids possess two or more divergent genomes ("homoeologues") in a common nucleus, intergenic chimeras can form during the PCR amplification of any gene. Here we report a high frequency of PCR-induced recombination for four low-copy genes from allotetraploid cotton ( Gossypium hirsutum). Amplification products from these genes ( Myb3, Myb5, G1262 and CesA1) range in length from 860 to 4,050 bp. Intergenomic recombinants were formed frequently, accounting for 23 of the 74 (31.1%) amplicons evaluated, with the frequency of recombination in individual reactions ranging from 0% to approximately 89%. Inspection of the putative recombination zones failed to reveal sequence-specific attributes that promote recombination. The high levels of observed in vitro recombination indicate that the tacit assumption of exclusive amplification of target templates may often be violated, particularly from polyploid genomes. This conclusion has profound implications for population and evolutionary genetic studies, where unrecognized artifactually recombinant molecules may bias results or alter interpretations.

Descriptive epidemiology of thyroid cancer in Los Angeles County, 1972-1995.

OBJECTIVE: To examine the descriptive epidemiologic features of incident thyroid cancers diagnosed among Los Angeles County residents between 1972 and 1995. METHODS: The Los Angeles County/University of Southern California Cancer Surveillance Program (CSP) collected data on 8820 newly diagnosed thyroid cancer of cases occurring in Los Angeles County. Average annual age-adjusted incidence rates were calculated to study the epidemiology of each of the major histologic types of thyroid carcinoma. RESULTS: For all races combined, the age-adjusted incidence rates were 2.5 per 100,000 males and 6.0 per 100,000 females. Differences in incidence by ethnicity were particularly striking, with Filipinos demonstrating the highest incidence rates (4.44 per 100,000 males, 11.3 per 100,000 females). Over the 23-year period, thyroid cancer incidence rates increased 1.5% per year for males and 1% per year for females. By histology, papillary carcinoma rates increased over time and follicular carcinoma rates decreased. Non-Spanish surnamed white men employed in certain white-collar occupations and radiologic technicians were at greater risk of thyroid cancer. CONCLUSIONS: Additional research on the epidemiologic risk factors for thyroid cancer, particularly for gender and ethnicity, is needed to explain the marked elevated incidence rates among females and the Filipino population in Los Angeles County.

Cohort study of thyroid cancer in a San Francisco Bay area population.

Using data from a large health plan, we performed a cohort study of thyroid cancer among 204,964 persons (aged 10--89 at baseline in 1964--1973, 54% female) followed for a median of 20 years. There were 196 incident thyroid cancers (73 in men, 123 in women). Risk was independently and positively related to female gender [relative risk (RR) = 1.56, 95% confidence interval (CI) = 1.12--2.19], Asian race (RR = 2.86, 95% CI = 1.76--4.65), completed college or post-graduate education (RR = 1.76, 95% CI = 1.20--2.59), history of goiter (RR = 3.36, 95% CI = 1.82--6.20), radiation of the neck region (RR = 2.33, 95% CI = 1.28--4.23) and family history of thyroid disease (RR = 2.18, 95% CI = 1.17--4.05). An inverse association was found for black race (RR = 0.55, 95% CI = 0.33--0.91). Cigarette smoking, alcohol consumption, personal history of hyperthyroidism, hypothyroidism, overweight or obesity, weight gain since age 20, height, occupational exposures, reproductive factors, oral contraceptives and hormone use did not show statistically significant relations to thyroid cancer. These results provide further evidence for a role of female gender, radiation, goiter, Asian race, high educational attainment and family history of thyroid disease in the etiology of thyroid cancer.