Randomized Trial of Food Effect on Pharmacokinetic Parameters of ABX464 Administered Orally to Healthy Male Subjects

Impact of Obefazimod on Viral Persistence, Inflammation, and Immune Activation in People With Human Immunodeficiency Virus on Suppressive Antiretroviral Therapy

BACKGROUND

Persistence of viral reservoirs has been observed in people with human immunodeficiency virus (HIV), despite long-term antiretroviral therapy (ART), and likely contributes to chronic immune activation and inflammation. Obefazimod is a novel drug that inhibits human immunodeficiency virus type 1 (HIV-1) replication and reduces inflammation. Here we assess whether obefazimod is safe and might impact HIV-1 persistence, chronic immune activation, and inflammation in ART-suppressed people with HIV.

METHODS

We evaluated obefazimod-related adverse events, changes in cell-associated HIV-1 DNA and RNA, residual viremia, immunophenotype, and inflammation biomarkers in blood and rectal tissue. We compared 24 ART-suppressed people with HIV who received daily doses of 50 mg obefazimod for 12 weeks (n = 13) or 150 mg for 4 weeks (n = 11) and 12 HIV-negative individuals who received 50 mg for 4 weeks.

RESULTS

The 50- and 150-mg doses of obefazimod were safe, although the 150-mg dose showed inferior tolerability. The 150-mg dose reduced HIV-1 DNA (P = .008, median fold change = 0.6) and residual viremia in all individuals with detectable viremia at baseline. Furthermore, obefazimod upregulated miR-124 in all participants and reduced the activation markers CD38, HLA-DR, and PD-1 and several inflammation biomarkers.

CONCLUSIONS

The effect of obefazimod by reducing chronic immune activation and inflammation suggests a potential role for the drug in virus remission strategies involving other compounds that can activate immune cells, such as latency-reversing agents.

ABX464 (obefazimod) for patients with COVID-19 at risk for severe disease: miR-AGE, a randomized, double-blind placebo-controlled trial

Background

ABX464 (obefazimod) is a small molecule that upregulates a single microRNA (miR-124) in immune cells and reduces the production of various inflammatory cytokines and chemokines.

Objective

We assessed the efficacy and safety of the standard of care (SoC) plus oral obefazimod (SoC plus ABX464), 50 mg once daily, versus the SoC plus placebo for prevention of severe acute respiratory syndrome in patients with coronavirus disease 2019 (COVID-19) who are at risk for severe disease.

Methods

Eligible patients for this phase 2/3 double-blind, placebo-controlled miR-AGE study were randomized (2:1) into 2 groups: SoC-ABX464 (n = 339) and SoC-placebo (n = 170). The primary end point was the percentage of patients who did not require use of high-flow oxygen or invasive or noninvasive mechanical ventilation within 28 days. The safety analyses included patients who had been randomly assigned and had received at least 1 dose of the study treatment.

Results

At the time of the interim analysis, obefazimod showed no benefit over placebo when added to the SoC; the study enrollment was stopped for futility. The evaluation of the safety of obefazimod in 505 patients showed significantly more treatment-emergent adverse events in the SoC-ABX464 group than in the SoC-placebo group (P = .007). Frequently reported AEs in the SoC-ABX464 group included headache (14.6%), abdominal pain (9.6%), diarrhea (9.0%), back pain (6.9%), and nausea (6.0%). No treatment-related changes in laboratory parameters were reported.

Conclusion

For patients who have severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and are at risk for severe COVID-19, obefazimod, 50 mg, provided no benefit over placebo when added to the SoC, although it did have a good safety profile (comparable to that reported in many therapeutic areas).

MicroRNAs in T Cell-Immunotherapy

MicroRNAs (miRNAs) act as master regulators of gene expression in homeostasis and disease. Despite the rapidly growing body of evidence on the theranostic potential of restoring miRNA levels in pre-clinical models, the translation into clinics remains limited. Here, we review the current knowledge of miRNAs as T-cell targeting immunotherapeutic tools, and we offer an overview of the recent advances in miRNA delivery strategies, clinical trials and future perspectives in RNA interference technologies.

Strategies to Modulate MicroRNA Functions for the Treatment of Cancer or Organ Injury

Cancer and organ injury-such as that occurring in the perioperative period, including acute lung injury, myocardial infarction, and acute gut injury-are among the leading causes of death in the United States and impose a significant impact on quality of life. MicroRNAs (miRNAs) have been studied extensively during the last two decades for their role as regulators of gene expression, their translational application as diagnostic markers, and their potential as therapeutic targets for disease treatment. Despite promising preclinical outcomes implicating miRNA targets in disease treatment, only a few miRNAs have reached clinical trials. This likely relates to difficulties in the delivery of miRNA drugs to their targets to achieve efficient inhibition or overexpression. Therefore, understanding how to efficiently deliver miRNAs into diseased tissues and specific cell types in patients is critical. This review summarizes current knowledge on various approaches to deliver therapeutic miRNAs or miRNA inhibitors and highlights current progress in miRNA-based disease therapy that has reached clinical trials. Based on ongoing advances in miRNA delivery, we believe that additional therapeutic approaches to modulate miRNA function will soon enter routine medical treatment of human disease, particularly for cancer or perioperative organ injury. SIGNIFICANCE STATEMENT: MicroRNAs have been studied extensively during the last two decades in cancer and organ injury, including acute lung injury, myocardial infarction, and acute gut injury, for their regulation of gene expression, application as diagnostic markers, and therapeutic potentials. In this review, we specifically emphasize the pros and cons of different delivery approaches to modulate microRNAs, as well as the most recent exciting progress in the field of therapeutic targeting of microRNAs for disease treatment in patients.

Safety, tolerability and impact on viral reservoirs of the addition to antiretroviral therapy of ABX464, an investigational antiviral drug, in individuals living with HIV-1: a Phase IIa randomised controlled study

OBJECTIVES

To assess the safety and tolerability as well as antiretroviral impact of ABX464, an oral investigational drug with a novel mechanism of HIV-1 inhibition (ClinicalTrials.gov NCT02735863).

METHODS

Randomised, double-blind, placebo-controlled, Phase IIa study in individuals living with HIV-1 on antiretroviral therapy at six clinical centres in Spain, France and Belgium. ABX464 was administered once a day to 22 fully controlled HIV-1-positive participants at two doses (50 mg, n=6 and 150 mg, n=16) versus placebo, which was given to eight participants for 28 days in combination with a boosted protease inhibitor (darunavir/ritonavir or darunavir/cobicistat). The primary objective of the study was to assess ABX464 safety and tolerability when used in combination with darunavir boosted therapy. The secondary objective was to study antiretroviral efficacy on viral reservoirs using time to viral rebound following treatment interruption. The impact of ABX464 on HIV-1 reservoirs was further assessed by measuring levels of total HIV-1 in peripheral blood mononuclear cells (PBMCs) in the intervention arm versus placebo. A positive response was defined as an absolute reduction in HIV-1 DNA of at least 50 copies/10⁶ PBMCs and a relative decrease >25% of HIV-1 DNA level.

RESULTS

Twenty-six of the 30 randomly allocated participants completed the study according to the study protocol. ABX464 was found to be safe and well tolerated with the majority of adverse events (AEs) being mild or moderate. Of the participants, 22 (73.3%) experienced treatment-associated AEs (93.8%, 66.7%, 37.5% in the ABX464 150-mg, 50-mg dose and placebo arms, respectively). Percentages for combined grade 3/4 AEs for the three arms were 6.3%, 0% and 12.5%, respectively. Median time (Kaplan-Meier estimates) to viral rebound for ABX464 150-mg, 50-mg and placebo arms were 12.0 (95% confidence interval [CI]: 10-15), 15.5 (95% CI 14-22) and 15.5 (95% CI 1-22) days, respectively with no significant difference between the 150-mg treatment arm and placebo. Median changes in total HIV-1 DNA copies/10⁶ PBMCs for ABX464 150-mg, 50-mg and placebo arms after 28 days of treatment were -40 (range -434 to +194), -115 (range -116 to -114) and 25 (range -35 to +218), respectively, showing a decrease in the intervention arms. There were 6/14, 2/2, and 0/4 responders for ABX464 150 mg, 50 mg and placebo, respectively. No significant difference was seen between treatment arms and placebo with respect to these virological parameters.

CONCLUSIONS

This small controlled study confirmed the good safety and tolerability of ABX464 and provides some evidence of a potential reduction of the HIV-1 reservoir in terms of HIV-1 DNA levels in PBMCs when it was added to an HIV-1 protease inhibitor-based regimen. These results will need to be confirmed in a larger study.

The Anti-Hiv Candidate Abx464 Dampens Intestinal Inflammation by Triggering Il-22 Production in Activated Macrophages

The progression of human immunodeficiency virus (HIV) is associated with mucosal damage in the gastrointestinal (GI) tract. This damage enables bacterial translocation from the gut and leads to subsequent inflammation. Dextran sulfate sodium (DSS-exposure) is an established animal model for experimental colitis that was recently shown to recapitulate the link between GI-tract damage and pathogenic features of SIV infection. The current study tested the protective properties of ABX464, a first-in-class anti-HIV drug candidate currently in phase II clinical trials. ABX464 treatment strongly attenuated DSS-induced colitis in mice and produced a long-term protection against prolonged DSS-exposure after drug cessation. Consistently, ABX464 reduced the colonic production of the inflammatory cytokines IL-6 and TNFα as well as that of the chemoattractant MCP-1. However, RNA profiling analysis revealed the capacity of ABX464 to induce the expression of IL-22, a cytokine involved in colitis tissue repair, both in DSS-treated mice and in LPS-stimulated bone marrow-derived macrophages. Importantly, anti-IL-22 antibodies significantly reduced the protective effect of ABX464 on colitis in DSS-treated mice. Because reduced IL-22 production in the gut mucosa is an established factor of HIV and DSS-induced immunopathogenesis, our data suggest that the anti-inflammatory properties of ABX464 warrant exploration in both HIV and inflammatory ulcerative colitis (UC) disease.

Safety, Pharmacokinetics, and Antiviral Activity of a Novel HIV Antiviral, ABX464, in Treatment-Naive HIV-Infected Subjects in a Phase 2 Randomized, Controlled Study

We investigated the safety and antiviral effects of an anti-HIV compound (ABX464) with a unique mechanism of viral replication inhibition. This was a randomized, double-blind, placebo-controlled, dose-ranging study in treatment-naive HIV-infected patients. Participants were assigned to eight groups; each group included eight subjects receiving either the study compound, ABX464 (n = 6), or the corresponding placebo (n = 2), according to a randomization code. The first dose administered was 25 mg, given once or 3 times a day over a 2- to 3-week period. Ascending doses of up to 150 mg were delivered after review of the safety data. The primary objective of the study was to assess the safety and tolerability of ABX464 after repeated oral administrations in subjects infected by HIV. Sixty-six subjects were enrolled and were randomized. Sixty-three subjects completed the study according to the study protocol. Twenty-one adverse events (AEs) were reported by 7 subjects out of 16 (44%) who received placebo, and 158 AEs were reported by 39 subjects out of 50 (78%) who received the study drug. In the ABX464 treatment group, all of these adverse events were mild to moderate. No subjects discontinued treatment due to drug-related AEs. Administration of ABX464 at up to 150 mg once a day was safe and well tolerated in HIV-infected subjects. An efficacy signal with respect to a reduction of the viral load by ABX464 was detected, mainly in subjects treated at the highest dose. Further studies will be required to demonstrate antiviral effects in HIV-infected subjects in combination with other antiretroviral therapies. (This study is registered on the ClinicalTrials.gov website under registration no. NCT02452242.)