Preexposure Prophylaxis for Prevention of HIV Acquisition Among Adolescents: Clinical Considerations, 2020.

Preexposure prophylaxis (PrEP) with antiretroviral medication has been proven effective in reducing the risk for acquiring human immunodeficiency virus (HIV). The fixed-dose combination tablet of tenofovir disoproxil fumarate (TDF)/emtricitabine (FTC) was approved by the U.S. Food and Drug Administration (FDA) for use as PrEP for adults in 2012. Since then, recognition has been increasing that adolescents at risk for acquiring HIV can benefit from PrEP. In 2018, FDA approved revised labeling for TDF/FTC that expanded the indication for PrEP to include adolescents weighing at least 77 lb (35 kg) who are at risk for acquiring HIV. In 2019, FDA approved the combination product tenofovir alafenamide (TAF)/FTC as PrEP for adolescents and adults weighing at least 77 lb (35 kg), excluding those at risk for acquiring HIV through receptive vaginal sex. This exclusion is due to the lack of clinical data regarding the efficacy of TAF/FTC in cisgender women.Clinical providers who evaluate adolescents for PrEP use must consider certain topics that are unique to the adolescent population. Important considerations related to adolescents include PrEP safety data, legal issues about consent for clinical care and confidentiality, the therapeutic partnership with adolescents and their parents or guardians, the approach to the adolescent patient's clinical visit, and medication initiation, adherence, and persistence during adolescence. Overall, data support the safety of PrEP for adolescents. PrEP providers should be familiar with the statutes and regulations about the provision of health care to minors in their states. Providers should partner with the adolescent patient for PrEP decisions, recognizing the adolescent's autonomy to the extent allowable by law and including parents in the conversation about PrEP when it is safe and reasonable to do so. A comprehensive approach to adolescent health is recommended, including considering PrEP as one possible component of providing medical care to adolescents who inject drugs or engage in sexual behaviors that place them at risk for acquiring HIV. PrEP adherence declined over time in the studies evaluating PrEP among adolescents, a trend that also has been observed among adult patients. Clinicians should implement strategies to address medication adherence as a routine part of prescribing PrEP; more frequent clinical follow-up is one possible approach.PrEP is an effective HIV prevention tool for protecting adolescents at risk for HIV acquisition. For providers, unique considerations that are part of providing PrEP to adolescents include the possible need for more frequent, supportive interactions to promote medication adherence. Recommendations for PrEP medical management and additional resources for providers are available in the U.S. Public Health Service clinical practice guideline Preexposure Prophylaxis for the Prevention of HIV Infection in the United States - 2017 Update and the clinical providers' supplement Preexposure Prophylaxis for the Prevention of HIV Infection in the United States - 2017 Update: Clinical Providers' Supplement (https://www.cdc.gov/hiv/clinicians/prevention/prep.html).

Clinical Development of Therapeutic Agents for Hospitalized Patients With Influenza: Challenges and Innovations.

BACKGROUND: Since 1999, the US Food and Drug Administration approved neuraminidase and endonuclease inhibitors to treat uncomplicated outpatient influenza but not severe hospitalized influenza. After the 2009 pandemic, several influenza hospital-based clinical therapeutic trials were unsuccessful, possibly due to certain study factors. Therefore, in 2014, the US Health and Human Services agencies formed a Working Group (WG) to address related clinical challenges. METHODS: Starting in 2014, the WG obtained retrospective data from failed hospital-based influenza therapeutic trials and nontherapeutic hospital-based influenza studies. These data allowed the WG to identify factors that might improve hospital-based therapeutic trials. These included primary clinical endpoints, increased clinical site enrollment, and appropriate baseline enrollment criteria. RESULTS: During 2018, the WG received retrospective data from a National Institutes of Health hospital-based influenza therapeutic trial that demonstrated time to resolution of respiratory status, which was not a satisfactory primary endpoint. The WG statisticians examined these data and believed that ordinal outcomes might be a more powerful primary endpoint. Johns Hopkins' researchers provided WG data from an emergency-department (ED) triage study to identify patients with confirmed influenza using molecular testing. During the 2013-2014 influenza season, 4 EDs identified 1074 influenza-patients, which suggested that triage testing should increase enrollment by hospital-based clinical trial sites. In 2017, the WG received data from Northwestern Memorial Hospital researchers regarding 703 influenza inpatients over 5 seasons. The WG applied National Early Warning Score (NEWS) at patient baseline to identify appropriate criteria to enroll patients into hospital-based therapeutic trials. CONCLUSIONS: Data received by the WG indicated that hospital-based influenza therapeutic trials could use ordinal outcome analyses, ED triage to identify influenza patients, and NEWS for enrollment criteria.

Regulatory challenges in developing long-acting antiretrovirals for treatment and prevention of HIV infection.

PURPOSE OF REVIEW: To outline some of the regulatory challenges inherent to the development of long-acting antiretrovirals (ARVs) for the treatment or prevention of HIV infection. RECENT FINDINGS: Despite advances in drug development that have reduced ARV dosing to once daily, suboptimal drug adherence remains an obstacle to successful HIV treatment. Further, large randomized trials of once daily oral ARVs for preexposure prophylaxis (PrEP) have shown that drug adherence correlates strongly with prophylactic effect and study outcomes. Thus, the prospect of developing long-acting ARVs, which may mitigate drug adherence issues, has attracted considerable attention lately. SUMMARY: Because of their pharmacokinetic properties, the development of long-acting ARVs can present novel regulatory challenges. Chief among them is determining the appropriate dosing regimen, the need for an oral lead-in, and whether existing data with an approved oral agent, if available, can be leveraged for a treatment or prevention indication. For PrEP, because validated biomarkers are lacking, additional nonclinical studies and evaluation of tissue concentrations in multiple compartments may be necessary to identify optimal dosages. Study design and choice of controls for registrational trials of new long-acting PrEP agents might also prove challenging following the availability of an oral PrEP drug.

Case report: Rectal adminstration of ivermectin to a patient with Strongyloides hyperinfection syndrome.

Strongyloides hyperinfection syndrome may be complicated by paralytic ileus that interferes with the absorption of oral anti-helminthics. We report on the administration of ivermectin as a rectal enema preparation to a renal transplant recipient with Strongyloides hyperinfection syndrome and progressive ileus. Attempts at treatment using nasogastric albendazole and ivermectin were unsuccessful despite clamping the nasogastric tube after drug administration. Ivermectin tablets were ground to a powder, resuspended in a commercially available suspending agent, and administered per rectum. The suspending agent was chosen for its near-physiologic osmolality to allow longer retention, in contrast to many enema preparations that have a laxative effect. The patient improved markedly within 72 hours of initiation of the therapy per rectum and recovered fully. Ivermectin administered as an enema may be beneficial in patients with severe strongyloidiasis who are unable to absorb or tolerate oral therapy.

Novel clinical trial designs for the development of new antiretroviral agents.

The resounding success of combination antiretroviral efficacy for both treatment-naïve and treatment-experienced patients - with 70-90% viral suppression rates in recent studies - has made registration trials for new agents challenging. With the inevitable specter of drug resistance, new agents must have a pathway to approval. The Forum for Collaborative HIV Research obtained input from concerned stakeholders including industry, clinical sciences, community advocacy, and regulatory sciences (Food and Drug Administration and European Medicines Agency) to discuss how safety and efficacy of new agents could be demonstrated. Recognizing the shortfalls of superiority or noninferiority trials in this environment, a new trial design for treatment-experienced patients, minimizing the risk for drug resistance but allowing full assessment of safety, was proposed. The antiviral efficacy of an active investigational drug would be assessed by comparison to placebo as an add-on to a failing regimen in a short, 10-14-day study followed by institution of an optimized background regimen (OBR) in both arms with investigational drug given to all patients. The follow-on stage would assess dose response, safety, durability of initial response, and development of resistance. Additionally, a second safety trial could be conducted comparing patients randomized to the investigational agent with a new OBR to those on a new OBR and placebo. Finally, approval decisions could consider other long-term safety endpoints. Exposing treatment-naïve patients to investigational agents remains a controversial issue; stakeholders have different interpretations of risk-benefit for trials in this population that necessitate careful consideration before initiating trials in them.

No association of abacavir use with myocardial infarction: findings of an FDA meta-analysis.

BACKGROUND: Several studies have reported an association between abacavir (ABC) exposure and increased risk of myocardial infarction (MI) among HIV-infected individuals. Randomized controlled trials (RCTs) and a pooled analysis by GlaxoSmithKline, however, do not support this association. To better estimate the effect of ABC use on risk of MI, the US Food and Drug Administration (FDA) conducted a trial-level meta-analysis of RCTs in which ABC use was randomized as part of a combined antiretroviral regimen. METHODS: From a literature search conducted among 4 databases, 26 RCTs were selected that met the following criteria: conducted in adults, sample size more than 50 subjects, status completed, not a pharmacokinetic trial, and not conducted in Africa. The Mantel-Haenszel method, with risk difference and 95% confidence interval, was used for the primary analysis, along with additional alternative analyses, based on FDA-requested adverse event reports of MI provided by each investigator. RESULTS: The 26 RCTs were conducted from 1996 to 2010, and included 9868 subjects (5028 ABC and 4840 non-ABC). Mean follow-up was 1.43 person-years in the ABC group and 1.49 person-years in the non-ABC group. Forty-six (0.47%) MI events were reported [24 (0.48%) ABC and 22 (0.46%) non-ABC], with no significant difference noted between the 2 groups (risk difference of 0.008% with 95% confidence interval: -0.26% to 0.27%). CONCLUSIONS: To the best of our knowledge, our study represents the largest trial-level meta-analysis to date of clinical trials in which ABC use was randomized. Our analysis found no association between ABC use and MI risk.

Primary cutaneous fungal infections in solid organ transplantation: a case series.

Cutaneous fungal infections in solid-organ transplant patients present in a variety of nonspecific ways, requiring a high index of suspicion to diagnose correctly. In the present series of four transplant recipients, subsequent primary cutaneous fungal infections presented as papules, plaques, ulcers and subcutaneous nodules. Transplantations included one cardiac, two renal and one renal-pancreatic transplant. Fungal infections were limited to the skin; there was no evidence of disseminated disease in any case. The pathogens isolated were Scedosporium apiospermum (Pseudallescheria boydii), Alternaria species, Aspergillus fumigatus, and a coelomycete in the Coniothyrium-Microsphaeropsis complex of dark molds. Individuals were successfully treated with surgical debridement, antifungal agents, and reduction of immunosuppressive therapy. All patients and allografts survived. Accurate diagnosis, aggressive surgery and appropriate antifungal therapy, combined with close outpatient follow-up, optimize the likelihood of a cure in a transplant population.