Clinical and Economic Impact of Ibalizumab for People With Multidrug-Resistant HIV in the United States

A Synthetic Multivalent Lipopeptide Derived from Pam3CSK4 with Irreversible Influenza Inhibition and Immuno-Stimulating Effects

The activation of the host adaptive immune system is crucial for eliminating viruses. However, influenza infection often suppresses the innate immune response that precedes adaptive immunity, and the adaptive immune responses are typically delayed. Dendritic cells, serving as professional antigen-presenting cells, have a vital role in initiating the adaptive immune response. In this study, an immuno-stimulating antiviral system (ISAS) is introduced, which is composed of the immuno-stimulating adjuvant lipopeptide Pam3CSK4 that acts as a scaffold onto which it is covalently bound 3 to 4 influenza-inhibiting peptides. The multivalent display of peptides on the scaffold leads to a potent inhibition against H1N1 (EC50  = 20 nM). Importantly, the resulting lipopeptide, Pam3FDA, shows an irreversible inhibition mechanism. The chemical modification of peptides on the scaffold maintains Pam3CSK4's ability to stimulate dendritic cell maturation, thereby rendering Pam3FDA a unique antiviral. This is attributed to its immune activation capability, which also acts in synergy to expedite viral elimination.

DNA damage contributes to age-associated differences in SARS-CoV-2 infection

Coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is known to disproportionately affect older individuals. How aging processes affect SARS-CoV-2 infection and disease progression remains largely unknown. Here, we found that DNA damage, one of the hallmarks of aging, promoted SARS-CoV-2 infection in vitro and in vivo. SARS-CoV-2 entry was facilitated by DNA damage caused by extrinsic genotoxic stress or telomere dysfunction and hampered by inhibition of the DNA damage response (DDR). Mechanistic analysis revealed that DDR increased expression of angiotensin-converting enzyme 2 (ACE2), the primary receptor of SARS-CoV-2, by activation of transcription factor c-Jun. Importantly, in vivo experiment using a mouse-adapted viral strain also verified the significant roles of DNA damage in viral entry and severity of infection. Expression of ACE2 was elevated in the older human and mice tissues and positively correlated with γH2AX, a DNA damage biomarker, and phosphorylated c-Jun (p-c-Jun). Finally, nicotinamide mononucleotide (NMN) and MDL-800, which promote DNA repair, alleviated SARS-CoV-2 infection and disease severity in vitro and in vivo. Taken together, our data provide insights into the age-associated differences in SARS-CoV-2 infection and a novel approach for antiviral intervention.

Rational Design and In Vivo Characterization of mRNA-Encoded Broadly Neutralizing Antibody Combinations against HIV-1

Monoclonal antibodies have been used successfully as recombinant protein therapy; however, for HIV, multiple broadly neutralizing antibodies may be necessary. We used the mRNA-LNP platform for in vivo co-expression of 3 broadly neutralizing antibodies, PGDM1400, PGT121, and N6, directed against the HIV-1 envelope protein. mRNA-encoded HIV-1 antibodies were engineered as single-chain Fc (scFv-Fc) to overcome heavy- and light-chain mismatch. In vitro neutralization breadth and potency of the constructs were compared to their parental IgG form. We assessed the ability of these scFv-Fcs to be expressed individually and in combination in vivo, and neutralization and pharmacokinetics were compared to the corresponding full-length IgGs. Single-chain PGDM1400 and PGT121 exhibited neutralization potency comparable to parental IgG, achieving peak systemic concentrations ≥ 30.81 μg/mL in mice; full-length N6 IgG achieved a peak concentration of 974 μg/mL, but did not tolerate single-chain conversion. The mRNA combination encoding full-length N6 IgG and single-chain PGDM1400 and PGT121 was efficiently expressed in mice, achieving high systemic concentration and desired neutralization potency. Analysis of mice sera demonstrated each antibody contributed towards neutralization of multiple HIV-1 pseudoviruses. Together, these data show that the mRNA-LNP platform provides a promising approach for antibody-based HIV treatment and is well-suited for development of combination therapeutics.

A Protein-Based, Long-Acting HIV-1 Fusion Inhibitor with an Improved Pharmacokinetic Profile

Recently, a series of highly effective peptide- or protein-based HIV fusion inhibitors have been identified. However, due to their short half-life, their clinical application is limited. Therefore, the development of long-acting HIV fusion inhibitors is urgently needed. Here, we designed and constructed a protein-based, long-acting HIV fusion inhibitor, termed FLT (FN3-L35-T1144), consisting of a monobody, FN3, which contains an albumin-binding domain (ABD), a 35-mer linker (L35), and a peptide-based HIV fusion inhibitor, T1144. We found that FLT bound, via its FN3 component, with human serum albumin (HSA) in a reversible manner, thus maintaining the high efficiency of T1144 against infection by both HIV-1 IIIB (X4) and Bal (R5) strains with IC₅₀ of 11.6 nM and 15.3 nM, respectively, and remarkably prolonging the half-life of T1144 (~27 h in SD rats). This approach affords protein-based HIV fusion inhibitors with much longer half-life compared to enfuvirtide, a peptide-based HIV fusion inhibitor approved for use in clinics. Therefore, FLT is a promising candidate as a new protein-based anti-HIV drug with an improved pharmacokinetic profile.

Achieving virological control in pan-resistant HIV-1 infection: A case series

Background

HIV-1 pan-resistance refers to a reduced susceptibility to nucleoside reverse transcriptase inhibitors, non-nucleoside reverse transcriptase inhibitors, protease inhibitors and integrase strand tranfer inhibitors. Although still anecdotal, its management remains a concern both for affected people living with HIV (PLWH) and for public health.

Methods

We described genotypic resistance testing (GRT) of three PLWH with a documented poor virological response to previous antiretroviral therapies, who started ibalizumab, an anti-CD4 monoclonal antibody, combined with an optimized background therapy. Both historical and most recent GRT on plasma RNA and peripheral blood mononuclear cell DNA were interpreted according to the Stanford HIVDb version 9.0 (last updated on 22 February, 2021). After the switch to a regimen including the monoclonal antibody, HIV-1 RNA has been quantified biweekly (PCR Cobas® HIV-1 test 6800 Systems, Roche Diagnostics). Follow-up was censored at data freezing (16 January, 2021).

Findings

We report findings from heavily treatment-experienced PLWH with a pan-resistant HIV-1 infection, who achieved virological control once introduced injections of ibalizumab, that is free from cross-resistance with all the antiretroviral drugs available and ensures patient adherence due to a close monitoring attributable to the route of administration, combined with recycled enfuvirtide and an optimized background regimen, selected on the basis of an accurate evaluation of resistance mutations.

Interpretation

In these cases, this new approach has revealed to be a turning point in achieving virological control.

Funding

None, this research was supported by internal funding.

Exploring the application of immunotherapy against HIV infection in the setting of malignancy: A detailed review article

According to the Joint United Nations Programme on HIV/AIDS (UNAIDS), as of 2019, approximately 42.2 million people have died from acquired immunodeficiency syndrome (AIDS)-related illnesses since the start of the epidemic. Antiretroviral therapy (ART) has significantly reduced mortality, morbidity, and incidence of the human immunodeficiency virus (HIV)/AIDS-defining cancers, taming once-dreaded disease into a benign chronic infection. Although the treatment has prolonged the patients' survival, general HIV prevalence has increased and this increase has dovetailed with an increasing incidence of Non-AIDS-defining cancers (NADCs) among people living with HIV (PLWH). This is happening when new promising approaches in both oncology and HIV infection are being developed. This review focuses on recent progress witnessed in immunotherapy approaches against HIV-related, Non-AIDS-defining cancers (NADCs), and HIV infection.

The Cost-Effectiveness and Budget Impact of Ibalizumab-uiyk for Adults with Multidrug-Resistant HIV-1 Infection in the United States

BACKGROUND

Ibalizumab-uiyk (ibalizumab) is a first-in-class, long-acting, postattachment HIV-1 inhibitor for adults with multidrug-resistant (MDR) HIV-1 infection. This analysis examines the cost-effectiveness and budget impact of ibalizumab treatment for this difficult-to-treat population in the United States.

METHODS

A Markov model followed cohorts of adults with MDR HIV-1 infection through two final lines of antiretroviral therapy: ibalizumab + optimized background therapy (OBT) or OBT alone followed by nonsuppressive therapy. Model inputs were based on ibalizumab clinical trial data, market uptake projections, and published literature, with costs in 2019 dollars. The cost-effectiveness analysis assessed costs and health outcomes from a health care sector perspective for individuals receiving ibalizumab + OBT versus OBT alone over a lifetime time horizon. The budget-impact analysis estimated the impact on payer budgets of the introduction of ibalizumab over 3 years for a hypothetical commercial health plan.

RESULTS

Compared with individuals receiving OBT alone, individuals receiving ibalizumab + OBT incurred higher costs but lived longer, healthier lives, with an incremental cost of $133,040 per QALY gained. For a hypothetical commercial health plan with 1 million members, the introduction of ibalizumab + OBT was estimated to increase budgets by $217,260, $385,245, and $560,310 ($0.018, $0.032, and $0.047 per member per month) in years 1, 2, and 3, respectively. These results were found to be robust in sensitivity and scenario analyses.

CONCLUSIONS

Ibalizumab may represent a cost-effective and affordable option to improve health outcomes for individuals with MDR HIV-1 infection.

Fostemsavir: The first oral attachment inhibitor for treatment of HIV-1 infection

PURPOSE

The pharmacology, pharmacokinetics, and role in therapy of fostemsavir in management of HIV-1 infection are reviewed, with an emphasis on clinical efficacy and safety data from phase 2 and phase 3 clinical trials.

SUMMARY

Fostemsavir (Rukobia, ViiV Healthcare), is a prodrug of temsavir, a novel pyridine compound with potent activity against HIV-1. Fostemsavir, the first oral attachment inhibitor, was approved and granted the breakthrough therapy designation by the Food and Drug Administration for use in combination with other antiretroviral agents for the treatment of HIV-1 infection in heavily treatment-experienced adults. As absorption of temsavir is not altered with increased gastric pH, patients may take acid suppressive agents such as famotidine during fostemsavir therapy.Temsavir is primarily metabolized through hydrolysis but also via cytochrome P-450 (CYP) oxidation; therefore, coadministration of fostemsavir with strong CYP3A inducers such as rifampin, carbamazepine, phenytoin, mitotane, enzalutamide, or St John's wort is contraindicated because it may result in significantly lower temsavir exposure, which can ultimately impair virologic response. The most common adverse reactions associated with fostemsavir use include nausea, diarrhea, headache, abdominal pain, dyspepsia, fatigue, rash, and sleep disturbance.

CONCLUSION

Fostemsavir may be an effective option for heavily treatment-experienced adults with multidrug-resistant HIV-1 infection. Fostemsavir is a particularly attractive treatment option for patients who are no longer able to achieve viral suppression with use of currently available antiretroviral therapies and who are able to adhere to a twice-daily oral regimen.

Antiretroviral Drugs for Treatment and Prevention of HIV Infection in Adults: 2020 Recommendations of the International Antiviral Society-USA Panel

Importance

Data on the use of antiretroviral drugs, including new drugs and formulations, for the treatment and prevention of HIV infection continue to guide optimal practices.

Objective

To evaluate new data and incorporate them into current recommendations for initiating HIV therapy, monitoring individuals starting on therapy, changing regimens, preventing HIV infection for those at risk, and special considerations for older people with HIV.

Evidence Review

New evidence was collected since the previous International Antiviral (formerly AIDS) Society-USA recommendations in 2018, including data published or presented at peer-reviewed scientific conferences through August 22, 2020. A volunteer panel of 15 experts in HIV research and patient care considered these data and updated previous recommendations.

Findings

From 5316 citations about antiretroviral drugs identified, 549 were included to form the evidence basis for these recommendations. Antiretroviral therapy is recommended as soon as possible for all individuals with HIV who have detectable viremia. Most patients can start with a 3-drug regimen or now a 2-drug regimen, which includes an integrase strand transfer inhibitor. Effective options are available for patients who may be pregnant, those who have specific clinical conditions, such as kidney, liver, or cardiovascular disease, those who have opportunistic diseases, or those who have health care access issues. Recommended for the first time, a long-acting antiretroviral regimen injected once every 4 weeks for treatment or every 8 weeks pending approval by regulatory bodies and availability. For individuals at risk for HIV, preexposure prophylaxis with an oral regimen is recommended or, pending approval by regulatory bodies and availability, with a long-acting injection given every 8 weeks. Monitoring before and during therapy for effectiveness and safety is recommended. Switching therapy for virological failure is relatively rare at this time, and the recommendations for switching therapies for convenience and for other reasons are included. With the survival benefits provided by therapy, recommendations are made for older individuals with HIV. The current coronavirus disease 2019 pandemic poses particular challenges for HIV research, care, and efforts to end the HIV epidemic.

Conclusion and Relevance

Advances in HIV prevention and management with antiretroviral drugs continue to improve clinical care and outcomes among individuals at risk for and with HIV.

Antibody-based strategies in HIV therapy

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Antibody therapies offer a unique mechanism of action, decreased resistance and improved safety.

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Ibalizumab is a CD4 post-attachment inhibitor and leronlimab is a CCR5 inhibitor.

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Ibalizumab is approved for multi-drug-resistant human immunodeficiency virus (MDR HIV) treatment in combination with antiretroviral therapy.

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Leronlimab is being studied for treatment of MDR HIV and as maintenance monotherapy.

Antibody-based strategies have been introduced for a number of disease states, but represent a novel approach in the management of human immunodeficiency virus (HIV). Ibalizumab and leronlimab are monoclonal antibodies with unique mechanisms as a CD4-directed post-attachment inhibitor and a C-C chemokine receptor type 5-directed inhibitor, respectively. These antibody-based strategies are generally well tolerated, have a favourable pharmacokinetic profile allowing for less-frequent dosing, and have a high barrier to resistance. Ibalizumab is currently approved by the US Food and Drug Administration (US FDA) for management of multi-drug-resistant (MDR) HIV infection in patients who are failing their current regimens. Clinical data demonstrated impressive antiretroviral activity with ibalizumab among a complex HIV population in combination with an optimized background regimen, where limited therapeutic options exist. To date, leronlimab has not been granted approval by the US FDA, but has been designated fast-track status. Leronlimab is being studied as a maintenance monotherapy agent in virologically suppressed patients, as well as for treatment of MDR HIV infection in patients who are failing their current regimens. Currently available data in both of these potential areas appear promising for leronlimab. The mechanism of action, pharmacokinetic profile, efficacy and safety of these novel antibody-based strategies represent an advance in the management of HIV. Future studies and post-marketing experience will further determine longer-term clinical efficacy, safety and resistance data for ibalizumab and leronlimab.

Ibalizumab: The First Monoclonal Antibody for the Treatment of HIV-1 Infection

OBJECTIVE

To review the efficacy and safety of ibalizumab (IBA) in the treatment of HIV-1 infection.

DATA SOURCES

A literature search was performed using PubMed and Google Scholar (2010 to mid-June 2020) with the search terms TMB-355, TNX-355, and ibalizumab. Other resources included abstracts presented at recent conferences and the manufacturer's website and prescribing information.

STUDY SELECTION AND DATA EXTRACTION

All relevant English-language articles of studies assessing the efficacy and safety of IBA were included.

DATA SYNTHESIS

IBA is a monoclonal antibody that blocks HIV-1 from infecting CD4+ T cells. IBA is approved by the Food and Drug Administration, in combination with other antiretrovirals (ARVs), for the treatment of HIV-1 infection in heavily treatment-experienced adults with multidrug-resistant (MDR) HIV-1 infection failing their current ARVs. IBA demonstrated significant and sustained antiviral activity in patients with MDR HIV-1 infection who had advanced disease and limited treatment options. It carries a warning regarding the development of immune reconstitution inflammatory syndrome. Common adverse reactions include diarrhea, dizziness, nausea, and rash.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

IBA represents an attractive option for treatment-experienced adults with advanced HIV-1 infection who are no longer able to achieve viral suppression on oral ARV therapy alone and who are able to adhere to an infusion therapy every 2 weeks. As with other biologics, there is a potential for the development of antibodies to IBA that can compromise its efficacy and safety.

CONCLUSION

IBA provides a needed treatment option to achieve and maintain viral suppression in heavily treatment-experienced adults with MDR HIV-1 infection.