Advertisement covers ASM/ICAAC 2016


Weekly PRO 140 Antibody Injections May Work as HIV Maintenance Therapy

June 20, 2016

Weekly injections of a monoclonal antibody known as PRO 140 may work as a stand-alone treatment for individuals living with HIV, according to a study presented at ASM Microbe 2016, in Boston.

The phase-2b study followed 39 people who were living with CCR5-tropic HIV. CCR5 is a receptor on the CD4 cell that most strains of HIV use as a point of entry. PRO 140 is able to bind to CCR5, preventing HIV infection.

The study participants achieved undetectable viral loads (below 40 copies/mL) on standard once-daily antiretroviral therapy. They were then switched to weekly subcutaneous injections of PRO 140 monotherapy. After they maintained viral suppression for 13 weeks, 16 participants were trained to self-administer the weekly injections.


There were 15 participants included in the final results, with 86.7% male, 20% non-white, a median age of 55 years and median CD4 count of 586 cells/mm3. Out of those 15, 10 participants are still on PRO 140 monotherapy and have maintained viral suppression for almost 18 months, according to a study press release.

"The PRO 140 treatment was well tolerated by patients with no discontinuation or drug-related adverse effects," said lead author Paul J. Maddon, M.D., Ph.D., according to the study press release. "Importantly, PRO 140 monotherapy can allow patients to avoid the potential toxicity of [antiretroviral therapy] while preserving future drug options," Maddon added.

Three participants experienced virologic failure at a median time of 169 days. They were subsequently restarted on standard antiretroviral therapy and achieved an undetectable viral load after a median of 29 days. Additionally, one participant with an undetectable viral load discontinued the PRO 140 treatment at week 47 because of relocation.

"PRO 140 may offer a simple, long-acting, single-agent maintenance therapy after initial [antiretroviral therapy] in selected patients with HIV infection," Maddon concluded.

The researchers plan to move on to a larger phase-2b or phase-3 study.

PRO 140 is the experimental drug that the actor Charlie Sheen, who publicly disclosed his HIV status in November 2015, recently revealed he was receiving as part of a clinical trial.

Here's a video from the antibody developers showing how PRO 140 combats HIV:

Warren Tong is the senior science editor for and

Follow Warren on Twitter: @WarrenAtTheBody.

Copyright © 2016 Remedy Health Media, LLC. All rights reserved.

Related Stories

Taking Atripla Three Days a Week Maintains Undetectable HIV Viral Load, Pilot Study Finds
Investigational Integrase Inhibitor Bictegravir Safe and Effective Against HIV in Early Study

This article was provided by TheBodyPRO. It is a part of the publication ASM Microbe 2016.


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.