Recent Use of Pediatric Extrapolation in Pediatric Drug Development in US

The regulatory standards of the United States Food and Drug Administration (FDA) require substantial evidence of effectiveness from adequate and well-controlled trials, for drugs developed in both adults and children. However, when scientifically justified, relying on extrapolation may be acceptable. Historically, the FDA's extrapolation approach was based on draft guidance published in 2014, which introduced the categories of full, partial, and no extrapolation. The European Medicines Agency (EMA) took a different view on pediatric extrapolation. To better understand the use of extrapolation to support pediatric drug development and approval, we reviewed the pediatric labeling changes published by the FDA, focusing on the labeling updates between 1/1/2015 and 7/31/2021, the period where the extrapolation approach is in transition to harmonize with the EMA. Within this time window, among the 265 drugs and biological products with pediatric labeling changes, 169 (63.8%) were identified where extrapolation was used. This includes 64 (24.2%) labeling changes, where full extrapolation was used, and 105 (39.6%) labeling changes, where partial extrapolation was used. The major disease areas that extrapolation was used include neuroscience (40/53, 75.5%) and infectious disease (20/28, 71.4%). The extrapolation approach was identified in terms of source population beyond the use of adult as well as extrapolation from clinical trials conducted in the same drug class. The use of extrapolation increased the rates of new and expanded pediatric indication in the period. This review gives the most recent landscape of pediatric labeling changes using extrapolation. With the released ICH (International Council for Harmonization) E11A guidance in April 2022, the paper also provides insights for future pediatric drug development programs.

Efficacy and safety of an albiglutide liquid formulation compared with the lyophilized formulation: A 26-week randomized, double-blind, repeat-dose study in patients with type 2 diabetes mellitus

AIMS

Compare the efficacy and safety of albiglutide from a ready-to-use, single-dose, auto-injector system with the lyophilized product in patients with type 2 diabetes mellitus (T2DM).

METHODS

In this phase 3 study, 308 patients between 18 and 80 years with T2DM and experiencing inadequate glycemic control on their current regimen of diet/exercise alone or in combination with metformin were randomized 1:1 to weekly injections for 26 weeks with an active albiglutide auto-injector and placebo lyophilized dual-chamber cartridge (DCC) pen injector (n = 154) or active albiglutide lyophilized DCC pen injector and placebo liquid auto-injector (n = 154). Participants received liquid or lyophilized albiglutide 30 mg for 4 weeks, and then 50 mg for the remaining 22 weeks. Change in HbA_1c and fasting plasma glucose (FPG), pharmacokinetics, and safety were assessed.

RESULTS

In the albiglutide liquid and lyophilized drug product groups, 55.6% (85/153) and 45.5% of patients (70/154) had a baseline HbA_1c ≥ 8.0%, respectively. The model-adjusted least squares (LS) mean change in HbA_1c from baseline at week 26 was -1.1% (95% CI: -1.3, -1.0) and -1.2% (95% CI: -1.3, -1.0; noninferiority P = 0.0002) in the albiglutide liquid and lyophilized product groups, respectively. Similarly, the model-adjusted LS mean change in FPG from baseline at week 26 in the albiglutide liquid and lyophilized product groups was -2.2 (95% CI: -2.6, -1.8) mmol/L and -1.9 (95% CI: -2.3, -1.5) mmol/L, respectively. No new safety concerns were identified.

CONCLUSION

Change from baseline in HbA_1c for albiglutide liquid was noninferior to lyophilized drug product in patients with T2DM.

Prediction of pediatric death in the year after hospitalization: a population-level retrospective cohort study

BACKGROUND

The study of how the quality of pediatric end-of-life care varies across systems of health care delivery and financing is hampered by lack of methods to adjust for the probability of death in populations of ill children.

OBJECTIVE

To develop a prognostication models using administratively available data to predict the probability of in-hospital and 1-year postdischarge death.

METHODS

Retrospective cohort study of 0-21 year old patients admitted to Pennsylvania hospitals from 1994-2001 and followed for 1-year postdischarge mortality, assessing logistic regression models ability to predict in-hospital and 1-year postdischarge deaths.

RESULTS

Among 678,365 subjects there were 2,202 deaths that occurred during the hospitalization (0.32% of cohort) and 860 deaths that occurred 365 days or less after hospital discharge (0.13% of cohort). The model predicting hospitalization deaths exhibited a C statistic of 0.91, with sensitivity of 65.9% and specificity of 92.9% at the 99th percentile cutpoint; while the model predicting 1-year postdischarge deaths exhibited a C statistic of 0.92, with sensitivity of 56.1% and specificity of 98.4% at the 99th percentile cutpoint.

CONCLUSIONS

Population-level mortality prognostication of hospitalized children using administratively available data is feasible, assisting the comparison of health care services delivered to children with the highest probability of dying during and after a hospital admission.

Differential effects of extended-release carvedilol and extended-release metoprolol on lipid profiles in patients with hypertension: results of the Extended-Release Carvedilol Lipid Trial

Some beta-blockers, although they are effective antihypertensive agents, may adversely effect dyslipidemia and decrease insulin sensitivity. beta-blockers without adverse metabolic effects may provide an improvement in long-term hypertension therapy. Hypertensive patients (n = 568) without diabetes, not requiring lipid-lowering therapy, were randomized to once-daily extended-release carvedilol or extended-release metoprolol and titrated to target blood pressure (BP). Co-primary endpoints were comparison between groups in high-density lipoprotein (HDL) or triglycerides at 24 weeks. Extended-release carvedilol was superior to extended-release metoprolol in meeting the primary endpoint of a difference in triglycerides; the median % change in triglycerides being -8.026% (P = .0141; 97.5% confidence interval [CI], -15.35, -0.67)] from baseline to 24 weeks. Triglycerides were unchanged with carvedilol and increased with metoprolol. There was no significant difference in effect on HDL. BP was similar between treatment groups. There was a significant decrease with extended-release carvedilol vs. extended-release metoprolol in insulin (-2.56 muU/mL [P = .0213; 95% CI, -4.74 to -0.38]) and c-peptide [(-0.43 ng/mL [P = .0007; 95% CI, -0.68 to -0.18]). In hypertension, extended-release carvedilol resulted in lower triglycerides, insulin, and C-peptide levels compared with extended-release metoprolol. Similar effects were observed in high-risk subgroups. Both treatments were well tolerated. This differential metabolic profile could be useful in determining antihypertensive treatment options.

Distance from home when death occurs: a population-based study of Washington State, 1989-2002

OBJECTIVE

For patients who die in hospitals, the regionalization of tertiary health care services may be increasing the home-to-hospital distance, particularly for younger patients whose care is especially regionalized and for whom access to and use of home hospice services remains limited. The objective of this study was to test the hypotheses that the distance from home at the time of death in a hospital has increased over time and is inversely related to the age of the dying patient.

METHODS

A population-based case series was conducted in Washington State of all deaths of state residents from 1989 to 2002. The main outcome measure was driving distance between home residence and location at the time of death.

RESULTS

The overall mean distance from home to the hospital where death occurred has increased by 1% annually. Children who died in hospitals were much farther from home than their adult counterparts: the mean distance was 37.4 km for neonates and 50.9 km for children who were aged 1 to 9 years, compared with 19.9 km for adults who were aged 60 to 79 years and 14.0 km for patients who were older than 79 years. Disparities of distance were even greater among patients who were at the 90th percentile for distance (85.6 km for neonates compared with 30.8 for patient who were older than 79 years).

CONCLUSIONS

The distance between home residence and the hospital where death occurs is greatest for children and has increased over time. Both of these findings have implications for the design of local and regional pediatric end-of-life supportive care services.

BH3 peptidomimetics potently activate apoptosis and demonstrate single agent efficacy in neuroblastoma

The major impediment to cure for many malignancies is the development of therapy resistance with resultant tumor progression. Genetic alterations leading to subversion of inherent apoptosis pathways are common themes in therapy resistance. Bcl-2 family proteins play a critical role in regulating mitochondrial apoptosis that governs chemotherapeutic effects, and defective engagement of these pathways contributes to treatment failure. We have studied the efficacy of BH3 peptidomimetics consisting of the minimal death, or BH3, domains of the proapoptotic BH3-only proteins Bid and Bad to induce apoptosis using neuroblastoma (NB) as a model system. We demonstrate that BH3 peptides, modified with an arginine homopolymer for membrane transduction (called r8-BidBH3 and r8-BadBH3, respectively), potently induce apoptosis in NB cells, including those with MYCN amplification. Cell death is caspase 9 dependent, consistent with a requirement for the intrinsic mitochondrial pathway. Substitutions at highly conserved residues within the r8-BidBH3 peptide abolish apoptotic efficacy supporting activity through specific BH domain interactions. Concomitant exposure to r8-BadBH3 and r8-BidBH3 at sublethal monotherapy doses revealed potent synergy consistent with a competitive displacement model, whereby BH3 peptides displace sequestered BH3 proteins to induce cell death. Further, BH3 peptides demonstrate antitumor efficacy in a xenograft model of NB in the absence of additional genotoxic or trophic stressors. These data provide proof of principle that targeted re-engagement of apoptosis pathways may be of therapeutic utility, and BH3-like compounds are attractive lead agents to re-establish therapy-induced apoptosis in refractory malignancies.

Baseline dimensions of the human vagina

BACKGROUND

Vaginal anatomy has been poorly studied. This study aimed to measure baseline dimensions of the undistended vagina of women of reproductive age.

METHODS

We combined baseline information collected from five clinical trials using magnetic resonance imaging (MRI) to quantify distribution of a vaginal gel. Seventy-seven MRI scans were performed on 28 women before gel application to establish baseline vaginal measurements. Average dimensions were calculated for each woman and for the population. The influence of potential covariates (age, height, weight and parity) on these dimensions was assessed.

RESULTS

MRI measurements are reproducible. The SD surrounding the mean at each anatomical site, and with summary measurements, was significantly smaller with each subject compared with the population. Mean vaginal length from cervix to introitus was 62.7 mm. Vaginal width was largest in the proximal vagina (32.5 mm), decreased as it passed through the pelvic diaphragm (27.8 mm) and smallest at the introitus (26.2 mm). Significant positive associations were parity with vaginal fornix length, age with pelvic flexure width and the height with width at the pelvic flexure.

CONCLUSION

No one description characterized the shape of the human vagina. Although there is variation among women, variables such as parity, age and height are positively associated with differences in baseline dimensions.

The optimal analysis of MRI data to quantify the distribution of a microbicide

OBJECTIVE

The objective of this study was to systematically review the use of MRI for the evaluation of deployment characteristics of vaginal microbicides and to understand the relationship of gel spread with potential influencing factors.

METHODS

Data from four clinical trials that used MRI to assess the deployment of a vaginal gel were combined. A linear mixed model best represented the spread of gel over time. Significant covariates that influence vaginal gel spread are baseline dimensions of the vagina, time from insertion, gel type, ambulation and volume of gel.

RESULTS

These data demonstrate that MRI has outstanding intraperson validity and reproducibility. Therefore, paired design, using linear modeling adjusting for significant covariates, is the most efficient study design for comparison of products or volumes. Division of the vagina into two distinct anatomical regions best explains difference in gel spread, i.e., upper area (above the pelvic diaphragm) and lower area (below pelvic diaphragm).

CONCLUSION

We conclude that the concept of spread from the cervix to the introits, in one dimension, is inadequate to explain spread of gel due to the complex shape of the vagina.

MRI changes due to early-delayed conformal radiotherapy and postsurgical effects in patients with brain tumors

PURPOSE

Discernment of radiotherapy (XRT) effects vs. tumor activity is difficult in brain tumor patients during the months after XRT when white matter hyperintensities sometimes emerge. We examined brain scans in XRT-treated vs. untreated patients for early-delayed post-XRT effects.

METHODS AND MATERIALS

Brain regions susceptible to XRT injury were examined on magnetic resonance imaging (MRI) for T2-weighted hyperintensities and atrophy in 37 adults with low-grade primary brain tumors (13 nonirradiated and 24 irradiated). Cases evidencing recurrence/growth over the study period were censored. Interactions with age, mood, fatigue, medications, tumor type and grade, extent of resection, and laterality of MRI changes were examined.

RESULTS

Hyperintensity and atrophy ratings over time for the treated and untreated groups were not significantly different. White matter atrophy increased unrelated to XRT. In all patients combined, white matter atrophy and hyperintensities were greater at all time points and more lateralized in surgically treated patients.

CONCLUSIONS

Radiotherapy status was not related to changes in MRI ratings during the weeks/months after XRT. Findings contradict assumptions about radiographically evidenced early-delayed XRT effects. Increases in T2-weighted hyperintensities during the 1-6-month period post-conformal radiotherapy for low-grade tumors are likely not related to early-delayed XRT effects.

Distribution of a 3.5-mL (1.0%) C31G vaginal gel using magnetic resonance imaging

C31G (Savvy) has been developed as a topical vaginal microbicide with broad-spectrum antibacterial and antiviral properties. The objective of this study was to evaluate the distribution of a 1.0% concentration of (3.5 mL) C31G vaginal gel in the human pelvis using magnetic resonance imaging (MRI). Gel delivery with a standard applicator was primarily to the upper vagina and was well tolerated. Vaginal mucosal coverage at 18 min was excellent with 92% linear coverage and 75% surface contact coverage of the vagina. The upper vagina was almost completely covered and gel was also noted in the lower vagina. Coverage 6 h after application was substantially decreased, with 60% of maximal linear coverage and 41% surface contact. There was a very minimal coverage of the vaginal mucosa noted 24 h following insertion. Simulated intercourse resulted in relatively little change in overall distribution at all three time points. Repeat application of the gel may be necessary if intercourse has not occurred within the first few hours after initial insertion.

In vivo distribution of a vaginal gel: MRI evaluation of the effects of gel volume, time and simulated intercourse

A microbicide is designed to coat the vaginal epithelium and prevent transmission of HIV. Complete coverage is desired for optimal protection. In vivo factors affecting coverage have not yet been studied. This randomized crossover trial evaluates the effect of gel volume and patient activity upon vaginal epithelial coating. Gynol II gel was mixed with a magnetic resonance imaging (MRI) contrast agent. Ten women self-inserted, on separate visits, 3 or 5 mL of gel and underwent serial MRI scanning both before and after simulated intercourse. Gel spread was dependent upon time and volume. There was modest spread during the first hour and greater spread 6 h after insertion. Five milliliters of gel resulted in statistically significantly greater coverage immediately following insertion, within the first 30 min and at 6 h after insertion. Simulated intercourse greatly enhances gel spread. After simulated intercourse, the distribution of the gel at each volume was similar. Less leakage of gel was reported with the smaller volume.

Length of stay, conditional length of stay, and prolonged stay in pediatric asthma

OBJECTIVE

To understand differences in length of stay for asthma patients between New York State and Pennsylvania across children's and general hospitals in order to better guide policy.

DATA SOURCES/STUDY SETTING

All pediatric admissions for asthma in the states of Pennsylvania and New York using claims data obtained from each state for the years 1996-1998, n = 38,310.

STUDY DESIGN

A retrospective cohort design to model length of stay (LOS), the probability of prolonged stay, conditional length of stay (CLOS or the LOS after stay is prolonged), and the probability of readmission, controlling for patient factors, state, location and hospital type. ANALYTIC METHODS: Logit models were used to estimate the probability of prolonged stay and readmission. The LOS and the CLOS were estimated with Cox regression. Model variables included comorbidities, income, race, distance from hospital, and insurance type. Prolonged stay was based on a Hollander-Proschan "New-Worse-Than-Used" test, corresponding to a three-day stay.

PRINCIPAL FINDINGS

The LOS was longer in New York than Pennsylvania, and the probabilities of prolonged stay and readmission were much higher in New York than Pennsylvania. However, once an admission was prolonged, there were no differences in CLOS between states (when readmissions were not added to the LOS calculation). In both states, children's hospitals and general hospitals had similar adjusted LOS.

CONCLUSIONS

Management of asthma appears more efficient in Pennsylvania than New York: Less severe patients are discharged faster in Pennsylvania than New York; once discharged, patients are less likely to be readmitted in Pennsylvania than New York. However, once a stay is prolonged, there is little difference between New York and Pennsylvania, suggesting medical care for severely ill patients is similar across states. Differences between children's and general hospitals were small as compared to differences between states. We conclude that policy initiatives in New York, and other states, should focus their efforts on improving the care provided to less severe patients in order to help reduce overall length of stay.

Temperament and character in women with anorexia nervosa

The present study examined temperament differences among anorexia nervosa (AN) subtypes and community controls, as well as the effect of body weight on personality traits in women with AN. Temperament and Character Inventory (TCI) scores were compared between 146 women with restrictor-type AN (RAN), 117 women with purging-type AN (PAN), 60 women with binge/purge-type AN (BAN), and 827 community control women (CW) obtained from an archival normative database. Women with AN scored significantly higher on harm avoidance and significantly lower on cooperativeness than CW. Subtype analyses revealed that women with RAN and PAN reported the lowest novelty seeking, RAN women the highest persistence and self-directedness, and PAN women the highest harm avoidance. Body mass index had a nominal effect on subgroup differences, suggesting that personality disturbances are independent of body weight. Findings suggest that certain facets of temperament differ markedly between women with AN, regardless of diagnostic subtype, and controls. More subtle temperament and character differences that were independent of body weight emerged that distinguish among subtypes of AN.