A quantitative systems pharmacology model of plasma kallikrein-kinin system dysregulation in hereditary angioedema.

Hereditary angioedema (HAE) due to C1-inhibitor deficiency is a rare, debilitating, genetic disorder characterized by recurrent, unpredictable, attacks of edema. The clinical symptoms of HAE arise from excess bradykinin generation due to dysregulation of the plasma kallikrein-kinin system (KKS). A quantitative systems pharmacology (QSP) model that mechanistically describes the KKS and its role in HAE pathophysiology was developed based on HAE attacks being triggered by autoactivation of factor XII (FXII) to activated FXII (FXIIa), resulting in kallikrein production from prekallikrein. A base pharmacodynamic model was constructed and parameterized from literature data and ex vivo assays measuring inhibition of kallikrein activity in plasma of HAE patients or healthy volunteers who received lanadelumab. HAE attacks were simulated using a virtual patient population, with attacks recorded when systemic bradykinin levels exceeded 20 pM. The model was validated by comparing the simulations to observations from lanadelumab and plasma-derived C1-inhibitor clinical trials. The model was then applied to analyze the impact of nonadherence to a daily oral preventive therapy; simulations showed a correlation between the number of missed doses per month and reduced drug effectiveness. The impact of reducing lanadelumab dosing frequency from 300 mg every 2 weeks (Q2W) to every 4 weeks (Q4W) was also examined and showed that while attack rates with Q4W dosing were substantially reduced, the extent of reduction was greater with Q2W dosing. Overall, the QSP model showed good agreement with clinical data and could be used for hypothesis testing and outcome predictions.

Effectiveness and safety of lanadelumab in ethnic and racial minority subgroups of patients with hereditary angioedema: results from phase 3 studies.

BACKGROUND: The COVID-19 pandemic has highlighted disparities in healthcare, particularly in the United States, even though disparities have existed since the organization of the modern healthcare system. Recruitment of patients from racial and ethnic minority groups is often minimal in phase 3 clinical trials, and is further exacerbated in the case of trials for rare diseases such as hereditary angioedema (HAE). This can lead to a gap in the understanding of minority patients' experiences with these diseases and their response to potential treatment options. METHODS: We reviewed data from phase 3 double-blind (HELP) and open-label extension (HELP OLE) trials of lanadelumab, a monoclonal antibody developed for long-term prophylaxis against attacks of HAE. Efficacy (attack rate reduction) and safety (adverse events) results from White patients were compared descriptively to those from Hispanic/Latino patients, Black/African Americans, and other minority Americans. RESULTS: Not surprisingly, few minorities were recruited across both studies: 9.5% Black, 2.4% Asian, and 7.1% Hispanic/Latino versus 88.1% White and 91.7% non-Hispanic/non-Latino received lanadelumab in HELP, and 4.7% Black, 0.9% Asian, 0.9% other, and 6.1% Hispanic/Latino versus 93.4% White and 93.4% non-Hispanic/non-Latino were enrolled in HELP OLE. Although these studies were conducted in the United States, Canada, Europe, and Jordan, all minorities were from the United States. Despite the number of minority patients being far less than expected for the population, there was no evidence that either efficacy or adverse event profiles differed between ethnic or racial groups. CONCLUSIONS: The HELP and HELP OLE studies described herein recruited far fewer minorities than would be ideal to represent these populations. However, evidence suggests that the effectiveness and tolerance of lanadelumab are similar between the groups. Nonetheless, the disparity in recruitment into research for minorities has significant room for improvement. Trial registration NCT02586805, registered 26 October 2015, https://clinicaltrials.gov/ct2/show/record/NCT02586805 . NCT02741596, registered 18 April 2016, https://clinicaltrials.gov/ct2/show/NCT02741596 .

Transition of Care from Pediatric to Adult Care in Eosinophilic Esophagitis: Insights From a Patient Perspective Survey.

ABSTRACT: Eosinophilic esophagitis (EoE) is a chronic immune-mediated disease. Patients with a childhood diagnosis require ongoing disease management in adulthood; however, knowledge of the patient experience during pediatric to adult healthcare transition is lacking. Here, an online survey captured patient perceptions of the challenges faced by patients with EoE in the United States during transition to adult healthcare, and which resources, if implemented, could better support transition. Of 67 respondents, 91% (n = 61) were under adult care at the time of survey completion. Aspects that respondents struggled with most included meal planning, food shopping, cooking/finding foods that did not exacerbate their condition, and knowledge of insurance coverage. Although most respondents reported confidence in having the knowledge to manage their EoE, almost half of the respondents worried about managing their condition in the future. Resources detailing diet, medication and insurance management strategies could support the transition to adult healthcare for patients with EoE.

Lanadelumab demonstrates rapid and sustained prevention of hereditary angioedema attacks.

BACKGROUND: Lanadelumab demonstrated efficacy in preventing hereditary angioedema (HAE) attacks in the phase 3 HELP Study. OBJECTIVE: To assess time to onset of effect and long-term efficacy of lanadelumab, based on exploratory findings from the HELP Study. METHODS: Eligible patients with HAE type I/II received lanadelumab 150 mg every 4 weeks (q4wks), 300 mg q4wks, 300 mg q2wks, or placebo. Ad hoc analyses evaluated day 0-69 findings using a Poisson regression model accounting for overdispersion. Least-squares mean monthly HAE attack rate for lanadelumab was compared with placebo. Intrapatient comparisons for days 0-69 versus steady state (days 70-182) used a paired t test for continuous endpoints or Kappa statistics for categorical endpoints. RESULTS: One hundred twenty-five patients were randomized and treated. During days 0-69, mean monthly attack rate was significantly lower with lanadelumab (0.41-0.76) vs placebo (2.04), including attacks requiring acute treatment (0.33-0.61 vs 1.66) and moderate/severe attacks (0.31-0.48 vs 1.33, all P ≤ .001). More patients receiving lanadelumab vs placebo were attack free (37.9%-48.1% vs 7.3%) and responders (85.7%-100% vs 26.8%). During steady state, the efficacy of lanadelumab vs placebo was similar or improved vs days 0-69. Intrapatient differences were significant with lanadelumab 300 mg q4wks for select outcomes. Lanadelumab efficacy was durable-HAE attack rate was consistently lower vs placebo, from the first 2 weeks of treatment through study end. Treatment emergent adverse events were comparable during days 0-69 and 70-182. CONCLUSION: Protection with lanadelumab started from the first dose and continued throughout the entire study period.

Clinical significance of hyperbilirubinemia among HIV-1-infected patients treated with atazanavir/ritonavir through 96 weeks in the CASTLE study.

CASTLE was a randomized 96-week study that demonstrated that atazanavir/ritonavir (ATV/r) was noninferior to lopinavir/ritonavir (LPV/r) in treatment-naïve HIV-infected patients. Analyses were carried out among patients who received ATV/r in the CASTLE study to better understand the clinical significance of unconjugated hyperbilirubinemia associated with administration of boosted ATV. Hyperbilirubinemia was defined as total bilirubin (conjugated and unconjugated) elevation greater than 2.5 times the upper limit of normal (grade 3-4). Patients in the ATV/r arm were assessed based on the presence or absence of hyperbilirubinemia through week 96. Analyses included number of confirmed virologic responders (CVR; HIV RNA<50 copies per milliliter), impact of hyperbilirubinemia on symptoms, elevations in liver enzymes, patient quality of life, and medication adherence. Through 96 weeks in the CASTLE study, 44% of patients who received ATV/r had hyperbilirubinemia at any time point, and between 12.5% and 21.6% had hyperbilirubinemia at any single study visit. At 96 weeks, 74% of patients overall and 84% and 69% of patients with and without hyperbilirubinemia, respectively, achieved CVR. Symptoms of jaundice or scleral icterus occurred in 5% of patients overall and in 11% with hyperbilirubinemia and 0% without hyperbilirubinemia. Four percent of patients with and 3% of patients without hyperbilirubinemia had grade 3-4 elevations in liver transaminases. Less than 1% of patients discontinued treatment due to hyperbilirubinemia. There were no differences in quality of life or adherence between patients with or without hyperbilirubinemia. In the CASTLE study, hyperbilirubinemia observed in the ATV/r group did not negatively impact clinical outcomes in HIV-infected patients.

Enfuvirtide (T-20): potentials and challenges.

Enfuvirtide is a fusion inhibitor used for the treatment of HIV infection. It is an injectable drug, with the patient being responsible for reconstitution as well as injection. The authors present the results of Phase III trials with enfuvirtide. A summary of efficacy, tolerability, pharmacokinetics, resistance, and adverse events from the Phase III trials with enfuvirtide is presented. Enfuvirtide is well tolerated, and no limiting pharmacokinetic interactions have been published thus far. A review of patient perception of self-injection is also summarized. The data reviewed demonstrate that most patients find self-injection easy and do not find that it interferes with activities of daily living. Data on injection site reactions (ISRs), one of the most common adverse events of enfuvirtide, is highlighted, as is nursing management of ISRs. Finally, the authors discuss research that could help further understanding of enfuvirtide and examine some barriers clinicians may face when prescribing this medication.

Tolerance of efavirenz-induced central nervous system side effects in HIV-infected individuals with a history of substance abuse.

PURPOSE: There is no published data looking at tolerance of efavirenz (EFV) in patients who abuse cocaine or alcohol (EtOH). The objective of this study was to determine whether individuals with a current or past history of cocaine or EtOH abuse are more likely to experience EFV-induced central nervous system (CNS) side effects that warrant discontinuation of EFV compared with those who do not abuse substances. METHOD: Retrospective chart review of all patients who received a nonnucleoside reverse transcriptase inhibitor (NNRTI) at an inner city Ryan White Title III-supported health clinic during 1992-2001. RESULTS: During the study period, 99/279 (78% African American, 88% male) patients were prescribed an NNRTI. Patients on an NNRTI with either a history of or current substance abuse (SA) abused cocaine (30%), EtOH (70%), or marijuana (33%). Of these, 38% abused more than one substance. There were 39/63 EFV patients who were substance abusers compared with 16/36 patients not on EFV who were substance abusers (p =.09). Examining patients on EFV, 6/24 with SA and 7/39 without SA reported a CNS side effect (p =.54). Among patients on EFV, 4/24 with SA versus 13/39 without SA reported stopping EFV (p =.24). CONCLUSION: SA did not have a significant effect on patients' ability to remain on EFV. Patients who abused cocaine or EtOH or smoked marijuana were at no more risk of exhibiting CNS side effects than those who denied a history of substance abuse.

Nonnucleoside reverse transcriptase inhibitor resistance among antiretroviral-naive HIV-positive pregnant women.

From 1999 to 2001, the overall prevalence of resistance in the antiretroviral (ART)-naive population in St. Louis, Missouri, was 17%. We sought to determine if resistance testing in ART-naive HIV-positive pregnant women identified resistant mutations, which would modify our initial choice of therapy. A retrospective chart review was performed on all HIV-positive pregnant women seen from January 2000 to December 2001 at a university hospital. There were 72 pregnancies. Twenty-seven of 72 patients were ART naive. Genotype testing was performed in 18 of 27 naive patients. Three of 18 ART-naive patients (17%) had primary resistance (95% CI: 4%-41%) by genotype to NNRTIs. The primary mutation, G190S, conferring resistance to NNRTIs was present in 1 patient. Another had the K103N mutation. One had the K103R mutation, which conferred phenotypic resistance to NNRTIs by 8.3-fold, warranting a change in the initial regimen. In our community, resistance testing in ART-naive pregnant patients is warranted. Switching later to a more complex regimen during pregnancy may adversely affect adherence, resulting in virologic failure. Strategies to avoid prescribing a suboptimal regimen include waiting to initiate ART until the resistance testing results are available and/or beginning ART with a protease inhibitor-based regimen if the patient is already in the third trimester of pregnancy at the time of her initial clinic presentation.