TheBodyPRO Covers CROI 2018


Ibalizumab Phase 3 Results and Susceptibility to Drug-Resistant HIV

March 28, 2018

CROI 2018 included a poster on the most recent HIV drug, ibalizumab, which was given FDA approval in the US during the conference week.

Ibalizumab is a monoclonal antibody that post-attachment, blocks HIV entry into cells while preserving normal CD4 functions. After an initial loading dose, it is given by infusion every two weeks.

Baseline susceptibility data was presented for 38/40 highly treatment-experienced participants in the 24-week, single arm, phase 3 TBM-301 study. At baseline, 50% of participants had resistance to at least three classes, with major mutations to NRTIs, NNRTIs, PIs and INIs on 93%, 85%, 83% and 61%, respectively.


Results from the main study were previously reported in HTB last year, but in summary, include 83% of participants meeting the primary endpoint of >0.5 log reduction in viral load seven days after adding a single dose as virtual monotherapy to the background failing combination and mean viral load reduction of 1.1 log copies/mL. Background ART was then optimised with 24-week follow-up. [3]

At week 24, viral load was <50 copies/mL in 43% (50% < 200 c/mL) with median viral load reductions of 1.6 log at week 24.

The poster at CROI presented results of in vitro analysis showing that ibalizumab retained sensitivity irrespective of baseline resistance to NRTIs, NNRTIs, PIs and INSTIs.


Although ibalizumab is not currently approved in the EU, the company are actively pursuing the regulatory pathway in Europe.


  1. Weinheimer S et al. Ibalizumab susceptibility in patient HIV isolates resistant to antiretrovirals. 25th CROI, 4-7 March 2018, Boston. Poster abstract 561. (abstract and poster)
  2. HTB. FDA approves ibalizumab in the US to treat multidrug HIV resistance. (06 March 2018).
  3. HTB. Ibalizumab infusion reduces viral load in people with HIV multi-drug resistance. HTB (29 November 2017).

[Note from TheBodyPRO: This article was originally published by HIV i-Base on March 28, 2018. We have cross-posted it with their permission.]

Related Stories

An Overview of Trogarzo (Ibalizumab-Uiyk)

This article was provided by HIV i-Base. It is a part of the publication The 25th Conference on Retroviruses and Opportunistic Infections. Visit HIV i-Base's website to find out more about their activities, publications and services.

No comments have been made.

Add Your Comment:
(Please note: Your name and comment will be public, and may even show up in
Internet search results. Be careful when providing personal information! Before
adding your comment, please read's Comment Policy.)

Your Name:

Your Location:

(ex: San Francisco, CA)

Your Comment:

Characters remaining:

Please note: Knowledge about HIV changes rapidly. Note the date of this summary's publication, and before treating patients or employing any therapies described in these materials, verify all information independently. If you are a patient, please consult a doctor or other medical professional before acting on any of the information presented in this summary. For a complete listing of our most recent conference coverage, click here.


The content on this page is free of advertiser influence and was produced by our editorial team. See our content and advertising policies.