Gender Parity in Clinical PrEP Trials. Reply

Twice-Yearly Lenacapavir or Daily F/TAF for HIV Prevention in Cisgender Women

BACKGROUND

There are gaps in uptake of, adherence to, and persistence in the use of preexposure prophylaxis for human immunodeficiency virus (HIV) prevention among cisgender women.

METHODS

We conducted a phase 3, double-blind, randomized, controlled trial involving adolescent girls and young women in South Africa and Uganda. Participants were assigned in a 2:2:1 ratio to receive subcutaneous lenacapavir every 26 weeks, daily oral emtricitabine-tenofovir alafenamide (F/TAF), or daily oral emtricitabine-tenofovir disoproxil fumarate (F/TDF; active control); all participants also received the alternate subcutaneous or oral placebo. We assessed the efficacy of lenacapavir and F/TAF by comparing the incidence of HIV infection with the estimated background incidence in the screened population and evaluated relative efficacy as compared with F/TDF.

RESULTS

Among 5338 participants who were initially HIV-negative, 55 incident HIV infections were observed: 0 infections among 2134 participants in the lenacapavir group (0 per 100 person-years; 95% confidence interval [CI], 0.00 to 0.19), 39 infections among 2136 participants in the F/TAF group (2.02 per 100 person-years; 95% CI, 1.44 to 2.76), and 16 infections among 1068 participants in the F/TDF group (1.69 per 100 person-years; 95% CI, 0.96 to 2.74). Background HIV incidence in the screened population (8094 participants) was 2.41 per 100 person-years (95% CI, 1.82 to 3.19). HIV incidence with lenacapavir was significantly lower than background HIV incidence (incidence rate ratio, 0.00; 95% CI, 0.00 to 0.04; P<0.001) and than HIV incidence with F/TDF (incidence rate ratio, 0.00; 95% CI, 0.00 to 0.10; P<0.001). HIV incidence with F/TAF did not differ significantly from background HIV incidence (incidence rate ratio, 0.84; 95% CI, 0.55 to 1.28; P = 0.21), and no evidence of a meaningful difference in HIV incidence was observed between F/TAF and F/TDF (incidence rate ratio, 1.20; 95% CI, 0.67 to 2.14). Adherence to F/TAF and F/TDF was low. No safety concerns were found. Injection-site reactions were more common in the lenacapavir group (68.8%) than in the placebo injection group (F/TAF and F/TDF combined) (34.9%); 4 participants in the lenacapavir group (0.2%) discontinued the trial regimen owing to injection-site reactions.

CONCLUSIONS

No participants receiving twice-yearly lenacapavir acquired HIV infection. HIV incidence with lenacapavir was significantly lower than background HIV incidence and HIV incidence with F/TDF. (Funded by Gilead Sciences; PURPOSE 1 ClinicalTrials.gov number, NCT04994509.).

Assessment of the Immunogenicity Potential for Oligonucleotide-Based Drugs

Therapeutic oligonucleotides (ONs) have characteristics of both small molecules and biologics. Although safety assessment of ONs largely follows guidelines established for small molecules, the unique characteristics of ONs often require incorporation of concepts from the safety assessment of biologics. The assessment of immunogenicity for ON therapeutics is one area where the approach is distinct from either established small molecule or biologic platforms. Information regarding immunogenicity of ONs is limited, but indicates that administration of ONs can result in antidrug antibody formation. In this study, we summarize the collective experience of the Oligonucleotide Safety Working Group in designing the immunogenicity assessment appropriate for this class of therapeutic, including advice on assay development, clinical monitoring, and evaluation of the impact of immunogenicity on exposure, efficacy, and safety of therapeutic ONs.

Unsupervised Machine Learning to Detect and Characterize Barriers to Pre-exposure Prophylaxis Therapy: Multiplatform Social Media Study

Background

Among racial and ethnic minority groups, the risk of HIV infection is an ongoing public health challenge. Pre-exposure prophylaxis (PrEP) is highly effective for preventing HIV when taken as prescribed. However, there is a need to understand the experiences, attitudes, and barriers of PrEP for racial and ethnic minority populations and sexual minority groups.

Objective

This infodemiology study aimed to leverage big data and unsupervised machine learning to identify, characterize, and elucidate experiences and attitudes regarding perceived barriers associated with the uptake and adherence to PrEP therapy. This study also specifically examined shared experiences from racial or ethnic populations and sexual minority groups.

Methods

The study used data mining approaches to collect posts from popular social media platforms such as Twitter, YouTube, Tumblr, Instagram, and Reddit. Posts were selected by filtering for keywords associated with PrEP, HIV, and approved PrEP therapies. We analyzed data using unsupervised machine learning, followed by manual annotation using a deductive coding approach to characterize PrEP and other HIV prevention-related themes discussed by users.

Results

We collected 522,430 posts over a 60-day period, including 408,637 (78.22%) tweets, 13,768 (2.63%) YouTube comments, 8728 (1.67%) Tumblr posts, 88,177 (16.88%) Instagram posts, and 3120 (0.6%) Reddit posts. After applying unsupervised machine learning and content analysis, 785 posts were identified that specifically related to barriers to PrEP, and they were grouped into three major thematic domains: provider level (13/785, 1.7%), patient level (570/785, 72.6%), and community level (166/785, 21.1%). The main barriers identified in these categories included those associated with knowledge (lack of knowledge about PrEP), access issues (lack of insurance coverage, no prescription, and impact of COVID-19 pandemic), and adherence (subjective reasons for why users terminated PrEP or decided not to start PrEP, such as side effects, alternative HIV prevention measures, and social stigma). Among the 785 PrEP posts, we identified 320 (40.8%) posts where users self-identified as racial or ethnic minority or as a sexual minority group with their specific PrEP barriers and concerns.

Conclusions

Both objective and subjective reasons were identified as barriers reported by social media users when initiating, accessing, and adhering to PrEP. Though ample evidence supports PrEP as an effective HIV prevention strategy, user-generated posts nevertheless provide insights into what barriers are preventing people from broader adoption of PrEP, including topics that are specific to 2 different groups of sexual minority groups and racial and ethnic minority populations. Results have the potential to inform future health promotion and regulatory science approaches that can reach these HIV and AIDS communities that may benefit from PrEP.

Evaluation of efficacy and safety of antisense inhibition of apolipoprotein C-III with volanesorsen in patients with severe hypertriglyceridemia

INTRODUCTION

Severe hypertriglyceridemia (sHTG) is a complex disorder of lipid metabolism characterized by plasma levels of triglyceride (TG) greater than 885 mg/dl (>10 mmol/L). The treatment of sHTG syndromes is challenging because conventional treatments are often ineffective in reducing TG under the threshold to prevent acute pancreatitis (AP). The inhibition of APOC3, which encodes a protein involved in triglyceride (TG)-rich lipoproteins (TGRLs) removal, has been reported to be a novel target for the treatment of sHTG. Volanesorsen is a second-generation antisense oligonucleotide inhibiting apoC-III transcription/translation that has been recently approved in Europe for Familial Chylomicronemia Syndrome (FCS) treatment.

AREAS COVERED

This review summarizes the evidences on the efficacy and safety of volanesorsen for the treatment of sHTG syndromes.

EXPERT OPINION

Volanesorsen effectively reduces TG in sHTG through a mechanism that is mainly LPL-independent, potentially decreasing the risk of AP. Some safety concerns have been raised with the use of volanesorsen, mainly represented by the occurrence of thrombocytopenia. Due to the potential severity of side effects, some caution is needed before affirming the long-term utility of this drug. Despite this, volanesorsen currently remains the only drug that has been demonstrated effective in FCS, which otherwise remains an untreatable disease.