Selective Inhibition of NaV1.8 with VX-548 for Acute Pain.

BACKGROUND: The NaV1.8 voltage-gated sodium channel, expressed in peripheral nociceptive neurons, plays a role in transmitting nociceptive signals. The effect of VX-548, an oral, highly selective inhibitor of NaV1.8, on control of acute pain is being studied. METHODS: After establishing the selectivity of VX-548 for NaV1.8 inhibition in vitro, we conducted two phase 2 trials involving participants with acute pain after abdominoplasty or bunionectomy. In the abdominoplasty trial, participants were randomly assigned in a 1:1:1:1 ratio to receive one of the following over a 48-hour period: a 100-mg oral loading dose of VX-548, followed by a 50-mg maintenance dose every 12 hours (the high-dose group); a 60-mg loading dose of VX-548, followed by a 30-mg maintenance dose every 12 hours (the middle-dose group); hydrocodone bitartrate-acetaminophen (5 mg of hydrocodone bitartrate and 325 mg of acetaminophen every 6 hours); or oral placebo every 6 hours. In the bunionectomy trial, participants were randomly assigned in a 2:2:1:2:2 ratio to receive one of the following over a 48-hour treatment period: oral high-dose VX-548; middle-dose VX-548; low-dose VX-548 (a 20-mg loading dose, followed by a 10-mg maintenance dose every 12 hours); oral hydrocodone bitartrate-acetaminophen (5 mg of hydrocodone bitartrate and 325 mg of acetaminophen every 6 hours); or oral placebo every 6 hours. The primary end point was the time-weighted sum of the pain-intensity difference (SPID) over the 48-hour period (SPID48), a measure derived from the score on the Numeric Pain Rating Scale (range, 0 to 10; higher scores indicate greater pain) at 19 time points after the first dose of VX-548 or placebo. The main analysis compared each dose of VX-548 with placebo. RESULTS: A total of 303 participants were enrolled in the abdominoplasty trial and 274 in the bunionectomy trial. The least-squares mean difference between the high-dose VX-548 and placebo groups in the time-weighted SPID48 was 37.8 (95% confidence interval [CI], 9.2 to 66.4) after abdominoplasty and 36.8 (95% CI, 4.6 to 69.0) after bunionectomy. In both trials, participants who received lower doses of VX-548 had results similar to those with placebo. Headache and constipation were common adverse events with VX-548. CONCLUSIONS: As compared with placebo, VX-548 at the highest dose, but not at lower doses, reduced acute pain over a period of 48 hours after abdominoplasty or bunionectomy. VX-548 was associated with adverse events that were mild to moderate in severity. (Funded by Vertex Pharmaceuticals; VX21-548-101 and VX21-548-102 ClinicalTrials.gov numbers, NCT04977336 and NCT05034952.).

Fold rise in antibody titers by measured by glycoprotein-based enzyme-linked immunosorbent assay is an excellent correlate of protection for a herpes zoster vaccine, demonstrated via the vaccine efficacy curve.

BACKGROUND: The phase III Zostavax Efficacy and Safety Trial of 1 dose of licensed zoster vaccine (ZV; Zostavax; Merck) in 50-59-year-olds showed approximately 70% vaccine efficacy (VE) to reduce the incidence of herpes zoster (HZ). An objective of the trial was to assess immune response biomarkers measuring antibodies to varicella zoster virus (VZV) by glycoprotein-based enzyme-linked immunosorbent assay as correlates of protection (CoPs) against HZ. METHODS: The principal stratification vaccine efficacy curve framework for statistically evaluating immune response biomarkers as CoPs was applied. The VE curve describes how VE against the clinical end point (HZ) varies across participant subgroups defined by biomarker readout measuring vaccine-induced immune response. The VE curve was estimated using several subgroup definitions. RESULTS: The fold rise in VZV antibody titers from the time before immunization to 6 weeks after immunization was an excellent CoP, with VE increasing sharply with fold rise: VE was estimated at 0% for the subgroup with no rise and at 90% for the subgroup with 5.26-fold rise. In contrast, VZV antibody titers measured 6 weeks after immunization did not predict VE, with similar estimated VEs across titer subgroups. CONCLUSIONS: The analysis illustrates the value of the VE curve framework for assessing immune response biomarkers as CoPs in vaccine efficacy trials. CLINICAL TRIALS REGISTRATION: NCT00534248.

Health behaviors of cancer survivors of different sexual orientations.

OBJECTIVE: This study identifies differences by sexual orientation in health behaviors of cancer survivors. METHODS: We pooled data from the 2001, 2003, and 2005 California health interview survey to compare cancer survivors' alcohol use, smoking, exercise, fruit and vegetable consumption, weight, and physician visits by sexual orientation. RESULTS: Female bisexual cancer survivors were 2.2 times more likely to report being a current smoker and were 0.39 times less likely to report physical inactivity compared with female heterosexual cancer survivors. Lesbian cancer survivors were 7.4 times more likely to have visited a physician during the past year than female heterosexual cancer survivors. Among male cancer survivors, both gay and bisexual men had significantly lower odds (OR = 0.4) of being overweight or obese, and bisexual men were 3.0 times more likely to engage in vigorous activity and 7.8 times more likely to visit physicians compared with heterosexual men. CONCLUSIONS: This study's prevalence estimates of behavioral risk factors of gay, lesbian, and bisexual cancer survivors suggest considerable need for promotion of healthy lifestyle behaviors. We discuss the need for future studies with lesbian, gay, and bisexual cancer survivors.

Protective locus against renal scarring on chromosome 11 in affected sib pairs with familial vesicoureteral reflux identified by single nucleotide polymorphism linkage analysis.

PURPOSE: We identified the loci associated with renal scarring risk and protection in affected sib pairs with familial vesicoureteral reflux. MATERIALS AND METHODS: A genome-wide analysis of vesicoureteral reflux with high density single nucleotide polymorphisms was conducted in 43 families with 2 or more affected children. A total of 43 probands and 58 affected siblings were included in the analysis. Genomic DNA was extracted from blood or saliva from all patients. All nuclear families had complete parental genotypes and all were Caucasian. Renal scarring was present in 23 of the 43 probands as detected by dimercapto-succinic acid imaging. easyLINKAGE software was used for the genome-wide linkage analysis. A LOD (logarithm [base 10] of odds) score of 3.3 or greater was considered significant evidence of linkage and a LOD score of 2.4 or greater but less than 3.3 was considered suggestive evidence of linkage. RESULTS: Using the affected sib pair method of analysis, a statistically significant linkage peak with a multipoint LOD score of 3.66 for patients without renal scarring was identified on chromosome 11 at 47.97 cM. For the scarring group a peak with a multipoint LOD score of 2.69 was identified on chromosome 17, which provides suggestive evidence of linkage. CONCLUSIONS: Our results suggest that a locus on chromosome 11 is associated with protection against renal scarring in patients with vesicoureteral reflux. In addition, a new locus on chromosome 17 may be linked to renal scarring. Our results suggest that multiple genes contribute to the formation of the vesicoureteral reflux phenotype, with patients having a unique susceptibility to renal injury/damage.

Adult health behaviors over the life course by sexual orientation.

OBJECTIVES: We estimated differences in health behaviors among adults by sexual orientation. METHODS: We pooled 4 years of data (2001, 2003, 2005, and 2007) from the California Health Interview Survey. We estimated the frequency of smoking, alcohol use, healthy dietary behaviors, physical activity, and health care utilization, and we used logistic regression modeling to determine the odds of each behavior with increasing age and for 2 age groups: younger than 50 years and 50 years old or older. RESULTS: At any adult age, lesbians had greater odds of smoking and binge drinking than did heterosexual women, and gay and bisexual men had greater health care utilization than did heterosexual men. Other risk behaviors differed with age. CONCLUSIONS: Some behavioral change interventions should target lesbians, gays, and bisexuals at all ages, whereas other interventions should specifically target individuals at younger ages.

An entropy-based nonparametric test for the validation of surrogate endpoints.

We present a nonparametric test to validate surrogate endpoints based on measure of divergence and random permutation. This test is a proposal to directly verify the Prentice statistical definition of surrogacy. The test does not impose distributional assumptions on the endpoints, and it is robust to model misspecification. Our simulation study shows that the proposed nonparametric test outperforms the practical test of the Prentice criterion in terms of both robustness of size and power. We also evaluate the performance of three leading methods that attempt to quantify the effect of surrogate endpoints. The proposed method is applied to validate magnetic resonance imaging lesions as the surrogate endpoint for clinical relapses in a multiple sclerosis trial.

Cancer survivorship and sexual orientation.

BACKGROUND: Lesbian, gay, and bisexual populations are not part of cancer surveillance, resulting in scarce information about the cancer survivorship of these populations. To address this information gap, the authors examined the prevalence of cancer survivorship by sexual orientation and cancer survivors' self-reported health by sexual orientation. METHODS: The authors explored these issues by analyzing pooled data from the California Health Interview survey from 2001, 2003, and 2005. By using descriptive statistics and logistic regressions, they examined the cancer prevalence in men and women by sexual orientation and subsequently compared the self-reported health of male and female cancer survivors by sexual orientation. RESULTS: Among women, the authors found no significant differences in cancer prevalence by sexual orientation, but lesbian and bisexual female cancer survivors had 2.0 and 2.3× the odds of reporting fair or poor health compared with heterosexual female cancer survivors. Among men, we found significant differences in cancer prevalence, with gay men having 1.9× the odds of reporting a cancer diagnosis compared with heterosexual men. There were no differences by sexual orientation in male cancer survivors' self-reported health. CONCLUSIONS: Our novel findings suggest sex differences in the impact of cancer on lesbian, gay, and bisexual cancer survivors. Lesbian and bisexual cancer survivors need to be targeted by programs and services to assist these cancer survivors in improving their health perceptions, whereas healthcare providers and public health agencies need to be made aware of the higher prevalence of cancer in gay men to prevent future cancers through increased screening and primary prevention.

An ecological analysis of colorectal cancer incidence and mortality: differences by sexual orientation.

BACKGROUND: Some have suggested gays and lesbians may carry a greater burden of colorectal cancer. To date, individual sexual orientation data are not available in cancer surveillance registries. This prevents an assessment of differences in colorectal cancer incidence and mortality by sexual orientation, using individual-level data. METHODS: We use an ecological approach to examine differences in colorectal cancer incidence and mortality by county-level sexual orientation data. From the Surveillance, Epidemiology and End Results (SEER) Program we obtain population-based surveillance data on colorectal cancer incidence and mortality from 1996 to 2004. We use Census 2000 data on same-sex partnered households, a proxy of sexual orientation, to derive county-level sexual orientation data. Using multiple regression models, we examined the county-level association of sexual minority density with colorectal cancer incidence and mortality. RESULTS: After controlling for race and SES, we identify a significant positive association between greater density of sexual minority men and women and colorectal cancer incidence. With respect to colorectal cancer mortality, we identify a positive association with density of sexual minority men, but not women. CONCLUSIONS: In the absence of surveillance data on sexual minority individuals, ecological analyses provide estimates of associations at the aggregate level, thereby providing crucial information for follow-up studies.

Disease Modification in Alzheimer's Disease: Current Thinking.

Alzheimer's disease (AD) has increasingly been recognized as a huge unmet medical need. Currently, there is no approved drug to cure, prevent, or even slow down the disease. It is imperative to develop disease-modifying treatments for AD to alter the underlying disease progression. This paper reviews the most up-to-date regulatory guidance on how to demonstrate disease modification and provides an overview of available methodologies and applications to clinical trials. The intent is to assist the field with future clinical trials designed to demonstrate disease-modifying effect in AD. The methodologies may be generalizable to broader neurodegenerative diseases.

Safety and efficacy of neublastin in painful lumbosacral radiculopathy: a randomized, double-blinded, placebo-controlled phase 2 trial using Bayesian adaptive design (the SPRINT trial).

Neublastin (BG00010) is a first-in-class, glial cell-derived neurotrophic factor shown in preclinical studies and an early clinical trial to have potential for the treatment of neuropathic pain. SPRINT was a phase 2, multicenter, double-blinded, placebo-controlled study to evaluate efficacy/safety of 5 neublastin doses (50, 150, 400, 800, and 1200 µg/kg) administered as an intravenous injection 3 times/week for 1 week in patients with chronic painful lumbosacral radiculopathy, utilizing Bayesian response-adaptive study design. Primary endpoint was change from baseline in mean 24-hour average general pain intensity over a 5-day period (week 1) after the last dose, analyzed using a Bayesian normal dynamic linear model. One hundred seventy-six patients were randomized and received treatment (placebo n = 48, 50 µg/kg n = 38, 150 µg/kg n = 13, 400 µg/kg n = 16, 800 µg/kg n = 20, 1200 µg/kg n = 41). Among the tested neublastin doses, the lowest dose (50 µg/kg) showed the greatest difference from placebo for change from baseline in mean average general pain intensity at week 1 after last dose, followed by the highest dose (1200 µg/kg) (posterior mean difference -1.36 [95% credible interval -2.22 to -0.52] and -0.75 [-1.59 to 0.08], respectively). Similar trends were observed in secondary efficacy endpoints. The most common adverse event in all neublastin dose groups was pruritus (79% vs 10% with placebo). There was no dose-response relationship with respect to primary/secondary efficacy outcomes or incidence of pruritus, despite dose-proportional increases in serum neublastin concentrations. In conclusion, while this study showed some evidence of pain relief with neublastin, particularly at the lowest dose, there was no clear dose-response relationship for pain reduction or the most common adverse event of pruritus.

Predictors of the placebo analgesia response in randomized controlled trials of chronic pain: a meta-analysis of the individual data from nine industrially sponsored trials.

A large number of analgesics have failed to prove superiority over placebo in randomized controlled trials (RCTs), and as this has been related to increasing placebo responses, there is currently an interest in specifying predictors of the placebo response. The literature on placebo mechanisms suggests that factors related to patients' expectations of treatment efficacy are pivotal for the placebo response. Also, general characteristics of RCTs have been suggested to influence the placebo response. Yet, only few meta-analyses have directly tested these hypotheses. Placebo data from 9 industrially sponsored, randomized, double-blind, placebo-controlled, multicenter phase III trials in 2017 adult patients suffering from chronic painful osteoarthritis (hip or knee) or low back pain were included. The primary outcome was pain intensity. Based on previous studies, we chose 3 expectancy-related primary predictors: type of active medication, randomization ratio, and number of planned face-to-face visits. In addition, explorative analyses tested whether RCT and patients' characteristics predicted the placebo response. Opioid trials, a high number of planned face-to-face visits, and randomization ratio predicted the magnitude of the placebo response, thereby supporting the expectancy hypothesis. Exploratory models with baseline pain intensity, age, washout length, and discontinuation because of adverse events accounted for approximately 10% of the variability in the placebo response. Based on these results and previous mechanisms studies, we think that patients' perception of treatment allocation and expectations toward treatment efficacy could potently predict outcomes of RCTs.

Health Conditions in Younger, Middle, and Older Ages: Are There Differences by Sexual Orientation?

PURPOSE: Sexual minorities engage in more risk behaviors at a younger age than heterosexuals and many are subject to minority stress from a young age, which raises questions about the age at which sexual minorities' experience morbidities. Our objective was to estimate the prevalence of health conditions among young, middle age, and older age groups to examine sexual orientation differences while stratifying by gender. METHODS: We pooled 4 years of data from the California Health Interview Survey to obtain a representative sample of the male and female population in California, allowing us to examine health conditions by sexual orientation in three age strata, age 20-39, age 40-59, and age 60 and older. RESULTS: Compared with same-gender heterosexuals, sexual minority women had a higher likelihood of physical morbidities (disability: adjusted odds ratio [AOR] 2.66 for lesbians and AOR 2.21 for bisexuals; arthritis: AOR 2.12 for lesbians) at a young age, whereas gay men had a higher likelihood of heart disease (AOR 2.78) and cancer (AOR 4.75) at a young age. Across the life span, sexual minorities had higher likelihoods of poor mental health than heterosexuals. CONCLUSION: These findings suggest that at a young age, sexual minorities experience more morbidities than heterosexual individuals. Consideration should be given to early detection, identification, and treatment of these conditions among sexual minorities particularly at younger ages.

Sexual minority population density and incidence of lung, colorectal and female breast cancer in California.

OBJECTIVE: Risk factors for breast, colorectal, and lung cancer are known to be more common among lesbian, gay, and bisexual (LGB) individuals, suggesting they may be more likely to develop these cancers. Our objective was to determine differences in cancer incidence by sexual orientation, using sexual orientation data aggregated at the county level. METHODS: Data on cancer incidence were obtained from the California Cancer Registry and data on sexual orientation were obtained from the California Health Interview Survey, from which a measure of age-specific LGB population density by county was calculated. Using multivariable Poisson regression models, the association between the age-race-stratified incident rate of breast, lung and colorectal cancer in each county and LGB population density was examined, with race, age group and poverty as covariates. RESULTS: Among men, bisexual population density was associated with lower incidence of lung cancer and with higher incidence of colorectal cancer. Among women, lesbian population density was associated with lower incidence of lung and colorectal cancer and with higher incidence of breast cancer; bisexual population density was associated with higher incidence of lung and colorectal cancer and with lower incidence of breast cancer. CONCLUSIONS: These study findings clearly document links between county-level LGB population density and cancer incidence, illuminating an important public health disparity.