Safety and immunogenicity of the protein-based PHH-1V compared to BNT162b2 as a heterologous SARS-CoV-2 booster vaccine in adults vaccinated against COVID-19: a multicentre, randomised, double-blind, non-inferiority phase IIb trial.

Background: A SARS-CoV-2 protein-based heterodimer vaccine, PHH-1V, has been shown to be safe and well-tolerated in healthy young adults in a first-in-human, Phase I/IIa study dose-escalation trial. Here, we report the interim results of the Phase IIb HH-2, where the immunogenicity and safety of a heterologous booster with PHH-1V is assessed versus a homologous booster with BNT162b2 at 14, 28 and 98 days after vaccine administration. Methods: The HH-2 study is an ongoing multicentre, randomised, active-controlled, double-blind, non-inferiority Phase IIb trial, where participants 18 years or older who had received two doses of BNT162b2 were randomly assigned in a 2:1 ratio to receive a booster dose of vaccine-either heterologous (PHH-1V group) or homologous (BNT162b2 group)-in 10 centres in Spain. Eligible subjects were allocated to treatment stratified by age group (18-64 versus ≥65 years) with approximately 10% of the sample enrolled in the older age group. The primary endpoints were humoral immunogenicity measured by changes in levels of neutralizing antibodies (PBNA) against the ancestral Wuhan-Hu-1 strain after the PHH-1V or the BNT162b2 boost, and the safety and tolerability of PHH-1V as a boost. The secondary endpoints were to compare changes in levels of neutralizing antibodies against different variants of SARS-CoV-2 and the T-cell responses towards the SARS-CoV-2 spike glycoprotein peptides. The exploratory endpoint was to assess the number of subjects with SARS-CoV-2 infections ≥14 days after PHH-1V booster. This study is ongoing and is registered with ClinicalTrials.gov, NCT05142553. Findings: From 15 November 2021, 782 adults were randomly assigned to PHH-1V (n = 522) or BNT162b2 (n = 260) boost vaccine groups. The geometric mean titre (GMT) ratio of neutralizing antibodies on days 14, 28 and 98, shown as BNT162b2 active control versus PHH-1V, was, respectively, 1.68 (p < 0.0001), 1.31 (p = 0.0007) and 0.86 (p = 0.40) for the ancestral Wuhan-Hu-1 strain; 0.62 (p < 0.0001), 0.65 (p < 0.0001) and 0.56 (p = 0.003) for the Beta variant; 1.01 (p = 0.92), 0.88 (p = 0.11) and 0.52 (p = 0.0003) for the Delta variant; and 0.59 (p ≤ 0.0001), 0.66 (p < 0.0001) and 0.57 (p = 0.0028) for the Omicron BA.1 variant. Additionally, PHH-1V as a booster dose induced a significant increase of CD4+ and CD8+ T-cells expressing IFN-γ on day 14. There were 458 participants who experienced at least one adverse event (89.3%) in the PHH-1V and 238 (94.4%) in the BNT162b2 group. The most frequent adverse events were injection site pain (79.7% and 89.3%), fatigue (27.5% and 42.1%) and headache (31.2 and 40.1%) for the PHH-1V and the BNT162b2 groups, respectively. A total of 52 COVID-19 cases occurred from day 14 post-vaccination (10.14%) for the PHH-1V group and 30 (11.90%) for the BNT162b2 group (p = 0.45), and none of the subjects developed severe COVID-19. Interpretation: Our interim results from the Phase IIb HH-2 trial show that PHH-1V as a heterologous booster vaccine, when compared to BNT162b2, although it does not reach a non-inferior neutralizing antibody response against the Wuhan-Hu-1 strain at days 14 and 28 after vaccination, it does so at day 98. PHH-1V as a heterologous booster elicits a superior neutralizing antibody response against the previous circulating Beta and the currently circulating Omicron BA.1 SARS-CoV-2 variants in all time points assessed, and for the Delta variant on day 98 as well. Moreover, the PHH-1V boost also induces a strong and balanced T-cell response. Concerning the safety profile, subjects in the PHH-1V group report significantly fewer adverse events than those in the BNT162b2 group, most of mild intensity, and both vaccine groups present comparable COVID-19 breakthrough cases, none of them severe. Funding: HIPRA SCIENTIFIC, S.L.U.

Limited Humoral and Specific T-Cell Responses After SARS-CoV-2 Vaccination in PWH With Poor Immune Reconstitution.

BACKGROUND: We analyzed humoral and cellular immune responses induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) messenger RNA (mRNA) vaccines in people with human immunodeficiency virus (HIV; PWH) who had CD4+ T-cell counts <200/µL (HIV<200 group). METHODS: This prospective cohort study included 58 PWH in the HIV<200 group, 36 with CD4+ T-cell counts >500/µL (HIV>500 group), and 33 HIV-1-negative controls (control group). Antibodies against the SARS-CoV-2 spike protein (anti-S immunoglobulin [Ig] G) and the receptor-binding domain (anti-RBD IgG) were quantified before and 4 weeks after the first and the second doses of BNT162b2 or mRNA-1273 (at week 8). Viral neutralization activity and T-cell responses were also determined. RESULTS: At week 8, anti-S/anti-RBD IgG responses increased in all groups (P < .001). Median (interquartile range) anti-S and anti-RBD IgG levels at week 8 were 153.6 (26.4-654.9) and 171.9 (61.8-425.8) binding antibody units (BAU)/mL, respectively, in the HIV<200 group, compared with 245.6 (145-824) and 555.8 (166.4-1751) BAU/mL in the HIV>500 group and 274.7 (193.7-680.4) and 281.6 (181-831.8) BAU/mL in controls (P < .05). Neutralizing capacity and specific T-cell immune responses were absent or reduced in 33% of those in the HIV<200 group, compared with 3.7% in the HIV>500 group (P < .01). CONCLUSIONS: One-third of PWH with CD4+ T-cell counts <200/µL show low anti-S/anti-RBD IgG levels, reduced in vitro neutralization activity against SARS-CoV-2, and no vaccine-induced T cells after receiving coronavirus disease 2019 mRNA vaccines.

Safety, immunogenicity and effect on viral rebound of HTI vaccines in early treated HIV-1 infection: a randomized, placebo-controlled phase 1 trial.

HIVACAT T-cell immunogen (HTI) is a novel human immunodeficiency virus (HIV) vaccine immunogen designed to elicit cellular immune responses to HIV targets associated with viral control in humans. The AELIX-002 trial was a randomized, placebo-controlled trial to evaluate as a primary objective the safety of a combination of DNA.HTI (D), MVA.HTI (M) and ChAdOx1.HTI (C) vaccines in 45 early-antiretroviral (ART)-treated individuals (44 men, 1 woman; NCT03204617). Secondary objectives included T-cell immunogenicity, the effect on viral rebound and the safety of an antiretroviral treatment interruption (ATI). Adverse events were mostly mild and transient. No related serious adverse events were observed. We show here that HTI vaccines were able to induce strong, polyfunctional and broad CD4 and CD8 T-cell responses. All participants experienced detectable viral rebound during ATI, and resumed ART when plasma HIV-1 viral load reached either >100,000 copies ml-1, >10,000 copies ml-1 for eight consecutive weeks, or after 24 weeks of ATI. In post-hoc analyses, HTI vaccines were associated with a prolonged time off ART in vaccinees without beneficial HLA (human leukocyte antigen) class I alleles. Plasma viral load at the end of ATI and time off ART positively correlated with vaccine-induced HTI-specific T-cell responses at ART cessation. Despite limited efficacy of the vaccines in preventing viral rebound, their ability to elicit robust T-cell responses towards HTI may be beneficial in combination cure strategies, which are currently being tested in clinical trials.

Challenges of HIV therapeutic vaccines clinical trials design.

PURPOSE OF THE REVIEW: To discuss main challenges of therapeutic vaccine clinical trials design, implementation and analyses in the HIV cure field. RECENT FINDINGS: Therapeutic vaccines are progressively being postulated as T-cell stimulating agents to use in combination HIV cure strategies, with the addition of immunomodulators, latency reversing agents and/or broadly neutralizing antibodies. Although promising strategies are rapidly evolving in preclinical studies using nonhuman primate models, translation into human testing in randomized controlled clinical trials is more challenging and expensive to conduct. Adaptive designs, access to cohorts of early-treated individuals, consensus on how to safely conduct analytical treatment interruptions, use of alternative statistical methods, development of point-of-care/home-based testing technologies and ensuring early engagement of communities where research is being developed are some of the critical aspects to consider to facilitate clinical trial development in the HIV cure field. SUMMARY: Design and development of HIV therapeutic vaccine clinical trials poses many challenges, from Phase 0/pilot studies to Phase I/II trials in which efficacy of the intervention is being tested and antiretroviral therapy cessation is needed, complexity of cure trials progressively increases. Understanding fundamental issues and careful planning of therapeutic vaccine clinical trials is crucial to minimize design flaws, reduce loss of follow-ups and missing data while ensuring participant's safety and guarantee valid and accurate analyses and thus, better contribute towards an HIV cure.

Removal of doravirine by haemodialysis in people living with HIV with end-stage renal disease.

OBJECTIVES: To evaluate the effect of haemodialysis on doravirine concentrations in people living with HIV (PLWH) undergoing routine haemodialysis. METHODS: An exploratory clinical trial that included PLWH undergoing intermittent haemodialysis was undertaken. After enrolment (day 1), doravirine 100 mg once daily was added to stable combined ART for 5 days. On day 6, blood samples were collected from each participant at the beginning and at the end of a dialysis session. Additionally, paired samples of blood entering ('in') and leaving ('out') the dialyser and the resulting dialysate were collected during the dialysis session to evaluate drug removal during dialysis. Doravirine concentrations in plasma and in the dialysate were determined by LC-MS/MS. The ratio of doravirine concentrations in plasma after/before the haemodialysis session and the haemodialysis extraction coefficient were calculated for each participant. The study was registered at https://www.clinicaltrials.gov (NCT04689737). RESULTS: Eight participants (six male) were included. The median (range) age and BMI were 49.5 (28-67) years and 23.6 (17.9-34.2) kg/m2, respectively. The doravirine dialysis extraction ratio was 34.3% (25.8%-41.4%). The ratio of doravirine concentrations in plasma after/before the haemodialysis session was 0.8 (0.6-1.0). At the end of the haemodialysis session (time post-dose 20.8-27.3 h), doravirine concentrations in plasma were 785 (101-1851) ng/mL. CONCLUSIONS: Despite moderate removal of doravirine by haemodialysis, trough doravirine concentrations in plasma after the haemodialysis sessions remained in excess of the protein-binding-adjusted EC50 (5 ng/mL). Doravirine dosage adjustments are unnecessary in PLWH undergoing intermittent haemodialysis.

Altered T-cell subset distribution in the viral reservoir in HIV-1-infected individuals with extremely low proviral DNA (LoViReTs).

BACKGROUND: HIV cure strategies aim to eliminate viral reservoirs that persist despite successful antiretroviral therapy (ART). We have previously described that 9% of HIV-infected individuals who receive ART harbor low levels of provirus (LoViReTs). METHODS: We selected 22 LoViReTs matched with 22 controls ART suppressed for more than 3 years with fewer than 100 and more than 100 HIV-DNA copies/106  CD4+ T cells, respectively. We measured HIV reservoirs in blood and host genetic factors. Fourteen LoViReTs underwent leukapheresis to analyze replication-competent virus, and HIV-DNA in CD4+ T-cell subpopulations. Additionally, we measured HIV-DNA in rectum and/or lymph node biopsies from nine of them. RESULTS: We found that LoViReTs harbored not only lower levels of total HIV-DNA, but also significantly lower intact HIV-DNA, cell-associated HIV-RNA, and ultrasensitive viral load than controls. The proportion of intact versus total proviruses was similar in both groups. We found no differences in the percentage of host factors. In peripheral blood, 71% of LoViReTs had undetectable replication-competent virus. Minimum levels of total HIV-DNA were found in rectal and lymph node biopsies compared with HIV-infected individuals receiving ART. The main contributors to the reservoir were short-lived transitional memory and effector memory T cells (47% and 29%, respectively), indicating an altered distribution of the HIV reservoir in the peripheral T-cell subpopulations of LoViReTs. CONCLUSION: In conclusion, LoViReTs are characterized by low levels of viral reservoir in peripheral blood and secondary lymphoid tissues, which might be explained by an altered distribution of the proviral HIV-DNA towards more short-lived memory T cells. LoViReTs can be considered exceptional candidates for future interventions aimed at curing HIV.

Absence of drug-drug interactions between γ-hydroxybutyric acid (GHB) and cobicistat.

OBJECTIVES: Potential interactions between CYP3A4 inhibitors and γ-hydroxybutyric acid (GHB) have been suggested as a possible explanation for cases of GHB overdose in recent years among people living with HIV engaged in chemsex. Our objective was to assess the effect of cobicistat on the pharmacokinetics of GHB. METHODS: Fifteen healthy adults were enrolled in this randomized, double-blind, placebo-controlled, two-arm, crossover clinical trial. Participants underwent two 5 day treatment periods with at least a 1 week washout period between them. In each treatment period, participants received cobicistat (150 mg q24h orally) or matched placebo. On day 5 of each treatment period, participants were given a single oral dose of GHB (25 mg/kg). Plasma concentrations of GHB, subjective effects, blood pressure, heart rate and oxygen saturation were monitored for 5 h after dosing. GHB pharmacokinetic and pharmacodynamic parameters were calculated for each participant during each study period by non-compartmental analysis and were compared using linear mixed-effects models. The study was registered at https://www.clinicaltrialsregister.eu (Eudra-CT number 2019-002122-71) and at https://clinicaltrials.gov (NCT04322214). RESULTS: Ten participants completed the two study periods. No drug-related adverse events that necessitated subject withdrawal or medical intervention occurred during the study. Compared with placebo, none of the primary pharmacokinetic parameters of GHB was substantially changed by the administration of GHB with cobicistat. Similarly, no differences regarding subjective or physiological effects were observed when GHB was administered alone or with cobicistat. CONCLUSIONS: Neither pharmacokinetic nor pharmacodynamic drug-drug interactions between cobicistat and GHB were identified in this study.

Correction to: Novel Approaches Towards a Functional Cure of HIV/AIDS.

The first author currently listed as Lucia Bailon Alvarez should be Lucia Bailon.

Novel Approaches Towards a Functional Cure of HIV/AIDS.

Therapeutic approaches towards a functional cure or eradication of HIV have gained renewed momentum upon encouraging data emerging from studies in SIV monkey models and recent results from human clinical studies. However, a multitude of questions remain to be addressed, including how to deal with the latent viral reservoir, how to boost the host immune response to the virus and what the hurdles are to reach relevant viral compartments in the body. Advances have been made especially with regard to identifying agents that can reactivate the latent virus in vivo and boost the cellular and humoral immunity, but it remains largely unclear whether any of these strategies can awaken a sufficiently large fraction of the viral reservoir and whether the boosted immunity can prevent rapid viral replication once antiretroviral treatments are stopped.

HIV-1 DNA decay dynamics in early treated individuals: practical considerations for clinical trial design.

BACKGROUND: Initiation of combination antiretroviral therapy (cART) soon after HIV-1 infection limits the establishment of viral reservoirs. Thus, early treated individuals are preferred candidates to evaluate novel viral remission strategies. However, their cART-dependent HIV-1 DNA decay dynamics are still poorly defined. This can hamper the design and interpretation of results from clinical trials intended to further reduce viral reservoirs. OBJECTIVES: To clarify the duration of cART needed for the HIV-1 reservoir to be stabilized in early treated individuals. METHODS: We characterized the longitudinal decline of total HIV-1 DNA levels by droplet digital PCR in 21 individuals initiating cART within 6 months after estimated HIV-1 acquisition. Measurements were taken at cART initiation, after 6 months and annually until Year 4. Correlations between virological and clinical parameters were statistically analysed. Statistical modelling was performed applying a mixed-effects model. RESULTS: Total HIV-1 DNA experienced a median overall decrease of 1.43 log10 units (IQR = 1.17-1.69) throughout the 4 years of follow-up. Baseline levels for total HIV-1 DNA, viral load, absolute CD4+ T cell count and CD4+/CD8+ ratio correlate with final HIV-1 DNA measurements (R2 = 0.68, P < 0.001; R2 = 0.54, P = 0.012; R2 = -0.47, P = 0.031; and R2 = -0.59, P = 0.0046, respectively). Statistical modelling shows that after 2 years on cART the viral reservoir had reached a set point. CONCLUSIONS: A waiting period of 2 years on cART should be considered when designing interventions aiming to impact latent HIV-1 reservoir levels and viral rebound kinetics after cART discontinuation, in order to facilitate interpretation of results and enhance the chance of viral control.

Ambrisentan use in a HIV-1 infected patient with end-stage renal disease and pulmonary hypertension: minimal removal by hemodialysis - a case report.

BACKGROUND: Ambrisentan is a selective endothelin receptor antagonist used for the treatment of pulmonary arterial hypertension (PAH). Little is known about ambrisentan removal by hemodialysis in patients with end-stage renal disease (ESRD). CASE PRESENTATION: A 53-year-old woman with HIV/hepatitis C virus (HCV) co-infection, PAH and ESRD on regular hemodialyis was admitted in our hospital due to refractory heart failure while on treatment with bosentan (125 mg twice daily) and tadalafil (20 mg once daily) for PAH and antiretroviral treatment (cART) including darunavir/cobicistat (800/150 mg once daily). Excessive exposure to bosentan due to drug interactions between bosentan and darunavir/cobicistat was suspected. Bosentan was replaced by ambrisentan, with progressive improvement in her clinical condition. Pre- and postdialyzer cocentrations of ambrisentan in plasma were determined and hemodialysis extraction ratio for ambrisentan was 2%. CONCLUSIONS: Our results suggest that hemodialysis results in minimal ambrisentan removal, and therefore no specific ambrisentan dosage adjustment seems to be required in ESRD patients undergoing hemodialysis.

Effect of mono/dual antiretroviral therapy on suppression of HCV and HIV during treatment of HCV infection in HIV/HCV-coinfected patients / Efecto de la terapia antirretroviral mono/dual sobre la supresión de VHC y VIH durante el tratamiento de la infección por VHC en pacientes co-infectados de VIH/VHC

OBJECTIVE: Data of hepatitis C treatment with direct-acting antivirals (DAAs) in HIV infected patients are limited to a few number of antiretroviral therapies (ART). The aim of this study was to assess the effectiveness and safety of non-conventional ART as monotherapy or dual therapy (MDT) when combined with DAA. METHODS: Retrospective review of HIV/HCV-coinfected patients treated with DAAs during one year in 3 centers. Sustained virologic response 12 weeks after therapy (SVR) and maintenance of HIV viral suppression were compared between patients receiving triple ART (TT) or MDT. RESULTS: Overall 485 patients were included (359 receiving TT and 126 MDT). HCV SVR was 93.4% (95%CI, 90.8% to 95.3%) in the intention-to-treat analysis without differences between groups: 92.8% on TT vs 95.2% on MDT (p = 0.3). HCV virological failure was associated with lower CD4 + cell count at baseline (for every 100-cell/μl increment: OR, 0.8; 95%CI, 0.7-0.9; p = 0.01) and with liver stiffness (for every 10-unit increment: OR, 1.5; 95%CI 1.2-1.8; p < 0.01). HIV-RNA during HCV treatment or 12 weeks after was detectable in 23 patients on TT (6.6%) and 9 (7.2%) patients on MDT (p = 0.8). The median (IQR) change in CD4 + cell count was not significantly different between the groups: 15 (-55 to 115) in TT vs -12 (-68 to 133) cells/μl in MDT (p = 0.8). CONCLUSION: DAAs obtain high rates of SVR among HIV/HCV-coinfected patients independently of whether TT or non-conventional ART is used. Suppression of HIV was maintained in both groups

OBJETIVO: Los datos sobre el tratamiento de la hepatitis C con antivirales de acción directa (AAD) en los pacientes infectados por VIH se limitan a un escaso número de terapias antirretrovirales (TARV). El objetivo de este estudio fue valorar la efectividad y seguridad de las TARV no convencionales, como monoterapia y terapia dual (MDT), al combinarse con AAD. MÉTODOS: Revisión retrospectiva de pacientes co-infectados por VIH/VHC, tratados con AAD durante un año en 3 centros. Se comparó la respuesta virológica sostenida (RVS) a las 12 semanas de la terapia, y el mantenimiento de la supresión viral del VIH, entre los pacientes que recibieron triple TARV o MDT. RESULTADOS: Se incluyó a un total de 485 pacientes (359 que recibieron triple TARV y 126 que recibieron MDT). La RVS de VHC fue del 93,4% (IC 95%: 90,8-95,3%) en el análisis por intención de tratar, sin diferencias entre grupos: 92,8% en el grupo triple TARV vs. 95,2% en el grupo MDT (p = 0,3). El fracaso virológico de VHC se asoció a un menor recuento basal de células CD4+ (para cada incremento de 100células/μl: OR: 0,8; IC 95%: 0,7-0,9; p = 0,01) y a la rigidez hepática (para cada incremento de 10 unidades: OR: 1,5; IC 95%: 1,2-1,8; p < 0,01). El ARN-VIH durante el tratamiento de VHC, o transcurridas 12 semanas, fue detectable en 23 pacientes en el grupo triple TARV (6,6%) y 9 (7,2%) pacientes en el grupo MDT (p = 0,8). El cambio medio (RIC) en el recuento de células CD4 + no fue significativamente diferente entre ambos grupos: 15 (de -55-115) en el grupo triple TARV vs. -12 (de -68-133) células/μl en el grupo MDT (p = 0,8). CONCLUSIÓN: Los AAD obtienen tasas altas de RVS entre los pacientes co-infectados de VIH/VHC, independientemente de si se utiliza triple TARV o TARV no convencional. La supresión de VIH se mantuvo en ambos grupos

Effect of mono/dual antiretroviral therapy on suppression of HCV and HIV during treatment of HCV infection in HIV/HCV-coinfected patients.

OBJECTIVE: Data of hepatitis C treatment with direct-acting antivirals (DAAs) in HIV infected patients are limited to a few number of antiretroviral therapies (ART). The aim of this study was to assess the effectiveness and safety of non-conventional ART as monotherapy or dual therapy (MDT) when combined with DAA. METHODS: Retrospective review of HIV/HCV-coinfected patients treated with DAAs during one year in 3 centers. Sustained virologic response 12 weeks after therapy (SVR) and maintenance of HIV viral suppression were compared between patients receiving triple ART (TT) or MDT. RESULTS: Overall 485 patients were included (359 receiving TT and 126 MDT). HCV SVR was 93.4% (95%CI, 90.8% to 95.3%) in the intention-to-treat analysis without differences between groups: 92.8% on TT vs 95.2% on MDT (p=0.3). HCV virological failure was associated with lower CD4+cell count at baseline (for every 100-cell/µl increment: OR, 0.8; 95%CI, 0.7-0.9; p=0.01) and with liver stiffness (for every 10-unit increment: OR, 1.5; 95%CI 1.2-1.8; p<0.01). HIV-RNA during HCV treatment or 12 weeks after was detectable in 23 patients on TT (6.6%) and 9 (7.2%) patients on MDT (p=0.8). The median (IQR) change in CD4+cell count was not significantly different between the groups: 15 (-55 to 115) in TT vs -12 (-68 to 133) cells/µl in MDT (p=0.8). CONCLUSION: DAAs obtain high rates of SVR among HIV/HCV-coinfected patients independently of whether TT or non-conventional ART is used. Suppression of HIV was maintained in both groups.