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.

Purpose of review 

Antiretroviral options for patients infected with multiclass resistant HIV-1 warrant the development of new agents with unique mechanisms of action and modes of delivery. Here we review one such agent, ibalizumab, a parenteral CD4 postattachment inhibitor that has demonstrated efficacy as part of combination antiretroviral therapy in the treatment of HIV-1.

Recent findings 

In a phase III clinical trial in HIV-infected participants with multiclass antiretroviral drug resistance, the intravenous administration of ibalizumab led to declines in plasma HIV-1 RNA more than 0.5 log in 83% of participants at 1 week. An optimized background antiretroviral regimen was then added, and plasma HIV-1 RNA became less than 50 copies/ml in 43% of participants at 24 weeks. Adverse effects of ibalizumab were uncommon and generally low grade. Ibalizumab was approved by the US Food and Drug Administration on March 16, 2018, under the trade name Trogarzo.

Summary 

Ibalizumab has demonstrated both safety and efficacy in the treatment of HIV-1 infection. Its primary use will be in the setting of multidrug resistant virus as part of combination antiretroviral therapy. Further enhancements of ibalizumab to prolong its clearance and broaden its activity are in development.