Moving fast but going slow: coordination challenges for trials of COVID-19 post-exposure prophylaxis

An unprecedented volume of research has been generated in response to the COVID-19 pandemic. However, there are risks of inefficient duplication and of important work being impeded if efforts are not synchronized. Excessive reliance on observational studies, which can be more rapidly conducted but are inevitably subject to measured and unmeasured confounders, can foil efforts to conduct rigorous randomized trials. These challenges are illustrated by recent global efforts to conduct clinical trials of post-exposure prophylaxis (PEP) as a strategy for preventing COVID-19. Innovative strategies are needed to help overcome these issues, including increasing communication between the Data Safety and Monitoring Committees (DSMCs) of similar trials. It is important to reinforce the primacy of high-quality trials in generating unbiased answers to pressing prevention and treatment questions about COVID-19

Can herpes simplex virus type 2 suppression slow HIV disease progression: a study protocol for the VALacyclovir In Delaying Antiretroviral Treatment Entry (VALIDATE) trial

<p>Abstract</p> <p>Background</p> <p>Although highly active antiretroviral therapy (HAART) has dramatically decreased HIV-related morbidity and mortality, the associated costs, toxicities, and resistance risks make the potential delay of HAART initiation an attractive goal. Suppression of herpes simplex virus type 2 (HSV-2) may be a novel strategy for achieving this goal because HSV-2 is associated with clinically significant increases in HIV viral load, the primary driver of HIV disease progression.</p> <p>Methods/Design</p> <p>The VALacyclovir In Delaying Antiretroviral Treatment Entry (VALIDATE) trial is a multicentre, randomized, fully blinded, clinical trial of twice daily valacyclovir 500 mg versus placebo for delaying the need for initiating HAART among HIV-1, HSV-2 co-infected HAART-naïve adults. 480 participants from Canada, Brazil and Argentina will undergo quarterly clinical follow-up until reaching the composite primary endpoint of having a CD4+ T-cell count ≤ 350 cells/mm³or initiation of HAART for any reason, whichever occurs first. The primary analysis will use a proportional hazards model, stratified by site, to estimate the relative risk of progression to this endpoint associated with valacyclovir. Secondary analyses will compare the rates of change in CD4 count, median log₁₀HIV viral load, drug-related adverse events, frequency of HSV reactivations, rate of acyclovir-resistant HSV, and quality of life between study arms.</p> <p>Discussion</p> <p>Although HIV treatment guidelines continue to evolve, with some authorities recommending earlier HAART among asymptomatic individuals, the potential delay of HAART remains a clinically relevant goal for many. If shown to be of benefit, implementation of the VALIDATE intervention will require careful consideration of both individual patient-level and public health implications.</p> <p>Trial Registration</p> <p>Current Controlled Trials ISRCTN66756285</p> <p>ClinicalTrials.gov NCT00860977</p

31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two

Background The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd. Methods We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background. Results First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001). Conclusions In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival

Left out but not forgotten: Should closer attention be paid to coinfection with herpes simplex virus type 1 and HIV?

Herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) are among the most common coinfections seen in individuals infected with HIV-1. Most research on HSV-HIV coinfection has focused on HSV-2, and in particular, on its impact on HIV transmission. HSV-2 is associated with micro- and macroulcerations in genital mucosal surfaces, increased numbers of HIV target cells in genital mucosal tissue and increases in plasma HIV viral load of up to 0.5 log10 copies/mL, such that HSV-2 infection increases the risk of both HIV acquisition and transmission. Because plasma HIV RNA levels are a major determinant of rates of CD4 cell decline, HSV-2 coinfection may also adversely affect the progression of HIV disease. Anti-HSV medications have in fact been associated with reciprocal decreases in HIV viral load in short-term studies. These findings have led to the development of several clinical trials of HSV-2 suppression as strategies for preventing HIV transmission and slowing the rate of HIV disease progression. HSV-1 coinfection has largely been ignored from this growing body of research, yet there are several reasons that this coinfection remains an important issue for study. First, the seroprevalence of HSV-1 is consistently higher than that of HSV-2 among both HIV-infected and HIV-uninfected populations, underscoring the relevance of HSV-1 coinfection to the majority of HIV-infected persons. Second, pre-existing HSV-1 antibodies in individuals may modulate the course of subsequently acquired HSV-2 infection; the implications of such changes on HSV-HIV coinfection remain unexplored. Third, HSV-1 and HSV-2 are closely related viruses that share 83% genetic homology. Their virological and pathobiological similarities suggest that their implications on HIV pathogenesis may be similar as well. Finally, HSV-1 is becoming increasingly relevant because the incidence of genital HSV-1 has risen. Although genital herpes is traditionally associated with HSV-2, recent studies have shown that the majority of serologically confirmed primary genital herpes in some settings is attributable to HSV-1. Because the genital tract is an important site of biological interaction between HSV and HIV, this epidemiological change may be clinically important

Treatment-emergent reverse transcriptase resistance during antiretroviral therapy with bictegravir, tenofovir alafenamide, and emtricitabine: A case series

OBJECTIVES: Bictegravir/tenofovir alafenamide/emtricitabine (BIC/TAF/FTC) is a complete regimen for the treatment of HIV with a high barrier to resistance and few reported cases of treatment failure. We present three cases of treatment-emergent resistance to nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs) in patients with suboptimal treatment adherence and assess whether the resistance-associated mutations were present before BIC/TAF/FTC initiation or emerged during therapy. METHODS: We used genotypic drug resistance testing by Sanger sequencing to identify emergent resistance mutations in plasma viral load specimens collected after combination antiretroviral therapy initiation in all participants. Additionally, we performed ultra-deep sequencing by Illumina MiSeq on the earliest available plasma HIV-1 viral load specimen and on any available specimens closest in time to the initiation of BIC/TAF/FTC therapy to identify low-abundance resistance mutations present in the viral quasispecies. RESULTS: All three participants developed NRTI resistance after prolonged exposure and incomplete adherence to BIC/TAF/FTC. The T69N, K70E, M184I, and/or T215I mutations identified in clinical samples at the time of virological failure were not present on deep sequencing of either baseline samples or samples collected before BIC/TAF/FTC initiation. CONCLUSIONS: Despite a generally high genetic barrier to resistance, NRTI resistance-associated mutations may emerge during therapy with BIC/TAF/FTC in the setting of suboptimal adherence

Alendronate/Vitamin D for attenuating bone mineral density loss during antiretroviral initiation: a pilot randomized controlled trial

Background: Antiretroviral therapy (ART) initiation is associated with decreases in bone mineral density (BMD). Objectives: To plan for a larger trial, we sought to obtain preliminary estimates for the difference in the change in BMD at 48 weeks achieved with 24 weeks of prophylactic alendronate/vitamin D during ART initiation compared to no intervention, the within-group standard deviation of this change, and intra-patient correlation coefficient for repeated BMDs. Secondary objectives included assessing enrollment feasibility, treatment acceptability, adherence and safety. Methods: We randomized treatment-naïve HIV-positive adults initiating tenofovir disoproxil fumarate/emtricitabine/elvitegravir/cobicistat or abacavir/lamivudine/dolutegravir 1:1:1 to immediate alendronate/vitamin D3 70 mg/5600 IU for 24 weeks (concomitant treatment arm, CTA), the same intervention starting 24 weeks after study entry (delayed treatment arm, DTA), or no bone anti-resorptive therapy (standard of care, SOC). We assessed BMD, acceptability, adverse events and drug adherence at baseline, week 24 and week 48. Results: Of 29 included participants, 72% initiated TDF/FTC/ELV/c and 28% initiated ABC/3TC/DTG. Median (IQR) CD4 count was 388 (303,525) cells/mm3 and median plasma HIV RNA was 4.45 (2.26, 4.84) log10 copies/mL. The mean (SD) percentage change in BMD for the CTA and DTA combined was 1.95% (2.53%), 0.38% (3.34%), and −0.57% (3.50%) at the lumbar spine, femoral neck and total hip respectively at 48 weeks. The ICC among repeated measurements of BMD was 0.978, 0.964, and 0.967 at these sites, respectively. Enrollment feasibility, drug acceptability, adherence, and tolerability were good. Conclusions: Our findings inform the sample size for a larger trial of bone anti-resorptive therapy during ART initiation and support feasibility

Preparing for PrEP: Perceptions and Readiness of Canadian Physicians for the Implementation of HIV Pre-Exposure Prophylaxis

<div><p>Recent evidence has demonstrated the efficacy of pre-exposure prophylaxis (PrEP) for HIV prevention, but concerns persist around its use. Little is known about Canadian physicians' knowledge of and willingness to prescribe PrEP. We disseminated an online survey to Canadian family, infectious disease, internal medicine, and public health physicians between September 2012–June 2013 to determine willingness to prescribe PrEP. Criteria for analysis were met by 86 surveys. 45.9% of participants felt “very familiar” with PrEP, 49.4% felt that PrEP should be approved by Health Canada, and 45.4% of respondents were willing to prescribe PrEP. Self-identifying as an HIV expert (odds ratio, OR = 4.1, 95% confidence interval, CI = 1.6–10.2), familiarity with PrEP (OR = 5.0, 95%CI = 1.3–19.0) and having been asked by patients about PrEP (OR = 4.0, 95%CI = 1.5–10.5) were positively associated with willingness to prescribe PrEP on univariable analysis. The latter two were the strongest predictors on multivariate analysis. Participants cited cost and efficacy as major concerns. 75.3% did not feel that information had been adequately disseminated among physicians. In summary, Canadian physicians demonstrate varying levels of support for PrEP and express concerns about its implementation. Further research on real-world effectiveness, continuing medical education, and clinical support is needed to prepare physicians for this prevention strategy.</p></div

Familiarity with and attitudes regarding PrEP^a.

a<p>Values shown are number (percentage) or median (IQR).</p>b<p>Responses may not sum to 86 due to missing values.</p>c<p>Proportion of respondents willing to prescribe PrEP based on current knowledge for high-risk patients who have a mechanism to cover medication costs.</p>d<p>Response to question “According to one study among men who have sex with men (MSM), oral PrEP provided 44% protection against HIV infection overall and 73% protection in participants who used PrEP consistently (i.e. took the medication on a regular schedule and did not miss doses). Other studies show that PrEP provides a similar level of protection among heterosexual men and women. Considering this level of protection, do you believe Health Canada should approve PrEP for use in Canada?”</p

Considerations in the implementation of PrEP ranked by order of importance.

<p>Bars represent percentage of respondents.</p